Difference in the influence of maternal and paternal NIDDM on pancreatic beta-cell activity and blood lipids in normoglycaemic non-diabetic adult offspring.

The 75-g oral glucose tolerance test was performed in 38 normoglycaemic (World Health Organization criteria) non-diabetic volunteers, aged 31-40 years, of whom 20 had a non-insulin-dependent diabetic (NIDDM) mother and 18 had an NIDDM father. At the time of the study the offspring of NIDDM mothers had a somewhat higher body mass index (BMI) (males: 26.5 +/- 1.0 (mean +/- SEM), females: 27.5 +/- 1.5 kg/m2) than the offspring of NIDDM fathers (males: 23.4 +/- 0.9, females: 24.2 +/- 1.2 kg/m2). There was no difference in the time-course of glycaemia; however the serum concentrations of immunoreactive insulin (IRI), C-peptide and proinsulin were significantly higher in offspring of NIDDM mothers than in offspring of NIDDM fathers: area under the curve (AUC) serum IRI: 0.928 +/- 0.091 vs 0.757 +/- 0.056 nmol.l-1.h-1, p = 0.019; serum C-peptide: 6.379 +/- 0.450 vs 4.753 +/- 0.242 nmol.l-1.h-1, p = 0.004; serum proinsulin: 172 +/- 40 vs 51 +/- 7 pmol.l-1.h-1, p = 0.008). Serum IRI correlated with BMI, but C-peptide and proinsulin did not, and after accounting for BMI by covariance analysis they remained significantly higher in offspring of NIDDM mothers. In this group serum proinsulin was significantly higher in male than in female offspring (AUC serum proinsulin: 289 +/- 68 vs 77 +/- 27 pmol.l-1.h-1, P = 0.015). Male offspring of NIDDM mothers also had significantly higher serum triglyceride levels than females of the same group and than offspring of NIDDM fathers. The offspring (male and female) of NIDDM mothers had slightly lower serum apolipoprotein A-I levels than the offspring of NIDDM fathers. Significant correlations were found between serum triglycerides, HDL-cholesterol and apolipoprotein B, and serum concentrations of pancreatic beta-cell peptides, mostly in the offspring of NIDDM mothers; however, they did not display unequivocal association with gender within this group. The data are consistent with clinical observations of a greater risk of NIDDM transmission from the mother than from the father, and may suggest that male offspring are more exposed to this risk than female offspring.