G. William Lyerly

The Association Between Cardiorespiratory Fitness and Risk of All-Cause Mortality Among Women With Impaired Fasting Glucose or Undiagnosed Diabetes Mellitus

OBJECTIVE To evaluate the independent and joint associations among cardiorespiratory fitness (CRF), body mass index, and risk of mortality from any cause among women with impaired fasting glucose (IFG) or undiagnosed diabetes mellitus (DM). PATIENTS AND METHODS Female patients (N=3044; mean age, 47.4 years) with IFG or undiagnosed DM completed a maximal exercise treadmill test (between January 26, 1971, and March 21, 2001). The women had no history of a cardiovascular disease event or diagnosed DM at baseline. Cardiorespiratory fitness was defined categorically as low (bottom 20%), moderate (middle 40%), or high (upper 40%) according to previously published Aerobics Center Longitudinal Study guidelines. Body mass index was calculated as the weight in kilograms divided by the height in meters squared (kg/m 2 ). RESULTS During a 16-year follow-up period, 171 deaths occurred. There was an inverse association between CRF and all-cause mortality risk. Women with moderate or high CRF were at lower risk of mortality (moderate CRF, 35% lower; high CRF, 36% lower; P trend =.03) than those with low CRF. An exercise capacity lower than 7 metabolic equivalents was associated with a 1.5-fold higher risk of death than an exercise capacity of 9 metabolic equivalents or higher ( P trend =.05). The multivariate adjusted hazard ratios (HRs), including adjustments for CRF, were higher for heavier patients than for patients of normal weight (overweight patients: HR, 0.86; 95% confidence interval, 0.57-1.30; obese patients: HR, 1.19; 95% confidence interval, 0.70-2.03; P trend =.84). Combined analyses showed that women who were overweight or obese and unfit (low CRF) were at more than twice the risk of death than women who were of normal weight and fit (moderate or high CRF). CONCLUSION Cardiorespiratory fitness, not body mass index, is a significant predictor of all-cause mortality among women with IFG or undiagnosed DM. Assessing CRF levels provides important prognostic information independent of traditional risk factors.

Moderate intensity exercise training reverses functional aerobic impairment in HIV-infected individuals

Abstract HIV infection and HIV drug therapies result in physical and psychological challenges to those living with HIV. These conditions contribute to decreased functional aerobic capacity (FAC). The aim of this study was to determine the effects of a combined moderate-intensity aerobic and resistance exercise intervention on the FAC of HIV-infected individuals. Forty HIV-infected individuals were randomized to an exercise group (EX) who completed six weeks of moderate-intensity exercise training, or to a control group (CON) that did not receive the exercise intervention. Twice weekly, the EX group completed 30 minutes of moderate-intensity aerobic training followed by moderate-intensity resistance training. Prior to, and following, the intervention the FAC for each subject was determined by graded exercise treadmill stress test (GXT). At baseline testing, the mean FAC as determined by treadmill time-based estimation of maximal oxygen consumption was 25% below age-predicted values, a level of reduction indicating the presence of functional aerobic impairment (FAI). Following the intervention, the EX had a significant increase in time to fatigue and estimated VO2 max (p<.001). Further, FAI was eliminated (1% above age predicted values) during the exercise training. The EX group also experienced decreased heart rates during Stages 1 (p=.02), 2 (p=.01), 4 (p=.05) and 6 (p=.02) of the GXT. The CON had no significant changes during the intervention period. These data indicate that six weeks of combined moderate-intensity aerobic and resistance training can improve FAC and eliminate FAI in those with HIV. Results suggest that the functional limitations common in HIV-infected individuals are due in part to detraining that is reversible through moderate exercise adherence.

Maximal Exercise Electrocardiography Responses and Coronary Heart Disease Mortality Among Men With Diabetes Mellitus

Background— An abnormal ECG during maximal exercise testing has been shown to be a powerful predictor of future coronary heart disease (CHD) mortality in asymptomatic men. However, little is known about the relationship between exercise ECG responses and CHD risk in men with diabetes mellitus. Methods and Results— We examined the association between exercise ECG responses and mortality in 2854 men with documented diabetes mellitus (mean age 49.5 years) who completed a maximal treadmill exercise test during the period from 1974 to 2001 and who were without a previous cardiovascular disease (CVD) event at baseline. Mortality due to all causes, CHD, and CVD were the main outcome measures across categories of exercise ECG responses, with stratification by cardiorespiratory fitness, quantified as treadmill test duration. During an average follow-up of 16 years, 441 deaths (210 CVD and 133 CHD) were identified. Across normal, equivocal, and abnormal exercise ECG groups, age- and examination year–adjusted CHD mortality rates per 10 000 person-years were 23.0, 48.6, and 69.0, respectively (Ptrend<0.001). After further adjustment for fasting plasma glucose level, smoking, body mass index, hypercholesterolemia, hypertension, family history of CVD or diabetes mellitus, abnormal resting ECG responses, and cardiorespiratory fitness, hazard ratios (95% confidence intervals) were 1.00 (referent), 1.68 (1.01 to 2.77), and 2.21 (1.41 to 3.46; Ptrend<0.001). Similar patterns of associations were noted between exercise ECG testing and both CVD and all-cause mortality risk. Conclusions— Among men with diabetes mellitus, equivocal and abnormal exercise ECG responses were associated with higher risk of all-cause, CVD, and CHD mortality.

Impact of Aerobic and Resistance Exercise on the Health of HIV-Infected Persons

Individuals infected with HIV experience numerous comorbidities caused by the disease progression and medications, lack of (or inability to perform) physical activity, malnutrition, or a combination of these causes. Common symptoms include loss of muscle mass, fatigue, lypodystrophy, lypoatrophy, and decreases in strength, functional capacity, and overall quality of life. Studies have shown that exercise is a potential treatment of many of these symptoms. Research suggests that exercise may produce beneficial physiological changes in the HIV-infected population such as improved body composition and increases in both strength and endurance. In addition, psychological conditions such as depression and anxiety have been shown to be positively affected by exercise. The purpose of this review is to examine the literature regarding effects of aerobic, resistance, and combined aerobic and resistance exercise training on HIV-infected individuals.

Maximal Exercise Electrocardiographic Responses and Coronary Heart Disease Mortality Among Men With Metabolic Syndrome

OBJECTIVE To examine the association between abnormal exercise electrocardiographic (E-ECG) test results and mortality (all-cause and that resulting from coronary heart disease [CHD] or cardiovascular disease [CVD]) in a large population of asymptomatic men with metabolic syndrome (MetS). PATIENTS AND METHODS A total of 9191 men (mean age, 46.9 years) met the criteria of having MetS. All completed a maximal E-ECG treadmill test (May 14, 1979, through April 9, 2001) and were without a previous CVD event or diabetes at baseline. Main outcomes were all-cause mortality, mortality due to CHD, and mortality due to CVD. Cox regression analysis was used to quantify the mortality risk according to E-ECG responses. RESULTS During a follow-up of 14 years, 633 deaths (242 CVD and 150 CHD) were identified. Mortality rates and hazard ratios (HRs) across E-ECG responses were the following: for all-cause mortality: HR, 1.36; 95% confidence interval (CI), 1.09-1.70 for equivocal responses and HR, 1.41; 95% CI, 1.12-1.77 for abnormal responses (P(trend)<.001); for mortality due to CVD: HR, 1.29; 95% CI, 0.88-1.88 for equivocal responses and HR, 2.04; 95% CI, 1.46-2.84 for abnormal responses (P(trend)<.001); and for mortality due to CHD: HR, 1.62; 95% CI, 1.02-2.56 for equivocal responses and HR, 2.45; 95% CI, 1.62-3.69 for abnormal responses (P(trend)<.001). A positive gradient for CHD, CVD, and all-cause mortality rates across E-ECG categories within 3, 4, or 5 MetS components was observed (P<.001 for all). CONCLUSION Among men with MetS, an abnormal E-ECG response was associated with higher risk of all-cause, CVD, and CHD mortality. These findings underscore the importance of E-ECG tests to identify men with MetS who are at risk of dying.