Abstract: Objective To investigate the relationship between dietary acid load and gestational diabetes mellitus (GDM) risk in pregnant women. Methods A prospective study was conducted in 1 788 pregnant women recruited from Suzhou Ninth Hospital Affiliated to Soochow University. The semi-quantitative Food Frequency Questionnaire (FFQ) was used to assess dietary intake for 74 common daily foods at a gestational age of fewer than 20 weeks. The potential renal acid load (PRAL), net endogenous acid production (NEAP), and the ratio of animal protein to potassium (A∶P ratio) were used to estimate dietary acid load. A glucose tolerance test (OGTT) of 75 grams of glucose orally administered for 2 hours after an 8-hour fast was performed to diagnose GDM at 24-28 weeks of gestation. Results The values of the PRAL, NEAP, and A∶P ratio were (0.9±11.2) mEq/day, (44.3±17.7) mEq/day, and (9.7±6.2), respectively. The dietary acid load was significantly positively correlated with the intake of red meat, poultry, fish, and eggs, and negatively correlated with the intake of vegetables, fruits, nuts, and legumes (all P<0.05). The lowest and highest quantiles of dietary acid load were compared, including the PRAL (OR=2.27, 95% CI: 1.37, 3.69, P=0.002), NEAP (OR=2.03, 95% CI: 1.22, 3.28, P= 0.011), and A∶P ratio (OR=2.12, 95% CI: 1.33, 3.35, P = 0.004) significantly increased the risk of GDM. In addition, the dietary acid load was correlated with an increase in postprandial blood glucose (PBG) at 1 hour and PBG at 2 hours after load (both P<0.05). Conclusion There is a positive correlation between dietary acid load during pregnancy and the risk of GDM in pregnant women, suggesting that reducing dietary acid load is an effective preventive strategy to reduce the incidence of GDM.

Key words: Dietary acid load, Gestational diabetes mellitus, Prospective cohort