Geoffrey E. Moore

Health-related fitness and quality of life in organ transplant recipients

BACKGROUND The purpose of this study was to describe the levels of health-related fitness and quality of life in a group of organ transplant recipients who participated in the 1996 U.S. Transplant Games. METHODS A total of 128 transplant recipients were selected on a first reply basis for testing. Subjects with the following organ types were tested: kidney (n=76), liver (n=16), heart (n=19), lung (n=6), pancreas/kidney (n=7), and bone marrow (n=4). Cardiorespiratory fitness (peak oxygen uptake) was measured using symptom-limited treadmill exercise tests with expired gas analysis. The percentage of body fat was measured using skinfold measurements, and the Medical Outcomes Short Form questionnaire (SF-36) was used to evaluate health-related quality of life. RESULTS Participants achieved near age-predicted cardiorespiratory fitness (94.7+/-32.5% of age-predicted levels). Scores on the SF-36 were near normal. The active subjects (76% of total sample) had significantly higher levels of peak VO2 and quality of life and a lower percentage of body fat compared with inactive subjects (P<0.01). CONCLUSIONS Although this is a highly select group which is not representative of the general transplant population, the data suggest that near-normal levels of physical functioning and quality of life are possible after transplantation and that those who participate in regular physical activity may achieve even higher levels.

Improvement of Insulin Sensitivity by Short-term Exercise Training in Hypertensive African American Women

African American women have a high prevalence of insulin resistance, non-insulin-dependent diabetes mellitus, obesity, and hypertension that may be linked to low levels of physical activity. We sought to determine whether 7 days of aerobic exercise improved glucose and insulin metabolism in 12 obese (body fat >35%), hypertensive (systolic blood pressure > or =140 and/or diastolic blood pressure > or =90 mmHg) African American women (mean age 51+/-8 years). Insulin-assisted frequently-sampled intravenous glucose tolerance tests were performed at baseline and 14 to 18 hours after the 7th exercise session. There was no significant change in maximal oxygen consumption, body composition, or body weight after the 7 days of aerobic exercise. The insulin sensitivity index increased (2.68+/-0.45 x 10[-5] to 4.23+/-0.10 x 10[-5] [min(-1)/pmol/L], P=.02). Fasting (73+/-9 to 50+/-9 pmol/L, P=.02) and glucose-stimulated (332+/-58 to 261+/-45 pmol/L, P=.05) plasma insulin levels decreased. Additional measures related to the insulin resistance syndrome also changed with the 7 days of exercise: basal plasma norepinephrine concentrations were reduced (2.46+/-0.27 to 1.81+/-0.27 nmol/L, P=.02) and sodium excretion rate increased from 100+/-13 to 137+/-7 mmol/d (P=.03); however, there was no change in potassium excretion or 24-hour ambulatory blood pressure. We conclude that a short-term aerobic exercise program improves insulin sensitivity in African American hypertensive women independent of changes in fitness levels, body composition, or body weight. The present study indicates that short-term exercise can improve insulin resistance in hypertensive, obese, sedentary African American women and confirms previous reports that a portion of the exercise-induced improvements in glucose and insulin metabolism may be the result of recent exercise.

Moderate physical activity is associated with higher bone mineral density in postmenopausal women.

OBJECTIVES: To determine the associations between different levels of habitual physical activity, hormone replacement therapy (HRT), and bone mineral density (BMD) in postmenopausal women.

Exercise-associated collapse in cyclists is unrelated to endotoxemia

Endotoxemia occurs when intestinal ischemia allows bacterial lipopolysaccharide to translocate from colonic flora into the bloodstream, which triggers release of cytokines that can cause hypotension, rigors, fever, shock, and even death. Recently, blood endotoxin levels were shown to be higher in athletes needing medical attention (330 pg.ml-1) than in their competitors with similar performances (81 pg.ml-1). Though there were no data showing that these athletes had elevated core temperatures or severe illness, speculation followed that endotoxin may play a causal role in heat stroke. We examined the relationship between endotoxemia and mild post-exertional illness in 39 cyclists after a 100-mile ride. Thirteen cyclists had at least one of the following: orthostatic hypotension, rigors, nausea, vomiting, diarrhea, or syncope. Only 2/26 case-controls had any of these symptoms. Data were collected on vital signs, hemoglobin, sodium, creatine kinase, creatinine, and uric acid. Endotoxin titer was determined by chromogenic assay; tumor necrosis factor alpha (TNF-alpha) titer was determined by ELISA. One ill cyclist had an endotoxin level of 330 pg.ml-1, one control had an endotoxin level of 150 pg.ml-1, but endotoxin level was < or = 64 pg.ml-1 in all others. Comparison of pre- and post-ride data showed that controls increased creatine kinase activity (154 +/- 34 vs 561 +/- 191 IU.dl, P < 0.05), creatinine concentration (1.5 +/- 0.0 vs 1.6 +/- 0.0 mg.dl-1, P < 0.05), and uric acid concentration (5.4 +/- 0.3 vs 6.3 +/- 0.3 mg.dl-1, P < 0.05). Ill cyclists had lower serum sodium than post-ride controls (138 +/- 2 vs 142 +/- 0.6 mEq.l-1, P < 0.05), but there were no differences between groups in CK, creatinine, or uric acid. These findings suggest that endotoxemia may complicate, but does not cause mild post-exertional illness in cyclists.

Specific genetic markers of endurance performance and VO2max.

Specific genetic markers of endurance performance and VO2max. Exerc. Sport Sci. Rev., Vol. 29, No. 1, pp 15-19, 2001. Recent advances have revolutionized genetic studies of quantitative traits. Mitochondrial DNA and creatine kinase variations may influence VO2max. Other data strongly suggest that angiotensin-converting enzyme genotype affects VO2max and endurance performance capacity, but the mechanisms are unclear. A recent genome-wide scan study also has provided candidate loci requiring further study.

Enhanced cardiovascular hemodynamics in endurance-trained postmenopausal women athletes.

PURPOSE We sought to determine whether older women athletes who had habitually performed vigorous endurance exercise training had higher stroke volumes and cardiac outputs than sedentary postmenopausal women during maximal exercise. METHODS Seventeen endurance-trained, postmenopausal women athletes (age 65 +/- 4 yr; VO2max 2.11 +/- 0.31 L x min(-1), 38.3 mL x kg(-1) x min(-1)) and 14 sedentary, postmenopausal women (age 63 +/- 5 yr; VO2max 1.41 +/- 0.22 L x min(-1), 23.7 +/- 3.5 mL x kg(-1) x min(-1)) performed maximal treadmill exercise while cardiac output (via acetylene rebreathing) and other cardiovascular hemodynamics were measured. Approximately half of the subjects in each group were on hormone replacement therapy (HRT). RESULTS The greater VO2max of the athletes was the result of a greater cardiac output (12.8 +/- 1.6 vs. 9.3 +/- 1.4 L x min(-1)) resulting from their significantly larger stroke volume (80 +/- 10 vs 57 +/- 10 mL) at maximal exercise. There were no significant differences in maximal cardiac output or maximal stroke volume related to HRT status in the sedentary women or athletes. CONCLUSIONS These data indicate that endurance-trained, competitive, postmenopausal women have higher stroke volumes and cardiac outputs during maximal exercise, than their sedentary peers. However, these data suggest that HRT may not affect maximal CV function in sedentary or endurance-trained postmenopausal women.

Exercise and organ transplantation

The advent of better surgical techniques and medications to prevent rejection have increased the number of organ transplantations being performed each year. As these patients are surviving longer, non-transplant physicians assume an increasingly large role in the care of these patients. After the trauma of the transplantation has receded, quality of life issues become important and exercise is a potentially important component of their care. This article will attempt to define the risks and benefits of exercise with respect to various types of organ transplantation. Finally, the injury surveillance results of the National Transplant Olympics will be reviewed as an example of what can be accomplished safely by patients who have received organ transplantation.

FABP2 GENOTYPE IS ASSOCIATED WITH INSULIN SENSITIVITY IN OLDER WOMEN

This study determined whether sequence variations in genes related to glucose and insulin metabolism are associated with insulin sensitivity in postmenopausal women after accounting for habitual physical activity levels, body composition, and hormone-replacement therapy (HRT). Eighteen sedentary, 19 physically active, and 23 athletic postmenopausal white women underwent a frequently sampled intravenous glucose tolerance test to determine insulin sensitivity (S(I)) and dual-energy x-ray absorptiometry to determine body composition. After accounting for the effects of body composition, habitual physical activity levels, and HRT status, S(I) was 26% lower in subjects with the Thr54 fatty acid-binding protein 2 (FABP2) allele compared with Ala54 homozygotes (4.3 +/- 0.5 v 5.8 +/- 0.6 microU x 10(-4)/min/mL; P <.05). Angiotensin-converting enzyme genotype was not significantly associated with S(I). There were no significant associations between Gln27Glu beta(2)-adrenergic receptor or Pro12Ala peroxisome proliferator-activated receptor gamma variants and glucose or insulin kinetic parameters. It was concluded that FABP2 genotype influences insulin sensitivity independent of body composition, habitual physical activity levels, and HRT status in postmenopausal white women.