Novel insights into stroke risk beyond resting and maximal bicycle exercise systolic blood pressure.

OBJECTIVE: Previous research has shown an association between moderate workload exercise blood pressure (BP) and coronary disease, whereas maximal exercise BP is associated with stroke. We aimed to investigate the association between the increase in BP during maximal exercise and the long-term risk of stroke in healthy, middle-aged men. METHODS: Two thousand and fourteen men were included in the Oslo Ischemia Study in the 1970s. In the present study, we examined baseline data of the 1392 participants who remained healthy and performed bicycle exercise tests both at baseline and 7 years later. Cox proportional hazard was used to assess the risk of stroke in participants divided into quartiles based on the difference between resting and maximal workload SBP (ΔSBP) at baseline, adjusting for resting BP, age, smoking, serum cholesterol and physical fitness. Follow-up was until the first ischemic or hemorrhagic stroke through 35 years. RESULTS: There were 195 incident strokes; 174 (89%) were ischemic. In univariate analyses, there were significant positive correlations between age, resting SBP, resting DBP and SBP at moderate and maximal workload, and risk of stroke. In the multivariate analysis, there was a 2.6-fold (P < 0.0001) increase in risk of stroke in ΔSBP quartile 4 (ΔSBP > 99 mmHg) compared with ΔSBP quartile 2 (ΔSBP 73-85 mmHg), which had the lowest risk of stroke. ΔSBP quartile 1 had a 1.7-fold (P = 0.02) increased risk compared with quartile 2, suggesting a J-shaped association to stroke risk. CONCLUSION: Stroke risk increased with increasing difference between resting and maximal exercise SBP, independent of BP at rest, suggesting that an exaggerated BP response to physical exercise may be an independent predictor of stroke.

Ten-year prediction of cardiovascular disease in healthy Norwegian men, based on NORRISK-2. / Tiårsprediksjon av hjerte- og karsykdom hos friske norske menn basert på NORRISK-2.

BACKGROUND: Norwegian guidelines for primary prevention of cardiovascular disease recommend the use of the NORRISK-2 risk model, with some additions. We wished to investigate whether NORRISK-2 could predict cardiovascular disease in healthy Norwegian men who took part in the Oslo Ischaemia Study. MATERIAL: NORRISK-2 scores were calculated for 2 014 men in the age group 40-60 years who were included in the Oslo Ischaemia Study in 1972-75. Cox regression analyses were used to calculate the hazard ratio for death and cardiovascular disease within ten years of the participants' initial assessment. RESULTS: No participant was lost to follow-up of the 2 014 men, 125 died in the first ten years after inclusion, 61 of whom died from cardiovascular disease. Those who died were older than those who survived, with a larger proportion of daily smokers, and they had higher systolic blood pressure and resting pulse, increased total cholesterol and lower physical fitness. The majority of those who died from acute myocardial infarction and ischaemic stroke within ten years were classified in the high-risk group in NORRISK-2. INTERPRETATION: NORRISK-2 satisfactorily identified the high-risk persons in this cohort of healthy, middle-aged Norwegian men. This supports use of the Norwegian guidelines in the decision on possible primary protection against cardiovascular disease.

Exercise Systolic Blood Pressure at Moderate Workload Is Linearly Associated With Coronary Disease Risk in Healthy Men.

There is no consensus on the definition of an exaggerated increase in systolic blood pressure (SBP) during exercise. The aim was to explore a potential threshold for exercise SBP associated with increased risk of coronary heart disease in healthy men using repeated exercise testing. Two thousand fourteen healthy white male employees were recruited into the Oslo Ischemia Study during early 1970s. At follow-up 7 years later, 1392 men were still considered healthy. A bicycle exercise test at 100 W workload was performed at both visits. Cox regression analyses were performed with increasing cutoff levels of peak exercise SBP at 100 W workload (SBP100W) from 160 mm Hg to 200 mm Hg, adjusted for cardiovascular risk factors and physical fitness. Participants with SBP100W below cutoff level at both baseline and first follow-up were compared with participants with SBP100W equal to or above cutoff level at both visits. Compared with participants with SBP100W below all cutoff levels between 165 and 195 mm Hg, coronary heart disease risk was increased among participants with SBP100W equal to or above cutoff at all levels. There was no evidence of a distinct threshold level for coronary heart disease risk, and the relation between SBP100W and coronary heart disease appears linear. When investigating exercise SBP at moderate workload measured at 2 exercise tests in healthy middle-aged white men, there is increasing risk of coronary heart disease with increasing exercise SBP independent of SBP at rest. The association is linear from the low range of exercise SBP, and there is no sign of a distinct threshold level for increased coronary disease risk.

SBP above 180 mmHg at moderate exercise workload increases coronary heart disease risk in healthy men during 28-year follow-up.

OBJECTIVE: We investigated the association between exercise SBP at a moderate workload and long-term risk of coronary heart disease (CHD) in men who were healthy when assessed by two bicycle exercise tests 7 years apart. METHODS: During 1972-1975, apparently healthy men (n = 1999) were initially enrolled following thorough medical examination and ECG-monitored bicycle exercise test. Participants (n = 1392) who were healthy also at a second exercise test 7 years later were included in the present study. They were divided into quartiles, Q1-Q4, according to the highest SBP during the initial 6 min of the exercise test on a moderate workload of 100 W (SBP100W) at 7 years and followed for up to 28 years. Adjusted Cox regression was used to estimate CHD risk defined as first occurrence of angina pectoris, nonfatal myocardial infarction or CHD mortality. RESULTS: During follow-up, 452 of the 1392 men suffered incident CHD, and unadjusted, there was increased risk of CHD with increasing SBP100 W, with significant differences between Q1-Q4. In the multivariate analysis adjusting for classical coronary risk factors, including SBP at rest, there was increased risk of CHD in Q3 (SBP100 W above 180 mmHg) and Q4 (SBP100 W above 200 mmHg) compared with Q1 (≤160 mmHg, lowest SBP100 W), hazard ratios 1.42 (CI 1.07-1.90) and 1.93 (CI 1.38-2.70), respectively. CONCLUSION: Healthy middle-aged men had increased long-term risk of CHD with exercise SBP above 180 mmHg at moderate workload. The prognostic impact of SBP above 180 mmHg at exercise is independent of classical coronary risk factors and blood pressure at rest.

Physical fitness is a modifiable predictor of early cardiovascular death: A 35-year follow-up study of 2014 healthy middle-aged men.

Background Physical fitness has been shown to predict cardiovascular death during long-term follow-up. In the present study we aimed to investigate how physical fitness and other cardiovascular risk factors at middle-age influenced the risk of cardiovascular death during the early (0-11 years), intermediate (12-23 years) and late (24-35 years) parts of a 35-year observation period. Methods and results Age-adjusted physical fitness was calculated in 2014 apparently healthy, middle-aged men after maximal bicycle electrocardiogram-tests in 1972-1975 (Survey 1) and 1979-1982 (Survey 2). The men were assessed through 35 years after Survey 1, and 28 years after Survey 2 by Cox proportional hazards models. Low Survey 1 physical fitness was independently associated with increased risks of early and intermediate, but not late, cardiovascular death. Survey 1 to Survey 2 change in physical fitness, age, smoking status, systolic blood pressure and cholesterol impacted cardiovascular death risks in all periods. Family history of coronary heart disease impacted early and intermediate, but not late, cardiovascular death. Conclusions Most classical cardiovascular risk factors were strong predictors of early, intermediate and late cardiovascular death. Physical fitness measured at median age 50 years was independently associated with risk of early cardiovascular death, but the association weakened as time progressed. Change in physical fitness during middle-age impacted cardiovascular death risk in a full lifetime perspective. Thus, our data suggest that physical fitness is a modifiable cardiovascular risk factor with limited duration in contrast to the sustained impact of smoking, blood pressure and cholesterol on cardiovascular mortality.