Anthropometric measures of body fat and obesity-related cancer risk: sex-specific differences in Framingham Offspring Study adults.

Background/objective: Obesity has been associated with the risk of developing certain cancers. A limited number of studies have examined effects of various anthropometric measures of body composition on cancer risk. The aim of this study was to estimate the sex-specific effects of various anthropometric measures on risk of obesity-related cancers (ObCa).

Subjects/methods: Data on body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), and hip circumference (HC) among 3818 45-69-year olds in the Framingham Offspring Study were included. Cox proportional hazards models were used to estimate adjusted risks of 16 obesity-related cancers, with the most common being postmenopausal breast, endometrial, and colon cancers.

Results: Obesity as measured by BMI in both men and women was a predictor of ObCa; those in the highest quintile (Q5) of BMI (>30.07 in women; >30.80 kg/m in men) had more than twice the risk of ObCa (HR = 2.07; 95% CI: 1.06-4.07 (women) and HR = 2.25; 95% CI: 1.08-4.69 (men)). Waist-related measures (WC, WHtR) were stronger predictors of ObCa in men than in women, and HC confounded the relations between waist size and cancer risk. After adjusting for HC, men in Q5 of WC had more than a threefold increased risk of ObCa (HR: = 3.22; 95% CI: 1.39-7.45). Comparable effects in women were weak and non-statistically significant. Results were similar for WHtR. Finally, an inverse J-shaped relation was found between HC and ObCa after adjusting for WC among men but not in women.

Conclusions: These results suggest that obesity as measured by BMI is a predictor of obesity-related cancer risk in men and women. They also suggest that waist and hip circumference measures are interrelated and confound the independent effects of each measure. Among men, a large waist size and a small hip size are independent predictors of cancer risk.