Incidence, Prevalence, and Outcomes of Hand Manifestations in Patients With Diabetes Mellitus: A Comprehensive Literature Review

Abstract

Diabetes mellitus is a metabolic disease that results in long-term hyperglycemia. Among the many long-term complications associated with diabetes, manifestations in the hand include Dupuytren’s contracture, trigger finger, compressive neuropathies, and infections. These conditions can have a profound impact on a patient’s quality of life, highlighting the importance of timely recognition and treatment of these manifestations. This review aims to provide updated information regarding the incidence and outcomes of these clinical manifestations in the diabetic versus nondiabetic population. A systematic review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist was performed. The literature search included the use of PubMed and Ovid databases to find relevant articles that were then selected based on an inclusion criterion that required level 4 evidence. Diabetes mellitus results in an increased incidence of Dupuytren’s contracture, trigger finger, carpal tunnel syndrome, cubital tunnel syndrome, and hand infections. Dupuytren’s, trigger finger, and carpal tunnel syndrome all had similar outcomes, while diabetic patients had worse outcomes related to infections. There was a lack of data regarding the effect of diabetes on cubital tunnel syndrome. Future studies should be performed to analyze the effects of diabetes mellitus on hand manifestations, particularly regarding the outcomes of diabetic patients with cubital tunnel syndrome.

Introduction

Diabetes mellitus (DM) is a common endocrine disorder that causes long-term hyperglycemia and results in a number of metabolic and structural changes involving nearly every organ system in the body. Recent Centers for Disease Control and Prevention data estimate the prevalence of the disease to be more than 37 million patients in the United States, ¹ making health problems related to diabetes a common cause for presentation to primary care physicians and specialists alike. Among the complications of long-term hyperglycemia are a constellation of conditions in the hand including Dupuytren’s contracture, trigger finger, compressive neuropathies, and infections. ² While the mechanism underlying some of these conditions in the diabetic population remains incompletely understood, they are thought to result primarily from microvascular and macrovascular insults and the deposition of advanced glycation end products. ³ As the rate of diabetes grows worldwide, it is necessary to understand the link between this disease and debilitating hand manifestations that can provide another obstacle to a patient’s everyday life. Our understanding of these conditions within the diabetic population continues to grow as newer studies focus on diabetes as a patient risk factor and population-based databases become more widely used. Examining the interventional outcomes of these hand manifestations in diabetic versus nondiabetic patients is paramount for assessing potential to recover. Outcomes will also help analyze the severity of having diabetes with these complications and how detrimental they can be. This will hopefully raise clinical suspicion of hand manifestations of diabetes leading to earlier detection and management. This review presents updated information on the incidence, treatment options, complications, and overall outcomes of treating these conditions within the diabetic population.

Methods

A comprehensive literature search of hand complications of DM was performed to identify current information regarding the prevalence and outcomes of complications affecting the diabetic population. A systematic review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist was performed. A search of the National Library of Medicine (PubMed) and Ovid databases was performed using the keywords “diabetic hand, diabetes, Dupuytren’s contracture, carpal tunnel syndrome (CTS), hand infection, and trigger finger” in various combinations. Different search strategies were used for each database corresponding with the different search filters available. Data were extracted from the tables, figures, and text of all included articles.

The search strategy included literature published between the years 1994 and 2023. Studies were selected based on their relevance to musculoskeletal hand conditions in the diabetic population. Studies were eligible for inclusion if they were published in English, involved human beings in peer-reviewed journals, and included level 4 evidence or above. Excluded items from the search included non–English-language articles, meeting abstracts, editorials, and any publications with level 5 evidence.

Results

Eligible studies and data extraction were conducted independently by 2 authors (T.G.K. and A.N.S.). After removing duplicates from the database search, the articles were screened by title. The articles were then evaluated by abstracts and complete text according to the criteria for eligibility. The 2 authors resolved any disagreements regarding inclusion or exclusion criteria via consensus.

The literature search yielded 1981 articles and 1349 articles were selected for further analysis after the removal of duplicated studies. The articles were then screened by title and abstract, in which 1231 articles were excluded. Articles were excluded as a result of study design, lack of complete article, language different from that of the inclusion criteria, and lower evidence level 5 articles.

The remaining 118 full-text articles were then analyzed to select the most relevant studies that fulfilled the inclusion criteria. This analysis resulted in 40 studies being included in the systematic literature review. The literature search design and selection process is illustrated in the flow diagram (Figure 1).

Figure 1.

Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram representing the literature review process.

Dupuytren’s Contracture

Dupuytren’s contracture is characterized by development of fibrotic nodules and cords within the palmar fascia and skin, which can lead to finger contractures. Dupuytren’s disease in isolation will manifest the stereotypical cords while demonstrating normal adjacent skin free from the thickening and waxy changes found in limited joint mobility. The same glycosylation end products, which are more abundant in diabetic patients, ³ are theorized to contribute to cross-linking of collagen and the development of the nodules and cords of Dupuytren’s contracture.

It has been suggested that Dupuytren’s occurs more commonly in the diabetic population. ³ - ⁵ However, the magnitude of the effect of diabetes on Dupuytren’s incidence remains incompletely defined. The high-level studies of this effect come via a recent meta-analysis which showed a prevalence of 31% among diabetic patients, with an odds ratio (OR) of 3.9 for type 1 DM and 3.0 for type 2 DM when compared with the nondiabetic population ⁶ as well as a recent systematic review that found a strong association between higher A1c values and the development of Dupuytren’s in 27 of the 37 articles evaluated. They noted, however, that many of these studies were limited by a small sample size or poor study design. ⁷ In contrast, a recent population-based study using the International Classification of Diseases codes found a much more modest association. Among the 238 259 diabetic patients in the database, only 1.43% also carried a diagnosis of Dupuytren’s for an OR of 1.08 compared with the rest of the study population. ⁸ Likewise, the A1c association was fairly modest, with ORs of 1.19, 1.32, 1.46, and 1.36 for hemoglobin A1c (HbA1c) ranges 7.0 to 7.9, 8.0 to 8.9, 9.0 to 9.9, and 10.0+, respectively. ⁸

Treatment recommendations for Dupuytren’s contracture remain the same in the diabetic population as for the general nondiabetic patient. Outcome scores appear to be similar between diabetic and nondiabetic patients treated with open surgery. A 2014 study which included 20 patients with diabetes and 161 patients without diabetes found no difference in Quick Disabilities of the Arm, Shoulder and Hand score (a test using 11 measurable items to assess upper limb function) improvement between the 2 groups (10 vs 11, P = .58).9 To date, there are no studies comparing outcomes of needle aponeurotomy or collagenase injections between diabetic and nondiabetic patients. In summary, prior case series–based studies have shown a strong association between diabetes and Dupuytren’s, whereas some newer database studies show a much more modest association. More work needs to be performed to elucidate whether treatment outcomes differ between these groups.

Trigger Finger

Trigger finger symptoms include pain, catching, locking, or a palpable nodule at the A1 pulley. Diabetes is associated with both a higher incidence of trigger finger^1,2,10,11 and a higher incidence of multiple finger involvement. ¹² Studies have shown a prevalence of 5% to 20%, although a more recent study of 250 000 patients indicated a much lower yearly prevalence of 1.5%. ¹¹

Treatment options for trigger finger include corticosteroid injection, percutaneous release, and open release, which may be performed in the clinic or the operating room. After corticosteroid injections, diabetic patients typically experience a modest increase in glycemic levels that normalizes within 2 to 5 days. ¹³ Catalano et al ¹³ found a highest single daily mean increase in glucose levels of 32.7 mg/dL, which they did not deem to be clinically significant. Some older studies of strictly diabetic cohorts had found a relatively low response rate to corticosteroid injections among the diabetic population, ¹⁴ leading some to suggest that the treatment algorithm should differ for diabetic patients. Luther et al ¹⁵ published a cost analysis in 2016 which concluded that it is more cost-effective to proceed directly to open release in diabetic patients, although a response from Teemu and Sandeep noted that their cost analysis burdened the injection group with OR costs, whereas the analysis for the immediate open release was calculated using open release in the clinic. In a revised analysis by Teemu, injections were found to still be cost-effective in the diabetic population. ¹⁶

Furthermore, recent studies have questioned whether success rates are actually lower for diabetic patients. ¹⁷ A 2020 database study by Nasser found that among 29 722 patients who underwent treatment for trigger finger, the success rate for first-time corticosteroid injections was nearly identical for diabetic and nondiabetic patients (72% and 73%, respectively). ¹⁸ This suggests that corticosteroid injections should be a first-line treatment for diabetic patients with trigger finger. Studies looking at percutaneous release have found that it is effective in the diabetic population in the short term, but that diabetic patients may have a higher risk of recurrent triggering or pain. Siddiqui et al ¹⁹ found no recurrent triggering, but a 40% incidence of pain at 1 month in the DM group as compared with 0% incidence of pain in the non-DM group. Huang et al, ²⁰ on the other hand, found an increased risk of recurrent triggering in patients with DM (15.2% vs 4.6%) and an overall decreased satisfaction rate. Several recent small studies of open trigger finger release have shown no difference in surgeon-reported or patient-reported outcomes between diabetic and nondiabetic patients. ¹² One recent study showed a higher rate of postoperative stiffness ²¹ ; however, they did not measure preoperative stiffness, so it is difficult to interpret the significance of that finding. In contrast, a large retrospective database study of 209 634 Medicare patients did show a slightly increased rate of revision surgery (OR = 1.2), postoperative stiffness (OR = 1.2), and infection (OR = 1.6). ²²

Carpal Tunnel Syndrome

Carpal tunnel syndrome represents the most common peripheral mononeuropathy and results from compression of the median nerve within the carpal tunnel. It most frequently manifests as numbness and tingling in the thumb, index, long finger, and radial border of the ring finger. If the compression is severe enough in degree or duration, motor symptoms may develop including weakness and atrophy of the thenar eminence. While diabetes has traditionally been thought to be a risk factor for CTS, recent literature has been mixed. A large 2014 study in the Netherlands found that while diabetic patients were more likely to have CTS, it was not an independent predictor. ²³ On the contrary, a 2016 meta-analysis of 36 studies found diabetes resulted in an OR of 1.6 for CTS ²⁴ and a large longitudinal cohort study out of Sweden in 2020 found that diabetes presented a hazard ratio of 2.52 for the development of CTS. ²⁵

Diagnosis within the diabetic population may sometimes be complicated by the presence of polyneuropathy, although electrodiagnostic tests are still generally reliable. ²⁶ More recently, ultrasound has gained interest as a possible diagnostic tool for CTS. However, diabetic patients may have increased cross-sectional area at multiple areas in the median nerve even in the absence of carpal tunnel symptoms. ²⁷ It is unclear whether this represents early, subclinical CTS or whether diabetic patients may have morphologically different nerves. However, in the presence of symptoms and nerve conduction studies indicating CTS, carpal tunnel release proves to be an effective treatment for diabetic patients.^20,28 In general, diabetic patients experience a similar magnitude of improvement after surgery, although they tend to have worse preoperative symptoms and may not achieve full symptomatic recovery. ²⁸ At this time, it is unclear what the role of nerve conduction studies and ultrasound may play in screening and early treatment for asymptomatic diabetic patients.

Cubital Tunnel Syndrome

Cubital tunnel syndrome (CuTS) results from compression of the ulnar nerve at the elbow. In the early stages, it causes numbness and tingling in the ring and small fingers with progression in the later stages to weakness and atrophy of the intrinsic muscles of the hand. A few recent population-based studies have shown an incidence within the general public of 26.3 to 36.1 cases per 100 000 person years. ²⁹ While there is scarcity of data about the incidence among diabetic patients, a recent longitudinal cohort study using the Swedish National Registry indicated a hazard ratio of 2.51 for diabetic patients to develop ulnar neuropathy of the elbow. ²⁵ Zhang et al ³⁰ have also found that diabetes is a risk factor for concurrent CTS and CuTS. Some studies suggest that many diabetic patients without clinical evidence of ulnar nerve compromise may nonetheless have electromyography and nerve conduction evidence of CuTS. Gündüz et al ³¹ found in their series that in 33.3% of upper extremities of diabetic patients, there was electrodiagnostic evidence of ulnar nerve dysfunction at the elbow, but only 0.7% of those patients had symptoms suggestive of CuTS. This may pose a challenge for diagnosis within the diabetic population. Similar to the diagnosing of CTS, ultrasound has gained interest recently as an adjunct for diagnosis of CuTS, although it appears that, as in the case of imaging of the median nerve at the wrist, a high percentage of diabetic patients have increased cross-sectional area of the ulnar nerve in the absence of symptoms. ³²

As far as surgical outcomes, Tong et al ³³ did not find diabetes to be a predictor of poorer outcomes among patients with severe CuTS. However, Camp et al ³⁴ found that diabetes was a risk factor for requiring revision surgery, indicating that diabetic patients may not expect the same outcomes or satisfaction after surgery as their nondiabetic counterparts. Overall, more studies are needed to determine the prevalence of CuTS among diabetic patients and to determine how diagnostic modalities should differ with this population.

Infection

Diabetes is a well-known risk factor for infections of the upper extremities as well as a risk factor for severe infections such as necrotizing fasciitis. The increased risk of infection has generally been attributed to long-term effects of hyperglycemia including impairments in vascularity, decreased neutrophil activity, and dysfunctional chemotaxis. ³⁵ Within the hand literature, most data on infection come in the form of case series, which tend to show overall poor glycemic control among patients who require operative debridement. Öztürk et al ³⁶ found in their review of 32 publications and 704 total infectious cases that these patients had an average HbA1c of 10.6%. Estrella and Lee ³⁷ also concluded in their case-control study that among diabetic patients, increased HbA1c was a risk factor for infection. In general, diabetic patients with hand infections tend to be more likely to present with an infection without any history of trauma (relative risk = 1.39). ³⁸ They are also more likely to experience complications, with Houshain et al ³⁹ finding a complication rate of 60% among diabetic patients compared with 10.7% of patients without diabetes. Sharma et al ³⁸ found that patients were more likely to require admission, undergo multiple debridements, develop deep infection or osteomyelitis, and require amputation. In general, the literature supports a lower threshold for prompt and thorough debridement due to this population’s impaired ability to overcome infection and to heal wounds.

In contrast, for diabetic patients undergoing elective soft tissue–only procedures, which last less than 2 hours, infection rates are very low. This literature does not support administering preoperative antibiotics in these cases. ⁴⁰

A concise summary of all results can be seen in table 1.

Table 1.

Incidence and Outcomes of Hand Conditions Associated With Diabetes Mellitus.

Hand manifestations	Incidence associated with diabetes mellitus	Interventional outcomes vs nondiabetic patients
Dupuytren’s contracture	31% increase in incidence	Similar outcomes
Trigger finger	20% increase in incidence	Complications of percutaneous release surgery are increased
Carpal tunnel syndrome	Hazard ratio: 2.52	Similar outcomes
Cubital tunnel syndrome	Hazard ratio: 2.51	More studies needed
Infection	Significantly more infections, associated with poor glycemic control	60% vs 10% rate of infection

Discussion

Diabetes mellitus has long been associated with complications within the hand including Dupuytren’s contracture, trigger finger, de Quervain tenosynovitis, compressive neuropathies, infections, and pain. Dupuytren’s contracture was shown to occur more commonly in the diabetic population, and the magnitude of this was variable between studies. Newer studies have shown a weaker link between the 2. There were not enough data on treatment outcomes versus a nondiabetic population. This should be studied directly for future research. Trigger finger is more common in the diabetic population. Newer evidence suggests that corticosteroid injections cause mild, transient increases in glucose levels and that they have a similar success rate as those performed in nondiabetic patients. Complications from percutaneous or open treatment may be slightly higher in this population. Through a meta-analysis, it was found that having diabetes resulted in an OR of 1.6 and hazard ratio of 2.52, therefore showing a link between diabetes and CTS. Carpal tunnel syndrome can be effectively diagnosed with electrodiagnostic studies even among diabetic patients with polyneuropathy. Diabetic patients can expect a similar degree of improvement after carpal tunnel when compared with their nondiabetic counterparts, but they may not have full recovery due to more significant presenting symptoms. Most studies do not show a significant difference in complication rates or need for prophylactic antibiotics. Ulnar neuropathy at the elbow is an area of active study. It appears that the incidence of electrodiagnostic evidence of this condition within the diabetic population may be much higher than the clinical incidence. Likewise, ultrasound studies have shown increased cross-sectional areas of the ulnar nerve at the cubital tunnel in the absence of symptoms of ulnar neuropathy. At this point, it is unclear how to interpret this information and how it should guide clinical practice.

Future studies should aim to further hone in on a clear diagnosis of CuTS in relation to diabetes to find a concrete link between the 2. Diabetic individuals are at a higher risk of infections of the hand. The average hemoglobin of a diabetic patient with a hand infection was 10.6%, and the chance of having a hand infection increased linearly with hemoglobin percentage. It was found that diabetic patients were much more likely to have complications of a hand infection versus patients without diabetes (60%-10.7%). These complications ranged from admission, multiple debridements, osteomyelitis, and amputation.

There are some limitations in this literature review as a result of the lack of uniformity in the sample study criteria of analyzed publications. The different studies included in this review contain a high degree of methodological heterogeneity, providing a limited interpretation of causality. There was also heterogeneity in the reporting of patient outcomes among studies used in the review, providing a source of bias. Furthermore, the literature search was limited to articles published in English, which prevented the use of references in other languages that may have contributed to the review of diabetic hand manifestations. Future reviews should be performed using quantitative analysis to illustrate specific results, particularly regarding the outcomes of diabetic patients with CuTS.