Among female cancer patients, obesity and low levels of physical activity may be associated with increased inflammation and a higher risk of cancer mortality, a recent study concluded. The findings were presented at the Society of Gynecologic Oncology 50th Annual Meeting.
The Third U.S. National Health and Nutrition Examination Survey (NHANES III) was queried for data on female cancer patients between 1988 and 1994. Obesity was defined as a body mass index (BMI) ≥ 30 kg/m2. The researchers defined physical activity as less active, about the same, and more active in comparison to patients’ peers. C-reactive protein (CRP) and fibrinogen were used as inflammatory biomarkers.
NAHNES III provided data on 3,380 women; the median age was 55 years (range 40–89 years). Of the total cohort, 87% of patients were white and 10% were black. Just over a quarter (27%) of the cohort was obese, with a BMI ≥ 30 kg/m2, and the remaining 73% were classified as nonobese (BMI < 30 kg/m2). The patients were also stratified by activity level: 21% were less active, 45% were about the same, and 34% were relatively more active. The mean CRP was 0.52 mg/DL, and mean fibrinogen was 309 mg/dL. When analyzed separately based on obesity status, obese women had higher mean CRP levels compared to non-obese women (0.76 mg/dL vs 0.43 mg/dL, P < 0.001), as well as higher fibrinogen levels (332.16 mg/dL vs 300.31 mg/dL, P < 0.001). Women with higher physical activity, compared to the less active patients, had lower CRP (0.42 mg/dL vs 0.66 mg/dL, P < 0.001) and fibrinogen (300.44 mg/dL vs 325.61 mg/dL, P = 0.001) levels.
In multivariate analysis, obesity and lower physical activity were independently associated with increased cancer mortality (obesity: hazard ratio [HR] = 1.58, 95% CI 1.06–2.34, P = 0.024; lower physical activity: HR = 1.67, 95% CI 1.03–2.70, P = 0.038). The researchers also observed that while increasing physical activity in non-obese women reduced their risk of cancer mortality (P = 0.01), increased activity in obese women did not reduce their risk of cancer death (P = 0.21). In a subset analysis of the obese patients, increase in physical activity did not lower the risk of cancer mortality (P = 0.21); however, in the nonobese patients, increase in physical activity significantly decreased the risk of cancer death (P = 0.01).
The authors concluded that obesity and lower physical activity were both associated with increased inflammation and risk for cancer death, and while increased physical activity may reduce cancer mortality risk in non-obese women, it does not lower the risk in obese women.
Chana JK, Mannb AK, Koh-Bell A, et al. The impact of obesity and physical activity on inflammation and cancer mortality in women.