Letters Section Editor: Stephen J. Lurie,
MD, PhD, Senior Editor.
To the Editor. Rates of death from coronary
heart disease (CHD) among Alaska Natives have historically been lower than
those among nonnative Alaskans.1 However,
in light of the impact of Western acculturation (ie, high-fat diet, smoking,
and sedentary lifestyle) on the prevalence of heart disease among other Native
groups,2 we investigated the possibility
of similar recent trends in CHD mortality and risk factors among Alaska Natives.
To compare trends in CHD mortality and differences in prevalence of
CHD risk factors between Alaska Natives and nonnative Alaskans, we analyzed
CHD mortality rates from death certificate data and CHD risk factors from
Alaska's Behavioral Risk Factor Surveillance System (BRFSS). The BRFSS has
been administered in Alaska since 1991, with sample sizes initially exceeding
1500 and currently exceeding 2500 participants annually. The validity of BRFSS
measures for CHD risk factors are well substantiated.3 The
BRFSS and death certificate data supplement each other in that the former
provides an indication of the relative risk of CHD and the latter provides
actual CHD mortality rate comparisons between Alaska Natives and nonnative
We used the Alaska Section of Epidemiology death certificate database
for 1980-1989 and Alaska Bureau of Vital Statistics data for 1979 and 1990-2002
to determine CHD mortality rates. To increase the sensitivity of determining
risk for CHD in the target population, we analyzed CHD (International Classification of Diseases, Ninth Revision codes 410-414,
and 429.2; 10th Revision codes I20-I25) mortality
based on any mention of the condition on the death certificate, limiting our
analysis to Alaska residents aged 40 years or older. Individuals were included
in the analysis if their race, sex, and cause of death were recorded (0.9%
of records excluded). With the exception of 1979, when contributing causes
of death were not available on death certificates, methods of computerizing
multiple causes of death were comparable across the entire time period. We
adjusted mortality rates for age to the 2000 US standard population using
the direct method.
We used Alaska BRFSS self-reported data (1991-2002) to compute prevalence
for current smoking, overweight/obesity (body mass index ≥25), diabetes
mellitus, hypertension, hypercholesterolemia, and sedentary lifestyle among
Alaska Natives and nonnative Alaskans.
Figure 1 shows the trends
in CHD mortality rates for Alaska Natives and nonnative Alaskans over 6 time
periods. From 1979-1982 to 1999-2002, rates of CHD mortality decreased from
671 to 375 deaths/100 000 among nonnative Alaskans and from 409 to 363
deaths/100 000 among Alaska Natives.
During 1979-1982 through 1987-1990, the average rate of CHD mortality
was significantly lower for Alaska Native vs nonnative Alaskan men (589 vs
850 deaths/100 000; relative risk [RR], 0.69; 95% confidence interval
[CI], 0.50-0.95) and combined sexes (438 vs 591 deaths/100 000; RR, 0.74;
95% CI, 0.57-0.97). It was also lower for women, but not significantly (297
vs 383 deaths/100 000; RR, 0.78; 95% CI, 0.49-1.22). During 1991-1994
through 1999-2002, there were no significant differences in CHD mortality
between Alaska Native vs nonnative Alaskan men (566 vs 549 deaths/100 000;
RR, 1.03; 95% CI, 0.81-1.32), women (262 vs 301 deaths/100 000; RR, 0.87;
95% CI, 0.61-1.23), or both sexes combined (398 vs 418 deaths/100 000;
RR, 0.95; 95% CI, 0.78-1.17).
During 1991-2002, hypertension, overweight/obesity, smoking, and sedentary
lifestyle were significantly more prevalent among Alaska Natives than among
nonnative Alaskans (Table 1).
The BRFSS data for 1991-2002, the only years for which such data exist
in Alaska, reveal higher a prevalence of CHD risk factors among Alaska Natives.
Tobacco smoking, introduced to Alaska Natives by Western explorers in the
mid-1700s,4 is significantly more prevalent
among Alaska Natives than among nonnative Alaskans. Moreover, recent dietary
changes among Alaska Natives, as well as modern conveniences such as grocery
stores, tap water, electricity, and utility vehicles, have substantially altered
the lifestyle of Alaska Natives.5 Correspondingly,
sedentary lifestyle and overweight/obesity are now significantly more prevalent
among Alaska Natives than among nonnative Alaskans. Consistent with increasing
trends in BMI, the prevalence of diabetes mellitus among Alaska Natives is
also increasing steadily6; the self-reported
prevalence of diabetes among Alaska Natives is now similar to that of nonnative
Alaskans. Finally, while hypertension was once rare among Alaska Natives,7 they now have a higher prevalence of hypertension
than do nonnative Alaskans.
Alaska Natives were previously at lower risk for death from CHD than
were nonnative Alaskans; however, this discrepancy has disappeared. Alaska
Natives currently have a higher prevalence of numerous risk factors for CHD
compared with nonnative Alaskans.
McLaughlin JB, Middaugh JP, Utermohle CJ, Asay ED, Fenaughty AM, Eberhart-Phillips JE. Changing Patterns of Risk Factors and Mortality for Coronary Heart Disease Among Alaska Natives, 1979-2002. JAMA. 2004;291(21):2545-2546. doi:10.1001/jama.291.21.2545