Background: Single measurements of peak oxygen uptake (V O 2 ) have been shown to predict mortality in patients with cystic fibrosis (CF) although no longitudinal study of serial measurements has been reported in children. A study was undertaken to determine whether the initial, final, or the rate of fall of forced expiratory volume in 1 second (FEV 1 ) or peak V O 2 was a better predictor of mortality. Methods: Twenty eight children aged 8-17 years with CF performed annual pulmonary function and maximal exercise tests over a 5 year period to determine FEV 1 and peak V O 2 , magnitude of their change over time, and survival over the subsequent 7-8 years. Analysis was done using Kaplan-Meier curves and Cox proportional hazard model. Results: Peak V O 2 fell during the observation period in 70% of the patients, with a mean annual decline of 2.1 ml/min/kg. Initial peak V O 2 was not predictive of mortality but rate of decline and final peak V O 2 of the series were significant predictors. Patients with peak V O 2 less than 32 ml/min/kg exhibited a dramatic increase in mortality, in contrast to those whose peak V O 2 exceeded 45 ml/min/kg, none of whom died. The first, last, and rate of decline in FEV 1 over time were all significant predictors of mortality. Conclusions: Higher peak V O 2 is a marker for longer survival in CF patients.

ABSTRACT. Rationale. This study was designed to examine the relationships among weight, asthma severity, physical activity, and aerobic fitness in children with asthma.Subjects and Methods. Sixty-four asthmatic children 8 to 12 years old (53% female) were assessed while attending a summer asthma camp. Measures included height and weight, spirometry, histamine bronchial provocation challenge, maximal aerobic power, and questionnaires to quantify habitual activity, perceived activity limitations due to asthma, perceived competence in physical activity, and attitudes toward physical activity. Asthma severity was determined from spirometric indices (forced expiratory volume during the first second), degree of airway hyperresponsiveness, and amount of medication prescribed.Results. There was no correlation between asthma severity and aerobic fitness. Only perceived competence at physical activity was found to have a significant correlation with aerobic fitness. Appropriate-weight, overweight, or obese (defined by body mass index) children all had similar results for maximum aerobic power and level of habitual activity. However, overweight or obese children reported greater limitation of physical activity. Their asthma-impairment scores were higher than the scores of appropriate-weight peers, although standard measures of pulmonary function were no different among groups. The higher asthma-severity scores were related to greater medication needs in the overweight or obese children with asthma.Conclusions. Lower maximum aerobic power in asthmatic children is related more to how capable they perceive themselves than to asthma severity. Overweight asthmatic children experience greater limitation of physical activity and thus are prescribed more medication, although by standard measures of asthma severity, they are very similar to normal-weight peers with asthma. Efforts should be directed at understanding the reasons responsible for reduced exercise tolerance before escalating pharmacologic treatment. Pediatrics 2004;113:e225-e229. URL: http://www.pediatrics.org/cgi/content/full/113/3/e225; asthma, exercise, physical activity, obesity.ABBREVIATIONS. FVC, forced vital capacity; FEV 1 , forced expiratory volume during the first second; ATS, American Thoracic Society; PC 20 , provocative concentration causing a 20% fall in FEV 1 ; BMI, body mass index. E xercise-induced bronchoconstriction affects a majority of children with asthma, 1 and the resulting unpleasant symptoms may incline the child to refrain from such activity. According to current treatment guidelines, a diagnosis of asthma should not deter a child from physical activity, inasmuch as normal physical activity is a recognized goal of optimal asthma control. 2 There are conflicting studies regarding fitness levels in children with asthma. [3][4][5][6][7][8] If children with asthma indeed are less fit than their nonasthmatic peers, then elucidation of the reason(s) responsible would enable clinicians to direct educational and therapeutic effects to enable their pa...

Many teenagers who struggle with chronic fatigue have symptoms suggestive of autonomic dysfunction that may include lightheadedness, headaches, palpitations, nausea, and abdominal pain. Inadequate sleep habits and psychological conditions can contribute to fatigue, as can concurrent medical conditions. One type of autonomic dysfunction, postural orthostatic tachycardia syndrome, is increasingly being identified in adolescents with its constellation of fatigue, orthostatic intolerance, and excessive postural tachycardia (more than 40 beats/min). A family-based approach to care with support from a multidisciplinary team can diagnose, treat, educate, and encourage patients. Full recovery is possible with multi-faceted treatment. The daily treatment plan should consist of increased fluid and salt intake, aerobic exercise, and regular sleep and meal schedules; some medications can be helpful. Psychological support is critical and often includes biobehavioral strategies and cognitive–behavioral therapy to help with symptom management. More intensive recovery plans can be implemented when necessary.

No abstract