Diabetic Nephropathy versus Diabetic Retinopathy in a Chinese Population: A Retrospective Study

BACKGROUND It has been reported that diabetic nephropathy and diabetic retinopathy are associated with each other through a shared pathophysiological mechanism. However, it is quite difficult to differentiate diabetic nephropathy from other glomerular diseases if diabetic retinopathy is absent in patients, and the only way to do this is to perform renal biopsies. The objective of this study was to test the hypothesis that diabetic nephropathy patients with and without diabetic retinopathy have different clinical and laboratory profiles. MATERIAL AND METHODS Medical records of type 2 diabetes mellitus patients with confirmed diabetic nephropathy were reviewed and analyzed with appropriate statistical modalities. Presence of arteriolar sclerosis of the carotid artery, abdominal aorta, upper extremities, and first-order aortic branches was regarded as a peripheral vascular disease. RESULTS Out of 217 type 2 diabetes mellitus patients with confirmed diabetic nephropathy, retinopathy was present in 106 (48.8%), while 111 (51.2%) had no evidence of retinopathy. About 45% of patients had pure diabetic nephropathy without any diagnosis of non-diabetic renal diseases, of which membranous nephropathy was most common. Diabetic nephropathy patients with retinopathy and those without retinopathy differed in duration of hypertension (p=0.041), serum creatinine (p=0.031), albumin (p=0.001), and erythrocyte sedimentation rate (p=0.001). Moreover, male preponderance (p<0.001), older age (p=0.033), and increased levels of albumin (p=0.033) were significantly associated with pure diabetic nephropathy without retinopathy. CONCLUSIONS Diabetic nephropathy patients with and without diabetic retinopathy have different clinical and laboratory profiles.