A Follow-Up Study of Diabetic Oklahoma Indians: Mortality and causes of death

Abstract

OBJECTIVE— To determine the mortality rates and causes of death for diabetic Oklahoma Indian adults by sex and age. RESEARCH DESIGN AND METHODS— This was a cohort follow-up study with baseline examination between 1972–1980 and the mortality follow-up between 1986 and 1989. Mean follow-up time was 10 ± 4 yr. A quasi-random sample of 1012 (379 men and 633 women) NIDDM American Indians in Oklahoma was performed. Mean age was 52 yr and duration was 7 yr at baseline. Mean degree of Indian blood was 92% (77% full blood). At follow-up, 548 (54%) were alive, 452 (45%) were decreased, and 12 (1%) could not be traced. RESULTS— Death certificates were obtained and coded (ICD-9) for 439 (97%) of the deceased. Mean annual mortality rates were 4.99% for men and 4.17% for women, with an increasing trend with age for both sexes. Compared with the general population of Oklahoma, the observed/expected ratios for number of deaths were 2.92 for men and 4.09 for women (P < 0.0001). The three leading causes of death were circulatory disease (38%), diabetes (24%), and malignant neoplasms (12%). CONCLUSIONS— There is an excessively high mortality among diabetic Oklahoma Indians compared with the general population in the state and with diabetic patients in other populations.