A1C and Survival in Maintenance Hemodialysis Patients
- Kamyar Kalantar-Zadeh, MD, PHD, MPH12,
- Joel D. Kopple, MD23,
- Deborah L. Regidor, MPH13,
- Jennie Jing, MS1,
- Christian S. Shinaberger, MPH13,
- Jason Aronovitz, DO4,
- Charles J. McAllister, MD4,
- David Whellan, MD, MPH5 and
- Kumar Sharma, MD6
- 1Harold Simmons Center for Kidney Disease Research and Epidemiology, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California
- 2Division of Nephrology and Hypertension, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California
- 3Department of Epidemiology, UCLA School of Public Health, Los Angeles, California
- 4DaVita, Inc., El Segundo, California
- 5Division of Cardiology, Dorrance Hamilton Research Laboratories, Thomas Jefferson University, Philadelphia, Pennsylvania
- 6Center for Novel Therapies for Kidney Disease, Dorrance Hamilton Research Laboratories, Thomas Jefferson University, Philadelphia, Pennsylvania
- Address correspondence and reprint requests to Kamyar Kalantar-Zadeh, MD, PhD, MPH, Division of Nephrology and Hypertension, Harbor-UCLA Medical Center, 1124 West Carson St., C1-Annex, Torrance, CA 90509-2910. E-mail: kamkal{at}ucla.edu
Abstract
OBJECTIVE—The optimal target for glycemic control has not been established in diabetic dialysis patients.
RESEARCH DESIGN AND METHODS—To address this question, the national database of a large dialysis organization (DaVita) was analyzed via time-dependent survival models with repeated measures.
RESULTS—Of 82,933 patients undergoing maintenance hemodialysis (MHD) in DaVita outpatient clinics over 3 years (July 2001 through June 2004), 23,618 diabetic MHD patients had A1C measurements at least once. Unadjusted survival analyses indicated paradoxically lower death hazard ratios (HRs) with higher A1C values. However, after adjusting for potential confounders (demographics, dialysis vintage, dose, comorbidity, anemia, and surrogates of malnutrition and inflammation), higher A1C values were incrementally associated with higher death risks. Compared with A1C in the 5–6% range, the adjusted all-cause and cardiovascular death HRs for A1C ≥10% were 1.41 (95% CI 1.25–1.60) and 1.73 (1.44–2.08), respectively (P < 0.001). The incremental increase in death risk for rising A1C values was monotonic and robust in nonanemic patients (hemoglobin >11.0 g/dl). In subgroup analyses, the association between A1C >6% and increased death risk was more prominent among younger patients, those who had undergone dialysis for >2 years, and those with higher protein intake (>1 g · kg−1 · day−1), blood hemoglobin (>11 g/dl), or serum ferritin values (>500 ng/ml).
CONCLUSIONS—In diabetic MHD patients, the apparently counterintuitive association between poor glycemic control and greater survival is explained by such confounders as malnutrition and anemia. All things equal, higher A1C is associated with increased death risk. Lower A1C levels not related to malnutrition or anemia appear to be associated with improved survival in MHD patients.
- AGE, advanced glycation end product
- CKD, chronic kidney disease
- MHD, maintenance hemodialysis
- MICS, malnutrition-inflammation complex syndrome
- USRDS, U.S. Renal Data System
Footnotes
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Published ahead of print at http://care.diabetesjournals.org on 2 March 2007. DOI: 10.2337/dc06-2127.
A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C Section 1734 solely to indicate this fact.
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- Accepted February 13, 2007.
- Received October 16, 2006.
- DIABETES CARE
