Associations of glycemic control with cardiovascular outcomes among us hemodialysis patients with diabetes mellitus

Abstract

Background-There is a lack of data on the relationship between glycemic control and cardiovascular end points in hemodialysis patients with diabetes mellitus. Methods and Results-We included adult Medicare-insured patients with diabetes mellitus who initiated in-center hemodialysis treatment from 2006 to 2008 and survived for > 90 days. Quarterly mean time-averaged glycated hemoglobin (HbA1c) values were categorized into < 48 mmol/mol (< 6.5%) (reference), 48 to < 58 mmol/mol (6.5% to < 7.5%), 58 to < 69 mmol/mol (7.5% to < 8.5%), and ≥69 mmol/mol (=8.5%). Medicare claims were used to identify outcomes of cardiovascular mortality, nonfatal myocardial infarction (MI), fatal or nonfatal MI, stroke, and peripheral arterial disease. We used Cox models as a function of time-varying exposure to estimate multivariable adjusted hazard ratios and 95%CI for the associations between HbA1c and time to study outcomes in a cohort of 16 387 eligible patients. Patients with HbA1c 58 to < 69 mmol/mol (7.5% to < 8.5%) and ≥69 mmol/mol (=8.5%) had 16% (CI, 2%, 32%) and 18% (CI, 1%, 37%) higher rates of cardiovascular mortality (P-trend=0.01) and 16% (CI, 1%, 33%) and 15% (CI, 1%, 32%) higher rates of nonfatal MI (P-trend=0.05), respectively, compared with those in the reference group. Patients with HbA1c =69 mmol/mol (≥8.5%) had a 20% (CI, 2%, 41%) higher rate of fatal or nonfatal MI (P-trend=0.02), compared with those in the reference group. HbA1c was not associated with stroke, peripheral arterial disease, or all-cause mortality. Conclusions-Higher HbA1c levels were significantly associated with higher rates of cardiovascular mortality and MI but not with stroke, peripheral arterial disease, or all-cause mortality in this large cohort of hemodialysis patients with diabetes mellitus.