Medical Nutrition Therapy in Type 1 Diabetes Mellitus

T1 diabetes mellitus (T1DM) is a common and chronic endocrine disorder in young adolescents. It contributes to 5%–10% of total diabetes population.[1] T1DM is the 2^nd most common chronic disease in children in India with an annual incidence of 3 cases/year/1 lakh (IDF 7^th edition). With the aim of addressing the relative scarcity of information on youth onset diabetes in India, the Indian Council of Medical Research (ICMR) established “the Registry of People with Diabetes with Young Age at Onset (YDR).” Recent publication from ICMR sponsored multicentric, hospital-based young diabetes registry (onset of diabetes below 25 years) observed more than 80% of young diabetes individuals are suffering from T1DM[2] (YDR).

T1DM is characterized by absolute insulin deficiency secondary to T-cell-mediated autoimmune destruction of pancreatic β-cells, and these patients have autoantibodies to glutamic acid decarboxylase, insulin autoantigen, insulin which can be detected before clinical diagnosis and their titers decline with time. T1DM typically presents in children but can present much later in life. Bimodal age presentation has been described with a peak around puberty and another peak between 20 and 30 years of age.

Irrespective of etiology of diabetes good glycemic control reduces diabetes-related complications (DCCT and UKPDS). To achieve good glycemic control major arms of management of T1DM are medical nutrition therapy (MNT), exercise, intensive insulin therapy, adjunct oral antidiabetic agents (pioglitazone in T1DM), and self-monitoring of blood glucose. In each treatment, regimen MNT plays pivotal role to achieve target glycemic control (HbA1c <7, preprandial blood glucose of 70–130 mg/dl,[3] and 2 h postprandial <180 mg/dl).[3] Design of MNT is determined by multiple factors such as weight, body mass index, physiological state (pregnancy), and associated complication. Nutrition is one of the most important pillars of diabetes management. All patients with T1DM should receive nutrition counseling and be given individualized meal plans based on cultural, regional, traditional and seasonal variations and their socioeconomic status and familial food preferences should be considered while formulating a meal plan. This requires understanding of how different foods affect blood glucose levels, and they should be taught about carbohydrate counting and insulin dose adjustments. Nutrition recommendations[4] for children and adolescents with T1DM are focused on achieving blood glucose goals without risk of severe hypoglycemia, normal growth and development, and the metabolic parameters within normal limits. Although we have various nutritional guidelines, India specific guidelines and recommendations on dietary prescription is necessary for betterment in the management of T1DM. Especially, it is very important in India context due to the diversity of India. An Indian study conducted by Kalra et al., published in IJEM 2017 on current indications of nutritional care in children with T1DM in India, has highlighted various dietary prescription practices by health-care practitioners (HCPs) across India in T1DM with the help of questionnaires.[5]

This study showed a huge diversity in current practice regarding dietary prescriptions. Among the guidelines in the current use, 40% of HCPs used age specific nutrition for children, 35% used ISPAD guidelines, 30% had their own center-specific methods, and 20% used the American Diabetes Association nutritional guidelines[3] for T2DM. This study showed that regarding preferred methods of prescribing diet, 65% of HCPs mentioned that they provide individualized meal plans and some used printed diet charts (30%), the plate method (20%), and pyramid method (18%) were the methods frequently used. Components of dietary prescription included were calorie content, carbohydrate content, and blood glucose values as major aspects while glycemic index, carbohydrate type (simple vs. complex), and fiber content as minor aspects. A majority of HCPs considered dietary adjustments in meal plan is the best method, so as to allow to have food of choice by the child with T1DM. For this, they used food exchange method as the most preferred method of diet adjustment.[5] This study also showed that parent education and family support to the child and repeated diet prescriptions play an important role in ensuring diet adherence.

Salient points to be concerned in proposed guidelines as per respondents include:[5]

• Carbohydrate content of various Indian food preparations

• Mix and match techniques (with quantity described) to make every food healthy, for example, dal chawal, potato fingers, and sprouts counseling techniques for both child and parents

• Recipes of low-calorie desserts recipes based on regional cuisine

• Age-specific guidelines

• Notes for diet in various situations such as school, festivals, and birthday parties.

Patients with T1DM have a high risk of developing other autoimmune disorders such as Hashimoto's thyroiditis, Addison's disease, celiac disease (CD), pernicious anemia the association is due to a common genetic and immunological background as both the diseases are associated with the major histocompatibility complex class II antigen DQ2 encoded by the alleles, DQA1−501 and DQB1−201 and HLADR3/DQ2.[6,7,8] The estimated prevalence of CD in T1DM is 0.6%–16.4%[8,9,10] and it affects at least 10% of patients with type 1 diabetes at some point in their lives. All patients with T1DM CD do not have gastrointestinal symptoms. Therefore, children diagnosed with T1DM should undergo routine screening for CD and are tested for autoantibody (anti-Ttg immunoglobulin) at the onset of DM and then annually during follow-up but it is debated his timing and frequency of screening. Sole treatment of CD is gluten free diet (GFD).[10] If antibodies are present, it is mandatory to perform eosophagogastroduodenoscopy with bowel biopsy to confirm the diagnosis.[6] The presence of mucosal atrophy is an indication to start GFD, which forms a standard therapy for CD. Strict compliance to GFD is essential to prevent acute (malabsorption, Failure to thrive (FTT)) and chronic (intestinal lymphoma, infertility, and osteoporosis) complications. GFD added to diabetic dietary regimen imposes practical limitations and leads to lifestyle restriction in children, leading to noncompliance to GFD. A study by Valerio et al.[11] found that only 59% of patients with T1DM and CD were compliant to strict GFD while 78% with the only CD was complaint to GFD. Moreover, combining GFD in T1DM children is challenging as it is of high glycemic index in contrast to diabetic diet should have low glycemic index. This will influence the glycemic control, glycemic variability, insulin dosage, lipid profiles, and other long-term complications. Moreover, GFD could modify anthropometric parameters such as height, weight, body mass index (BMI), and growth velocity. Effect of GFD on T1DM by Abid et al.[12] documented GFD showed benefits by decreasing the episodes of severe hypoglycemia while no changes in standard deviation score for BMI, HbA1C with GFD mean insulin requirement.

In recent years, the use of adjunctive therapies to insulin—those that improve glucose metabolism and reduce insulin side effects—have become a popular topic of interest. A number of oral anti-diabetic agents have been tested in clinical trials as insulin adjuncts for management of T1DM, including thiazolidinediones,[13] biguanides,[14] glucagon-like peptide 1 analogs,[15] alpha glucosidase inhibitors, dipeptidyl peptidase-4 (DPP-4) inhibitors,[16] and sodium glucose co-transport-2 (SGLT-2) inhibitors.[17] Currently, pramlintide, a peptide hormone analog, is the only insulin adjunct that is approved by the U. S. Food and Drug Administration for T1DM.[17] The effect of SGLT-2 inhibitors, with a unique mechanism of insulin-independent glucose disposal, represents a promising new therapy for T1DM. The available studies suggest that SGLT-2 inhibitors are an effective and safe insulin adjunct therapy, improving glycemic control, reducing body weight, and metabolic parameters such as blood pressure and plasma lipid profile. Taken together, the aforementioned suggests a potential benefit of cardiovascular and kidney protection, and the use of SGLT-2 inhibitors may play an important role in decreasing T1DM complications.[17] However, the patients should be emphasized to be compliant with insulin therapy and should be educated to match their food intake and exercise according to insulin schedule and regimen.

Individuals with T1DM and CD needs special dietary plans, and high index of suspicion and routine screening of CD in T1DM individuals helps in prevention of CD-related complications.[18,19] India is a country of diversity and needs India specific guide lines for our population for T1DM.