Value of Estimated Glomerular Filtration Rate and Albuminuria in Predicting Cardiovascular Risk in Patients with Type 2 Diabetes without Cardiovascular Disease

INTRODUCTION: Onset of nephropathy in patients with type 2 diabetes (T2DM) increases the cardiovascular disease (CVD) risk. Association of the parameters of diabetic nephropathy such as albuminuria and estimated Glomerular filtration rate (eGFR) with predicted CVD risk has not been studied in Sri Lankan patients with T2DM. METHODS: In a cross-sectional study of patients who underwent single visit screening at a diabetes center in Sri Lanka, we obtained demographic and biochemical data. Those with urine albumin excretion over 30 mg/g creatinine were considered as having albuminuria, and eGFR was calculated using modified diet in renal disease (MDRD) formula. Ten-year coronary heart disease risk (CHDR) in all patients was calculated using United Kingdom Prospective Diabetes Study risk engine, and those with CHDR > 10% were considered as having high risk. Spearman correlation was used to study the association between eGFR and CHDR, and logistic regression analysis was carried out to study the association of albuminuria and eGFR with high (>10%) CHDR. RESULTS: Of the patients with diabetes studied (n=2434), 64% (1563) were males. Mean (SD) age and duration of diabetes were 52 (11) and 9 (3) years, respectively. Normoalbuminuria, microalbuminuria, and macroalbuminuria were observed in 16.4%, 14.8%, and 68.7% of patients, respectively. Three hundred ninety-four (16.2%) patients had eGFR < 60 ml/min. Moderate correlation was observed between eGFR and predicted CHDR [r = (-0.4), P<0.01] and between eGFR and fatal CHDR (FCHDR) [r = (-0.5), P<0.01]. Independent t-test showed that patients with eGFR < 60 ml/min were older and had longer diabetes duration and lesser BMI compared to those who had eGFR > 60 ml/min (P < 0.01). On logistic regression, nephropathy according to eGFR became a strong predictor for high CHDR (OR; 3.497, 95% CI 2.08 to 5.87), and nephropathy according to albuminuria and both albuminuria and eGFR was not significant predictor of CHDR. CONCLUSIONS: Predicted CHDR shows a moderate and significant association with eGFR in patients with T2DM without symptomatic CVD. eGFR is a stronger predictor than albuminuria in predicting high CHDR in patients with T2DM. Intensification of CVD prevention measures should be done more confidently among patients with T2DM and reduced eGFR than in those with albuminuria alone.