Comparison of insulin sensitivity indices for detection of double diabetes in Indian adolescents with type 1 diabetes

Double diabetes-when type 1 diabetes meets type 2 diabetes: definition, pathogenesis and recognition

Currently, the differentiation between type 1 diabetes (T1D) and type 2 diabetes (T2D) is not straightforward, and the features of both types of diabetes coexist in one subject. This situation triggered the need to discriminate so-called double diabetes (DD), hybrid diabetes or type 1.5 diabetes, which is generally described as the presence of the insulin resistance characteristic of metabolic syndrome in individuals diagnosed with T1D. DD not only raises the question of proper classification of diabetes but is also associated with a significantly greater risk of developing micro- and macroangiopathic complications, which was independent of glycaemic control. When considering the global obesity pandemic and increasing incidence of T1D, the prevalence of DD may also presumably increase. Therefore, it is of the highest priority to discover the mechanisms underlying the development of DD and to identify appropriate methods to prevent or treat DD. In this article, we describe how the definition of double diabetes has changed over the years and how it is currently defined. We discuss the accuracy of including metabolic syndrome in the DD definition. We also present possible hypotheses connecting insulin resistance with T1D and propose possible methods to identify individuals with double diabetes based on indirect insulin resistance markers, which are easily assessed in everyday clinical practice. Moreover, we discuss adjuvant therapy which may be considered in double diabetic patients.

Insulin Resistance in Adolescents and Youth With Type 1 Diabetes: A Review of Problems and Solutions

Though insulin resistance (IR) was previously considered a feature of only type 2 Diabetes (T2DM), its development in type 1 Diabetes (T1DM) is not an uncommon occurrence, the causes of which are multifactorial (gender, pubertal status, diabetes duration, ethnicity, genetics, adiposity, glycemic control, chronic inflammation). Despite improvements in glucose, blood pressure and lipid profile, vascular complications (coronary artery disease and nephropathy) continue to remain common causes of morbidity and mortality in T1DM. Aggressive glycemic control reduces but does not eliminate the risk of IR. IR accelerates the development of micro and macrovascular complications, many of which can be potentially reversed if diagnosed and managed early. Lack of endogenous insulin production makes estimation of insulin sensitivity in T1DM difficult. As hyperinsulinemic-euglycemic clamp studies are cumbersome and invasive, the use of prediction equations for calculating estimated insulin sensitivity may prove to be useful. Along with intensive insulin therapy, dietary modifications and increasing physical activity, the role of Metformin in managing IR in T1DM is becoming increasingly popular. Metformin adjunct therapy in T1DM has been shown to improve insulin sensitivity, glycemic control, lipid profile, body composition, vascular smooth muscle function, thereby reducing the risk of vascular complications, as well as reversal of early vascular dysfunction. However, further studies to assess long-term efficacy and safety of Metformin use in adolescents and youth with T1DM are needed. This review aims at revisiting the pathophysiology of IR in T1DM and techniques of identifying those at risk so as to put into action various strategies for management of the same.

A Cross-Sectional Multicentre Study to Validate Insulin Sensitivity Index Cut-Offs for Detection of Metabolic Syndrome in Indian Adolescents with Type-1 Diabetes

Background

A previous study compared insulin sensitivity indices for the detection of double diabetes (DD) in Indian adolescents with type-1 diabetes (T1D) and derived a cut-off to predict future risk for the development of metabolic syndrome (MS) in adolescents with T1D. We conducted the current study with the aim to validate these cut-offs for detecting DD among Indian subjects with T1D from various geographical locations.

Methods

This multicentric cross-sectional study included 161 Indian adolescents with T1D. Demographic, anthropometric, clinical, and biochemical data were collected using standard protocols. Insulin sensitivity (IS) was calculated using various equations developed to determine insulin sensitivity in subjects with T1D. Metabolic syndrome was diagnosed using International Diabetes Federation (IDF) Consensus Definition 2017.

Results

We report 4.3% prevalence of MS in Indian adolescents with T1D with an additional 29.8% of study participants at risk of development of MS. Low High density lipoprotein (HDL) (23.6%) was the commonest abnormal component of the MS definition. Insulin sensitivity calculated by an equation derived by the SEARCH group was the most appropriate index to identify MS and metabolic risk in Indian adolescents with T1D. The proposed cut-off of 5.48 had high specificity, positive predictive value, and negative predictive value in identifying the risk of the development of DD.

Conclusions

Insulin sensitivity calculated by the equation proposed by the SEARCH group together with cut-offs derived in earlier study may be used effectively to identify risk of development of MS/DD in Indian adolescents with T1D from various geographical locations.

Longitudinal trends in lipid profile in indian children and youth with type-1 diabetes: a 5-year follow up from a single centre

INTRODUCTION

High prevalence of dyslipidaemia in children and adolescents with type-1 diabetes (T1D) places them at increased risk of developing atherosclerosis leading to mortality caused by cardiovascular disease(CVD). Thus, screening for fasting blood lipids when diabetes is stabilized in children aged 11 years and above is routinely recommended with follow-up every 5 years.

OBJECTIVES

(1) To characterize the lipid profile of children and adolescents with respect to diabetes duration. (2) To describe longitudinal changes in lipid profile over a 5-year period in patients with T1D.

METHODS

This longitudinal 5-year follow-up study included 112 patients with T1D aged 3-18 years. Demographic data, anthropometry and laboratory measurements were performed using standard protocols at baseline and endline. P value < 0.05 was considered significant.

RESULTS

The prevalence of dyslipidaemia in our study was 49.5% with abnormal LDL as the most frequently deranged parameter. Duration of illness played a major role in deterioration of lipid profile mediated by triglyceride and VLDL. Duration of illness and fibre intake in diet significantly predicted the change in lipid profile which were driven by triglycerides and VLDL. Glycemic control, insulin sensitivity and serum TSH also significantly altered components of lipid profile with no impact on overall dyslipidaemia. A total of 6.5% subjects had LDL concentrations >130 mg/dl and the same proportion had non-HDL cholesterol concentrations >145 mg/dl at baseline while at endline, 11.9% subjects had LDL concentrations >130 mg/dl and 15.6% subjects had non-HDL cholesterol concentrations >145 mg/dl. 28.6% subjects with LDL > 130 mg/dl and non-HDL cholesterol >145 mg/dl at baseline had persistently elevated concentrations while 10.3% and 14.4% additional subjects developed elevated LDL and non-HDL cholesterol concentrations respectively during the study period.

CONCLUSIONS

The deterioration of lipid profile in T1D, due to increase in disease duration was chiefly mediated by increase in serum triglyceride and VLDL concentrations which may be prevented by improving glycaemic control, insulin sensitivity and fibre intake in diet.