Background and objective: In diabetics genetic predisposition, poor glycemic control and arterial hypertension contribute to nephropathy development in patients affected by diabetes mellitus. We set up the hypothesis that diabetic nephropathy and incisional hernia formation may have in common alterations of collagen composition and tested whether the occurrence of diabetic nephropathy coincides with wound healing disturbance (incisional herniation) or connective tissue diseases (inguinal herniation, umbilical herniation, aortic aneurysm, varicose veins, disc herniation).
Design: A questionnaire on surgical procedures, wound healing and connective tissue disorders was performed with 731 diabetics. Furthermore, test results for kidney function and damage (creatinine clearance, proteinuria) and blood sugar control (HbA1c) were recorded. Correlations between aforementioned connective tissue diseases and "advanced" diabetic nephropathy were calculated. "Advanced" diabetic nephropathy was assumed in patients with macroproteinuria, CKD stage 5 and/or end-stage renal disease. All diabetics with CKD stages 1 and 2 without proteinuria were included in the "control" group. A subgroup analysis on incisional hernia formation coinciding with diabetic nephropathy was performed in patients with previously performed abdominal surgery.
Results: In patients with advanced nephropathy, some diseases with connective tissue alterations, such as inguinal herniation, aortic aneurysms and varicose veins, did not occur more frequently than in patients without nephropathy. In diabetics with nephropathy, umbilical herniation (3 vs. 8.2 %, p = 0.04) and disc herniation rates (5.7 vs. 16.1 %, p = 0.002) were significantly lower. Subgroup analysis of patients with previously performed abdominal surgery (n = 381) revealed significantly higher incisional herniation rates when "advanced" diabetic nephropathy was present (16 % compared to 5.7 % without nephropathy, p = 0.016).
Conclusion: Our findings support the hypothesis that incisional hernia formation and diabetic nephropathy are positively correlated. Conversely, umbilical and disc herniation pathomechanisms are distinct, as these negatively correlate with the presence of advanced diabetic nephropathy.
Keywords: Chronic kidney disease; Connective tissue disease; Diabetic nephropathy; Incisional hernia; Risk factor.