Maternal characteristics associated with cardiometabolic status in early pregnancy

Abstract

Rationale & Background: During pregnancy, cardiometabolic adaptations occur to sustain fetal growth. Disruptions in maternal cardiometabolic status may arise related to maternal adiposity, dietary deficiencies or excesses, or sedentary behaviours in pregnancy. Clinically, maternal cardiometabolic dysfunction is associated with adverse health outcomes in both mothers and their offspring. We aimed to determine: 1) the contribution of maternal adiposity, diet and physical activity to maternal cardiometabolic status in early pregnancy using biomarkers of lipid and glucose profiles; 2) whether maternal adiposity measured by 4-site sum of skinfold thickness (SFT) or bioelectrical impedance analysis (BIA) yielded similar strength of association with cardiometabolic status. Study Design: Maternal blood samples, anthropometric and body adiposity, dietary and physical activity measures were collected from a subset of pregnant women in early pregnancy (12-17 wk gestation) prior to randomization to the Be Healthy in Pregnancy RCT. Blood samples were analyzed for fasting glucose, insulin, triglycerides, leptin, adiponectin, and C-reactive protein (CRP). Maternal adiposity was assessed by pre- pregnancy body mass index (pBMI) and two indirect quantitative measures of % body fat (BIA and 4-site SFT). Results: Of the 91 subjects (mean age= 31 ± 4 y), 46.2% were overweight/obese by pBMI. For both SFT and BIA, % body fat was positively associated with fasting glucose, insulin, triglyceride, leptin, and CRP concentrations, and negatively associated with adiponectin concentration, although the strength of the associations was greater for SFT than BIA. After adjustment for confounders, maternal adiposity remained significantly associated with all cardiometabolic biomarkers, except for adiponectin and CRP. Dietary polyunsaturated: saturated fat ratio, energy expenditure, high activity level, age, ethnicity and parity were significantly associated with some of the biomarkers. Conclusion: Maternal adiposity was predominantly associated with leptin, insulin, and glucose status in early pregnancy although dietary fat, energy, activity level, age, ethnicity and parity were also significantly associated with some biomarkers. Body fat estimated by SFT or BIA are generally comparable for use as a screening tool for cardiometabolic dysfunction in early pregnancy. In the clinical setting, BIA may be more easily adopted as it is faster and requires fewer technical skills by the operator than SFT measures.