New paper from Kåre I. Birkeland’s group

Ethnic differences in BMI, subcutaneous fat, and serum leptin levels during and after pregnancy and risk of gestational diabetes.

In the recently published paper by Sommer and co-workers, we show that South Asians have higher amounts of subcutaneous fat and serum leptin levels relative to their body mass index (BMI) than Europeans, which probably contributes to the increased risk of gestational diabetes (GDM) observed in South Asians. South Asians retain more weight and subcutaneous fat after delivery, potentially increasing their risk of adiposity and GDM in future pregnancies.

Serum leptin levels reflect the proportion of adipose tissue in the body, is highly correlated with fat mass, and correlates particularly well with subcutaneous fat in women. Several studies have observed higher serum leptin levels in individuals of South Asian than European descent for the same BMI, suggesting that BMI may be a poor indicator of adiposity in South Asians. Thus, subcutaneous fat and leptin may be better indicators of adiposity in a multi-ethnic population of pregnant women than body weight and BMI, and may account for some of the higher GDM risk observed in South Asians. We explored differences between European and South Asian women in BMI, subcutaneous fat and serum leptin during and after pregnancy, and their relationships with GDM.

South Asians had similar thickness of the triceps and suprailiac skinfolds, thicker subscapular skinfold and higher serum leptin than Europeans in early pregnancy, despite lower BMI. At 14 weeks after delivery, South Asians retained more weight and subcutaneous fat than Europeans and the leptin levels remained higher in South Asians compared to Europeans. Accordingly, parous South Asians had more subcutaneous fat and serum leptin than parous Europeans, while we did not find corresponding ethnic differences among nulliparous. BMI, subcutaneous fat and serum leptin were all positively associated with GDM. Some, but not all, of the ethnic difference in GDM risk was explained by skinfolds and especially serum leptin levels, but not by BMI.

Please click here to read the paper.