Nutritional interventions for reducing morbidity and mortality in people with HIV.

BACKGROUND: Adequate nutrition promotes and maintains optimal immune function. Dietary support may, therefore, improve clinical outcomes in HIV-infected individuals by reducing the incidence of HIV-associated complications and attenuating progression of HIV disease, thereby improving quality of life and ultimately reducing disease-related mortality. OBJECTIVES: To evaluate the effectiveness of various macronutrient interventions, such as a balanced diet or high protein, high carbohydrate, or high fat diets given orally, in reducing morbidity and mortality in adults and children living with HIV infection. SEARCH STRATEGY: We searched CENTRAL (up to March 2006), MEDLINE (1966 to March 2006), EMBASE (1988 to March 2006), LILACS (up to March 2006), and AIDSearch (up to March 2006). We also scanned reference lists of articles and contacted authors of relevant studies and other researchers. SELECTION CRITERIA: Randomised controlled trials evaluating the effectiveness of macronutrient interventions compared with no nutritional supplements or placebo in the management of adults and children infected with HIV. DATA COLLECTION AND ANALYSIS: Three reviewers independently applied study selection criteria, assessed study quality, and extracted data. Effects were assessed using weighted mean difference and 95% confidence intervals. Meta-analysis employed a fixed-effect model, except when the chi-square test for heterogeneity was significant (p<0.1). MAIN RESULTS: Eight trials (with a total of 486 participants), met the criteria for inclusion in our review. None of the studies reported on mortality, morbidity, or disease progression. Overall, macronutrient supplementation (with or without nutritional counselling) significantly improved energy intake (5 trials; n=254; WMD 367 kcal.day-1; 95% CI: 217 to 516) and protein intake (3 trials; n=128; WMD 17 g.day-1; 95% CI: 8 to 26) compared with no nutritional supplementation or placebo. There was no evidence of an effect on body weight (8 trials; n=423; WMD 0.24 kg; 95% CI: -0.6 to 1.1), fat mass (6 trials; n=305; WMD -0.73 kg; 95% CI: -1.83 to 0.37), fat-free mass (5 trials; n=311; WMD 0 kg; 95% CI: -2.3 to 2.4) or CD4 count (6 trials; n=271; WMD 0.23 cells.mm-3; 95% CI: -40.2 to 40.6). AUTHORS' CONCLUSIONS: Given the current evidence base, which is limited to a few small trials in high-income countries, no firm conclusions can be drawn about the effects of macronutrient supplementation on morbidity and mortality in people living with HIV.

Evaluation of maximal exercise performance, fatigue, and depression in athletes with acquired chronic training intolerance.

OBJECTIVE: This study compared differences in maximal strength and aerobic capacity and symptoms of fatigue and depression in athletes with acquired training intolerance (ATI) and control athletes (CON) matched for age and current training volume who did not have symptoms of excessive or chronic fatigue associated with their sporting activity. SETTING: University of Cape Town, Sports Science Institute of South Africa. PARTICIPANTS: Twenty ATI and 10 CON athletes participated in the trial. Although the ATI athletes reported symptoms of excessive fatigue during exercise, or symptoms of fatigue that occurred at rest and during activities of daily living, they did not fulfill the criteria for a diagnosis of chronic fatigue syndrome. MAIN OUTCOME MEASURES: A training and comprehensive medical history was recorded from all subjects. The Beck Depression Inventory Short Form (BDI-SF) was used to assess levels of depression in both ATI and control subjects. Maximal force output during a 5-second isometric voluntary knee extensor muscle contraction, and maximal aerobic capacity (VO2max), maximal heart rate (HRmax), and maximal blood lactate concentrations during a treadmill running test were measured in all subjects. RESULTS: There were no differences in maximal isometric force output, peak treadmill running speed, VO2max, HRmax, or blood lactate concentration at rest or after maximal exercise testing between the ATI and CON athletes. However, the BDI-SF scores were higher in the ATI (7.7 +/- 6.6 arbitrary units) than in the CON athletes (1.7 +/- 1.5 arbitrary units; (P = 0.0052). CONCLUSIONS: These findings suggest that the symptoms of excessive fatigue and acquired training intolerance described by these ATI athletes do not affect their maximal isometric and maximal aerobic capacity, and may be associated with psychologic depression in these athletes.

Skeletal muscle pathology in endurance athletes with acquired training intolerance.

BACKGROUND: It is well established that prolonged, exhaustive endurance exercise is capable of inducing skeletal muscle damage and temporary impairment of muscle function. Although skeletal muscle has a remarkable capacity for repair and adaptation, this may be limited, ultimately resulting in an accumulation of chronic skeletal muscle pathology. Case studies have alluded to an association between long term, high volume endurance training and racing, acquired training intolerance, and chronic skeletal muscle pathology. OBJECTIVE: To systematically compare the skeletal muscle structural and ultrastructural status of endurance athletes with acquired training intolerance (ATI group) with asymptomatic endurance athletes matched for age and years of endurance training (CON group). METHODS: Histological and electron microscopic analyses were carried out on a biopsy sample of the vastus lateralis from 18 ATI and 17 CON endurance athletes. The presence of structural and ultrastructural disruptions was compared between the two groups of athletes. RESULTS: Significantly more athletes in the ATI group than in the CON group presented with fibre size variation (15 v 6; p = 0.006), internal nuclei (9 v 2; p = 0.03), and z disc streaming (6 v 0; p = 0.02). CONCLUSIONS: There is an association between increased skeletal muscle disruptions and acquired training intolerance in endurance athletes. Further studies are required to determine the nature of this association and the possible mechanisms involved.

Comparative effects of zopiclone and loprazolam on psychomotor and physical performance in active individuals.

OBJECTIVE: Sedative hypnotics are used by athletes to alleviate precompetition anxiety and insomnia. The effects of these agents on exercise tolerance have not been extensively researched. DESIGN: To determine the effects of sedative hypnotics on psychomotor and physical performance, a double-blind, placebo- (P) controlled, cross-over designed trial investigated the effects of zopiclone (Z) and loprazolam (L) on performance in 12 athletes. INTERVENTION: Subjects ingested either P, Z (7.5 mg), or L (2 mg) on three different occasions separated by a 1-week washout period. Eye-hand coordination tests, a 30-m sprint test, an agility test, and a graded treadmill run to exhaustion for determination of VO2max were performed 10 hours after drug administration. RESULTS: Subjects reported a significantly greater hangover effect following ingestion of L (8/11 subjects) compared with ingestion of Z (3/11 subjects; p < 0.01). A greater number of subjects felt alert after ingestion of P (9/11 subjects) and Z (9/11 subjects) compared with L (4/11 subjects; p < 0.01). The results of the eye-hand coordination tests, the 30-m sprint, the T-test, the VO2max, and the time to exhaustion during the treadmill run were not significantly altered following the ingestion of P, Z, and L. There was a significant difference between the delta values for Z and L for the number of missed responses in the eye-hand coordination tests (p < 0.02). Therefore, following the ingestion of L, subjects experienced a significant hangover effect and altered reaction time, whereas the ingestion of Z did not significantly impair either psychomotor or physical performance in the administered tests. CLINICAL RELEVANCE: Investigate the extent of the effects of sedative hypnotics on exercise performances, enabling team physicians to prescribe such drugs to the athlete more effectively.