Association between parity and obesity patterns in a middle-aged and older Chinese population: a cross-sectional analysis in the Tongji-Dongfeng cohort study.

BACKGROUND: Higher parity has been implicated as a risk factor for obesity of women. The objective of the study was to examine whether parity was associated with general obesity or abdominal obesity, or both, among middle-aged and older Chinese women.

METHODS: A total of 12,829 Chinese women (mean age: 64.8 years) with at least one live birth were selected from the Dongfeng-Tongji Cohort Study (phase II). We used body mass index to assess general obesity, and waist-to-hip ratio (WHR), waist-to-height ratio (WHtR) and waist circumference (WC) to assess abdominal obesity. We used multivariate linear and logistic regression models to investigate the association between parity and obesity.

RESULTS: The values of all four obesity measures increased with the greater number of live births (P for trend <0.001). After adjustment for potential confounders, women with four or more children had 1.72 times (95 % confidence interval [CI], 1.41-2.10) higher risk of general obesity, and 1.93 (95 % CI, 1.57-2.37), 2.09 (95 % CI, 1.65-3.64) and 1.58 (95 % CI, 1.28-1.94) times risk of abdominal obesity assessed by WHR, WHtR and WC, respectively. Furthermore, we observed an ascending gradient between parity and the three abdominal obesity measures.

CONCLUSIONS: Parity was positively associated with risk of obesity, especially abdominal obesity, in the long term among Chinese women.