Background: We describe baseline renal function and albumin excretion rate in patients enrolled in Bypass Angioplasty Revascularization Investigation 2 Diabetes, a randomized clinical trial comparing the impact of revascularization and medical therapy with medical therapy alone and deferred or no revascularization and the impact of glycemic control with either insulin-providing or insulin-sensitizing drugs, on 5-year mortality.
Methods: Study participants had type 2 diabetes mellitus, documented coronary artery disease, and creatinine <2 mg/dL. Albuminuria status (albumin/creatinine ratio [ACR]) and estimated glomerular filtration rate (eGFR), using the abbreviated Modified Diet in Renal Disease equation, were determined at baseline. Univariate and multivariate relationships between baseline clinical characteristics and the presence of albuminuria and reduced eGFR rate were estimated.
Results: Two thousand one hundred forty-six subjects were included in the analysis. Forty-three percent of the cohort had evidence of kidney dysfunction at baseline: 23% had an eGFR > or =60 mL/min/1.73 m with either microalbuminuria ( >30 ACR; 17%) or macroalbuminuria (>300 ACR; 6%). Twenty-one percent had a reduced eGFR <60 mL/min/1.73 m; 52% with reduced eGFR had no albuminuria; 28% had microalbuminuria, and 20% had macroalbuminuria. Race, smoking status, duration of diabetes, hypertension, hemoglobin A1c, triglycerides, vascular disease, abnormal ejection fraction, and reduced eGFR were associated with greater albuminuria. Age, sex, duration of diabetes, ACR, hemoglobin A1c, high density lipoprotein, and number of hypertensive medications were associated with reduced eGFR.
Conclusion: Kidney dysfunction is common in older patients with type 2 diabetes mellitus and coronary artery disease; Albuminuria was present in 33%. Reduced eGFR was present in 21%, and half the patients with reduced eGFR had no evidence of albuminuria.