Unhealthy lifestyle can double risk of stroke
Smoking, drinking, poor diet and lack of exercise all increase the likelihood of stroke, the EPIC study has found.
This UK population-based prospective study looked at the impact of these health behaviours on the incidence of stroke in both men and women. The study enrolled 20,040 men and women aged 40-79 between 1993 and 1997 with no previous history of stroke or myocardial infarction. Participants were followed up until 2007, mean follow up 11.5 years.
Smoking status, physical activity, alcohol intake and plasma concentration of vitamin C, as a marker for fruit and vegetable intake, were assessed. Each participant was assigned 1 point for each area if:
• a current non-smoker
• physically active
• alcohol intake 1-14units/week
• plasma vitamin C ?50 µmol/l.
The minimum score was 0 (least healthy) and the maximum score 4. The incidence of stroke was used as the primary outcome measure.
There were 599 strokes in total. The results were subsequently adjusted for age, sex, BMI, systolic blood pressure, cholesterol, history of diabetes, aspirin use and social class.
The relative risk (RR) of stroke significantly increased with fewer favourable health behaviours compared with those with the best health score (4):
• RR 1.15 with a score of 3 (95% CI 0.89 -1.49)
• RR 1.58 with a score of 2 (95% CI 1.22 - 2.05)
• RR 2.18 with a score of 1 (95% CI 1.63 - 2.92)
• RR 2.31 with a score of 0 (95% CI 1.33 - 4.02).
There is reasonable public awareness of the effects of lifestyle on the incidence of coronary heart disease. However, cerebrovascular disease is perhaps less commonly attributed to poor lifestyle.
This study has shown that smoking, alcohol consumption >14 units/week, physical inactivity and poor diet, measured by a surrogate marker, can predict those patients more likely to have a stroke. This finding serves to support the concept of unhealthy lifestyles influencing cardiovascular risk rather than just coronary risk alone.
Myint PK, Luben RN, Wareham NJ et al. Combined effect of health behaviours and risk of first ever stroke in 20 040 men and women over 11 years' follow-up in Norfolk cohort of European Prospective Investigation of Cancer (EPIC Norfolk): prospective population study. BMJ 2009;338:b349Reviewer
Dr Peter Savill
GPwSI cardiology, Southampton