Vascular Risk Factor Prevalence and Trends in Native Americans with Ischemic Stroke.

Introduction: Native Americans have a higher incidence and prevalence of stroke and the highest stroke-related mortality among race-ethnic groups in the United States. We aimed to analyze trends in the ischemic stroke (IS) vascular risk factor prevalence in Native Americans along with a comparison to the other race-ethnic groups.

Methods: National Inpatient Sample (NIS) database was used to explore the prevalence of risk factors among hospitalized IS patients during 2000 - 2016. Prevalence estimates were calculated for each risk factor within each race-ethnic group in 6 time periods. Linear trends were explored using linear regression models, with differences in trends between the Native American group and the other race-ethnic groups assessed using interaction terms. The analysis accounted for the complex sampling design, including hospital clusters, NIS stratum, and trend weights for analyzing multiple years of NIS data.

Results: Native Americans constituted 5472 of the 1,278,784 IS patients. The age-and-sex-standardized prevalence of hypertension (slope = 2.24, p < 0.001), hyperlipidemia (slope = 6.29, p < 0.001), diabetes (slope = 2.04, p = 0.005), atrial fibrillation/flutter (trend slope = 0.80, p = 0.011), heart failure (trend slope = 0.73, p = 0.036) smoking (trend slope= 3.65, p < 0.001), and alcohol (slope = 0.60, p = 0.019) increased among Native Americans. They showed larger increases in hypertension prevalence compared to Blacks, Hispanics, and Asian/Pacific Islanders and in smoking prevalence compared to Hispanics and Asian/Pacific Islanders. By the year 2015-2016, Native Americans had the highest overall prevalence of diabetes, coronary artery disease, smoking, and alcohol among all race-ethnic groups.

Conclusion: The prevalence of most vascular risk factors among ischemic stroke patients has increased in Native Americans over the last two decades. Significantly larger increases in hypertension and smoking prevalence were seen in Native Americans compared to other groups along with them having the highest prevalence in multiple risk factors in recent years.