Risk factors for stroke in subjects with normal blood pressure: a prospective cohort study.
OBJECTIVE
Although stroke is strongly associated with hypertension, some individuals with normal blood pressure (BP) experience a stroke. This prospective study explored risk factors for stroke in subjects with normal BP.


METHODS
A total of 11,228 men and 17,174 women, 45 to 73 years old, were examined in a population-based cohort study. Normal BP was defined as BP <140/90 mm Hg and no treatment for hypertension. The incidence of stroke was followed over a mean period of 6 years.


RESULTS
In the cohort, 10,938 (38%) had normal BP. Of them, 56 patients experienced a first-ever stroke (12% of all stroke). Compared with subjects without stroke during follow-up, these stroke subjects were older, had lower education, were often smokers and alcohol nondrinkers, and had a history of coronary heart disease (CHD), gastric ulcer, or renal calculus. Subjects with stroke had a higher body mass index (BMI) and a high-normal BP (130 to 139/85 to 89 mm Hg) more often. In a backward stepwise Cox-regression analysis, age (per 1 year; relative risk [RR], 1.12), current smoking (RR, 3.21), BMI (per SD; RR, 1.39), high-normal diastolic BP (RR, 2.35), history of CHD (RR, 4.92), and gastric ulcer (RR, 2.21) remained significantly associated with incidence of stroke.


CONCLUSIONS
In subjects with normal BP, there are a number of potentially modifiable risk factors associated with an increased incidence of stroke.
Li
Cairu
C
Department of Community Medicine, Malmö University Hospital, Malmö, Sweden, 205-02. cairu.li@smi.mas.lu.se
Engström
Gunnar
G
Hedblad
Bo
B
Berglund
Göran
G
Janzon
Lars
L
D000368:Aged; D001794:Blood Pressure; D015992:Body Mass Index; D015331:Cohort Studies; D003327:Coronary Disease / Q000150:complications; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis; D007669:Kidney Calculi / Q000150:complications; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012044:Regression Analysis; D012306:Risk; D012307:Risk Factors; D012907:Smoking; D013276:Stomach Ulcer / Q000150:complications; D020521:Stroke / Q000175:diagnosis* / Q000473:pathology*; D013997:Time Factors