Overweight, centrally obese people at high risk of cancer at several sites

The combination of general and central obesity contributes to an increased risk of cancer at several sites, according to a study, noting that some of these associations are sex-specific.

The investigators included 386,101 UK Biobank participants (aged, 37–73 years; 54.5 percent women) and categorized them as normal weight (body mass index [BMI], 18.5–24.9 kg/m²) or overweight (including obese; BMI, ≥25 kg/m²) and as normal waist circumference (WC) or centrally obese (WC, ≥94 cm for men and ≥80 cm for women).

Four mutually exclusive group were derived, namely normal weight without central obesity, normal weight with central obesity, overweight without central obesity, and overweight with central obesity. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95 percent confidence intervals (CIs). Incidence of and mortality from cancer at 22 sites were the outcomes measured.

Over a mean follow-up of 8.8 years, men who were overweight and centrally obese were found to have a higher cancer incidence risk at three sites (stomach: HR, 1.75, 95 percent CI, 1.33–2.32; p=0.002; kidney: HR, 1.45, 95 percent CI, 1.17–1.81; p=0.016; colorectal: HR, 1.31, 95 percent CI, 1.17–1.47; p<0.001) compared with those with normal weight and WC.

Likewise, such associations were observed at four sites in women: endometrial (HR, 2.48, 95 percent CI, 2.06–2.98; p<0.001), uterine (HR, 2.23, 95 percent CI, 1.89–2.64; p<0.001), kidney (HR, 1.84, 95 percent CI, 1.37–2.46; p=0.001), and breast (HR, 1.24, 95 percent CI, 1.16–1.32; p<0.001); overweight and central obesity also correlated with all-cause cancer (HR, 1.07, 95 percent CI, 1.03–1.10; p=0.003).

Only endometrial cancer mortality (HR, 3.28, 95 percent CI, 1.77–6.07; p=0.004) was found to have a significant association with being overweight and centrally obese.