Incidence and risk factors for stroke in American Indians: the Strong Heart Study.
BACKGROUND
There are few published data on the incidence of fatal and nonfatal stroke in American Indians. The aims of this observational study were to determine the incidence of stroke and to elucidate stroke risk factors among American Indians.


RESULTS
This report is based on 4549 participants aged 45 to 74 years at enrollment in the Strong Heart Study, the largest longitudinal, population-based study of cardiovascular disease and its risk factors in a diverse group of American Indians. At baseline examination in 1989 to 1992, 42 participants (age- and sex-adjusted prevalence proportion 1132/100 000, adjusted to the age and sex distribution of the US adult population in 1990) had prevalent stroke. Through December 2004, 306 (6.8%) of 4507 participants without prior stroke suffered a first stroke at a mean age of 66.5 years. The age- and sex-adjusted incidence was 679/100 000 person-years. Nonhemorrhagic cerebral infarction occurred in 86% of participants with incident strokes; 14% had hemorrhagic stroke. The overall age-adjusted 30-day case-fatality rate from first stroke was 18%, with a 1-year case-fatality rate of 32%. Age, diastolic blood pressure, fasting glucose, hemoglobin A(1c,) smoking, albuminuria, hypertension, prehypertension, and diabetes mellitus were risk factors for incident stroke.


CONCLUSIONS
Compared with US white and black populations, American Indians have a higher incidence of stroke. The case-fatality rate for first stroke is also higher in American Indians than in the US white or black population in the same age range. Our findings suggest that blood pressure and glucose control and smoking avoidance may be important avenues for stroke prevention in this population.
Zhang
Ying
Y
Center for American Indian Health Research, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73190, USA. Ying-zhang4@ouhsc.edu
Galloway
James M
JM
Welty
Thomas K
TK
Wiebers
David O
DO
Whisnant
Jack P
JP
Devereux
Richard B
RB
Kizer
Jorge R
JR
Howard
Barbara V
BV
Cowan
Linda D
LD
Yeh
Jeunliang
J
Howard
W James
WJ
Wang
Wenyu
W
Best
Lyle
L
Lee
Elisa T
ET
D017677:Age Distribution; D017668:Age of Onset; D000368:Aged; D044383:Black People / Q000706:statistics & numerical data; D001786:Blood Glucose; D001794:Blood Pressure; D002543:Cerebral Hemorrhage / Q000208:ethnology / Q000401:mortality; D002544:Cerebral Infarction / Q000208:ethnology* / Q000401:mortality*; D005260:Female; D006801:Humans; D015994:Incidence; D007198:Indians, North American / Q000706:statistics & numerical data*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D017678:Sex Distribution; D012907:Smoking / Q000208:ethnology; D020521:Stroke / Q000208:ethnology* / Q000401:mortality*; D044465:White People / Q000706:statistics & numerical data
D001786:Blood Glucose