Incidence of lower-extremity amputation in American Indians: the Strong Heart Study.
OBJECTIVE
To define incidence and predictors of nontraumatic lower-extremity amputation (LEA) in a diverse cohort of American Indians with diabetes.


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, HbA(1c), 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 HbA(1c). 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 HbA(1c) 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.
Department of Epidemiology and Statistics, MedStar Research Institute, 6495 New Hampshire Ave., Suite 201, Hyattsville, MD 20783, USA. helaine.e.resnick@medstar.net
Helaine E
HE
Resnick
Elizabeth A
EA
Carter
Jay M
JM
Sosenko
Susan J
SJ
Henly
Richard R
RR
Fabsitz
Frederick K
FK
Ness
Thomas K
TK
Welty
Elisa T
ET
Lee
Barbara V
BV
Howard
D000671:Amputation, Surgical / Q000706:statistics & numerical data*; D001786:Blood Glucose / Q000032:analysis; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D048909:Diabetes Complications / Q000453:epidemiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007198:Indians, North American / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014481:United States / Q000453:epidemiology
D001786:Blood Glucose