Body fat distribution and breast cancer risk: findings from the Nigerian breast cancer study
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The relationship between overall obesity and breast cancer risk has been well recognized, but the role of central obesity in breast cancer development is uncertain.
Between 1998 and 2009, 1,233 invasive breast cancer cases and 1,101 community controls were recruited into the Nigerian Breast Cancer Study at Ibadan, Nigeria. Logistic regressions were used to calculate multivariate odds ratio (OR) and 95% confidence intervals (CI), adjusting for age, body mass index (BMI), and other known risk factors for breast cancer.
The OR for the highest quartile group of waist circumference relative to the lowest was 2.39 (95% CI, 1.59–3.60; P-trend <0.001). Comparing women with waist/hip ratio (WHR) in the lowest quartile group, the OR for women in the highest quartile category was 2.15 (95% CI, 1.61–2.85; P-trend <0.001). An inverse association was observed between hip circumference and breast cancer, with an OR of 0.36 for the highest quartile (95% CI, 0.24–0.55; P-trend <0.001). The effects of these three measures existed in both pre- and postmenopausal women. Of note, we found a significant interaction between WHR and BMI (P-interaction = 0.016): the OR comparing the highest to the lowest WHR quartile was 2.81 (95% CI, 1.90–4.16) for women with BMI < 25 kg/m2 and 1.70 (95% CI, 1.11–2.61) for women with BMI ≥ 25 kg/m2.
These results suggest that central adiposity, measured by waist circumference and waist/hip ratio, was an important risk factor for breast cancer in Nigerian women, and the effect of central adiposity was strong in normal-weight women.
KeywordsAfrica Breast neoplasms Body fat distribution Waist circumference Waist/hip ratio
The study was funded by the National Cancer Institute at the National Institutes of Health (CA-RO1 89085-01A and P50 CA125183) and the Dr. Ralph and Marian Falk Medical Research Trust. The authors thank the interviewers, data managers, and support staff at the University College Hospital Ibadan and the data managers at the University of Chicago for their diligent and professional work.
Conflict of interest
- 1.Ries L, Melbert D, Krapcho M et al (2008) SEER Cancer Statistics Review, 1975–2005. National Cancer Institute, BethesdaGoogle Scholar
- 2.Parkin DM, Whelan SL, Ferlay J et al. (2005) Cancer Incidence in Five Continents, vol I to VIII. IARC CancerBase No. 7, LyonGoogle Scholar
- 19.Fagherazzi G, Chabbert-Buffet N, Fabre A et al. (2011) Hip circumference is associated with the risk of premenopausal ER-/PR- breast cancer. Int J Obes (Lond). doi:10.1038/ijo.2011.66
- 25.Ogunjimi L, Ikorok M, Yusuf O (2010) Prevalence of obesity among Nigeria nurses: the Akwa Ibom State experience. Intern NGO J 5(2):45–49Google Scholar
- 31.WHO (1998–1999) WHO MONICA Project. MONICA Manual. http://www.ktl.fi/publications/monica/manual/index.htm
- 34.Royston P (2004) Multiple imputation of missing values. Stata J 4(3):227–241Google Scholar