Investigation Of Blood Lactate As A Marker Of Metabolic Dysfunction During Pregnancy

Previous work suggests blood lactate can be used as an indicator of metabolic disease, however, the utility of lactate as an indicator of metabolic dysfunction during pregnancy is unknown. PURPOSE: To determine if fasting or postprandial lactate is related to established markers of metabolic dysfunction (weight status, insulin resistance, substrate oxidation) during pregnancy. The ability to detect metabolic dysfunction during pregnancy has the potential to impact the immediate and future health of both mother and infant. METHODS: Lactate, glucose, and insulin values were assessed in 64 participants during late pregnancy (34.5 ± 1.7 weeks gestation) before (fasting) and after a high-fat meal (1 hr). Insulin and glucose levels were used to calculate HOMA-IR, which is an index of insulin resistance. Respiratory quotient (RQ), which reflects the relative contribution of fat and carbohydrate oxidation, was estimated using indirect calorimetry. Height (objectively assessed) and pre-pregnancy weight (self-reported) were used to estimate pre-pregnancy Body Mass Index (BMI). Means were compared and potential correlations were assessed using nonparametric tests. Partial correlations were used to adjust for potential confounders. RESULTS: Lactate was higher among those with pre-pregnancy overweight/obese (OWOB, n = 29) compared to lean (n = 35) (fasting: OWOB 0.90 ± 0.26 v lean 0.72 ± 0.26, p = 0.007; 1 hr: OWOB 1.01 ± 0.37 v lean 0.76 ± 0.28, p = 0.005). Fasting and 1 hr lactate values were positively correlated to fasting and 1 hr insulin and HOMA-IR (p < 0.05). When adjusting for pre-pregnancy BMI, only 1 hr lactate (not fasting) was correlated to insulin (1 hr) and HOMA-IR (fasting and 1 hr)(p < 0.05). Fasting and 1 hr lactate was positively correlated to 1 hr RQ and this remained when adjusting for pre-pregnancy BMI and HOMA-IR(p < 0.05). CONCLUSIONS: These data indicate lactate is associated with other markers of metabolic dysfunction during pregnancy. Future work should assess the clinical utility of lactate (fasting or postprandial), assessed at time points throughout pregnancy, as a potential biomarker for metabolic dysfunction or adverse obstetric outcomes, as in gestational or pre-pregnancy diabetes or fetal growth restriction. Funding was provided by NIH NIGMS Grant 5P20GM103436, WKU RCAP Grant 17-8011, and UTGSM Coffman Pediatric Research Endowment.