Relation of leisure-time physical activity and cardiorespiratory fitness to the risk of acute myocardial infarction.
ABSTRACT Previous studies have suggested that higher levels of regular physical activity and cardiorespiratory fitness are associated with a reduced risk of coronary heart disease. We investigated the independent associations of physical activity during leisure time and maximal oxygen uptake (a measure of cardiorespiratory fitness) with the risk of acute myocardial infarction.
During the period 1984 to 1989, we performed base-line examinations in 1453 men 42 to 60 years old who did not report having cardiovascular disease or cancer. Physical activity was assessed quantitatively with a detailed questionnaire, and maximal oxygen uptake was measured directly by exercise testing. During an average follow-up of 4.9 years, 42 of the 1166 men with normal electrocardiograms at base line had a first acute myocardial infarction.
After adjustment for age and the year of examination, the relative hazard (risk) of myocardial infarction in the third of subjects with the highest level of physical activity (> 2.2 hours per week) was 0.31 (95 percent confidence interval, 0.12 to 0.85; P = 0.02), as compared with the third with the lowest level (P = 0.04 for linear trend over all three groups). The relative hazard in the third with the highest maximal oxygen uptake (> 2.7 liters per minute) was 0.26 (95 percent confidence interval, 0.10 to 0.68; P = 0.006) (P = 0.006 for linear trend), after adjustment for age, the year and season when the examination was performed, weight, height, and the type of respiratory-gas analyzer used. After up to 17 confounding variables were controlled for, the relative hazards for the third of subjects with the highest level of physical activity (0.34; 95 percent confidence interval, 0.12 to 0.94; P = 0.04) and maximal oxygen uptake (0.35; 95 percent confidence interval, 0.13 to 0.92; P = 0.03), as compared with the values in the lowest third, were significantly (P < 0.05) less than 1.0.
Higher levels of both leisure-time physical activity and cardiorespiratory fitness had a strong, graded, inverse association with the risk of acute myocardial infarction, supporting the idea that lower levels of physical activity and cardiorespiratory fitness are independent risk factors for coronary heart disease.
SourceAvailable from: umu.diva-portal.org
[Show abstract] [Hide abstract]
ABSTRACT: Background: Stroke is a common cause of death, and a leading contributor to long-term disability. The cost associated with the disease is great. Several modifiable risk factors for stroke have been found in older cohorts; however, no study to date has investigated the effects of these risk factors from late adolescence. Methods: The study cohort comprised 811,579 Swedish men (mean age, 18 years) that participated in the mandatory military conscription service in Sweden between 1969 and 1986. Some risk factors for stroke, such as body mass index, systolic and diastolic blood pressure, and cognitive function, were assessed at conscription. Aerobic fitness was also assessed at conscription, using a braked ergometer cycle test. Other risk factors for stroke, including stroke in subjects' parents, and socioeconomic factors including highest achieved level of education and annual income 15 years after conscription, were collected through national register linkage using the personal identification number. Stroke diagnosis among the study participants was tracked in the National Hospital Discharge Patient Register. Results: During a median follow-up period of 33 years 6,180 ischemic strokes and 2,104 hemorrhagic strokes were diagnosed in the cohort at a mean age of 47.9 years. Strong independent risk factors (all p <1.0 × 10-(6)) for ischemic stroke included low aerobic fitness (hazard ratio [HR], 0.84 per standard deviation [SD] increase), high BMI (HR, 1.15 per SD increase), diabetes (HR, 2.85), alcohol intoxication (HR, 1.93), low annual income (HR, 0.85 per SD decrease), and stroke in the mother (HR, 1.31). Similar risk factors were found for hemorrhagic stroke including low aerobic fitness (HR, 0.82 per SD increase), high BMI (HR, 1.18 per SD increase) alcohol intoxication (HR, 2.92), diabetes (HR, 2.06), and low annual income (HR, 0.75). The population attributable risks associated with all evaluated risk factors were 69% for ischemic stroke and 88% for hemorrhagic stroke (p < 0.001 for both). Conclusions: In the present study we have shown that several known risk factors for stroke are present already in late adolescence, and that they are independent of each other. The strongest risk factors were low physical fitness, high BMI, diabetes, low annual income and a maternal history of stroke. Several of the aforementioned risk factors are potentially modifiable. © 2014 S. Karger AG, Basel.Cerebrovascular Diseases 12/2014; 39(1):63-71. DOI:10.1159/000369960 · 3.70 Impact Factor