Association of diabetes mellitus with prostate cancer grade and prostate-specific antigen in Chinese biopsy population

To investigate the association of diabetes mellitus with prostate cancer (PCa) grade and prostate-specific antigen (PSA) in Chinese biopsy population.We retrospectively evaluated data from 2032 patients who underwent prostate biopsies from 2010 to 2016 at our hospital. All diabetes cases were divided into sub-groups according to HbA1c (<6.5%, 6.5%-7.49% and ≥7.5%) and diabetes duration (0-5 years, 6-10 years and >10 years).Among 2032 men, 467 (23.0%) were diabetic and 674 (33.2%) were diagnosed with PCa. Diabetes increased the overall risk of PCa (OR = 1.51, 95%CI: 1.12-2.05, P = 0.007), especially high-grade PCa (OR = 2.30, 95%CI: 1.47-3.61, P < 0.001), but was not associated with low- or intermediate-grade PCa. High-grade PCa risk was markedly increased in patients with increased diabetic duration and HbA1c. Moreover, diabetics had a 22.8% lower geometric mean PSA level than non-diabetics (6.42 vs. 8.31 ng/mL, P < 0.001) and the difference increased with diabetic duration.Diabetes was associated with a higher risk of PCa detection, especially high-grade disease in Chinese biopsy patients. We speculate that low PSA levels in diabetics might delay and/or interfere with PCa detection, eventually leading to higher degree PCa on diagnosis.