Grade 2 and 3 Obesity and Diagnosed Prostate Cancer in Middle-Aged and Elderly Men: An Epidemiologic Study with Stratified Multistage Sampling Design

Background. The association of obesity with the odds of diagnosed prostate cancer (DPC) is inconclusive. Whether grade 2 or grade 3 obesity is associated with increased odds of DPC has not been investigated. Design and Methods. Cross-sectional data of 7,974 subjects aged ≥40 years were collected from the National Health and Nutrition Examination Survey 2001–2010. Odds ratios (ORs) of DPC associated with grade 2 or grade 3 obesity were estimated by conducting weighted logistic regression models. Results. The unadjusted rates of DPC did not differ significantly over grades of BMI ( ). After adjustment for different groups of potential confounding factors, grade 2 or grade 3 obesity was not significantly associated with the odds of DPC with ORs changing from 0.62 to 0.69 for grade 2 obesity and from 0.81 to 1.09 for grade 3 obesity. Moreover, morbid obesity (grade 2 and 3 obesity combined) was not linked to the odds of DPC. Conclusion. Grade 2 or grade 3 obesity was not associated with the odds of DPC. Whether they are associated with a substantially increased risk of high-grade DPC needs to be further investigated as accumulating evidence has shown that obesity increases the risk of high-grade disease. 1. Introduction Prostate cancer is the most commonly diagnosed non-skin cancer and the second leading cause of cancer death in American men [1, 2]. It is estimated that about one man in 6 will get prostate cancer and one man in 36 will die of this disease in the United States (US) [3]. Despite high comorbidities associated with prostate cancer, most men diagnosed with prostate cancer have survived from it. This should benefit from more cases being diagnosed in the early state due to the development of the prostate specific antigen (PSA) testing. While we do not know exactly what causes prostate cancer, we do know that certain risk factors are linked to the disease. Identification of risk factors of prostate cancer would be crucial for prevention and control of the disease. The established risk factors for prostate cancer include age, race/ethnicity, family history, and westernization [4–6]. Other potential factors need to be further investigated. The high prevalence of obesity is becoming a pandemic problem in the US. Medical costs associated with obesity were estimated at $147 billion, and medical costs for obese people were $1,429 higher than those of normal weight [7]. Obesity may increase the risk of a number of health conditions including hypertension, adverse lipid concentrations, heart disease, stroke, type 2 diabetes, and certain types of cancer