Lactation intensity and duration to postpartum diabetes and prediabetes risk in women with gestational diabetes

Objective: To investigate the association of lactation intensity and duration with postpartum diabetes and prediabetes risks among Chinese women with a history of gestational diabetes (GDM). Methods: We included 1260 women with a history of GDM who participated in the whole population's GDM universal screening survey by using the 1999 World Health Organization's criteria. Lactation intensity and lactation duration were collected by a standardized questionnaire. Postpartum diabetes and prediabetes risk were confirmed by an oral glucose tolerance test. Results: During a mean postpartum period of 3.65 years, we identified 114 cases of diabetes and 417 cases of prediabetes. The multivariable-adjusted hazard ratios based on different lactation intensity (exclusive formula, mixed feeding, and exclusive lactation) were 1.00, 0.68, 0.45 for diabetes (P_trend = 0.008), and 1.00, 0.74, and 0.61 for prediabetes (P_trend = 0.006), respectively. The multivariable-adjusted hazard ratios associated with different lactation duration (none, 0-6 months, 6-12 months, 12-18 months, and ≥18 months) were 1.00, 0.66, 0.42, 0.66, and 0.25 for diabetes (P_trend = 0.013), and 1.00, 0.82, 0.62, 0.67, and 0.63 for prediabetes (P_trend = 0.021), respectively. A restricted cubic spline curve showed a graded inverse association of lactation duration with the risks of diabetes and prediabetes (P_trend < 0.001). Conclusions: Higher-lactation intensity and longer-lactation duration were significantly associated with lower risks of postpartum diabetes and prediabetes among Chinese women with a history of GDM.