Autosomal dominant polycystic kidney disease reduces the risk of diabetes mellitus.

Background: Patients with autosomal dominant polycystic kidney disease (ADPKD) are at greater risk of new-onset diabetes after transplantation as compared with other renal graft recipients.

Methods: We mailed questionnaires to 459 ADPKD patients retrieved from the Polish Registry of ADPKD. We analyzed data from 291 respondents and 271 siblings with a known status of ADPKD and diabetes.

Results: The prevalence of transplant-unrelated diabetes was significantly higher in siblings without ADPKD (8.2%) than in respondents (1.7%; p = 0.0028) and their ADPKD siblings (2.0%; p = 0.023). Univariate logistic regression demonstrated that the prevalence odds ratio (POR) for transplant-unrelated diabetes in the pooled ADPKD group vs. siblings without ADPKD was 0.21 (95% CI: 0.08-0.54, p = 0.0013). Multivariate regression accounting for age and gender disclosed an even smaller POR for diabetes (0.18) in ADPKD patients (95% CI: 0.07-0.47, p = 0.00049). Age was a significant risk factor for diabetes (POR 1.05, 95% CI: 1.01-1.09 per year of life; p = 0.025) and gender was without effect. The prevalence of diabetes in females and males with vs. without ADPKD was similar (1.6% vs. 8.3%, p = 0.0091 for females; 2.2% vs. 8.0%, p = 0.069 for males). Age and gender were not inter-related. In the group of siblings without ADPKD diabetes was associated with higher age (62.2 +/- 15.6 vs. 47.0 +/- 16.3 years, p = 0.0053).

Conclusions: Our findings demonstrate lower prevalence of transplant-unrelated diabetes among ADPKD patients. We hypothesize that metabolic disturbances in polycystic kidneys suppress the synthesis of endogenous glucose and reduce renal breakdown of insulin.