Incidence of Lower-Extremity Amputation in American Indians
The Strong Heart Study
- Helaine E. Resnick, PHD, MPH1,
- Elizabeth A. Carter, MPH1,
- Jay M. Sosenko, MD, MS2,
- Susan J. Henly, PHD, RN3,
- Richard R. Fabsitz, PHD4,
- Frederick K. Ness, MD5,
- Thomas K. Welty, MD6,
- Elisa T. Lee, PHD7 and
- Barbara V. Howard, PHD1
- 1MedStar Research Institute, Hyattsville, Maryland
- 2University of Miami School of Medicine, Miami, Florida
- 3School of Nursing, University of Minnesota, Minneapolis, Minnesota
- 4National Heart, Lung, and Blood Institute, Bethesda, Maryland
- 5Diabetes Program, Mille Lacs Band of Ojibwe Indians, Mille Lacs, Minnesota
- 6Missouri Breaks Research, Timber Lake, South Dakota
- 7University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Address correspondence and reprint requests to Helaine E. Resnick, PhD, MPH, Department of Epidemiology and Statistics, MedStar Research Institute, 6495 New Hampshire Ave., Suite 201, Hyattsville, MD 20783. E-mail: helaine.e.resnick{at}medstar.net
Abstract
OBJECTIVE—To define incidence and predictors of nontraumatic lower-extremity amputation (LEA) in a diverse cohort of American Indians with diabetes.
RESEARCH DESIGN AND METHODS—The Strong Heart Study is a study of cardiovascular disease and its risk factors in 13 American-Indian communities. Data on the presence/absence of amputations were collected at each of three serial examinations (1989–1992, 1993–1995, and 1997–1999) by direct examination of the lower extremity. The logistic regression model was used to quantify the relationship between risk of LEA and potential risk factors, including diabetes duration, HbA1c, peripheral arterial disease, and renal function.
RESULTS—Of the 1,974 individuals with diabetes and without prevalent LEA at baseline, 87 (4.4%) experienced an LEA during 8 years of follow-up, and a total of 157 anatomical sites were amputated among these individuals. Amputation of toes was most common, followed by below-the-knee and above-the-knee amputations. Age-adjusted odds of LEA were higher among individuals with unfavorable combinations of risk factors, such as albuminuria and elevated HbA1c. Multivariable modeling indicated that male sex, renal dysfunction, high ankle-brachial index, longer duration of diabetes, less than a high school education, increasing systolic blood pressure, and HbA1c predicted LEA risk.
CONCLUSIONS—The 8-year cumulative incidence of LEA in American Indians with diabetes is 4.4%, with marked differences in risk by sex, educational attainment, renal function, and glycemic control.
- ABI, ankle-brachial index
- AKA, above-the-knee amputation
- BKA, below-the-knee amputation
- LEA, lower-extremity amputation
- SHS, Strong Heart Study
Footnotes
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The opinions expressed in this work are those of the authors and do not necessarily reflect the views of the Indian Health Service.
A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
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- Accepted April 30, 2004.
- Received February 18, 2004.
- DIABETES CARE
