The physiological role of leptin for anthropometrical changes in pregnancy

Abstract

Leptin is a small, hormone-like protein which is produced primarily by adipozytes and in smaller amounts in some other peripheral organs. This hormone participates in many human physiological processes. It also sauses changes in the energy uptake and expenditure that influence body weight. Alterations in leptin concentrations were observed to increase within the period of pregnancy when anthropometrical and metabolic alterations take place. The overall aim of the study was to evaluate changes of leptin levels in pregnancy and to evaluate association of these changes to anthropometrical parameters of pregnant women. We measured serum leptin levels in 67 pregnant women at 7–40 weeks of pregnancy and in 30 women during delivery by specific RIA methods. Anthropometrical examination included the following parameters: height, weight, BMI (kg/m²), thickness of skin folds, sizes of body. Relative and absolute amounts of body fats were also assessed by means of the bioelectrical impedance method and according to the Siri formula. The statistical reliability was provided. Total leptin levels rise from the beginning of pregnancy till the beginning of the 3rd trimester (26.8 ± 2.0 ng/ml to 34.1 ± 2.0 ng/ml). The highest level of leptin was found in the 2nd trimester (37.1 ± 2.3 ng/ml). During delivery leptin level was lower that during the 1st trimester; the average value was 22.23 ± 3.25 ng/ml. We found the most pronounced anthropometrical changes in the 2nd trimester of pregnancy. There was a significant (p < 0.001) correlation between maternal adipose tissue, weight, body šižęs and serum leptin concentration (ng/ml). During pregnancy leptin manifested itself in a feminine type of body composition: the largest accumulation of adipose tissue was found in the regions of the hip and the thigh. The anthropometry of women was significantly associated with leptin. These associations are necessary for modification of maternal homeostasis to provide nutritional support for the developing foetus and preparation for lactation following delivery. Keywords: leptin, pregnancy, anthropometry, BMI, adipose tissue