Rate of Gestational Weight Gain and Glucose-Insulin Metabolism Among Hispanic Pregnant Women With Overweight and Obesity.

Context: Hispanic women are at elevated risk of gestational glucose intolerance and postpartum type 2 diabetes compared with non-Hispanic White women. Identification of potentially modifiable factors contributing to this trajectory of beta-cell dysfunction is warranted.

Objective: We aimed to determine the association between rate of gestational weight gain (rGWG) and glucose-insulin metabolism in Hispanic pregnant women with overweight and obesity.

Methods: This cross-sectional, observational study, conducted from 2018-2020 at the clinical research center at University of California, Irvine, included 33 nondiabetic Hispanic pregnant women at 28 to 30 weeks' gestation with pre-pregnancy body mass index (BMI) 25.0 to 34.9 kg/m2. Participants consumed a standardized liquid mixed meal after an overnight fast. Serial blood samples were collected at fasting and up to 2 hours postprandial. The glucose and insulin area under the curve (AUC), insulin sensitivity index (ISI) and insulin secretion sensitivity index (ISSI)-2 were computed.

Results: Average rGWG (0.36 ± 0.22 kg/week) was classified as excessive in 60% of women. While rGWG was not associated with the glucose or insulin AUC or ISI, it accounted for 13.4% of the variance in ISSI-2 after controlling for covariates (maternal age, parity, and pre-pregnancy BMI); for each 1 unit increase in rGWG, ISSI-2 decreased 2.1 units (P = 0.015).

Conclusion: Even in the absence of gestational diabetes, rGWG was inversely associated with beta-cell function in a high-risk population of Hispanic pregnant women with overweight and obesity. Beta-cell decline is an established risk factor for transition to type 2 diabetes, and these cross-sectional findings highlight rGWG as a potentially modifiable contributor to this process.