Altered maternal lipid metabolism is associated with higher inflammation in obese women during late pregnancy

Inflammation is elevated in obese pregnant women and is associated with adverse maternal and neonatal outcomes. Maternal lipid metabolism and its relationships with maternal inflammation, insulin resistance and neonatal metabolic health are poorly understood in obese pregnant women. 18 lean (age: 26.1 ± 5.0 years, pre-pregnancy BMI: 21.5 ± 1.9 kg/m²) and 16 obese (age: 25.0 ± 4.8 years, pre-pregnancy BMI: 36.3 ± 4.3 kg/m²) women participated in this case-control study during the third trimester of pregnancy. Maternal plasma markers of insulin resistance (HOMA-IR) and inflammation (C-reactive protein (CRP)) were measured at rest, and lipid concentration and kinetics (lipid oxidation rate and lipolysis) were measured at rest, during a 30-minute bout of low-intensity (40% VO_2peak) exercise, and during a recovery period. Umbilical cord blood was collected for measurement of neonatal plasma insulin sensitivity, inflammation, and lipid concentration. Neonatal body composition was measured via air displacement plethysmography. Pregnant obese women had higher plasma CRP (9.1 ± 4.0 mg/L versus 2.3 ± 1.8 mg/L, p<0.001) and higher HOMA-IR (3.8 ± 1.9 versus 2.3 ± 1.5, p=0.009) compared to pregnant lean women. Obese women had higher lipid oxidation rates during recovery from low-intensity exercise (0.13 ± 0.03 g/min versus 0.11 ±0.04 g/min, p=0.02) that was associated with higher maternal CRP (r=0.55, p=0.001). Maternal CRP was positively associated with maternal HOMA-IR (r=0.40, p<0.02) and systolic blood pressure (r=0.40, p<0.02). Maternal lipid metabolism-associated inflammation may contribute to insulin resistance and higher blood pressure in obese women during pregnancy.