Risk Stratification with Oral Glucose Tolerance Test and Microalbuminuria in Patients with Chronic Heart Failure -Subanalysis of the SUPPORT Trial-

Background: Limited data exists for clinical utility of oral glucose tolerance test (OGTT) and microalbuminuria in patients with chronic heart failure (CHF). Methods: We analyzed 554 CHF patients (mean 66 yrs, women 25%, HbA1c 6.4%) from the control arm of the SUPPORT Trial. The primary outcome was a composite of all-cause death, myocardial infraction, stroke, and HF hospitalization for 5 years. For patients without diabetes mellitus (DM), we performed OGTT to detect newly-diagnosed diabetes mellitus (NDDM) and impaired glucose tolerance (IGT). Microalbuminuria was defined as spot urine albumin≥30 mg/L. Finally, we examined 283 DM (known DM 280, NDDM 3, mean 66 yrs, women 22%), 113 IGT (mean 67 yrs, women 30%) and 158 non-diabetic controls (mean 64 yrs, women 27%). Results: In the Cox model, adjusted hazard ratios (HRs) for IGT, DM (known and NDDM) and microalbuminuria were 0.98 (0.60–1.60, P = .93), 1.23 (0.81–1.87, P = .32), and 1.77 (1.24–2.52, P = .002) in the overall population. HRs for IGT with and without microalbuminuria were 0.78 (0.37–1.62, P = .50) and 2.16 (1.10–4.22, P = .025, P for interaction = 0.049) and HRs for DM with and without microalbuminuria were 1.40 (0.79–2.50, P = .25) and 2.05 (1.17–3.59, P = .012, P for interaction = 0.001), respectively. Conclusions: In CHF patients, IGT itself was not a prognostic factor but was associated with poor prognosis when complicated by microalbuminuria, showing clinical utility of combined assessment of OGTT and microalbuminuria.