Findings from epidemiologic studies on the association between diabetes and prostate cancer risk are inconsistent. However, data from at least three studies suggest that the direction and strength of this association differs according to duration of diabetes. To determine the potential effects of early-stage abnormal glucose metabolism on risk, we assessed the relationship of postload glycemia in the absence of self-reported diabetes with risk of prostate cancer mortality.
Data from the Chicago Heart Association Detection Project in Industry were used to examine this relationship. Between 1967 and 1973 some employees of 84 Chicago area organizations underwent a health screening examination. Blood was drawn for measurement of plasma glucose concentration approximately 1 h after a 50-g oral glucose load among 20,433 men. After a mean length of follow-up of 27 years, 176 men died of prostate cancer. Cox regression was used to compute adjusted relative risks (RRs) and 95% confidence intervals (CIs).
After controlling for age, body mass index, heart rate, education, and race, the RRs of prostate cancer mortality for postload plasma glucose levels of 6.7-8.8, 8.9-11, and > or = 11.1 mmol/L compared to < or = 6.6 mmol/L were 1.64, 1.37, and 1.64. respectively (p for trend=0.19). The RR (95% CI) associated with a 2.2 mmol/L (1 standard deviation) higher glucose concentration was 1.1 (0.95-1.2).
These results provide weak evidence of an association between hyperglycemia and prostate cancer mortality.