Physical Exercise in Cystic Fibrosis -studies on muscle strength, oxygen uptake and lung function in young adult patients

Muscular strength, lung function and exercise capacity are internationally reported to be markedly impaired in adult patients with cystic fibrosis (CF). Since 20 years physical exercise is one important part in the treatment of patients with CF in Sweden. Handgrip strength is reported to relate to nutrition and activity of daily living. Decreased handgrip strength has been found in patients with lung disease and a correlation to mortality has been claimed. The aims of this thesis were to evaluate the effects of different type of training in young adult patients with classic CF on muscular strength, lung function and exercise capacity and to compare baseline data with matched healthy controls. One additional aim was to evaluate the effect of general resistance training (RT) of the upper extremities on handgrip strength in healthy subjects. The effect on handgrip strength of 8 weeks of RT of the upper extremities was evaluated in healthy young adults. Muscular strength was assessed using 15 different tests representing hand-, arm/shoulder-, leg-, back- and abdominal muscles in patients with CF. Lung function was evaluated with spirometry, and exercise capacity was evaluated using an electromagnetic cycle ergometer. Serum levels of cytokines were investigated with ELISA technique and vitamin E with HPLC. The outcome of three months (m) of endurance training (ET) or RT followed by three m of mixed training performed three times weekly during 30-45 minutes was evaluated. Healthy female (F) subjects significantly increased handgrip strength after 8 weeks of a general RT program for the upper extremities. A sample of 33 patients with classic CF showed muscular strength comparable to that of healthy age and sex matched control subjects (CS), but F patients were weaker in handgrip strength than CS and did not improve after 6 m of training. At baseline one of the leg tests in each sex and sit-ups during 30 s in male patients also showed lower values than controls. Handgrip strength correlated to FEV1.0 in % of predicted values. In 19 patients muscular strength did not increase after 6 m, regardless of the kind of training. Three patients fulfilled the study on a lower and one on a higher frequency level and the result did not differ from the others. Maximal oxygen uptake (VO2max) and work load (Watt/kg) showed significant increase by ET compared to RT after 6 m. The FEV1.0 % predicted showed increase in M patients, who mainly performed ET. The results suggested that a 6 m program, 3 times/week of mainly ET may keep or even increase lung function but not muscular strength in young adult patients with CF. Conclusions: General RT of the upper extremities increased handgrip strength in healthy F subjects but not in CF. Young adult patients with CF, who have regular physical exercise as part of the treatment, showed mainly muscular strength comparable to that of healthy control subjects, a well preserved lung function and good oxygen uptake. Six m of either mainly ET or RT did not increase muscular strength, exercise capacity and oxygen uptake. Lung function, after 6 m with mainly ET, showed improvement compared to RT

Lung function in the aging Swedish cystic fibrosis population.

Swedish Cystic Fibrosis (CF) care follows international guidelines in general. The only difference in our CF care package since 25 years is the physiotherapy regimen. Airway clearance therapy has since the early 1980s, from the day of diagnosis, been based upon daily physical exercise in conjunction with techniques for transporting and evacuating mucus. Postural Drainage+/-percussion and vibration has not been used in any age. The aim of this study was to evaluate our CF care package. Lung function data from the start of the study and with a 3-year interval were collected in the entire Swedish CF population >/=7 years old. Data were analysed for the age groups 7-17 and >/=18 years of age. Change of lung function over the study period was calculated. The impact of chronic Pseudomonas aeruginosa (Pa) colonisation and basal FEV(1)%p was also evaluated in a linear mixed model. Data from 99% of the country-wide CF population were available at inclusion. Mean FEV(1)%p was 90+/-21 vs 73+/-26 in the different age groups and mean VC%p was 94+/-18 vs 91+/-20. Forty percent of the adult group was >/=30 years old. Overall, 41% were chronically Pa colonised. Mean annual FEV(1)%p rate of decline was 0.77 and 0.64 in the different age groups. Lung function among Swedish CF patients is good and annual rate of decline low, even in an old cohort. The large proportion of adult patients emphasises future demands on CF care

Cardiopulmonary exercise testing provides additional prognostic information in cystic fibrosis

Rationale: The prognostic value of cardiopulmonary exercise testing (CPET) for survival in cystic fibrosis (CF) in the context of current clinical management, when controlling for other known prognostic factors, is unclear. Objectives: To determine the prognostic value of CPET-derived measures beyond peak oxygen uptake (VO 2 peak) following rigorous adjustment for other predictors. Methods: Data from 10 CF centers in Australia, Europe, and North America were collected retrospectively. A total of 510 patients completed a cycle CPET between January 2000 and December 2007, of which 433 fulfilled the criteria for a maximal effort. Time to death/lung transplantation was analyzed using Cox proportional hazards regression. In addition, phenotyping using hierarchical Ward clustering was performed to characterize high-risk subgroups. Measurements and Main Results: Cox regression showed, even after adjustment for sex, FEV1% predicted, body mass index (z-score), age at CPET, Pseudomonas aeruginosa status, and CF-related diabetes as covariates in the model, that VO 2 peak in % predicted (hazard ratio [HR], 0.964; 95% confidence interval [CI], 0.944-0.986), peak work rate (% predicted; HR, 0.969; 95% CI, 0.951-0.988), ventilatory equivalent for oxygen (HR, 1.085; 95% CI, 1.041-1.132), and carbon dioxide (HR, 1.060; 95% CI, 1.007-1.115) (all P < 0.05) were significant predictors of death or lung transplantation at 10-year follow-up. Phenotyping revealed that CPET-derived measures were important for clustering. We identified a high-risk cluster characterized by poor lung function, nutritional status, and exercise capacity. Conclusions: CPET provides additional prognostic information to established predictors of death/lung transplantation in CF. High-risk patients may especially benefit from regular monitoring of exercise capacity and exercise counseling

Cardiopulmonary exercise testing provides additional prognostic information in cystic fibrosis

RATIONALE: The prognostic value of cardiopulmonary exercise testing (CPET) for survival in cystic fibrosis (CF) in the context of current clinical management, when controlling for other known prognostic factors is unclear. OBJECTIVES: To determine the prognostic value of CPET-derived measures beyond peak oxygen uptake (VO2peak) following rigorous adjustment for other predictors. MEASUREMENTS AND MAIN RESULTS: Data from 10 CF-centers in Australia, Europe and North America were collected retrospectively. 510 patients completed a cycle CPET between January 2000 and December 2007, of which 433 fulfilled the criteria for a maximal effort. Time to death/lung transplantation (LTx) was analyzed using Cox proportional hazards regression. In addition, phenotyping using hirarchical Ward's clustering was performed to characterize high risk subgroups. Cox regression showed - even after adjustment for sex, forced expiratory volume in 1s (%predicted), body mass index (z-score), age at CPET, Pseudomonas aeruginosa status, and CF-related diabetes as covariates in the model - that VO2peak in %predicted, hazard ratio (HR) 0.964 [95%-CI: 0.944-0.986], peak work rate (%predicted, HR 0.969 [0.951-0.988], ventilatory equivalent for oxygen (VE/VO2peak) HR 1.085 [1.041-1.132], and carbon dioxide (VE/VCO2peak), HR 1.060 [1.007-1.115], all P<0.05) were significant predictors of death or LTx at 10 years follow-up. Phenotyping revealed that CPET-derived measures were important for clustering. We identified a high risk cluster characterized by poor lung function, nutritional status and exercise capacity. CONCLUSIONS: In conclusion, CPET provides additional prognostic information to established predictors of death/LTx in CF. High risk patients may especially benefit from regular monitoring of exercise capacity and exercise counselling