Characteristics of Glucose Metabolism in Nordic and South Asian Subjects with Type 2 Diabetes

Abstract

BackgroundInsulin resistance and type 2 diabetes are more prevalent in people of South Asian ethnicity than in people of Western European origin. To investigate the source of these differences, we compared insulin sensitivity, insulin secretion, glucose and lipid metabolism in South Asian and Nordic subjects with type 2 diabetes.MethodsForty-three Nordic and 19 South Asian subjects with type 2 diabetes were examined with intra-venous glucose tolerance test, euglycemic clamp including measurement of endogenous glucose production, indirect calorimetry measuring glucose and lipid oxidation, and dual x-ray absorptiometry measuring body composition.ResultsDespite younger mean ± SD age (49.7±9.4 vs 58.3±8.3 years, p = 0.001), subjects of South Asian ethnicity had the same diabetes duration (9.3±5.5 vs 9.6±7.0 years, p = 0.86), significantly higher median [inter-quartile range] HbA1c (8.5 [1.6] vs 7.3 [1.6] %, p = 0.024) and lower BMI (28.7±4.0 vs 33.2±4.7 kg/m2, p<0.001). The South Asian group exhibited significantly higher basal endogenous glucose production (19.1 [9.1] vs 14.4 [6.8] µmol/kgFFM⋅min, p = 0.003). There were no significant differences between the groups in total glucose disposal (39.1±20.4 vs 39.2±17.6 µmol/kgFFM⋅min, p = 0.99) or first phase insulin secretion (AUC0–8 min: 220 [302] vs 124 [275] pM, p = 0.35). In South Asian subjects there was a tendency towards positive correlations between endogenous glucose production and resting and clamp energy expenditure.ConclusionsSubjects of South Asian ethnicity with type 2 diabetes, despite being younger and leaner, had higher basal endogenous glucose production, indicating higher hepatic insulin resistance, and a trend towards higher use of carbohydrates as fasting energy substrate compared to Nordic subjects. These findings may contribute to the understanding of the observed differences in prevalence of type 2 diabetes between the ethnic groups.

Comprehensive assessment of insulin resistance in non‐obese Asian Indian and Chinese men

“…Therefore, we could only compare the differences of insulin sensitivity at the skeletal muscle level and not hepatic IR. This might be important, as IR at skeletal muscle and hepatic tissues could be detected at a lower insulin infusion rate. A lower insulin infusion rate or the two‐step insulin clamp technique, such as those used by Takeno et al ,.…”

Cardiovascular Disease in South Asian Migrants

“…[53][54][55] In a study utilizing administrative health and immigration records, SA migrants to Canada had a significantly greater odds of 58 In a study based in the Netherlands, SA diabetics were 8-10 years younger, and had a 3.5 kg/m 2 (p=<0.001) lower BMI, and higher basal glucose production compared to Europids. 59 Increased IR was seen in the children of SA migrants born in the host country as compared to Europid children, suggesting that metabolic abnormalities begin to emerge far earlier than when a diagnosis of DM is made. 60 The very high burden of dysglycemia among SA migrants is likely a strong contributor to increased CVD risk, mortality and morbidity.…”

Substantial inter-individual variations in insulin secretion and sensitivity across the glucometabolic spectrum

“…Cohort II included 62 men and women >18 years of age with established T2D of Nordic or South Asian ethnicity, recruited to a randomized placebo-controlled vitamin D intervention trial. Details of the study design and main results have been published previously [10,11]. In this study, we have only used data from the baseline examinations.…”