Maternal serum levels of adiponectin and leptin in non-pregnant, normal pregnant and preeclamptic women

Adiponectin and leptin, bioactive substances produced and secreted by the adipose tissue and the placenta, are involved in the regulation of a variety of endocrine processes in the body. Limited and contradictory data exist, regarding the roles of adiponectin and leptin in normal pregnancy and preeclampsia. This study, therefore, sought to investigate the maternal serum levels of adiponectin and leptin during normal pregnancy and preeclampsia. A non-randomized case-control study was conducted among pregnant women who sought antenatal care at the Manhyia Government Hospital between January 2014 and March 2014. Forty non-pregnant women, sixty normal first trimester pregnant women, sixty normal second trimester pregnant women, sixty normal third trimester pregnant women and sixty preeclamptic third trimester women were enrolled in the study. The medical history, Body Mass Index and Blood Pressure of each participant were measured; and their blood and urine samples were collected for biochemical analysis. Among the non-pregnant women, adiponectin correlated significantly but inversely with leptin (r=-0.402, p<0.05) and BMI (r=-0.684, p<0.05), and leptin correlated significantly and directly with BMI (r=0.571, p<0.05). Among the pregnant women, adiponectin correlated significantly and inversely with leptin (r=-0.669, p<0.05), BMI (r=-0.620, p<0.05), and leptin correlated significantly and directly with BMI (r=0.710, p<0.05). Among the preeclamptic women, adiponectin correlated insignificantly with leptin (r=- 0.290, p>0.05) but significantly and inversely with BMI (r=-0.521, p<0.05), and leptin correlated significantly and directly with BMI (r=0.700, p<0.05). While adiponectin levels (p<0.05) and the adiponectin-leptin ratio (p<0.05) were higher in the normal-weight women than in their overweight counterparts, the exact opposite held true for leptin levels (p<0.05). With regards to the levels of the adipokines in the participants, adiponectin levels were highest in the first trimester pregnant women, higher in the non-pregnant women, high in the second trimester pregnant women and low in the third trimester pregnant women (p<0.05).Leptin levels, on the other hand, remained comparable between the non-pregnant and the first trimester pregnant women (p>0.05), high in the second trimester pregnant women and highest in the third trimester pregnant women (p<0.05).The adiponectin-leptin ratio was comparable between the non-pregnant women and the first ii trimester pregnant women (p>0.05), low in the second trimester pregnant women and lowest in the third trimester pregnant women (p<0.05). The levels of adiponectin (p<0.05), leptin (p<0.05) and the adiponectin-leptin ratio (p<0.05) were higher in the preeclamptic women than in the normal pregnant women. In assessing overweight, gravidity and parity as possible determinants of preeclampsia, it was observed that overweight women are at a higher risk to developing preeclampsia than their normal-weight counterparts [OR=2.14 (0.93 – 9.84), p<0.05)], primigravida pregnant women are at a higher risk of developing preeclampsia than multigravida pregnant women [OR =3.57(1.524-8.37), p<0.05]. It was also observed that nulliparous pregnant women are at a higher risk of developing preeclampsia than multiparous pregnant women [OR =3.88 (1.30-11.62), p<0.05], but at comparable risk with primiparous pregnant women at developing preeclampsia [OR=1.9(0.87-4.18), p>0.05]. However, primigravidity and nulliparity, as risk factors to developing preeclampsia, were observed to be independent on the pre-pregnancy levels of adiponectin and leptin, due to the comparable levels of each adipokine among the pregnant women on the bases of gravidity and parity (p>0.05). Among non-pregnant and normal pregnant women, adiponectin and leptin exhibit an inverse relationship, and while adiponectin varies inversely with BMI and gestational age, leptin varies directly with BMI and gestational age. However, on the emergence of preeclampsia, a condition whose occurrence is possibly dependent on the gravidity and parity status of a woman, and alterations in the adiponectin-leptin ratio which is partly influenced by body weight, some of these relationships become blunted, as the levels of adiponectin and leptin rise significantly. The fluctuations in the levels of adiponectin and leptin during normal pregnancy indicate that adiponectin and leptin may play vital roles during pregnancy; and the observed elevated levels of adiponectin, leptin and the adiponectin-leptin ratio during preeclampsia, indicates that knowledge of the levels and ratio of the two adipokines during pregnancy, could assist in the diagnosis and treatment of preeclampsia.

Source: KNUST