Diabetes Care, Vol 19, Issue 7 710-714, Copyright © 1996 by American Diabetes Association
Diabetes and nontraumatic lower extremity amputations. Incidence, risk factors, and prevention--a 12-year follow-up study in Nauru
AR Humphrey, GK Dowse, K Thoma and PZ Zimmet
International Diabetes Institute, Melbourne, Australia.
OBJECTIVE: To measure the 12-year incidence (1982-1994) of nontraumatic
lower extremity amputations (LEAs) in Nauruans, a population at high risk
for NIDDM, and to determine the risk factors for amputation in Nauruans
with diabetes. RESEARCH DESIGN AND METHODS: Amputation data were abstracted
from operating theater records in Nauru, hospital databases in Australia,
and Nauru government records. Baseline characteristics of a cohort of 1,564
Nauruans aged > or = 20 years examined during a population-based survey
in 1982 were used to determine risk factors for first LEAs. RESULTS: Over
this 12-year period, 46 first LEAs were performed on people with NIDDM, of
whom 30 were members of the 1982 study cohort. The incidence of first LEAs
in Nauruans aged > or = 25 years with NIDDM was 8.1 per 1,000
person-years in the study cohort and an estimated 7.6 per 1,000
person-years nationally. Amputations were associated significantly with
lower BMI, lower blood pressure, higher fasting plasma glucose (FPG) level,
and longer mean duration of diabetes at baseline, but levels of other risk
factors, including cigarette smoking, plasma triglycerides, and plasma
cholesterol, were also elevated in amputees. There were no amputations
among individuals with baseline FPG levels < 7.8 mmol/l, irrespective of
diabetes duration. FPG, baseline diabetes duration, and male sex were
independent risk factors for first amputation using the Cox proportional
hazards model. There was a decrease in the incidence of amputations after
the commencement of a national foot care health education and prevention
campaign in June 1992. CONCLUSIONS: The incidence of LEAs in diabetic
Nauruans was higher than in other populations after adjusting for age and
duration. Given the apparent success of the Nauruan footcare program in
reducing amputation rates, other populations with high rates of NIDDM and
LEAs should consider population-wide prevention strategies.