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BACKGROUND: There are inconsistent data regarding the association between metabolic factors, separately and combined, and the risk of prostate cancer and death from prostate cancer.

METHODS: In the Metabolic Syndrome and Cancer Project (Me-Can), data on body mass index (BMI); blood pressure; and blood levels of glucose, cholesterol, and triglycerides were collected for 289,866 men. Cox proportional hazard models were used to calculate relative risks (RRs) by exposures in quintiles as well as for z scores (with a mean of 0 and a standard deviation of 1) together with a composite sum of scores to assess the combined effect of metabolic factors. RRs were corrected for random errors in measurement.

RESULTS: During a mean follow-up of 12 years, 6673 men were diagnosed with prostate cancer and 961 died of the disease. Men with high levels of glucose and triglycerides were found to have a decreased risk of prostate cancer: top versus bottom quintile of glucose: RR, 0.82 (95% confidence interval [95% CI], 0.62-1.08; P value for trend = .03) and top versus bottom quintile of triglycerides: RR, 0.88 (95% CI, 0.74-1.04; P value for trend = .001). High BMI, elevated blood pressure, and a high composite z score were found to be associated with an increased risk of death from prostate cancer: top versus bottom quintile of BMI: RR, 1.36 (95% CI, 1.08-1.71); systolic blood pressure: RR, 1.62 (95% CI, 1.07-2.45); and per 1-unit increase of the composite z score: RR, 1.13 (95% CI, 1.03-1.25).

CONCLUSIONS: The authors found no evidence of an association between high levels of metabolic factors and the risk of prostate cancer, but high BMI, elevated blood pressure, and a composite score of all metabolic factors were associated with an increased risk of death from prostate cancer. 

Background: Men at risk of prostate cancer are also at risk of competing events but this has been ignored in most studies of metabolic aberrations and prostate cancer. The aim of this study was to assess probabilities of prostate cancer and prostate cancer death by use of competing risk analysis.

Methods: In the Metabolic syndrome and Cancer project (Me-Can), data on body mass index, blood pressure, glucose, total cholesterol, and triglycerides were collected from 285 040 men. Probabilities of prostate cancer, prostate cancer death and competing events, i.e. all-cause death or death from other causes, respectively, were calculated for men with normal (bottom 84%) and high (top 16%) levels of each metabolic factor and a composite score based on all metabolic factors

Results: During follow up, 5893 men were diagnosed with prostate cancer, 1013 men died of prostate cancer, and 26 328 men died of other causes. Men with high levels of metabolic factors had decreased probability of prostate cancer, similar probability of prostate cancer death, and increased probability of other causes of death compared to men with normal levels. After 1996, when prostate specific antigen was used for detection of prostate cancer, men up to 80 years with normal levels of metabolic factors had 13% probability of prostate cancer and 37% probability of death from all causes. For men with high levels of metabolic factors, corresponding probabilities were 12% and 47%.

Conclusions: Men with metabolic aberrations had a decreased probability of prostate cancer but a substantially higher probability of death from all causes.

Previous studies have shown that obesity and hypertension are associated with increased risk of renal cell carcinoma (RCC), but less is known about the association to other metabolic factors. In the Metabolic Syndrome and Cancer project (Me-Can) data on body mass index (BMI, kg/m2), blood pressure, and circulating levels of glucose, cholesterol, and triglycerides were collected from 560,388 men and women in cohorts from Norway, Austria, and Sweden. By use of Cox proportional hazard models, hazard ratios (HR) were calculated for separate and composite metabolic exposures. During a median follow-up of 10 years, 592 men and 263 women were diagnosed with RCC. Among men, we found an increased risk of RCC for BMI, highest vs. lowest quintile, (HR = 1.51, 95% CI 1.13-2.03), systolic blood pressure, (HR = 3.40, 95% CI 1.91-6.06), diastolic blood pressure, (HR = 3.33, 95% CI 1.85-5.99), glucose, (HR = 3.75, 95% CI 1.46-9.68), triglycerides, (HR = 1.79, 95% CI 1.00-3.21) and a composite score of these metabolic factors, (HR = 2.68, 95% CI 1.75-4.11). Among women we found an increased risk of RCC for BMI, highest vs. lowest quintile, (HR = 2.21, 95% CI 1.32-3.70) and the composite score, (HR = 2.29, 95% CI 1.12-4.68). High levels of the composite score were also associated with risk of death from RCC among both men and women. No multiplicative statistical or biological interactions between metabolic factors on risk of RCC were found. High levels of BMI, blood pressure, glucose and triglycerides among men and high BMI among women were associated with increased risk of RCC.

There are little data on the putative association between factors in the metabolic syndrome (MetS) and risk of bladder cancer. In the Metabolic Syndrome and Cancer project (Me-Can), measurements of height, weight, blood pressure and circulating levels of glucose, cholesterol, and triglycerides had been collected from 578,700 subjects in cohorts in Norway, Austria, and Sweden. We used Cox proportional hazard models to calculate relative risks (RRs) of bladder cancer by exposures divided into quintiles, in categories according to the World Health Organisation (WHO) and as a continuous standardized variable (z-score with mean = 0 and standard deviation = 1) for each separate component and its standardized sum, a composite MetS score. RRs were corrected for random error in measurements. During a mean follow-up of 11.7 years (SD = 7.6), 1,587 men and 327 women were diagnosed with bladder cancer. Significant associations with risk were found among men per one unit increment of z-score for blood pressure, RR = 1.13 (95% CI 1.03-1.25), and the composite MetS score, RR = 1.10 (95% CI 1.01-1.18). Among women, glucose was nonsignificantly associated with risk, RR = 1.41 (95% CI 0.97-2.06). No statistically significant interactions were found between the components in the MetS in relation to bladder cancer risk. Hypertension and a composite MetS score were significantly but modestly associated with an increased risk of bladder cancer among men and elevated glucose was associated with a nonsignificant increase in risk among women.