Association of diabetes and cancer mortality in American Indians: the Strong Heart Study.

PURPOSE: The metabolic abnormalities that accompany diabetes mellitus are associated with an increased risk of many cancers. These associations, however, have not been well studied in American Indian populations, which experience a high prevalence of diabetes. The Strong Heart Study is a population-based, prospective cohort study with extensive characterization of diabetes status. METHODS: Among a total cohort of 4,419 participants who were followed for up to 20 years, 430 cancer deaths were identified. RESULTS: After adjusting for sex, age, education, smoking status, drinking status, and body mass index, participants with diabetes at baseline showed an increased risk of gastric (HR 4.09; 95% CI 1.42-11.79), hepatocellular (HR 2.94; 95% CI 1.17-7.40), and prostate cancer mortality (HR 3.10; 95% CI 1.22-7.94). Further adjustment for arsenic exposure showed a significantly increased risk of all-cause cancer mortality with diabetes (HR 1.27; 95% CI 1.03-1.58). Insulin resistance among participants without diabetes at baseline was associated with hepatocellular cancer mortality (HR 4.70; 95% CI 1.55-14.26). CONCLUSIONS: Diabetes mellitus, and/or insulin resistance among those without diabetes, is a risk factor for gastric, hepatocellular, and prostate cancer in these American Indian communities, although relatively small sample size suggests cautious interpretation. Additional research is needed to evaluate the role of diabetes and obesity on cancer incidence in American Indian communities as well as the importance of diabetes prevention and control in reducing the burden of cancer incidence and mortality in the study population.

Acute myocardial infarction quality of care: the Strong Heart Study.

OBJECTIVES: Evaluate the quality of care provided patients with acute myocardial infarction and compare with similar national and regional data. DESIGN: Case series. SETTING: The Strong Heart Study has extensive population-based data related to cardiovascular events among American Indians living in three rural regions of the United States. PARTICIPANTS: Acute myocardial infarction cases (72) occurring between 1/1/2001 and 12/31/2006 were identified from a cohort of 4549 participants. OUTCOME MEASURES: The proportion of cases that were provided standard quality of care therapy, as defined by the Healthcare Financing Administration and other national organizations. RESULTS: The provision of quality services, such as administration of aspirin on admission and at discharge, reperfusion therapy within 24 hours, prescription of beta blocker medication at discharge, and smoking cessation counseling were found to be 94%, 91%, 92%, 86% and 71%, respectively. The unadjusted, 30 day mortality rate was 17%. CONCLUSION: Despite considerable challenges posed by geographic isolation and small facilities, process measures of the quality of acute myocardial infarction care for participants in this American Indian cohort were comparable to that reported for Medicare beneficiaries nationally and within the resident states of this cohort.

Physical activity levels in American-Indian adults: the Strong Heart Family Study.

BACKGROUND: A limited body of evidence, mostly based on self-report, is available regarding physical activity levels among American-Indian adults. PURPOSE: This study aims to examine physical activity levels objectively using pedometers among a large cohort of American-Indian adult participants in the Strong Heart Family Study (SHFS). METHODS: Physical activity levels in 2604 American-Indian adults, aged 18-91 years, from 13 American-Indian communities were assessed using Accusplit AE120 pedometers over a period of 7 days during 2001-2003. Anthropometric measurements were also assessed. All data analyses were conducted in 2008. Age-adjusted Pearson correlations were used to examine the relationship between average steps per day and age and anthropometric variables. Subjects were placed in age and BMI categories (according to National Heart, Lung, and Blood Institute cut points) to examine trends in physical activity with increasing age and BMI. RESULTS: Daily pedometer steps ranged from 1001 to 38,755. Mean step counts by age group for men were 5384 (aged 18-29 years); 5120 (aged 30-39 years); 5040 (aged 40-49 years); 4561(aged 50-59 years); 4321 (aged 60-69 years); and 3768 (aged >or=70 years) and for women, 5038 (aged 18-29 years); 5112 (aged 30-39 years); 5054 (aged 40-49 years); 4582 (aged 50-59 years); 3653 (aged 60-69 years); and 3770 (aged >or=70 years). A significant linear trend in physical activity was noted with increasing age (p=0.002 for men, p<0.0001 for women) and with increasing BMI (p=0.05 for men, p=0.04 for women). CONCLUSIONS: Objectively measured data suggest that inactivity is a problem among American-Indian adults and that a majority of American-Indian adults in the SHFS may not be meeting the minimum physical activity public health recommendations. Efforts to increase physical activity levels in this population are warranted.

Subjective and objective sleep quality and aging in the sleep heart health study.

OBJECTIVES: To examine the extent to which subjective and objective sleep quality are related to age independent of chronic health conditions. DESIGN: Cross-sectional study. SETTING: The Sleep Heart Health Study (SHHS) is a multicenter study designed to determine the cardiovascular consequences and the natural history of sleep disordered breathing. PARTICIPANTS: Five thousand four hundred seven community-dwelling adults who participated in the SHHS (mean age 63, range 45-99; 52% women). MEASUREMENTS: Unattended home polysomnography (PSG) and sleep questionnaires. RESULTS: Older age was associated with shorter sleep time, diminished sleep efficiency, and more arousals in men and women. In men, age was independently associated with more Stage 1 and Stage 2 sleep and less slow-wave (Stage 3 to 4) and rapid eye movement sleep. In women, older age was less strongly associated according to linear trend with sleep stage. Conversely, poor subjective sleep quality was not associated with older age in men, but older women had more trouble falling asleep, and there was a trend toward older women having more problems with waking up during the night and waking up too early. Associations between self-report and directly measured sleep time and sleep latency were low to moderate across age groups (correlation coefficient=0.06-0.32). CONCLUSION: Older age was more strongly associated with poorer sleep according to PSG in men than women, yet the subjective report of poor sleep with older age was stronger in women. The higher prevalence of chronic health conditions, including sleep apnea, in older adults did not explain changes of sleep parameters with aging and age-sex differences in these relationships.

Different factor loadings for SF36: the Strong Heart Study and the National Survey of Functional Health Status.

BACKGROUND: To increase our understanding of the psychometric characteristics and factor structure of the SF36 in older American Indian populations. METHODS: Between 1993 and 1995, SF36 data were collected from 3,488 Phase II participants of the Strong Heart Study (SHS) between the ages of 48 and 81. Comparison data were provided by an age- and gender-matched sample (n = 695) from the National Survey of Functional Health Status (NSFHS) conducted in 1989 and 1990. RESULTS: Generally, the basic psychometric analyses showed that the SF36 performed adequately in these older American Indians. Exploratory factor analyses indicated that a one-factor model best fit the data for both older groups. On the other hand, confirmatory factor analyses showed that a two-factor model with correlated factors provided a superior fit to the data than a one-factor model. An assumption of equivalent factor loadings for the SHS and NSFHS groups was untenable. CONCLUSION: These analyses demonstrate that use of summary scores assuming a differentiated physical/mental functioning structure is likely improper in at least some populations. The SF36 provides an important opportunity to understand cultural differences in the conceptualization and measurement of health-related quality of life.

Cardiovascular disease and risk factors in three Alaskan Eskimo populations: the Alaska-Siberia project.

OBJECTIVES: To determine the prevalence of CVD and to identify and characterize associated risk factors in three distinct Eskimo populations. STUDY DESIGN: Cross-sectional. METHODS: A slightly modified Strong Heart Study protocol was followed to examine 454 participants, aged 25-91, from four villages. RESULTS: Overall, 6% of the participants under 55 years of age and 26% of those > or = 55 years of age showed evidence of CHD by ECG, or in patient records. The prevalence of "definite coronary heart disease" (CHD) in women with glucose intolerance (GI) was 21.0%, compared to 2.4% in those with normal glucose tolerance (NGT). Men had comparable values of 26.7% and 6.3%. In addition, comparable values for "possible CHD" were 29.7% vs 6.0% for women and 21.4% vs 8.0% for men. GI was associated with relatively higher prevalences of CHD in women than in men (prevalence ratio = 8.5 vs 4.3). CHD was significantly related to age, glucose intolerance and insulin. Hypertension and obesity were significantly associated with CHD only in some ethnic groups. The prevalence of current smokers was 56%. CONCLUSIONS: Recent changes in lifestyle and diet of Alaskan Eskimos, leading to obesity, hypertension, insulin resistance and DM, contribute to an increased risk for cardiovascular disease.

C-reactive protein as a predictor of cardiovascular risk in a population with a high prevalence of diabetes: the Strong Heart Study.

BACKGROUND: High-sensitivity C-reactive protein (CRP) has been investigated extensively as a marker for predicting the risk of cardiovascular disease (CVD). CVD accounts for a large proportion of mortality and morbidity in American Indians; we sought to test the association of CRP and CVD in a population-based American Indian cohort 45 to 74 years old. METHODS AND RESULTS: Of 3277 participants who were CVD-free at baseline, 542 had CRP >10 mg/L and were excluded from analysis; 50.1% of those included had diabetes. There were 343 CVD events among this cohort during a median follow-up of 6.2 years. Multiple CVD risk factors were used as covariates in Cox proportional-hazard models. After exclusions, the median CRP (3.2 mg/L) was higher than reported in many other populations. CRP predicted CVD in models adjusted for traditional risk factors, but not when albuminuria and fibrinogen were included. In subgroup analysis, CRP was strongly related to incident CVD among nondiabetic women participants, even after adjustment for traditional CVD risk factors and other indicators of inflammation. Conversely, CRP was elevated beyond the useful range of the American Heart Association/Centers for Disease Control and Prevention clinical guidelines in 16% of this population, and CRP was not predictive of CVD in important subgroups, such as those with diabetes. CONCLUSIONS: CRP was a predictor of CVD in this American Indian population with a high prevalence of diabetes and other risk factors. The predictive ability of CRP varies considerably among subgroups with different risk factor profiles.