Abstract: PD47-02
Sources of Funding: Pirkanmaa Hospital District, memorial fund of Seppo Nieminen

Introduction

Diabetes has been associated with lowered overall risk of prostate cancer (PCa), yet the risk of high-grade tumors may be elevated. The role of hyperglycemia as PCa risk factor is unclear. We estimated PCa risk overall and by tumor grade and stage among men with diabetic fasting blood glucose level in a population-based cohort of Finnish men.

Methods

The study population of the Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC) was linked to the Fimlab laboratory database to obtain information on fasting plasma/blood glucose measurements since 1978. The data was available for 17,860 men. Based on the average yearly glucose level men were categorized as normoglycemic, prediabetic or diabetic for each follow-up year separately. Follow-up started at the FinRSPC baseline in 1996-1999 and continued until prostate cancer diagnosis, death, or the end of 2014._x000D_ Cox regression with adjustment for age, FinRSPC study arm and use of statins, antihypertensive drugs, NSAIDs, aspirin, 5α-reductase inhibitors and alpha-blockers was used to calculate hazard ratios (HRs) and 95% confidence intervals (95%CIs) for prostate cancer overall and separately for Gleason 6, Gleason 7-10, localized and metastatic tumors._x000D_

Results

During the median follow-up of 14.7 years a total of 1,663 new PCa cases were diagnosed. Compared to normoglycemic men, men with diabetic blood glucose level had increased risk of PCa (HR 1.52; 95% CI 1.31-1.75). The risk increase was observed for all tumor grades, but the risk of being diagnosed with metastatic PCa was not elevated. The risk increase was observed if the blood glucose level was diabetic in the 1990s (HR 1.39; 95% CI 1.16-1.67). Blood glucose level measured in the 1980s was not associated with the risk. Use of diabetic drugs removed the risk association; p for interaction by antidiabetic drug use < 0.001.

Conclusions

Men with diabetic fasting blood glucose level have an increased prostate cancer risk. The risk increase is long-term, initiating approximately a decade before the diagnosis. Use of antidiabetic drugs attenuates the risk increase.

Funding

Pirkanmaa Hospital District, memorial fund of Seppo Nieminen