Andreas Pittaras

Exercise Capacity and Mortality in Older Men A 20-Year Follow-Up Study

BACKGROUND Epidemiological findings, based largely on middle-aged populations, support an inverse and independent association between exercise capacity and mortality risk. The information available in older individuals is limited. METHODS AND RESULTS Between 1986 and 2008, we assessed the association between exercise capacity and all-cause mortality in 5314 male veterans aged 65 to 92 years (mean+/-SD, 71.4+/-5.0 years) who completed an exercise test at the Veterans Affairs Medical Centers in Washington, DC, and Palo Alto, Calif. We established fitness categories based on peak metabolic equivalents (METs) achieved. During a median 8.1 years of follow-up (range, 0.1 to 25.3), there were 2137 deaths. Baseline exercise capacity was 6.3+/-2.4 METs among survivors and 5.3+/-2.0 METs in those who died (P<0.001) and emerged as a strong predictor of mortality. For each 1-MET increase in exercise capacity, the adjusted hazard for death was 12% lower (hazard ratio=0.88; confidence interval, 0.86 to 0.90). Compared with the least fit individuals (< or =4 METs), the mortality risk was 38% lower for those who achieved 5.1 to 6.0 METs (hazard ratio=0.62; confidence interval, 0.54 to 0.71) and progressively declined to 61% (hazard ratio=0.39; confidence interval, 0.32 to 0.49) for those who achieved >9 METs, regardless of age. Unfit individuals who improved their fitness status with serial testing had a 35% lower mortality risk (hazard ratio=0.65; confidence interval, 0.46 to 0.93) compared with those who remained unfit. CONCLUSIONS Exercise capacity is an independent predictor of all-cause mortality in older men. The relationship is inverse and graded, with most survival benefits achieved in those with an exercise capacity >5 METs. Survival improved significantly when unfit individuals became fit.

Effects of regular exercise on blood pressure and left ventricular hypertrophy in African-American men with severe hypertension

BACKGROUND The prevalence of hypertension and its cardiovascular complications is higher in African Americans than in whites. Interventions to control blood pressure in this population are particularly important. Regular exercise lowers blood pressure in patients with mild-to-moderate hypertension, but its effects in patients with severe hypertension have not been studied. We examined the effects of moderately intense exercise on blood pressure and left ventricular hypertrophy in African-American men with severe hypertension. METHODS We randomly assigned 46 men 35 to 76 years of age to exercise plus antihypertensive medication (23 men) or antihypertensive medication alone (23 men). A total of 18 men in the exercise group completed 16 weeks of exercise, and 14 completed 32 weeks of exercise, which was performed three times per week at 60 to 80 percent of the maximal heart rate. RESULTS After 16 weeks, mean (+/- SD) diastolic blood pressure had decreased from 88 +/- 7 to 83 +/- 8 mm Hg in the patients who exercised, whereas it had increased slightly, from 88 +/- 6 to 90 +/- 7 mm Hg, in those who did not exercise (P = 0.002). Diastolic blood pressure remained significantly lower after 32 weeks of exercise, even with substantial reductions in the dose of antihypertensive medication. In addition, the thickness of the interventricular septum (P = 0.03), the left ventricular mass (P = 0.02), and the mass index (P = 0.04) had decreased significantly after 16 weeks in the patients who exercised, whereas there was no significant change in the nonexercisers. CONCLUSIONS Regular exercise reduced blood pressure and left ventricular hypertrophy in African-American men with severe hypertension.

Exercise Capacity and All-Cause Mortality in African American and Caucasian Men With Type 2 Diabetes

OBJECTIVE The purpose of this study was to assess the association between exercise capacity and mortality in African Americans and Caucasians with type 2 diabetes and to explore racial differences regarding this relationship. RESEARCH DESIGN AND METHODS African American (n = 1,703; aged 60 ± 10 years) and Caucasian (n = 1,445; aged 62 ± 10 years) men with type 2 diabetes completed a maximal exercise test between 1986 and 2007 at the Veterans Affairs Medical Centers in Washington, DC, and Palo Alto, California. Three fitness categories were established (low-, moderate-, and high-fit) based on peak METs achieved. Subjects were followed for all-cause mortality for 7.3 ± 4.7 years. RESULTS The adjusted mortality risk was 23% higher in African Americans than in Caucasians (hazard ratio 1.23 [95% CI 1.1–1.4]). A graded reduction in mortality risk was noted with increased exercise capacity for both races. There was a significant interaction between race and METs (P < 0.001) and among race and fitness categories (P < 0.001). The association was stronger for Caucasians. Each 1-MET increase in exercise capacity yielded a 19% lower risk for Caucasians and 14% for African Americans (P < 0.001). Similarly, the risk was 43% lower (0.57 [0.44–0.73]) for moderate-fit and 67% lower (0.33 [0.22–0.48]) for high-fit Caucasians. The comparable reductions in African Americans were 34% (0.66 [0.55–0.80]) and 46% (0.54 [0.39–0.73]), respectively. CONCLUSIONS Exercise capacity is a strong predictor of all-cause mortality in African American and Caucasian men with type 2 diabetes. The exercise capacity-related reduction in mortality appears to be stronger and more graded for Caucasians than for African Americans.

Exercise Capacity and Mortality in Hypertensive Men With and Without Additional Risk Factors

We assessed the association between exercise capacity and mortality in hypertensive men with and without additional cardiovascular risk factors. A cohort of 4631 hypertensive veterans, who successfully completed a graded exercise test at the Veterans Affairs Medical Center in Washington, DC, and Palo Alto, California, was followed for 7.7±5.4 years (35 629 person-years) for all-cause mortality. Fitness categories were established based on peak metabolic equivalent (MET) levels achieved. In each fitness category, we defined individuals with and without additional cardiovascular risk factors. Exercise capacity was the strongest predictor of all-cause mortality. The adjusted mortality risk was 13% lower for every 1-MET increase in exercise capacity. Compared with the very low fit (≤5.0 MET), the adjusted risk was 34% lower for those achieving 5.1 to 7.0 MET (low fit; hazard ratio: 0.66; CI: 0.58 to 0.76; P<0.001), 59% lower for the moderate fit (7.1 to 10.0 MET; hazard ratio: 0.41; CI: 0.35 to 0.50; P<0.001), and 71% lower for the high-fit category (>10.0 MET; hazard ratio: 0.29; CI: 0.21 to 0.40; P<0.001). Within the very-low-fit category, mortality risk was 47% higher for those with additional risk factors compared with individuals with no risk factors. This risk was eliminated for those in the next fitness category (5.1 to 7.0 MET) and was progressively reduced for the moderate and high-fit categories regardless of the presence or absence of additional risk factors. In conclusion, exercise capacity was the strongest predictor of all-cause mortality in hypertensive men. The increased risk imposed by low fitness and additional cardiovascular risk factors was eliminated by relatively small increases in exercise capacity and declined progressively with higher exercise capacity.

Cardiorespiratory fitness and coronary heart disease risk factor association in women

OBJECTIVES The purpose of this study was to examine the association between cardiorespiratory fitness and coronary risk factors in healthy, nonsmoking adult women. BACKGROUND A sedentary life-style is recognized as an independent risk factor for coronary heart disease, and increasing physical activity is strongly recommended to reduce this risk. However, studies examining the effects of increased physical activity on coronary heart disease risk factors in women are relatively few, and the findings have been equivocal. METHODS Subjects provided written informed consent, completed a questionnaire on medical history and performed an exercise tolerance test. Blood chemistry and lipid levels were determined from fasting blood samples. Three fitness categories were established on the basis of treadmill time to exhaustion and were adjusted for age. RESULTS The women in the lowest fitness category had less favorable lipid profiles, blood glucose levels, blood pressures and anthropometric indexes than those in the moderate and high fitness categories. CONCLUSIONS Moderate fitness (equivalent to 10 metabolic equivalents [METs]) is required to improve the coronary risk profile in women.

Exercise Capacity and Blood Pressure Associations With Left Ventricular Mass in Prehypertensive Individuals

Prehypertensive individuals are at increased risk for developing hypertension and cardiovascular disease compared with those with normal blood pressure. Early compromises in left ventricular structure may explain part of the increased risk. We assessed echocardiographic and exercise parameters in prehypertensive individuals (n=790) to determine associations between exercise blood pressure and left ventricular structure. The exercise systolic blood pressure at 5 metabolic equivalents (METs) and the change in blood pressure from rest to 5 METs were the strongest predictors of left ventricular hypertrophy. We identified the systolic blood pressure of 150 mm Hg at the exercise levels of 5 METs as the threshold for left ventricular hypertrophy. There was a 4-fold increase in the likelihood for left ventricular hypertrophy for every 10-mm Hg increment in systolic blood pressure beyond this threshold (OR: 1.15; 95% CI: 1.12 to 1.18). There was also a 42% reduction in the risk for left ventricular hypertrophy for every 1 MET increase in the workload (OR: 0.58; P<0.001). When compared with low-fit, moderate, and high-fit individuals exhibited significantly lower systolic blood pressure at an exercise workload of 5 METs (155±14 versus 146±10 versus 144±10; P<0.05), lower left ventricular mass index (48±12 versus 41±10 versus 41±9; P<0.05), and prevalence of left ventricular hypertrophy (48.3% versus 18.7% versus 21.6%; P<0.001). This suggests that moderate improvements in cardiorespiratory fitness achieved by moderate intensity physical activity can improve hemodynamics and cardiac performance in prehypertensive individuals and reduce the work of the left ventricle, ultimately resulting in lower left ventricular mass.

Exercise Capacity and All-Cause Mortality in Prehypertensive Men

BACKGROUND Prehypertension is associated with increased risk for mortality, a fact that generated a debate regarding the use of antihypertensive therapy in prehypertensives. Increased exercise capacity is associated with lower mortality risk, but little is known about its effects in prehypertensives. Thus, we evaluated the association between exercise capacity and all-cause mortality in prehypertensives. METHODS A graded exercise test was performed in 4,478 prehypertensive men at the Veterans Affairs Medical Centers in Washington, DC and Palo Alto, CA. Four fitness categories (quartiles) were defined based on peak metabolic equivalents (METs) achieved. All-cause mortality was assessed for both younger (<or=60 years) and older individuals. The mean follow-up period was 9.0 +/- 6.0 years. RESULTS Exercise capacity was a strong predictor of all-cause mortality, independent of traditional risk factors. The adjusted risk for all-cause mortality was reduced by 15% for every 1-MET increase in exercise capacity in the entire cohort, 18% for younger and 12% for older individuals. Compared to the Very-Low-Fit individuals (<or=6 METs) the adjusted mortality risk was 40% lower in Low-Fit (6.1-8.0 METs); 58% lower in Moderate-Fit (8.1-10 METs), and 73% lower in High-Fit individuals (>10 METs). The trends were similar but more pronounced among younger than older individuals. CONCLUSIONS A strong, inverse and graded association between exercise capacity and all-cause mortality was observed in prehypertensive individuals. The protective effects of increased fitness were more pronounced in younger than older individuals, suggesting that age should be more closely considered when assessing fitness and mortality relationships.

A graded association of exercise capacity and all-cause mortality in males with high-normal blood pressure

Abstract Introduction. Information regarding the effect of exercise capacity on mortality risk in individuals with high-normal blood pressure is severely limited. Thus, we evaluated the association of exercise capacity and all-cause mortality in individuals with high-normal blood pressure. Methods. Exercise test was performed in 1727 males with high-normal blood pressure at two Veteran sites (Washington, DC, and Palo Alto, CA). Fitness status was assessed in metabolic equivalents (METs) at exercise peak. All-cause mortality was recorded for a mean follow-up period of 9.8±6.0 years. Results. Exercise capacity was inversely associated with all-cause mortality, and the association was independent of traditional cardiovascular risk factors. For each 1 MET increase in exercise capacity, the adjusted mortality risk was reduced by 13%, underscoring the strong predictive value of exercise capacity that was confirmed by ROC analysis. Data analysis according to fitness levels revealed a threshold level of 4 METs, over which the mortality risk was progressively reduced by 30% (hazard ratio=0.70; CI 0.51–0.95) for those who achieved 4.1–6.0 METs and 61% (hazard ratio=0.39; CI 0.26–0.57) for those who achieved 8.1–10 METs. No additional reductions in risk were noted until the MET level achieved exceeded 12 METs. Conclusions. We observed a strong, inverse, graded and independent association between exercise capacity and all-cause mortality in individuals with high-normal blood pressure. Our findings indicate that a shift of the fitness curve to the right is associated with significant survival benefits, and even slight differences in fitness levels are associated with substantial reductions in mortality risk.

Body mass index, exercise capacity, and mortality risk in male veterans with hypertension

BACKGROUND Overweight and obesity are associated with increased risk of chronic diseases and mortality. Exercise capacity is inversely associated with mortality risk. However, little is known on the interaction between fitness, fatness, and mortality risk in hypertensive individuals. Thus, we assessed the interaction between exercise capacity, fatness, and all-cause mortality in hypertensive males. METHODS A graded exercise test was performed in 4,183 hypertensive veterans (mean age ± s.d.; 63.3 ± 10.5 years) at the Veterans Affairs Medical Center, Washington, DC. We defined three body weight categories based on body mass index (BMI): normal weight (BMI <25); overweight (BMI 25-29.9); and obese (BMI ≥30); and three fitness categories based on peak metabolic equivalents (METs) achieved: low-fit (≤5 METs); moderate-fit (5.1-7.5 MET); and high-fit (>7.5 METs). RESULTS During a median follow-up period of 7.2 years, there were 1,000 deaths. The association between exercise capacity and mortality risk was strong, inverse, and graded. For each 1-MET increase in exercise capacity the adjusted risk was 20% for normal weight, 12% for overweight, and 25% for obese (P < 0.001). When compared to normal weight but unfit individuals, mortality risks were 60% lower in the overweight/high-fit and 78% lower in the obese/high-fit individuals (P < 0.001). CONCLUSIONS Increased exercise capacity is associated with lower mortality risk in hypertensive males regardless of BMI. The risk for overweight and obese but fit individuals was significantly lower when compared to normal weight but unfit. These findings suggest that in older hypertensive men, it may be healthier to be fit regardless of standard BMI category than unfit and normal weight.

Exercise Capacity and All-Cause Mortality in Male Veterans With Hypertension Aged ≥70 Years

Aging, even in otherwise healthy subjects, is associated with declines in muscle mass, strength, and aerobic capacity. Older individuals respond favorably to exercise, suggesting that physical inactivity plays an important role in age-related functional decline. Conversely, physical activity and improved exercise capacity are associated with lower mortality risk in hypertensive individuals. However, the effect of exercise capacity in older hypertensive individuals has not been investigated extensively. A total of 2153 men with hypertension, aged ≥70 years (mean, 75±4) from the Washington, DC, and Palo Alto Veterans Affairs Medical Centers, underwent routine exercise tolerance testing. Peak workload was estimated in metabolic equivalents (METs). Fitness categories were established based on peak METs achieved, adjusted for age: very-low-fit, 2.0 to 4.0 METs (n=386); low-fit, 4.1 to 6.0 METs (n=1058); moderate-fit, 6.1 to 8.0 METs (n=495); high-fit >8.0 METs (n=214). Cox proportional hazard models were applied after adjusting for age, body mass index, race, cardiovascular disease, cardiovascular medications, and risk factors. All-cause mortality was quantified during a mean follow-up period of 9.0±5.5 years. There were a total of 1039 deaths or 51.2 deaths per 1000 person-years of follow-up. Mortality risk was 11% lower (hazard ratio, 0.89; 95% confidence interval, 0.86–0.93; P<0.001) for every 1-MET increase in exercise capacity. When compared with those achieving ⩽4.0 METs, mortality risk was 18% lower (hazard ratio, 0.82; 95% confidence interval, 0.70–0.95; P=0.011) for the low-fit, 36% for the moderate-fit (hazard ratio, 0.64; 95% confidence interval, 0.52–0.78; P<0.001), and 48% for the high-fit individuals (hazard ratio, 0.52; 95% confidence interval, 0.39–0.69; P<0.001). These findings suggest that exercise capacity is associated with lower mortality risk in elderly men with hypertension.