Objectives: To compare diabetic versus nondiabetic men with prostate cancer to understand whether diabetes mellitus (DM) imposes an additional burden on health-related quality of life (HRQOL) before and after radical prostatectomy, adjusting for obesity.
Methods: Data were abstracted from Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE), a disease registry of 12,005 men with localized prostate cancer. Men were included who had undergone surgical treatment from 1989 to 2003, had body mass index (BMI) information available, and had completed both a pretreatment and at least one posttreatment HRQOL questionnaire within 24 months. A repeated-measures model adjusted for baseline clinical and demographic variables was used to evaluate group differences.
Results: The 1248 men were divided into two groups (117 with DM and 1131 without DM) on the basis of a history of DM or the reporting of diabetes medication use. The diabetic men were significantly more likely to be older and nonwhite, have lower education and income, and be less likely to have private insurance. They also had significantly more comorbid conditions (other than DM) and a greater BMI at baseline. Urinary function differed by diabetes status, BMI, and the DM x BMI interaction, with diabetic men who had a greater BMI reporting greater declines in urinary function over time. No other statistically significant differences in HRQOL were observed, although trends by BMI were noted in sexual function and bowel bother.
Conclusions: Although previous studies of men with prostate cancer have found differences in HRQOL by obesity level, our results have indicated that the presence or absence of DM and a high BMI may have a greater impact on HRQOL than obesity alone.