Abstract
BACKGROUND: A resting heart rate may be correlated with an increased risk of stroke. Therefore, we explored the independent and joint influences of heart rate and body mass index on the incidence of stroke and its sub-types in a Chinese rural population. METHODS: Cox proportional hazard models were adopted for measuring the influence exerted by heart rate on stroke in the Tongxiang China Kadoorie Biobank prospective cohort analyses, in which 23,132 men and 32,872 women were included. Incident stroke refers to '24-hour acute focal disorder, considered to result from ischemia or intracranial hemorrhage'. RESULTS: Over a 6.9 year mean follow up period, 986 men and 925 women developed stroke, representing an incidence of 6.35 and 4.00 per 1,000 person-years. In contrast to men with heart rate < 69 beats/minute, men at heart rate ≥ 90 beats/minute could more probably develop stroke and ischemic stroke with representing hazard ratio [95% confidence interval (CI)] 1.29 (1.05 - 1.58), and 1.35 (1.06 - 1.71). An adjusted hazard ratio of 1.37 (95% CI = 1.06 - 1.74) and 1.46 (95% CI = 1.08 - 1.96) were respectively identified for stroke and ischemic stroke in non-overweight/obese male patients with heart rate ≥ 90 beats/minute. Joint analyses also favored the results. Unfortunately, non-significant results were found in women. CONCLUSION: Higher resting heart rate acts as an independent predictor of any stroke and ischemic stroke risk in adult Chinese male but not in female. This relationship was particularly evident among nonoverweight/obese male participants.