Constipation and diabetic kidney disease: The Fukuoka Diabetes Registry

Background: Constipation was shown to be associated with higher risk of end-stage kidney disease or incident chronic kidney disease, although evidence in diabetic patients is lacking. The objective of the present study was to examine the association between constipation and diabetic kidney disease (DKD). Methods: In total, 4826 Japanese outpatients with type 2 diabetes were classified according to presence or absence of constipation (defecation frequency < 3 times/week and/or taking laxative medication). DKD was defined as presence of decreased estimated glomerular filtration rate (eGFR < 60 ml/min/1.73 m²), and/or albuminuria (urinary albumin-to-creatinine ratio ≥ 30 mg/g). Odds ratios for the presence of DKD were computed by a logistic regression model. Results: Compared with participants without constipation, the age- and sex-adjusted odds ratio for presence of DKD was 1.58 (95% confidence interval 1.38–1.82) for those with constipation. This association persisted following adjustment for potential confounding factors. Decreased defecation frequency and laxative use were also significantly associated with higher prevalence of DKD. Overall, these findings were identical even when decreased eGFR and albuminuria were separately analyzed. Conclusions: Constipation was associated with higher likelihood of DKD in patients with diabetes, suggesting the importance of clinical assessment of constipation to identify patients at high risk of progression of kidney disease.