Dose-response association between adiposity and liver cancer incidence: a prospective cohort study among non-smoking and non-alcohol drinking Chinese women

Background Based on a population with very low prevalence of smoking and alcohol drinking, we examined the associations between overall obesity and fat distribution in middle age, obesity in early adulthood, and adult weight gain with the risk of liver cancer incidence. Methods The associations between body mass index (BMI) at study enrollment and at age 20, waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), adult weight gain, and annual average weight gain with the risk of liver cancer were estimated using Cox regression models. Multivariable-adjusted HRs and 95% confidence intervals (CIs) were calculated. Results After a mean follow-up time of 17.5 years, 241 liver cancer cases were identified from 69,296 participants. The HRs for per 5-kg/m2 increment of BMI, per 10-cm increment of WC and HC and per 0.1-unit increment of WHtR in middle age were 1.29 (95% CI: 1.07-1.57), 1.23 (95% CI: 1.05-1.43), 1.30 (95% CI: 1.10-1.55) and 1.37 (95% CI: 1.07-1.75), respectively. The HRs for per 5-kg increment of absolute adult weight gain and per 0.5-kg/year increment of annual average weight gain were 1.15 (95% CI: 1.06-1.25) and 1.44 (95% CI: 1.08-1.92). Conclusions Overall and abdominal obesity in middle age and weight gain through adulthood were positively associated with liver cancer risk among non-smoking and non-alcohol drinking women. Impact Based on a cohort of non-smoking and non-alcohol drinking women, the current study confirmed the association between obesity in middle age and increased liver cancer risk and suggested weight gain through adulthood as a risk factor for liver cancer.