Plasma amino acids in early and mid-pregnancy and their interplay with phospholipid fatty acids in association with the risk of gestational diabetes mellitus: results from a longitudinal prospective cohort

Objective We prospectively evaluated plasma AAs in early and mid-pregnancy and their interplay with phospholipid fatty acids (FAs) in association with GDM risk. 

Research Design and Methods From a longitudinal pregnancy cohort of 2,802 individuals, concentrations of 24 plasma AAs at 10-14 and 15-26 gestational weeks (GW) were assessed among 107 GDM cases and 214 non-GDM controls. We estimated odds ratios (aORs) and 95% confidence intervals (CIs) for the associations of plasma AAs and the joint associations of plasma AAs and phospholipid FAs with GDM risk, adjusting for risk factors including age, pre-pregnancy body mass index, and family history of diabetes. 

Results Glycine at 10-14 GW was inversely associated with GDM (aOR [95% CI] per standard deviation (SD) increment: 0.55 [0.39-0.79]). Alanine, aspartic acid, and glutamic acid at 10-14 GW were positively associated with GDM (1.43 [1.08-1.88], 1.41 [1.11-1.80], and 1.39 [0.98-1.98]). At 15-26 GW, findings for glycine, alanine, aspartic acid, and glutamine-to-glutamic acid-ratio were consistent with the directions observed at 10-14 GW. Isoleucine, phenylalanine, and tyrosine were positively associated with GDM (1.64 [1.19-2.27], 1.15 [0.87-1.53], and 1.56 [1.16-2.09]). All p-values for linear trend<0.05. Several AAs and phospholipid FAs were significantly and jointly associated with GDM. For instance, the lowest risk was observed among women with higher glycine and lower even-chain saturated FAs at 10-14 GW (aOR [95% CI]: 0.15 [0.06, 0.37]). 

Conclusions Plasma AAs may be implicated in GDM development starting in early pregnancy. Associations of AAs with GDM may be enhanced in the co-presence of phospholipid FA profile.