Effect of fasting plasma glucose on serum creatinine, urinary creatinine and urinary microalbumin in type 2 diabetics

Abstract

Diabetes mellitus is the leading cause of end stage renal disease (ESRD) and accounts for 30–50% of incident ESRD cases. Maintaining tight glycaemic control is important for prevention in end-stage renal disease patients with diabetic mellitus. This study was aimed to evaluate the effect of fasting plasma glucose (FPG) on serum creatinine, urinary creatinine and urinary microabumin in Type 2 diabetic patients attending Diabetic Center, Teaching Hospital, Jaffna. A total of 98 patients diagnosed as type 2 diabetics without chronic kidney diseases were included. FPG (Glucose Oxidase method), serum and urine creatinine (Jaffe Alkaline Picric Acid method) and random urine albumin (Immuno-turbidimetry method) were estimated. The strength of correlation was determined by Pearson correlation. The mean FPG, serum creatinine, urine albumin, urine creatinine and urine albumin to creatinine ratio were 136.17 (±53.92) mg/dL, 1.25 (±0.64) mg/dL, 18.9 (±16.2) mg/L, 1.21 (±0.80) g/L and 17.11 (±14.16) mg/g creatinine respectively. The association between the FPG and serum creatinine level was not significant (Pearson Chi-Square=1.99; p=0.37). Similar finding was observed for urine creatinine. Among the patients with albuminuria, 15% (n=15) were having the FPG level >126mg/dL while only 6% (n= 6) patients with albuminuria were having FPG level <100mg/dL (glycaemic control). In this study, 16 (n=4), 32 (n=8) and 52.0% (n=13) of patients had microalbuminuria with the FPG levels of <100, 100-126 and >126mg/dL respectively. The trend of microalbuminuria category was positive with FPG (Regression trend R2=0.99). FPG level showed weak positive correlatons with serum creatinine (r= 0.107, p= 0.293), urine albumin (r = 0.424, p= 0.001) and urine creatinine (r = 0.002, p= 0.982). In contrast, FPG significantly correlated with urine creatinine ratio (r = 0.422, p= 0.001). Serum creatinine level showed non significant correlations with urine albumin (r= 0.109, p= 0.283), urine creatinine (r= 0.138, p= 0.176) and urine albumin to urine creatinine ratio (r= 0.062, p= 0.546). This study revealed that, more than 75% of the diabetic patients were having poor glycaemic control and their serum and urine creatinine and urinary albumin levels were elevated. Poor glycaemic control leads to failure in renal functions. The FPG could be used to predict the excretion of albumin and early renal diseases in diabetic patients. However, the effects of duration of diabetes and the prolonged elevation of plasma glucose levels have to be studied to find their effect on albumin excretion.