Racial Differences in Glycemic Control in a Well-Functioning Older Diabetic Population

Findings from the Health, Aging and Body Composition study

  1. Nathalie de Rekeneire, MD1,
  2. Ronica N. Rooks, PHD2,
  3. Eleanor M. Simonsick, PHD3,
  4. Ronald I. Shorr, MD, MS4,
  5. Lewis H. Kuller, MD, DRPH5,
  6. Ann V. Schwartz, PHD6 and
  7. Tamara B. Harris, MD, MS1
  1. 1Laboratory of Epidemiology, Demography and Biometry, National Institute on Aging, Bethesda, Maryland
  2. 2Institute for Social Research, Social Environment and Health, University of Michigan, Ann Arbor, Michigan
  3. 3Gerontology Research Center, National Institute on Aging, Baltimore, Maryland
  4. 4Department of Preventive Medicine, University of Tennessee, Memphis, Tennessee
  5. 5Division of Geriatric Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
  6. 6Department of Epidemiology and Biostatistics, University of California, San Francisco, California
  1. Address correspondence and reprint requests to Nathalie de Rekeneire, MD, Laboratory of Epidemiology, Demography and Biometry, National Institute on Aging, Gateway Building, Suite 3C-309, 7201 Wisconsin Ave., Bethesda, MD 20892-9205. E-mail: rekenein{at}nia.nih.gov.

Abstract

OBJECTIVE—To evaluate racial differences and factors associated with worse glycemic control in well-functioning older individuals with type 2 diabetes. Our hypothesis was that glycemic control would be worse among black than white diabetic individuals but that this association would be explained by differences in severity of diabetes, health status, health care indicators, and social, psychological, or behavorial factors. We further hypothesized that the association of race with poorer glycemic control would be limited to those with lower education or lower income.

RESEARCH DESIGN AND METHODS—Cross-sectional analysis of 468 diabetic participants among a cohort of 3,075 nondisabled blacks and whites aged 70–79 years living in the community enrolled in the Health, Aging and Body Composition Study. Glycemic control was measured by the level of HbA1c.

RESULTS—A total of 58.5% of the diabetic individuals were black. Although control was poor in all diabetic participants (HbA1c ≥7% in 73.7%), blacks had worse glycemic control than whites (age- and sex-adjusted mean HbA1c, 8.4% in blacks and 7.4% in whites; P < 0.01). Race differences in glycemic control remained significant, even after adjusting for current insulin therapy, cardiovascular disease, higher total cholesterol, and not receiving a flu shot in the previous year, all of which were associated with higher HbA1c concentrations. Controlling for these factors reduced the association by 27%. Race remained an important factor in glycemic control, even when results were stratified by education or income.

CONCLUSIONS—HbA1c concentrations were higher in older black diabetic individuals. Differences in glycemic control by race were associated with disease severity, health status, and poorer quality of care, but these factors did not fully explain the higher HbA1c levels in older black diabetic individuals.

Footnotes

  • A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.

    • Accepted February 23, 2003.
    • Received October 16, 2002.
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