1373-P: Adherence to Healthy Lifestyle on Subsequent Risk of Type 2 Diabetes (T2D) among Women with a History of Gestational Diabetes Mellitus (GDM): A Prospective Cohort Study

Background: Women with a history of GDM are at exceptionally high risk of T2D but adopting a healthy lifestyle may mitigate this risk.

Methods: We analyzed 4,287 women with a prior clinician diagnosis of GDM from the Nurses’ Health Study II cohort as part of the Diabetes and Women’s Health Study. Healthy lifestyle factors, which were assessed every 2-4 years, included no current smoking, normal body mass index (<25 kg/m²), regular moderate-to-vigorous physical activity (>500 MET-min/week), high-quality diet (above median for the Alternative Healthy Eating Index), and moderate alcohol consumption (>0-15 g/day). Self-reported incident T2D was confirmed via validated supplementary questionnaire (98% concordance with medical records). Multivariate-adjusted Cox models were used to calculate the hazard ratio (HR) and 95% confidence interval (CI), adjusting for demographic, reproductive, and clinical characteristics.

Results: We ascertained 835 incident T2D cases during a median 27.9 years of follow-up. Compared to women reporting no healthy lifestyle factors, HR (95% CI) for risk of T2D among those with 1, 2, 3, 4, or 5 factors were 0.91 (0.64, 1.30), 0.62 (0.44, 0.87), 0.45 (0.31, 0.64), 0.33 (0.22, 0.48), and 0.13 (0.06, 0.28), respectively (P<_trend<0.001) (Table 1). When number of health lifestyle factors was modeled continuously, each additional factor was associated with a 29% lower risk of T2D, HR (95% CI): 0.71 (0.67, 0.76). In addition, >86% (population attributable risk [PAR]%: 86.3%; 95% CI: 70.6%, 93.7%) of T2D cases were theoretically preventable if participants had adherence to all 5 healthy lifestyle factors.

Conclusion: Adherence to healthy lifestyle factors was associated with a substantially lower likelihood of progressing to T2D in women with a history of GDM, and strategies to improve long-term adherence are warranted.