Background: Secular trends over 34 years (1965-1998) in overall and cause-specific mortality were examined in 4,623 Pima Indians >or=35 years old.
Methods: The underlying and contributing causes of the 1,363 deaths were determined from a review of all available clinical records; 540 of the deaths occurred in the 2,528 nondiabetic participants and 823 in the 2,095 participants who had diabetes during all or part of the study period. Age/sex-adjusted death rates were calculated across four 8.5-year time intervals.
Results: In the nondiabetic participants, the rate of death from natural causes declined gradually over time (20.4, 17.3, 17.3, and 16.0 deaths per 1,000 persons/year; P=.11); deaths from ischemic heart disease (IHD) were uncommon (n=22), and the rate did not change appreciably, remaining as the fifth leading natural cause of death. In the diabetic participants, the rate of death from natural causes was unchanged over time, but the rate of death from IHD (n=141) increased nearly twofold (3.3, 4.2, 6.4, and 6.4 deaths per 1,000 persons/year; P<.01), becoming the leading cause of death in the third and fourth time intervals.
Conclusions: The rate of death from IHD remained stable in nondiabetic Pima Indians but increased among those with diabetes. This finding suggests that, in the absence of diabetes, the underlying susceptibility to IHD in this population has not changed.