Effects of gender and height on the oral glucose tolerance test: the isfahan diabetes prevention study.

BACKGROUND

Impaired fasting glucose (IFG) is more prevalent in men, whereas impaired glucose tolerance (IGT) is more prevalent in women.

AIM

To determine whether gender difference in the prevalence of glucose intolerance is related to height.

METHODS

A cross-sectional study of 2,368 first-degree relatives (FDR) of patients with type 2 diabetes was conducted between years 2003 to 2005. All participants (614 men and 1754 women) were in the age range 30-60 years, and were FDR of consecutive patients from outpatient clinics at Isfahan Endocrine and Metabolism Research Centre, Iran. All subjects underwent a standard 75 g 2-h oral glucose tolerance test (OGTT). Weight, height, waist and hip circumference, and glycated haemoglobin were also measured.

RESULTS

IGT was more common amongst women (OR 0.66; 95% CI 0.51, 0.87),whereas diabetes (OR 1.31; 95% CI 0.96, 1.78), and IFG (OR 1.41; 95% CI 1.10, 1.80) was more common amongst men. Women had a lower mean fasting plasma glucose (FPG) (p < 0.001), but showed higher 2hPG, and FPG-2hPG increase (p < 0.001). The gender difference in mean 2hPG and FPG-2hPG increase, was not evident after adjustment for height. Negative correlation to height was observed in 2hPG and FPG-2hPG increase, both in men and women (p < 0.001), but height showed little association with FPG.

CONCLUSIONS

Women had higher mean 2hPG and FPG-2hPG increase, but showed a lower FPG level than men. The inverse association between height and 2hPG and FPG-2hPG increase may be explained by gender difference.