Zinc status in type 2 diabetic patients: relation to the progression of diabetic nephropathy.

Abstract

Zinc deficiency often occurs in patients with diabetes. Therefore, the relationship between zinc status and progression of nephropathy in diabetes has been explored. Total 300 diabetic patients and 100 non-diabetic healthy subjects (age matched) were selected followed by informed consent and divided into five groups as I: non-diabetic normotensive control; II: diabetic normotensive; III: diabetic hypertensive; IV: diabetic normotensive with microalbuminuria; V: diabetic hypertensive with microalbuminuria. The blood samples of all subjects were collected and analyzed for serum zinc, serum creatinine, and estimated-glomerular filtration rate (e-GFR). Urine zinc, creatinine and microalbuminuria concentrations were determined. The serum zinc levels were low (p<0.01) in diabetic patients as compared to non-diabetic control subjects. The lower levels (p<0.001) of serum zinc were observed in Group IV and V as compared to group I-III. Significantly low levels of e-GFR (p<0.05) and high levels of microalbuminuria (p<0.001) were observed in diabetic patients with low serum zinc level as compared to normal serum zinc level. Serum zinc level in diabetic patients was inversely correlated with serum creatinine(r=-0.331, p<0.001), microalbuminuria (r=-0.587, p<0.001) and positively with e-GFR (r=0.194, p<0.01). It is evident from this study that advancing diabetic nephropathy represented by decreasing GFR and increasing microalbuminuria is associated with lower serum zinc levels. It thus indicates the need for determining serum zinc levels and the effectiveness of zinc supplementation in diabetic patients, particularly during the assessment of kidney damage.