Prospective cohort studies of birth weight and risk of obesity, diabetes, and hypertension in adulthood among the Chinese population

Background: Low birth weight (LBW) has been associated with subsequent risks of obesity and certain chronic diseases, but evidence for the associations is limited for the Chinese population. Methods: In this study we analyzed data from two population-based prospective cohort studies, the Shanghai Women's Health Study and the Shanghai Men's Health Study, to examine the associations between LBW and the risk of obesity and chronic diseases. Birth weight was self-reported at baseline; anthropometric measurements were made at study enrollment. Type 2 diabetes mellitus (T2DM) diagnoses were self-reported, whereas hypertension diagnoses were based on self-report and blood pressure measurements at baseline and follow-up surveys. Results: Birth weight was available for 11 515 men and 13 569 women. Non-linear associations were observed for birth weight with baseline body mass index (BMI), waist circumference (WC), waist: hip ratio (WHR), and waist: height ratio (WHtR; P < 0.05 for non-linearity), and LBW was linked with lower BMI, smaller WC, and larger WHR and WHtR. An excess risk of T2DM was observed for LBW (<2500 g) versus birth weight 2500-3499 g since baseline (hazard ratio [HR] 1.17; 95% confidence interval [CI] 0.92-1.49) and since birth (HR 1.29; 95% CI 1.07-1.54), whereas the HRs for hypertension since baseline and birth were 1.13 (95% CI 1.01-1.27) and 1.20 (95% CI 1.11-1.30), respectively. The risk of the diseases decreased as birth weight increased up to similar to 4000 g; further increases in birth weight did not convey additional benefits. Conclusion: The results suggest that LBW, an index of poor intrauterine nutrition, may affect health risks later in life in the Chinese population.