Influence of Cardiovascular Fitness and Muscle Strength in Early Adulthood on Long-Term Risk of Stroke in Swedish Men

Abstract

Stroke afflicts ≈1 in 6 people in their lifetime, 1 causing 6.2 million deaths worldwide.2 To improve stroke prevention, knowledge of key risk factors, especially those that are modifiable such as physical activity, is essential. In middle-aged men 3 and women, 4 it has been shown that higher levels of physical activity are associated with reduced risk of future ischemic stroke (IS). Specifically, in 2 meta-analyses on 16 original studies of middle-aged men and women undertaking more intensive versus lower levels of physical activity, the overall risk reduction was 19% to 27%. 5,6 However, in these and most other such studies, physical activity is assessed by self-report in questionnaires and interviews in large numbers of subjects, yet it has been shown that self-report leaves the true degree of physical activity vulnerable to bias. 7Aerobic or cardiovascular fitness (henceforth fitness), however, can be measured objectively. Although measurement requires relatively time-consuming ergometric tests, and so has generated fewer observations and studies, it has been shown to be a more accurate predictor of cardiovascular risk Background and Purpose-Low cardiovascular fitness (fitness) in mid-and late life is a risk factor for stroke. However, the respective effects on long-term stroke risk of fitness and muscle strength in early adulthood are unknown. Therefore, we analyzed these in a large cohort of young men. There were stronger associations for fatal stroke. All 3 stroke types displayed similar associations. Associations between fitness and stroke remained when adjusted for muscle strength, whereas associations between muscle strength and stroke weakened/disappeared when adjusted for fitness. Conclusions-At the age of 18 years, low fitness and to a lesser degree low muscle strength were independently associated with an increased future stroke risk.

Warfarin treatment and risk of stroke among primary care patients with atrial fibrillation

“…Time was registered to first ischemic stroke, defined as having an ICD-10 code indicating an ischemic stroke (I63) in the Inpatient Register (hospital admissions) or in The Cause of Death Register (16). The follow-up period ran from registration of first AF diagnosis during the assessment period until hospitalisation of first ischemic stroke, death, emigration or the end of the study period on December 31, 2010, whichever came first.…”

A Growing Social Divide in Body Mass Index, Strength, and Fitness of Swedish Male Conscripts

“…During exercise, the work rate was successively increased until limited by exhaustion. Based on the final work rate (Wmax), a 9-level score served as a standardized measure of fitness calculated by the National Service Administration in Sweden [9], and for research purposes, the scores have been converted into fitness categories [10,11]. Raw data on Wmax were available for conscription years 1972e2005.…”

“…These weighted valuesdin Newton unitsd were integrated into an overall estimate of strength and divided into a 9-point scores (lowest to highest); the conversions have been performed continuously with a standardized algorithm by the National Service Administration in Sweden in such a way that they are comparable across years [9]. These scores have also been condensed into three functional categories corresponding to low, medium, and high workloads in a three-level classification described previously [10,11], which are used in this analysis.…”

Warfarin treatment and risk of myocardial infarction — A cohort study of patients with atrial fibrillation treated in primary health care

“…Time to first MI after registration of AF diagnosis during the assessment period until 31 December 2010, was defined as having an ICD-10 code indicating an acute myocardial infarction (I21) in the Patient Register (hospital admissions) or The Cause of Death Register [19]. …”