Glucose and Insulin responses in offspring of Nigerian Type 2 diabetics.

Abstract

Type 2 diabetes mellitus ha s a strong genetic basis a s evidence d by a concordance rate ranging between 60 and 90 % in monozygotic twins. Glucose and insulin response s to an oral glucose load were measured in 5 2 offspring of Nigerian Type 2 diabetics and 50 control subjects selected to achieve a similar distribution of age and gender. All subjects studied were glucose tolerant. In comparison with control subjects, offspring of Type 2 diabetics had a significantly higher mea n (SD ) (i) fasting plasma glucose level [69.2 (13.0) mg/d l vs. 62. 2 (7.6) mg/dl; P=0.0012] (ii) fasting plasma insulin level [26.6 (15.4)pIU/mi vs. 14.8 (6.8)pIU/ml; /><0.0001 ] (iii) 2 hours post glucose load jlasma insulin level [59.8 (33.9)pIU/ml vs.40. 9 (24.2)pIU/ml ; P=0.0028]. The mean (SD) 2-hour post glucose load plasma glucose level did not differ significantly between both"groups >f subjects [92.8 (23.8) mg/d l vs. 85. 5 (21.3 ) mg/dl ; P=0.11]. Further multiple regressional analysis showed that the jifferences in fasting plasma insulin and 2-hour post glucose oad insulin observed were only accounted for by the presence jf a parental history of diabetes and were not influenced significantly by BMI, waist and hip circumferences. This study shows that offspring o f Nigeria n Type 2 diabetics have hyperinsulinaemia, despite being glucose tolerant and this supports the insulin-resistance hypothesis for Type 2 DM. This implies that they are at a greater risk for developing diabetes mellitus and are therefore an important group for the primary prevention of Type 2 DM.