Determining the role of Maternal Leptin and Activity in Pregnancy Outcomes

Abstract

Leptin, an adipocytokine with an important role in energy homeostasis and other neuroendocrine functions, is found in higher levels in obese individuals. Maternal obesity is associated with numerous adverse pregnancy outcomes, such as miscarriage, gestational diabetes, gestational hypertension, and preeclampsia. However, the relationship between leptin, activity, and pregnancy outcomes is unclear. Some studies have found reduced leptin with physical activity and leptin is known to have direct effects on the cardiovascular system. Therefore, we hypothesized that women who have higher activity during pregnancy will have lower plasma leptin levels and experience fewer adverse outcomes during their pregnancy.In a cross‐sectional study, 100 pregnant women were co‐enrolled into the Maternal Fetal Tissue Bank (IRB#200901784) and this study (IRB#201502767). Pregnant women received triaxial accelerometers (Fitbit Zip) to wear throughout gestation. Maternal blood samples from each trimester were assayed in duplicate for plasma leptin concentration using an enzyme‐linked immunosorbent assay (ELISA). Pregnancy outcomes including maternal development of gestational diseases such as preeclampsia as well as mode of delivery, birthweight, fetal gender, and APGAR scores were extracted from the electronic health record (EPIC). Additionally, maternal demographics (age, race, and ethnicity) and health characteristics such as body mass index and any chronic health conditions at the beginning of pregnancy were recorded.Average step counts were obtained for the first (5523.77 ± 3720.33), second (5667.62 ± 4029.63), and third (4979.32 ± 3138.37) trimesters. In addition, no significant differences in average plasma leptin concentrations were obtained for the first (19839.8 ± 2390.9 pg/mL), second (11319.0 ± 2000.9 pg/mL), and third (26468.3 ± 5918.5 pg/mL) trimesters (P = 0.08). Leptin was only inversely correlated with activity in the first trimester (R2 =−0.32, P = 0.02), whereas no associations were detected in the 2nd and 3rd trimester. As an adverse outcome, we examined activity and leptin in patients with and without preeclampsia. The preeclamptic cohort took significantly fewer steps than the control group (5656.59 vs. 3586.72, P < 0.05) during the first trimester. The preeclamptic cohort also had a significantly higher average BMI (39 ± 6 vs. 27 ± 7, P = 0.02) and rates of chronic hypertension (67% vs. 6%, P < 0.001) than controls. Leptin was also significantly higher in the preeclamptic cohort than controls (52476.1 ± 10456.0 pg/mL vs. 16777.1 ± 1395.0 pg/mL, P <0.001).In conclusion, significant differences exist between the activity levels, leptin, and pregnancy outcomes of the preeclamptic and control groups.Support or Funding InformationThis work was supported by the following: American Physiological Society Undergraduate Summer Research Fellowship (UGSRF); University of Iowa Center for Hypertension Research; University of Iowa Hospitals & Clinics, Department of Obstetrics & Gynecology; University of Iowa Carver College of Medicine.