The risk of Parkinson's disease according to diabetic kidney disease status in a Korean population

•Reduced eGFR and proteinuria are independent risk factors for Parkinson's disease in patients with type 2 diabetes.•Having both decreased eGFR and proteinuria exacerbates the risk of Parkinson's disease compared to having either one alone.•The effect of diabetic kidney disease on the development of Parkinson's disease is larger in younger patients than elderly.