Skip to main content
NCBI home page
Journal of Diabetes Science and Technology logoLink to Journal of Diabetes Science and Technology
. 2024 Aug 18;20(1):184–192. doi: 10.1177/19322968241274796

Connected Pens or Smart Pens: Technology Needs Context

Lutz Heinemann 1,2,✉, Jochen Sieber 3, Bernd Kulzer 2,4
PMCID: PMC11571358  PMID: 39155529

Abstract

Subcutaneous insulin administration has come a long way; pens that are connected to smartphones/cloud enable data transfer about insulin dosing. The usage of detailed dosing information in a smart way can support the optimization of insulin therapy in many ways. This review discusses terminology aspects that are relevant to the optimal usage of this novel option for insulin administration. Taking such aspects into account might also be crucial to improving the uptake of these medical products. In contrast to systems for automated insulin delivery, people with diabetes have to administer the insulin dose themselves; the technology can only support them. Combining smart pens with systems for continuous glucose monitoring provides solutions that are close to an automated solution, but are more discrete and associated with lower costs.

Keywords: insulin pens, smart pens, insulin therapy, AID systems

Introduction

Over the last 100 years, there have been significant developments in the various systems for insulin administration: from syringes to pre-filled disposable and reusable insulin pens, to pens with a memory function for data related to insulin administration, to algorithm-controlled insulin pumps. 1 The latest developments in the field of pens are “connected” pens, which can transfer insulin application data to the cloud or an app on a smartphone. The range of technical solutions used here extends from rather simple solutions (= connected pens), in which caps are attached to available disposable pens, to complex solutions, that is, reusable, specifically designed and manufactured pens that are comparatively large and expensive; however, they also enable two-way communication between the pen and a back-end (= smart pens).

The basic idea of connected or smart pens is to close the gap between glucose monitoring—with conventional blood glucose monitoring systems or systems for continuous glucose monitoring (CGM)—and insulin application and to make insulin therapy data available digitally. In this sense, connected or smart pens represent a significant step forward compared with conventional syringes and pens; however, the degree to which these use data differs depending on the technological level of the given “pen.” The more complex smart pens offer a range of other functions, such as reminder functions for insulin application, double injection alerts, display of the last insulin dose, temperature display, battery status, or even the integration of a bolus calculator (BC; Table 1).2-4 In daily practice, people with diabetes (PwD) tend to forget insulin doses (“missed boli”) more often than one would assume; connected or smart pens can be of help with a reminder function for prandial or basal insulin, which also helps to avoid late bolus administration.5-7 In a sense, the health care provider (HCP) can evaluate how well a given person with diabetes adheres to his insulin therapy. 8

Table 1.

Functions of Connected or Smart Pens to Support Insulin Therapy.

• Insulin dose application reminder: The pen and/or the app show when the last insulin dose was applied and an indication is given when this dose should be applied.
• Double injection warning: The insulin pen recognizes whether an injection has already been made and warns against a double injection. This is particularly useful for older people who are a little forgetful and are thus warned of possible hypoglycemia caused by double injections.
• Display of the insulin dose applied: Helps the user to have an overview of the time and dose of the last insulin applications. Also, the pens can indicate if an injection of prandial or basal insulin was missed.
• Amount of insulin still available: Information for the user on how much insulin is still available in the pen/when the pen or the insulin cartridge in it should be changed.
• Bolus calculation: The pen/app shows the user how much insulin is still active in the body from the last application and calculates a suggestion for the next bolus.
• Insulin stability: By measuring the temperature in the pen, the user can be informed if it (and the insulin it contains) is stored inappropriately.
Open in a new tab

To date, connected or smart pens have primarily been used to administer the prandial insulin dose as one part of insulin therapy and not the basal insulin. However, there are also some approaches in which both prandial and basal insulin requirements are covered with such pens. The assumption is that automatic logging of insulin dosing details by connected or smart pens that provide information to the users—both PwD and HCPs—that enables them to make informed therapeutic decisions about insulin dosing during meals and/or adjustment of basal insulin therapy, which can also motivate PwD to pay more attention to their insulin therapy. Adequate usage of this information helps to increase time-in-range (TIR), time in tighter range, reduce the risk of hypoglycemic events, improve dosing adherence, and reduce the frequency of hyperglycemia, in people with either type of diabetes, insulin therapy, and age. 7 ,9-15 The observed improvements in glycemic control are assumed to reduce costs for the health care system according to an economic analysis from Sweden and one from Canada.5,16 Like with all other technical options for diabetes therapy, appropriate training and education programs are needed, and instruction of PwD is of crucial importance to achieve such benefits; however, the HCPs also have to learn how to analyze and interpret the data provided by connected or smart pens, followed by clear advice to the PwD. 17 This in turn also means the HCP works in an environment that enables such technological solutions.

This review aims to provide an overview of the various technological solutions for connected or smart pens and to discuss various aspects that are important for their optimal clinical use; it is not a systematic literature review. 18

Terminology Problems

In the literature (and also in the marketing material of the manufacturer), no clear naming for the various pens is used (see below). 19 Considerations on the terminology for connected or smart pens were also been expressed in other publications, but there is still no consensus in this respect like it is with automated insulin delivery (AID) systems 20 ; however, this should not be determined by the marketing departments of the manufacturers. One wonders who can carry out such harmonization, for example, diabetes associations.

Warshaw et al 21 propose a tiered approach (tier 0-5) for labeling the different pens depending on their capabilities: The term “smart pens” is used for complex solutions with an integrated BC that makes dosing suggestions (level 4) and those that automatically recognize patterns and make dosing suggestions based on transmitted glucose values (level 5). In other words, only the most technologically sophisticated form of smart pens, which can also be coupled with a CGM system, really deserves the name “smart pens.” When coupled to a CGM system, a dose suggestion, for example, for prandial insulin dose, can be calculated by the app on a smartphone or a remote computer in the cloud, creating a “closed” diabetes management system. 22 This might also provide access to such an advanced therapeutic option for PwD who otherwise have not the option (“underserved populations”). 23 In contrast to other systems for AID, the insulin application with such systems is not automated, as is usually the case with AID systems that rely on insulin pumps. Here, the “intelligence” lies in the apps or the software that analyzes the transmitted data. Such solutions require (uninterrupted) access to the internet, which is not always guaranteed. When a cap is placed on a disposable pen and the insulin application information is “only” forwarded to an app or the cloud for display and documentation and no calculations are made in any way based on the data, this pen is not smart, but it is “connected.” 9

In this context, it is worth mentioning that when using an AID system the user—at least currently and in the near future—also has to do manual interventions, for example, select the right insulin dose for a meal and apply this dose via the pump/user interface on his smartphone. The current generations of commercially available AID systems do not provide a “full closed-loop”; nevertheless, some of the open-source AID systems have algorithms that enable this.

Why Does Language (= Terminology) Matter?

To use a clear definition for connected or smart pens is not only relevant for the correct designation of these medical devices but is also important for their “categorization” in the correct cost groups for health insurance companies (at least in Germany and other European countries). 24 Differences in indirect costs associated with diabetes are often large and not well evaluated. In other words, the reimbursement of the costs for such devices, an extremely important point for their acceptance in the market, depends on the correct naming. It is of interest to note that until today, only one diabetes association has published a respective position paper, the Spanish Diabetes Association.8,9

As connected or smart pens are usually connected to an app or download platform, they can also be referred to as “connected or smart insulin pen systems.” The advantage of doing so is that it avoids confusion if not only the hormone insulin (in various formulations) is administered with such medical devices, but also, for example, “GLP-1 receptor agonists,” that is, other hormones or medications (see below).

What Is the Definition of “Smart” in the Context of Insulin Application?

According to Wikipedia, “smart” means “intelligent, or able to think quickly or intelligently in difficult situations.” Even the detection of a missed or delayed insulin dose can be described as “smart.” If this term only applies to more complex solutions, the smart pen must be able to both send and receive the data required to analyze, interpret, and recommend therapeutic measures. In this sense, the mere transfer of insulin data in one direction does not fall under the definition of smart pens; as stated before, such pens are better described as connected pens (some also call these “digital pens”). When using connected pens, PwD must draw the appropriate therapeutic conclusions from the data displayed by the app on a smartphone.

With truly smart pens, the user no longer has to recognize trends and patterns in the glucose progression and draw the right conclusions for appropriate changes to the insulin therapy; instead, a BC (which is implemented in the respective app) independently calculates a suggested dose for the prandial insulin dose based on the transmitted glucose data from the CGM system and the information about the carbohydrate content of the meal entered by the user. 25 Such a combination of different devices is also called a “smart insulin pen system,” which enables a “personalized insulin dosing.” 26 Such a system can also take additional information, for example, about physical activity, blood pressure, or environmental temperature, into account, which can be provided by wearables or smartphones (“digital ecosystem”).27,28 Health care providers might be alerted by such systems in case something went wrong with a given person with diabetes and might contact him. A simulation study shows that calculation and optimization of basal insulin doses (“insulin titration”) should also be possible based on the transmitted information of recent basal insulin doses in connection with glucose data provided by a CGM system. 29 However, the user has to apply the insulin dose in both cases himself. The advantages of such a “closed loop system” (which is not “automated” for insulin administration) are that no insulin pump needs to be worn on the body, which is an important aspect for many PwD who like discrete handling of their disease, and the lower costs associated.

Target Group/Users of Connected or Smart Pens

Connected or smart pens are most suitable for PwD who are reluctant to use an insulin pump or do not have access to one. People with type 2 diabetes (T2D) on conventional insulin therapy with multiple daily insulin injections (MDI) are a potential user group of connected or smart pens. With around two million people in Germany alone, this is a fairly large group, significantly larger than the group of people with type 1 diabetes (T1D). Among people with T2D, those who use a BOT (basal insulin-supported therapy) in particular are potential users of connected or smart pens. Many of these PwD titrate the insulin dose themselves or with the support of respective apps on their smartphones. Connected or smart pens are also helpful for PwD who find it difficult to adequately perform insulin therapy, for example, because they forget to dose, dose incorrectly, or overcorrect. Older PwD in particular can benefit from the options offered by connected smart pens, such as reminders and warnings of double insulin injections. 30 However, the massive increase in the use of GLP-1 receptor agonists in recent years reduces the importance of insulin therapy for many people with T2D. Nevertheless, connected or smart pens can also be used for the subcutaneous application of such drugs despite the fact that the requirements for the accuracy of the dose and the time of application are significantly lower for GLP-1 receptor agonists than for insulin.

Which Connected or Smart Pen for Which PwD?

The question of which connected or smart pen is best for which PwD depends directly on their individual needs and wishes, that is, the user should make their choice in consultation with the HCPs. The user’s decision is also influenced by factors like costs as reimbursement by health care insurance is currently not available for all connected or smart pens. 24 In terms of adequate expectation management of PwD, potential users of connected or smart pens must be given suitable training to explain their advantages, disadvantages, and limitations. People with diabetes might also be influenced by comments made on social media about the different pen variants.

In the outpatient sector, the nursing service that is taking care of PwD who are treated at home represents a potential user group of connected or smart pens, also because it is possible to document the insulin therapy carried out. The same applies to the inpatient sector; that is, in hospitals, retirement, and nursing homes, connected or smart pens can be used to avoid dosing errors, forgetting to administer insulin, and so on, which is also relevant for liability reasons. 31 Displaying glucose and insulin data on screens (“telemedicine”) in the ward can be of help for HCPs to keep an overview of glucose control of PwD. Such data can also be stored automatically in the electronic health record (EHR). 32 In principle, connected or smart pens can also be used for titrating insulin therapy under such conditions; adjusting the insulin dose to the current needs of the PwD is often not done adequately (“clinical inertia”). A reliable documentation of insulin doses can also be of relevance for clinical research and clinical development, also in a real-world setting. 33

Connected or Smart Pens That Are Currently Available on the European/German Market

The two insulin pens NovoPen 6 and NovoPen Echo from Novo-Nordisk have been on the market in Europe since 2021. 34 While the NovoPen allows a maximum dose of 60 units of insulin per single application, which can be dispensed per 1 unit, the NovoPen Echo is more suitable for children. It allows a maximal dose of 30 units of insulin per application, which can be delivered with half a unit of insulin. Both have a glass ampoule and are reusable. The battery has a lifespan of four to five years. Unfortunately, it is not possible to change or recharge the battery after this time. The dose and time since the last injection are displayed on the device and the injection history of the last three months is saved. The data can be transferred to analysis software (eg, glooko, Accu-Chek smart Pix, mySugr).

Emperra is presenting a stand-alone solution with the ESYSTA pen, which automatically transmits the quantities of insulin dispensed to an ESYSTA base by radio. This smart pen displays the last insulin dose administered and can store approx. 1000 data records. The ESYSTA-BT-Pen is equipped with a Bluetooth interface and transmits the injected insulin doses to the ESYSTA app on the smartphone, with which users can analyze the data. With the use of adapters, all commercially available 3 mL (100 IU/mL) insulin cartridges from insulin manufacturers can be used with the ESYSTA pen.

Medtronic is taking a different approach by combining a specially designed “InPenTM smart insulin pen system,” which is specially designed for the implementation of MDI by pairing it with a CGM system (Simplera). The InPen system contains a BC and displays the active insulin.

Sanofi offers a reusable pen cap that can be attached to both SoloStar and DoubleStar pens and records the time of the injections and the insulin dose. Injections are given in the same way as without the cap. The cap can be connected via Bluetooth to an app that records the dosage information.

In November 2023, Eli Lilly introduced the “Tempo Smart Button” in Germany as part of a pilot launch. This cap is compatible with the Tempo pens for Humalog, Lyumjev, and Abasaglar. At the touch of a button, data on the date and time of the last injection and the insulin dose are transmitted to an app, software, and/or other medical devices. This cap is currently still available on the German market and can therefore be prescribed, but no official launch has yet taken place. The corresponding compatible pens must be also prescribed; these are available from wholesalers. Glooko is currently compatible as an app for data transmission; in the future, this cap should be compatible with the G7 CGM system from Dexcom.

In other countries, there are already several other cap solutions that are designed for prefilled pens (eg, Dukada Trio, GoCarb, Timesulin).

Training of the Diabetes Team/HCPs

The members of the diabetes team/HCPs should know the specific features of each available pen so that PwD can use them appropriately and find the best system for them, that is, the one that best suits their needs, and educate them on the correct use and interpretation of data.

Pens and Waste/Environmental Changes

The global market for insulin pens is dominated by disposable pens; figures for 2022 indicate that almost 10 billion disposable pens will be produced each year, resulting in the generation of many tons of plastic waste. “Only” 126 million reusable pens are produced per year, although there appears to be no data on how long and how often the reusable pens are used in practice, that is, how many insulin applications are made with them.

The use of smart pens (but not that of connected pens, which are mainly disposable pens) should reduce the amount of “waste,” be it the product itself, but also the packaging, instructions for use, and so on, compared with the use of disposable pens. 35 As pens consist of various plastic materials (as well as electronic components and a battery), recycling these medical products is complex and costly. From a recycling point of view the lithium batteries in smart pens represent a critical topic. Currently, such batteries are nonreplaceable; however, this provides a design opportunity to extend the lifespan of such pens.

It is necessary to evaluate how reliable the function of these medical devices is in extreme climatic conditions, for example, during heat waves 36 : Not only can the accuracy of insulin delivery be impaired, for example, due to expansion of the insulin liquid, but the biological effect of the insulin itself can be impaired if the connected or smart pens are not stored at optimal temperatures; however, this holds true for conventional pens as well. 37

Acceptance of Connected or Smart Pens by the Market

There is little published information on the acceptance of the various connected or smart pens in clinical practice, although according to the results of a discrete choice experiment in people with T1D or T2D, they prefer connected pens. 38 Sales of these medical devices by the various manufacturers still appear to be moderate, despite the quite promising market size of $850 million in 2023 predicted by a market research company (https://www.gminsights.com/industry-analysis/smart-insulin-pens-market). The statements from a survey in Germany for the dt-report 2023 (www.dut-report.de) indicate a rather low level of interest: 336 diabetologists provided information on the degree of use of connected or smart pens, their current and future significance, the indications for various PwD groups, and the barriers to their use in clinical practice. According to the survey, connected or smart pens are used by 4.8% of all people with T1D and 1.5% of people with T2D. The usefulness of connected or smart pens is assessed more negatively compared with the previous year (2021: 16%; 2022: 8%), as is the assessment of their importance in five years (2021: 38%, 2022: 25%).

Hurdles for the Acceptance of Connected or Smart Pens

According to the responses given in the survey mentioned above, the main barriers to the use of connected or smart pens were the preference for disposable insulin pens (55% in favor), the low additional benefit for PwD (49%), and the lack of compatibility with glucose analysis software (45%). The insufficient choice of different connected or smart pens, the need to possibly change insulin type (44%), and the lack of compatibility with apps for data analysis (36%) were also perceived as obstacles. Currently, no significant additional benefit for their insulin therapy is seen by many PwD; there are some reasons for this low acceptance of connected or smart pens 39 :

  • A major practical barrier is that many PwD use insulins from different manufacturers for their insulin therapy, that is, a prandial insulin from one manufacturer and the basal insulin from another. They would then not only have to use different connected or smart pens (or a smart pen and a conventional pen) but also different apps.

  • Although connected or smart pens are of help in practical insulin therapy, the extent of this help is not considered to be particularly pronounced, which may also be due to a lack of training for users (and the diabetes team).

  • The interoperability of the available connected or smart pens is not yet available to the extent that they are compatible with various connected blood glucose monitoring systems, CGM systems, insulin pumps, and various glucose analysis programs.

  • There is a lack of applications to analyze the information for the practical implementation of insulin therapy and make it usable for people with diabetes and HCP.

  • As a result, a standardized concept for integrating the various therapeutic options of connected or smart pens into diabetes therapy is still lacking in clinical practice: Is the focus on titration of basal insulin or application of short-acting insulin before meals or as correction insulin?

  • The lack of a concept for integrating connected or smart pens into digital diabetes management is a further weakness.

AGP and Connected or Smart Pens

The integration of CGM data with the insulin dosing information provided by connected or smart pens into a single platform is an important option; however, some kind of standardization of the reports is needed to enhance clinical utility.40,41 An international expert panel has recently published a proposal for such a report after performing an extensive literature review and identification of examples of such reports. 42 This report brings all clinically relevant CGM-derived glucose and connected insulin pen metrics into a single simplified two-page report. The first page provides information about the TIR, a summary of key insulin and glucose metrics, the ambulatory glucose profile (AGP) curve, and a detailed basal (long-acting) insulin assessment. The second page provides information about the boli (mealtime and correction) applied, with information on meal timing, insulin-to-carbohydrate ratio (ICR), average bolus insulin dose, and number of days with bolus doses recorded. On this page also daily glucose profiles with an overlay of the timing and amount of basal and bolus insulin administered are given. Most probably, this report will evolve over the next few years, just as the AGP Report for CGM systems has evolved over the last 12 years. Implementation of such a report in the software/apps for the different connected or smart pens by the manufacturer is the necessary next step.

Evidence for the Clinical Use of Connected or Smart Pens

The number of publications reporting the results of clinical studies with connected or smart pens has increased in recent years; however, it is still relatively low. 43 Nevertheless, the published studies have shown that the use of connected or smart pens is associated with an improvement in glycemic control (= reduction in HbA1c levels) and a reduction in the frequency of hypoglycemic events, although their use has so far been investigated more in “simple” forms of insulin therapy. From the point of view of health care insurers, the use of connected or smart pens leads to additional costs, but there is no clear evidence that these costs are compensated for by adequate savings or medical benefits, which is important for reimbursement. So far, only one publication discusses the potential of smart pens to minimize the long-term costs and complications of diabetes and improve diabetes care overall. 44

More recently published studies provided an interesting insight into the clinical usage of pens. In one of them, the use of an ultrafast insulin analog (Fiasp) or conventional analog (Aspart) with and without a “smart pen cap” (Insulclock) was studied. 33 This retrospective real-world study involved 82 people with T1D who were on intensified insulin therapy. The risk of increased postprandial glucose excursions and hypoglycemia was evaluated depending on the use of the two insulins and the time of dosing concerning a hyperglycemic excursion. Nearly 2500 postprandial glucose excursions were included in the analysis. The use of faster prandial insulin and the avoidance of a second correction injection were associated with a lower risk of postprandial hypoglycemia. Specifically, the use of ultrafast insulin reduced the risk of postprandial hypoglycemia by 36%, even with delayed injection of up to 45 minutes after postprandial hyperglycemia (odds ratio [OR] = 0.64; P = .012), while avoiding a correction injection reduced the risk by 56% (OR = 0.44; P = .038).

Although the gap in glycemic outcomes achieved with AID systems versus MDI with connected or smart pens remains, some recent real-world analyses with the latter, provided by Bigfoot Biomedical from its first-ever prospective study (BURST) with its Unity-connected pen cap system, showed impressive improvements with 54 users: Three-month usage led to a HbA1c reduction of 1.3%, from a baseline of 9.2% to 7.9% (P < .001; adjusted difference of 1.2%). At three months, TIR was 59%, and time-above-range was 40%. A recent publication from Medtronic presented real-world data with their InPen showed a low rate of hyperglycemia alerts. For a high rate of glucose rising alerts, 49% of alerts were associated with an algorithmically identified missed meal dose—conversely, 51% of these alerts were nonactionable, as no missed meal had been identified. InPen and CGM users averaged 5.3 hours of missed insulin correction dose opportunities per day.

Medtronic published recently real-world findings of the InPen smart insulin pen paired with a CGM (= InPen system) used by 3793 people with T1D, 552 with T2D, and 808 unidentified. 2 This retrospective cohort analysis showed that in the overall and T1D populations, a dosing frequency of ≥3 doses per day and a missed dose frequency of <20% was associated with improved glycemia. In people with T2D, missing <20% of doses was the significant factor determining improved glycemia. Such insights into the dosing behavior on glycemic outcomes can support counseling strategies for the diabetes care team.

An evaluation of the association of insulin injection adherence, smart insulin pen engagement, and glycemic control using real-world data from 16 countries from adults self-administering basal insulin degludec and bolus insulin with a smart insulin pen (NovoPen 6 or NovoPen Echo Plus) alongside CGM was published recently. 11 Data from 3945 adults, including 25 157 fourteen-day periods with ≥70% CGM coverage, were analyzed. On average, 0.2 basal and 6.0 bolus insulin doses were missed over 14 days. The estimated probability of missing at least one basal insulin dose over 14 days was 17.6% (95% confidence interval [CI] = 16.5-18.7). Missing one basal or bolus insulin dose per 14 days was associated with a significant decrease in the percentage of TIR (3.9-10.0 mmol/L), of 22.8% (95% CI = 23.7-21.8) and 21.7% (95% CI = 21.8-21.6), respectively; therefore, missing two basal or four bolus doses would decrease TIR by >5%. Engagement with the usage of smart pens was associated positively with glycemic outcomes. This combined analysis of real-world smart pen and CGM data showed that missing two basal or four bolus insulin doses over 14 days would be associated with a clinically relevant decrease in TIR.

The Future of Connected or Smart Pens—What Further Developments Can Be Expected?

The connected or smart pens available to date represent the first generation of such medical devices, although it is highly likely that there will be dynamic further development that will make them even smarter, for example, by taking into account additional information provided by wearable devices (such as smartwatches) and smartphones. Wearables not only noninvasively record various vital parameters and physical activity of their users, but they also provide information on environmental conditions. This allows insulin therapy to be customized even more closely to the needs of the individual PwD and their life situation.

Smart pens that systematically make use of data provided by CGM systems (which is not the case with connected pens) could be advantageous for optimizing insulin therapy: Adapting insulin therapy directly to the current glucose values not only helps with choosing the “right” insulin dose; it should also reduce the risk of acute glucose fluctuations (= hypoglycemic events). Another option is automatic meal detection by analyzing the glucose profiles registered by the CGM system. 45 There will be diagnostic systems on the market that continuously monitor not only glucose but also ketone bodies (and other parameters such as lactate). 46

In the future, the physician (or a computer) may be able to “remotely adjust” the insulin dose if deemed necessary based on an analysis of the transmitted CGM data. By using artificial intelligence (AI), patterns in the glucose profiles can be automatically recognized and interpreted, and in the sense of decision support systems, the user can either receive clear instructions on the insulin dose or the calculated dose can be automatically set on the smart pen. The user injects only this insulin dose without having to think about the choice, which should fulfill the needs of many PwD. In the United States, the company Bigfoot recently received approval for a product that makes such dosage suggestions. This company was recently acquired by a major manufacturer of CGM systems (Abbott) (www.bigfootbiomedical.com/).

Summary and Outlook

Connected or smart pens offer a novel therapeutic option for millions of PwD using MDI to optimize their insulin therapy. They provide important information about the reality of insulin dosing and, especially in the context of CGM systems, make it easier to identify areas for improvement and to communicate these appropriately with users; however, several more pragmatic reasons make their use difficult in practice. Patient preference should be the top priority when choosing a connected or smart pen. In this context, a clear concept for their clinical use is needed; otherwise, one can say, we have a good technical solution; however, what is the clinical problem? Being connected or smart has to add value to the therapeutic concept and not just add padding to the price tag of this type of insulin pen. An in-depth analysis of data generated with connected or smart pens (which enables tracking of glucose profiles) might enable a better understanding of which gaps in insulin therapy with a given PwD exist and what the opportunities are to improve his care. Even if the start of the use of connected or smart pens is slow, the future of such pens appears to be positive.

Acknowledgments

We thank David Klonoff for his excellent comments.

Footnotes

Abbreviations: AGP, ambulatory glucose profile; AI, artificial intelligence; AID, automated insulin delivery; BC, bolus calculator; BOT, basal-assisted oral therapy; CGM, continuous glucose monitoring; EHR, electronic health record; HCPs, health care providers; MDI, multiple daily insulin injections; PwD, people with diabetes; SP, smart pens; TIR, time-in-range; T1D, type 1 diabetes; T2D, type 2 diabetes.

The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: L.H. is a shareholder of the Profil Institut für Stoffwechselforschung GmbH, Neuss, Germany. L.H. is a consultant for several companies that are developing novel diagnostic and therapeutic options for diabetes treatment. J.S. and B.K. report no conflict of interest.

Funding: The author(s) received no financial support for the research, authorship, and/or publication of this article.

References

  • 1. Masierek M, Nabrdalik K, Janota O, Kwiendacz H, Macherski M, Gumprecht J. The review of insulin pens-past, present, and look to the future. Front Endocrinol (Lausanne). 2022;13:827484. doi: 10.3389/fendo.2022.827484. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 2. MacLeod J, Im GH, Smith M, Vigersky RA. Shining the spotlight on multiple daily insulin therapy: real-world evidence of the InPen smart insulin pen. Diabetes Technol Ther. 2024;26(1):33-39. doi: 10.1089/dia.2023.0365. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 3. MacLeod J, Vigersky RA. A review of precision insulin management with smart insulin pens: opening up the digital door to people on insulin injection therapy. J Diabetes Sci Technol. 2023;17(2):283-289. doi: 10.1177/19322968221134546. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 4. Ahn DT. Automated bolus calculators and connected insulin pens: a smart combination for multiple daily injection insulin therapy. J Diabetes Sci Technol. 2022;16(3):605-609. doi: 10.1177/19322968211062624. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 5. Jendle J, Ericsson Å, Gundgaard J, Møller JB, Valentine WJ, Hunt B. Smart insulin pens are associated with improved clinical outcomes at lower cost versus standard-of-care treatment of type 1 diabetes in Sweden: a cost-effectiveness analysis. Diabetes Ther. 2021;12(1):373-388. doi: 10.1007/s13300-020-00980-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 6. Ekberg NR, Hartvig NV, Kaas A, Møller JB, Adolfsson P. Smart pen exposes missed basal insulin injections and reveals the impact on glycemic control in adults with type 1 diabetes. J Diabetes Sci Technol. 2024;18(1):66-73. doi: 10.1177/19322968221104142. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 7. Adolfsson P, Hartvig NV, Kaas A, Moller JB, Hellman J. Increased time in range and fewer missed bolus injections after introduction of a smart connected insulin pen. Diabetes Technol Ther. 2020;22(10):709-718. doi: 10.1089/dia.2019.0411. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 8. Moreno-Fernandez J, Díaz-Soto G, Girbes J, Arroyo FJ. Current perspective on the potential benefits of smart insulin pens on glycemic control in patients with diabetes: Spanish Delphi Consensus [published online ahead of print June 1, 2023]. J Diabetes Sci Technol. doi: 10.1177/19322968231178022. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 9. Tejera-Pérez C, Chico A, Azriel-Mira S, Lardiés-Sánchez B, Gomez-Peralta F, Área de Diabetes-SEEN. Connected insulin pens and caps: an expert’s recommendation from the area of diabetes of the Spanish endocrinology and nutrition society (SEEN). Diabetes Ther. 2023;14(7):1077-1091. doi: 10.1007/s13300-023-01417-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 10. Hellman J, Hartvig NV, Kaas A, Møller JB, Sørensen MR, Jendle J. Associations of bolus insulin injection frequency and smart pen engagement with glycaemic control in people living with type 1 diabetes. Diabetes Obes Metab. 2024;26(1):301-310. doi: 10.1111/dom.15316. [DOI] [PubMed] [Google Scholar]
  • 11. Danne TPA, Joubert M, Hartvig NV, Kaas A, Knudsen NN, Mader JK. Association between treatment adherence and continuous glucose monitoring outcomes in people with diabetes using smart insulin pens in a real-world setting. Diabetes Care. 2024;47(6):995-1003. doi: 10.2337/dc23-2176. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 12. Galindo RJ, Ramos C, Cardona S, et al. Efficacy of a smart insulin pen cap for the management of patients with uncontrolled type 2 diabetes: a randomized cross-over trial. J Diabetes Sci Technol. 2023;17(1):201-207. doi: 10.1177/19322968211033837. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 13. Gomez-Peralta F, Abreu C, Fernandez-Rubio E, et al. Efficacy of a connected insulin pen cap in people with noncontrolled type 1 diabetes: a multicenter randomized clinical trial. Diabetes Care. 2023;46(1):206-208. doi: 10.2337/dc22-0525. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 14. Adolfsson P, Björnsson V, Hartvig NV, Kaas A, Møller JB, Ogionwo Lange E. Improved glycemic control observed in children with type 1 diabetes following the introduction of smart insulin pens: a real-world study. Diabetes Ther. 2022;13(1):43-56. doi: 10.1007/s13300-021-01177-w. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 15. Klonoff DC, Zhang JY, Shang T, Mehta C, Kerr D. Pharmacoadherence: an opportunity for digital health to inform the third dimension of pharmacotherapy for diabetes. J Diabetes Sci Technol. 2021;15(1):177-183. doi: 10.1177/1932296820973185. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 16. Chan K, Hansen K, Muratov S, Khoudigian S, Lamotte M. Smart connected insulin dose monitoring technologies versus standard of care: a Canadian cost-effectiveness analysis. J Comp Eff Res. 2024;13(3):e230124. doi: 10.57264/cer-2023-0124. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 17. Sy SL, Munshi MM, Toschi E. Can smart pens help improve diabetes management. J Diabetes Sci Technol. 2022;16(3):628-634. doi: 10.1177/1932296820965600. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 18. Cranston I, Jamdade V, Liao B, Newson RS. Clinical, economic, and patient-reported benefits of connected insulin pen systems: a systematic literature review. Adv Ther. 2023;40(5):2015-2037. doi: 10.1007/s12325-023-02478-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 19. Heinemann L, Jendle J. Language matters: connected pens, smart pens, connected smart pens, or just digital pens? J Diabetes Sci Technol. 2023;17(4):875-877. doi: 10.1177/19322968221148508. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 20. Klonoff DC, Shang T, Zhang J. Automated insulin dosing systems or automated insulin delivery systems? it is time for consistency. J Diabetes Sci Technol. 2021;15(2):211-213. doi: 10.1177/1932296821993498. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 21. Warshaw H, Isaacs D, MacLeod J. The reference guide to integrate smart insulin pens into data-driven diabetes care and education services. Diabetes Educ. 2020;46(suppl 4):3S-20S. doi: 10.1177/0145721720930183. [DOI] [PubMed] [Google Scholar]
  • 22. Estremera E, Beneyto A, Cabrera A, Contreras I, Vehí J. Intermittent closed-loop blood glucose control for people with type 1 diabetes on multiple daily injections. Comput Methods Programs Biomed. 2023;236:107568. doi: 10.1016/j.cmpb.2023.107568. [DOI] [PubMed] [Google Scholar]
  • 23. Ebekozien O, Fantasia K, Farrokhi F, Sabharwal A, Kerr D. Technology and health inequities in diabetes care: how do we widen access to underserved populations and utilize technology to improve outcomes for all? Diabetes Obes Metab. 2024;26 (suppl 1):3-13. doi: 10.1111/dom.15470. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 24. Nolan T, Frazzitta M. Insurance coverage for emerging diabetes technologies: payers’ perspective. Diabetes Technol Ther. 2021;23(S3):S28-S35. doi: 10.1089/dia.2021.0262. [DOI] [PubMed] [Google Scholar]
  • 25. Diaz-Garelli F, Shah A, Mikhno A, Agrawal P, Kinnischtzke A, Vigersky RA. Using continuous glucose monitoring values for bolus size calculation in smart multiple daily injection systems: no negative impact on post-bolus glycemic outcomes found in real-world data [published online ahead of print September 24, 2023]. J Diabetes Sci Technol. doi: 10.1177/19322968231202803. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 26. Zahid M, Dowlatshahi S, Kansara AH, Sadhu AR. The evolution of diabetes technology—options toward personalized care. Endocr Pract. 2023;29(8):653-662. doi: 10.1016/j.eprac.2023.04.007. [DOI] [PubMed] [Google Scholar]
  • 27. Kompala T, Neinstein AB. Smart insulin pens: advancing digital transformation and a connected diabetes care ecosystem. J Diabetes Sci Technol. 2022;16(3):596-604. doi: 10.1177/1932296820984490. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 28. Harbison R, Hecht M, MacLeod J. Building a data-driven multiple daily insulin therapy model using smart insulin pens. J Diabetes Sci Technol. 2022;16(3):610-616. doi: 10.1177/1932296820951225. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 29. El Fathi A, Fabris C, Breton MD. Titration of long-acting insulin using continuous glucose monitoring and smart insulin pens in type 1 diabetes: a model-based carbohydrate-free approach. Front Endocrinol (Lausanne). 2021;12:795895. doi: 10.3389/fendo.2021.795895. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 30. Huang ES, Sinclair A, Conlin PR, et al. The growing role of technology in the care of older adults with diabetes. Diabetes Care. 2023;46(8):1455-1463. doi: 10.2337/dci23-0021. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 31. Gomez-Peralta F, Abreu C, Mazo ES. 195-OR: efficacy and feasibility of a telemedicine program for institutionalized elderly people with insulin-treated diabetes using continuous glucose monitoring and a connected insulin pen cap—the Trescasas Study. Diabetes. 2024;73(suppl 1). doi: 10.2337/db24-195-OR. [DOI] [Google Scholar]
  • 32. Espinoza JC, Yeung AM, Huang J, Seley JJ, Longo R, Klonoff DC. The need for data standards and implementation policies to integrate insulin delivery data into the electronic health record. J Diabetes Sci Technol. 2023;17(5):1376-1386. doi: 10.1177/19322968231178549. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 33. Gómez-Peralta F, Valledor X, López-Picado A, et al. Ultrarapid insulin use can reduce postprandial hyperglycemia and late hypoglycemia, even in delayed insulin injections: a connected insulin cap-based real-world study. Diabetes Technol Ther. 2024;26(1):1-10. doi: 10.1089/dia.2023.0321. [DOI] [PubMed] [Google Scholar]
  • 34. Sparre T, Hansen NB, Wernersson AS, Guarraia M. Development of an insulin pen is a patient-centric multidisciplinary undertaking: a commentary. J Diabetes Sci Technol. 2022;16(3):617-622. doi: 10.1177/19322968211058707. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 35. Heinemann L, Klonoff DC. Diabetes technology and waste: a complex story. J Diabetes Sci Technol. 2022;16(6):1381-1384. doi: 10.1177/19322968211022321. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 36. Heinemann L. Diabetes-technology and the environment: what do we have to consider? J Diabetes Sci Technol. 2023;17(3):607-610. doi: 10.1177/19322968221146194. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 37. Heinemann L, Braune K, Carter A, Zayani A, Kramer LA. Insulin storage: a critical reappraisal. J Diabetes Sci Technol. 2021:15(1):147-159. doi: 10.1177/1932296819900258. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 38. Seo J, Heidenreich S, Aldalooj E, et al. Patients’ preferences for connected insulin pens: a discrete choice experiment among patients with type 1 and type 2 diabetes. Patient. 2023;16(2):127-138. doi: 10.1007/s40271-022-00610-x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 39. Lingen K, Pikounis T, Bellini N, Isaacs D. Advantages and disadvantages of connected insulin pens in diabetes management. Endocr Connect. 2023;12(11):e230108. doi: 10.1530/EC-23-0108. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 40. Rodbard D, Garg SK. Standardizing reporting of glucose and insulin data for patients on multiple daily injections using connected insulin pens and continuous glucose monitoring. Diabetes Technol Ther. 2021;23(3):221-226. doi: 10.1089/dia.2021.0030. [DOI] [PubMed] [Google Scholar]
  • 41. Wolpert H, Polonsky WH, Rodbard D. Insulin metrics: need for development of consensus standards for reporting of insulin dosing data. Diabetes Technol Ther. 2021;23(7):522-526. doi: 10.1089/dia.2020.0631. [DOI] [PubMed] [Google Scholar]
  • 42. Simonson GD, Criego A, Battelino T, et al. Expert panel recommendations for a standardized ambulatory glucose profile report for connected insulin pens [published online ahead of print June 10, 2024]. Diabetes Technol Ther. doi: 10.1089/dia.2024.0107. [DOI] [PubMed] [Google Scholar]
  • 43. Heinemann L, Schnell O, Gehr B, Schloot NC, Gorgens SW, Gorgen C. Digital diabetes management: a literature review of smart insulin pens. J Diabetes Sci Technol. 2022;16(3):587-595. doi: 10.1177/1932296820983863. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 44. Sangave NA, Aungst TD, Patel DK. Smart connected insulin pens, caps, and attachments: a review of the future of diabetes technology. Diabetes Spectr. 2019;32(4):378-384. doi: 10.2337/ds18-0069. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 45. Corbett JP, Breton MD, Patek SD. A multiple hypothesis approach to estimating meal times in individuals with type 1 diabetes. J Diabetes Sci Technol. 2021;15(1):141-146. doi: 10.1177/1932296819883267. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 46. Huang J, Yeung AM, Bergenstal RM, et al. Update on measuring ketones. J Diabetes Sci Technol. 2024;18(3):714-726. doi: 10.1177/19322968231152236. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Journal of Diabetes Science and Technology are provided here courtesy of Diabetes Technology Society

RESOURCES