Anthropometric predictors of elevated prostate specific antigen among rural and urban Nigerians: a population-based...

Obesity has been associated with incidence and mortality of carcinoma of the prostate (CaP), but the relationship of BMI to CaP risk remains controversial across populations.

To describe the anthropometric correlates of elevated prostate specific antigen in Nigeria, a low-incidence region for CaP that currently reports rising incidence.

Weight, height and skin fold thickness were measured for men, aged 40 years and older. Waist-to-hip ratio (WHR) and body mass index (BMI) were computed. Prostate specific antigen (PSA) status and prostate size were determined. Mean anthropometric indices were compared across groups using Student's t-test, association between anthropometry and PSA was by Spearman's correlation, and mean PSA was tested for linearity across tertiles of anthropometry. Prediction of elevated PSA was determined by multivariate logistic regression controlling for age and prostate size.

Of 350 consecutive men contacted, 281(80.3%) completed the survey, mean age 56.9(13.5) years, and elevated PSA prevalence 31(11.0 %). WHR was 0.92 for rural and urban men, BMI (22.9 vs 24.7, p<0.002, and skin fold thickness was lower for rural men. PSA correlated directly with age, r=0.360, p<0.0001 and negatively with height, r=-0.136, p<0.023. WHR remained a significant predictor of elevated PSA,[OR 3.04 (95% CI 1.13 - 8.15)], after adjusting for age and enlarged prostate.

Central adiposity may be a more important predictor of elevated PSA than BMI in this population. There is need to investigate the role of hormonal, metabolic, and genetic correlates of central adiposity in carcinoma of the prostate risk in this population.