A survey of exercise testing and training in UK cystic fibrosis clinics.

BACKGROUND: Exercise testing is a valuable prognostic tool and exercise training has many health benefits in cystic fibrosis (CF). The objective of this study was to survey the provision of exercise testing and training in UK CF clinics. METHODS: A three-page questionnaire was used to determine the extent of, scope and importance assigned to exercise testing and training. RESULTS: Data from returned questionnaires showed that 38.9% of paediatric and 27.8% of adult patients had performed an exercise test in the preceding 12 months, most as part of an annual review process. Pulmonary rehabilitation programmes were accessible in only 31.3% of clinics, and only 26.0% provide exercise training programmes. When assigning importance for exercise testing on a scale from 1 'not important' to 5 'very important', the mean and median respondent scores were 3.5 and 4.0, respectively, and for the importance of training were 4.0 and 4.0, respectively. CONCLUSIONS: Despite the level of importance given to exercise testing and training by healthcare providers, exercise is underused as either an assessment tool or therapeutic intervention in the healthcare of patients with CF in the UK.

Early oxygen uptake recovery following exercise testing in children with chronic chest diseases.

The value of exercise testing as an objective measure of disease severity in patients with chronic chest diseases (CCD) is becoming increasingly recognized. The aim of this study was to investigate changes in oxygen uptake (VO2) during early recovery following maximal cardiopulmonary exercise testing (CPXT) in relation to functional capacity and markers of disease severity. Twenty-seven children with CCD (age 12.7 +/- 3.1 years; 17 female) [19 children with Cystic fibrosis (CF) (age 13.4 +/- 3.1 years; 10 female) and 8 with other stable non-CF chest diseases (NON-CF) (age 11.1 +/- 2.2 years; 7 female)] and 27 healthy controls (age 13.2 +/- 3.3 years; 17 female) underwent CPXT on a cycle ergometer. On-line respiratory gas analysis measured VO2 before and during CPXT to peak VO2) (VO2(peak)), and during the first 10 min of recovery. Early VO2 recovery was quantified by the time (sec) to reach 50% of the VO2 (peak) value. Early VO2 recovery was correlated against spirometry [forced expiratory volume in 1 sec (FEV(1)) and forced expiratory flow between 25% and 75% of the forced vital capacity (FEF(25-75))] and aerobic fitness (VO2)(peak)) as a measure of functional capacity. Disease severity was graded in the CF patients by the Shwachman score (SS). Compared to controls, children with CCD demonstrated a significantly reduced VO2(peak) (P = 0.011), FEV(1) (P < 0.001), FEF(25-75) (P < 0.001), and a significantly prolonged early (VO2) recovery (P = 0.024). In the CF patients the SS was significantly correlated with early VO2 recovery (r = -0.63, P = 0.004), FEV(1) (r = 0.72, P = 0.001), and FEF(25-75) (r = 0.57, P = 0.011). In the children with CCD, FEV(1), FEF(25-75), and BMI were not significantly correlated with VO2(peak) or early VO2 recovery. Lung function does not necessarily reflect aerobic fitness and the ability to recover from exercise in these patients. A significant relationship was found between VO2(peak) and early VO2 recovery (r = -0.39, P = 0.044) in the children with CCD, showing that a greater aerobic fitness corresponded with a faster recovery.

Relation between insulin-like growth factor-I, body mass index, and clinical status in cystic fibrosis.

OBJECTIVES: Despite improved nutrition and intensive treatment, subjects with cystic fibrosis have difficulty in maintaining anabolism during intercurrent infections, which can result in reduced body mass index and impaired skeletal growth. Insulin-like growth factor-I (IGF-I) and its binding protein IGFBP3 are sensitive to changes in nutritional status. The aim of this study was to determine the relation between circulating concentrations of these peptides, body mass index, and clinical status in cystic fibrosis. METHODS: Serum concentrations of IGF-I and IGFBP3 were measured in 197 subjects (108 males, 89 females; mean age 9.69 years, range 0.41-17.9 years) and these data were analysed with respect to body mass index, pubertal stage, and clinical status as assessed by Shwachman score and forced expiratory volume in one second (FEV1). RESULTS: The mean height SD score of the children studied was -0.2 (SD 1.14) and the body mass index SD score -0.26 (1.4). The body mass index SD score declined with increasing age (r = -0.18) and paralleled changes in IGF-I concentrations, which also declined. The IGF-I SD score (calculated from control data) correlated with age (r = -0.53). The abnormalities were most obvious during late puberty, when IGF-I and IGFBP3 concentrations were significantly reduced compared with those in control subjects matched for pubertal stage. The IGF-I SD score correlated with height SD score (r = 0.14) and the decline in IGF-I concentrations with the fall in body mass index SD score (r = 0.42). IGF-I SD scores also correlated with the Shwachman score (r = 0.33) and FEV1 (r = 0.17). CONCLUSIONS: The close relation between declining IGF-I and IGFBP3 concentrations and body mass index in patients with cystic fibrosis may simply reflect poor nutritional status and insulin hyposecretion. Nevertheless, IGF-I deficiency could also contribute towards the catabolism observed in these patients, and IGF-I SD scores correlated with other measures of clinical status such as the Shwachman score and FEV1.

Colonic stricture in a boy with cystic fibrosis.

Many problems may arise within the gastrointestinal tract of patients with cystic fibrosis. We report a new cause of subacute intestinal obstruction due to a fibrotic stricture of the ascending colon in a child with cystic fibrosis. Treatment was with a right hemicolectomy. There has been no recurrence after nine months follow-up. Recent similar cases suggest that this new pathology is linked to the use of enteric-coated high-strength pancreatin microspheres.

Relation of thickening of colon wall to pancreatic-enzyme treatment in cystic fibrosis.

Fibrotic strictures of the colon in association with colon-wall thickening on abdominal ultrasound have been described in children with cystic fibrosis. We determined the prevalence of colon-wall thickening in 99 children with cystic fibrosis (aged 6 months to 17 years, 45 male) and 38 healthy controls (aged 1 month to 39 years, 21 male). In controls, peristalsis was uniformly rapid and maximum wall thickness of the fully relaxed colon was 0.8 mm (median 0.6 mm). 24% of the patients had a colon-wall thickness of 1.5 mm or more (maximum 3.4 mm); 48% of children on high-strength pancreatin receiving more than 265 units/kg per day of protease had thickening of more than 1.5 mm compared with less than 12% of children on any other dose. Children on high-strength pancreatin were 5.2 (95% CI 1.2-21) times more likely to have colon-wall thickness of 1.5 mm or more than children taking less than 265 units/kg per day of protease in a standard-strength preparation. This risk rose to 10 (2.5-39) times more likely if laxatives were taken with a high-strength preparation. Lipase or amylase intake, age, sex, genotype, and other medical or drug history were not significantly associated with colon-wall thickening. 1 child required a hemicolectomy for bowel obstruction and another developed haemorrhagic colitis. In 17 children, 2 months after stopping high-strength, high protease, preparations and efforts to reduce enzyme intake, colon-wall thickness had regressed from a median 2.0 mm (range 1.0-3.4) to 1.8 mm (0.9-2.7) (p = 0.005). The use of high-strength pancreatin preparations in conjunction with a high protease intake probably causes thickening of the wall of the colon.

Prediction of hypoxaemia at high altitude in children with cystic fibrosis.

OBJECTIVE: To assess the usefulness of a hypoxic challenge in a laboratory at sea level in predicting acute desaturation at altitude in children with lung disease. DESIGN: Comparison of responses to hypoxic challenge in different settings. SUBJECTS: 22 children (12 boys) aged 11 to 16 years with cystic fibrosis in whom the mean forced expiratory volume in one second was 64% (range 24-100%). SETTING: Lung function laboratory, the Alps, and aboard commercial jet aircraft. MAIN OUTCOME MEASURES: Spirometric lung function at sea level and finger probe oximetry with air and 15% oxygen. Oximetry during high altitude flight and on a mountain at altitude of 1800 m. RESULTS: Significant desaturation (range 0 to 12%) occurred with all hypoxic challenges (P < 0.002). The best predictor of hypoxic response from a single reading was the laboratory test (r2 = 76% for flight and r2 = 47% for mountain altitude), but the mean errors of prediction were not clinically significantly different. In six children who showed the greatest desaturation the laboratory test overestimated desaturation, but other predictors underestimated desaturation in three by up to 5%. CONCLUSIONS: The laboratory hypoxic challenge directly predicted the worst case of desaturation during flight and at equivalent high altitude. Spirometry and baseline oxygen saturations may underestimate individual hypoxic response. The test may have wider applications to other patients with stable chronic lung diseases, particularly in determining who needs supplementary oxygen during air travel and who should be advised against holidays at high altitude.

The relationship between cleavage, DNA replication, and gene expression in the mouse 2-cell embryo.

The 2-cell stage of mouse embryogenesis is characterized by two phases of alpha-amanitin-sensitive polypeptide synthetic activity, which appear to mark the first major expression of the embryonic genome, as assessed by examination of in vitro translates of mRNA. Using populations of embryos synchronized to the first cleavage division, we have established that DNA replication takes place over the period 1 to 5.5 h after the first cleavage division; the two bursts of putative transcription take place before and immediately after DNA replication, and the translation products are detectable in each case within 3-4 h. In addition, we have shown that suppression of cytokinesis and the second round of DNA replication does not affect synthesis of the alpha-amanitin-sensitive polypeptides, and that neither DNA replication nor the loss of maternal mRNA that take place during the 2-cell stage are dependent upon synthesis of the alpha-amanitin-sensitive polypeptides.