The effects of metabolic conditions on prostate cancer incidence over 15 years of follow-up: results from the Olmsted County Study

Objective: • To determine if combinations of obesity, hypertension and diabetes influence the development of prostate cancer over 15 years of follow-up.

Patients and methods: • In 1990, a randomly selected cohort of Caucasian men from Olmsted County, MN, USA, aged 40-79 years, was recruited; 2445 completed a questionnaire that included physician-diagnosed diabetes and hypertension. • Anthropometric measures were collected during clinical examination. Biopsy-confirmed prostate cancer was identified from medical records. • Proportional hazards regression was used to estimate the effects of these metabolic conditions, both individually and in combination, on the incidence rate of prostate cancer.

Results: • Men with hypertension alone or in combination with diabetes were more likely to develop prostate cancer than were men without any of the metabolic conditions. • The metabolic syndrome - the presence of all three conditions compared with men with no metabolic components - was only minimally and inversely associated with prostate cancer [hazard ratio (HR): 0.81; 95% confidence interval (CI): 0.20, 3.3] and no monotonic association between the number of metabolic components and prostate cancer was observed.

Conclusions: • Our results suggest that it may not be sufficient to treat metabolic conditions as one variable when investigating the aetiology of prostate cancer in Caucasian men. • Further research should focus on the separate and combined effects of these metabolic conditions in large samples.