Serum leptin levels and their correlation with thyroid hormones in women with hyperemesis gravidarum

ABSTRACT

Leptin is a protein that regulates energy expenditure and food intake. It is found that maternal leptin level increases progressively during gestation. However, in other hypothesis, rapid increase in maternal leptin concentration disproportional to gestational week is a marker for hyperemesis gravidarum. To assess the maternal serum leptin, the adjusted leptin levels in first trimester women with hyperemesis gravidarum and with normal pregnancy and to find the correlation between leptin level and thyroid hormones in the two groups. A case-control study conducted in Al Yarmouk teaching hospital /department of obstetrics and gynaecology for one year from March 2009 to March 2010. A hundred pregnant women were enrolled in this study. Fifty women with hyperemesis gravidarum and fifty women without hyperemesis gravidarum as a control group were included in the study. The two groups were compared for age, parity, body mass index. Fasting serum thyroid stimulating hormone, free thyronine hormone, free thyroxine hormone and leptin levels were measured. The adjusted leptin level [ALL] maternal serum leptin level / gestational week, was calculated in each case. Body mass index was found significantly lower in the hyperemesis gravidarum group than in the control group[p=0.018]. The mean leptin level in the hyperemsis gravidarum group was14.78 +/- 4.46 ng /ml which was significantly higher [p=0.035] than the mean leptin level in the control group which was12.51 +/- 4.08 ng/ml. The mean adjusted leptin level in the hyperemsis gravidarum group was 1.86 +/- 0.23 which was significantly higher [p<0.001] than the mean adjusted leptin level in the control group which was1.38 +/- 0.20. Serum thyroid stimulating hormone was significantly lower [p=0.001] and free thyronine hormone, free thyroxin hormone levels were significantly higher [p<0.001,<0.001 respectively] in the hyperemesis gravidarum group than in the control group. Maternal serum leptin level was significantly higher in the HG group. ALL was also significantly higher in the HG group and there was no significant correlation between leptin level and thyroid hormones