Serum glucose, insulin and C-peptide response to oral glucose is not under evident genetic control in twins with parental NIDDM

Background and Aim: To evaluate the inheritance of serum-glucose, insulin and C-peptide response to oral glucose, we studied the heritability estimates in 25 pairs of healthy twins (12 monozygotic and 13 dizygotic) with parental non-insulin-dependent diabetes. Methods and Results: An oral-glucose tolerance test was performed: 18 per cent of the twins showed impaired glucose tolerance and 22 per cent were hyperinsulinaemic, one was diabetic. There was no significant difference in concordance for environmental factors (physical activity, diet, smoking, alcohol intake and living together or apart) between monozygotic twins. Conclusions: Genetic analysis did not reveal a substantial heritability for serum-glucose, insulin and C-peptide response to oral glucose, indicating that these parameters are not under evident genetic control in this subset of subjects with increased susceptibility for non-insulin-dependent diabetes. (C) 1997, Medikal Press.