Frequencies of pathogenic CFTR variants in Greek cystic fibrosis patients with allergic bronchopulmonary aspergillosis and Aspergillus fumigatus chronic colonization: A retrospective cohort study.

INTRODUCTION: The clinical spectrum of Aspergillus fumigatus diseases in cystic fibrosis (CF) patients, including allergic bronchopulmonary aspergillosis (ABPA) and Aspergillus fumigatus chronic colonization, has recently gained attention due to its association with the progression of lung disease. Our aim was to examine whether there is a difference on pathogenic variant frequencies of the CFTR gene between CF patients with ABPA and those with A. fumigatus chronic colonization. MATERIAL AND METHODS: Greek CF patients diagnosed with ABPA and/or A. fumigatus chronic colonization were grouped according to their CFTR genotype. Patients with "minimal" CFTR function were defined as carrying a combination of class I or II pathogenic variants, while patients with "residual" function as carrying at least one class III, IV, V or VI pathogenic variant. RESULTS: Fifty-four CF patients were included and all except one were defined as having "minimal" CFTR function. Among the 108 CFTR alleles, 69 (63.9%) of pathogenic variants belonged to class II, and 32 (29.6%) to class I. Five patients had a history of both ABPA and A. fumigatus chronic colonization. No significant difference was detected among patients diagnosed only with ABPA (n = 29) and those who had only a positive history of A. fumigatus chronic colonization (n = 20). The median age of ABPA diagnosis was significantly lower than the median age of A. fumigatus chronic colonization (P = 0.011), while no significant difference was detected on median FEV1% predicted. DISCUSSION: No significant differences were detected in the type of CFTR pathogenic variants among patients with ABPA and those with A. fumigatus colonization. Similar studies should be performed in larger CF populations of different ethnic origin to further confirm our results.

Adherence to Dietary Recommendations, Nutrient Intake Adequacy and Diet Quality among Pediatric Cystic Fibrosis Patients: Results from the GreeCF Study.

Nutrition is an important component of cystic fibrosis (CF) therapy, with a high-fat diet being the cornerstone of treatment. However, adherence to the dietary recommendations for CF appears suboptimal and burdensome for most children and adolescents with CF, leading to malnutrition, inadequate growth, compromised lung function and increased risk for respiratory infections. A cross-sectional approach was deployed to examine the degree of adherence to the nutrition recommendations and diet quality among children with CF. A total of 76 children were recruited from Aghia Sophia's Children Hospital, in Athens, Greece. In their majority, participants attained their ideal body weight, met the recommendations for energy and fat intake, exceeding the goal for saturated fatty acids consumption. Carbohydrate and fiber intake were suboptimal and most participants exhibited low or mediocre adherence to the Mediterranean diet prototype. It appears that despite the optimal adherence to the energy and fat recommendations, there is still room for improvement concerning diet quality and fiber intake.

Comparison of International Growth Standards for Assessing Nutritional Status in Cystic Fibrosis: The GreeCF Study.

OBJECTIVE: The aim of the study was to compare 3 international growth references and explore their differences in assessing growth in Greek school-aged patients with cystic fibrosis (CF). METHODS: Sample included 114 patients (50 boys, age 11.5 ±â€Š3.9 years), provided care at Aghia Sofia Children's Hospital, Greece. Anthropometrics and predicted forced expiratory volume in 1 second (FEV1%) were measured. Body mass index (BMI) and height z scores were computed according to the Centers for Disease Control and Prevention (CDC), World Health Organization (WHO), and International Obesity Task Force (IOTF) references. Agreement between methods was analyzed with kappa statistics, repeated-measures analysis of variance, and Bland-Altman analysis. The relationship between FEV1% and BMI was explored with linear regression. RESULTS: Mean CDC BMI z score was the lowest (0.06 ±â€Š1.08), followed by WHO (0.17 ±â€Š1.14) and IOTF (0.35 ±â€Š1.05) (P ≤ 0.001 for all). The CDC and WHO growth references highly agreed for most weight status strata and stunting; all other comparisons produced lower agreements. Except for CDC and IOTF BMI z scores, all other comparisons produced wide levels of agreement and proportional bias. CDC reference classified more children as attaining low or normal weight, against WHO or IOTF (P ≤ 0.001 for all). Lowest prevalence of ideal and excess weight was recorded by CDC, compared to all other standards (P ≤ 0.001 for all). All BMI z scores provided moderate associations with FEV1%. CONCLUSION: Large variations across weight status classification were present when employing 3 growth standards in school-aged patients . Given than BMI z-scores from all references provided comparable associations with pulmonary function, our data indicate that no studied reference is better than others in assessing growth in CF.

Hyperthyrotropinemia in newly diagnosed cystic fibrosis patients with pancreatic insufficiency reversed by enzyme therapy.

Patients with cystic fibrosis (CF) commonly present with an elevated TSH concentration, suggesting subclinical hypothyroidism. Its relation to concomitant pancreatic insufficiency and its natural course upon initiation of enzyme replacement have not been adequately studied. Herein, we investigated the thyroid function in newly diagnosed infants with CF and monitored the course of thyroid function response to pancreatic enzyme substitution treatment. Fourteen, newly diagnosed infants with CF and pancreatic insufficiency, were followed every 6-8 weeks for 6 months ensuing onset of pancreatic enzyme substitution therapy. All infants had normal TSH values on neonatal screening. Ten out of 14 (71%) had hyperthyrotropinemia and normal freeT4 values at presentation. No patient received thyroxine. Upon follow-up, after 6 months, TSH values normalized in 90% of infants with CF and hyperthyrotropinemia. Serum selenium levels were negatively correlated with TSH levels. CONCLUSION: Mild TSH elevation is a frequent finding in newly diagnosed cystic fibrosis patients with pancreatic insufficiency during infancy. TSH elevation resolves in most cases after initiation of enzyme substitution and improvement of nutritional status without any substitutive therapy with thyroxine. What is Known: • Newly diagnosed infants with cystic fibrosis often present with a state of hyperthyrotropinemia suggesting subclinical hypothyroidism. What is New: • Pancreatic enzyme substitution and improvement of nutrition restores normal TSH levels without the need of thyroxine therapy.

High attainment of optimal nutritional and growth status observed among Greek pediatric cystic fibrosis patients: results from the GreeCF study.

BACKGROUND: Pediatric cystic fibrosis (CF) patients suffer high rates of undernutrition, subject to several parameters. We aimed to assess growth and nutritional status of Greek children and adolescents with CF. METHODS: Eighty-four patients (35 boys) formed the sample. Anthropometrics and FEV1 were measured, growth and weight status were assessed. Body mass index (BMI), arm circumference (MUAC), fat (MUAFA) and muscle (MUAMA) were calculated. RESULTS: In the total sample, 6.0% of the patients were underweight, 4.8% stunted, 8.3% wasted and 17.9% in nutritional failure, whereas 59.5% attained the ideal BMI for CF. FEV1 positively associated with BMI (B=0.03, p≤0.003), weight (B=0.03, p≤0.003) and MUAMA z-scores (B=0.04, p≤0.005). Meconium ileus negatively associated with FEV1 (B=-14.17, p≤0.003) and stature (B=-0.65, p≤0.043). Pancreatic insufficiency negatively influenced MUAC and MUAFA z-scores (p≤0.05 for both). CONCLUSIONS: The examined CF patients appear to be thriving. Unlike published research, the participants' sex, gene mutation and acquisition of pathogens did not affect growth.

Early-Life Pseudomonas aeruginosa Infection in Cystic Fibrosis and Lung Disease Progression.

Lung disease in cystic fibrosis (CF) starts early, with studies identifying abnormalities on chest computed tomography (CT) scan even in infancy. In this retrospective study, abnormal chest CT was the main outcome; body mass index (BMI) z score and forced expiratory volume percent predicted (FEV1%) predicted at age 6 to 7 years were secondary outcomes. Pseudomonas aeruginosa infection prior to 12 months of age was the main explanatory variable. There was no association between early P aeruginosa infection and abnormal CT after adjustment for CFTR (cystic fibrosis transmembrane conductance regulator) functional mutation class, gender, and other pathogens (odds ratio = 0.30; 95% confidence interval = 0.07-1.35; P = .11). No significant associations were demonstrated for BMI z score and FEV1% predicted. Children with class I-III CFTR mutations had increased risk of abnormal CT findings (odds ratio = 11.67; 95% confidence interval = 1.11-115.06; P = .035) and lower FEV1% predicted (P = .04). In the current era, early-life P aeruginosa infection in CF might not influence the severity of lung disease in school age as much as previously. Larger studies are needed to confirm this finding.

Scedosporium apiospermum complex in cystic fibrosis; should we treat?

Species of the Scedosporium apiospermum complex are the second most frequent filamentous fungi after Aspergillus fumigatus that can be found in cystic fibrosis (CF). Mixed colonisation by S. apiospermum complex and A. fumigatus is also quite common. In this study we summarise all CF patients who were colonised by S. apiospermum complex during their childhood and we present two CF patients who were treated as fungal bronchitis due to S. apiospermum complex. The medical records of 400 CF patients were reviewed in order to identify those with positive respiratory cultures for S. apiospermum complex. Scedosporium apiospermum complex was isolated in 10 CF patients and six of them had more than two positive sputum cultures during the study period. By the time of first isolation, the median age was 14.5 years, the median BMI was 19.41 kg/m2 , the median predicted FEV1 % was 78.65% and six patients had a history of A. fumigatus isolation. Two patients presented symptoms of infection while they were colonised by S. apiospermum complex. A rapid remission of their symptoms was observed only when antifungal therapy was administered. Antifungal treatment should be considered in CF patients who present symptoms of infection not responding to antibacterial therapy and S. apiospermum complex is persistently growing in sputum cultures.

Body composition and lung function in children with cystic fibrosis and meconium ileus.

The aim of this study was to explore whether history of meconium ileus (MI) at birth in children and adolescents with cystic fibrosis (CF) adversely affects body composition and lung function in later life. Data of children and adolescents with CF who underwent spirometry and DXA as part of their routine care were analyzed. Associations between MI (explanatory variable) and areal bone mineral density (total body less head-TBLH aBMD), lean tissue mass (LTM), and fat mass (FM) (outcomes) were assessed using general linear models. Potential relationships of TBLH aBMD, LTM, and FM with FEV1 (additional outcome) were also explored. One hundred and one subjects with CF (mean age 14 ± 3 years) were included, 19 (18.8%) of whom had history of MI. Negative associations were demonstrated between history of MI and FEV1 (P = 0.04), TBLH aBMD (P = 0.03), and FM (P < 0.01) but not between history of MI and LTM (P = 0.07) after adjustment for other variables. Lung function was positively associated with TBLH aBMD (P < 0.01) and LTM (P = 0.02) but not with FM (P = 0.20). CONCLUSION: Among children and adolescents with CF, those with history of MI have lower bone mineral density, FM, and lung function. What is Known: • Among children and adolescents with cystic fibrosis, those with history of meconium ileus in the neonatal period are at risk of having lower body mass index percentile and FEV 1 percent predicted. What is New: • Children and adolescents with cystic fibrosis and history of meconium ileus have decreased bone mineral density and fat mass compared to patients without such history. • Lower lung function in children with MI coexists with suboptimal bone mineral density.

Study of Greek children and youths with cystic fibrosis identifies immunisation gaps and delays.

AIM: Data about immunisation rates in cystic fibrosis (CF) patients are scarce. We estimated the rates and timeliness of immunisations in CF patients aged 0.55-22 years. METHODS: We studied 122 subjects at a hospital in Greece in 2014. A standard questionnaire was used to collect data and parents' opinions about immunisations. RESULTS: The complete immunisation rates were 92.6% for diphtheria-tetanus-acellular pertussis-inactivated poliomyelitis-Haemophilus influenzae (DTaP-IPV-Hib), 96.7% for hepatitis A, 97.4% for hepatitis B, 97.4% for measles-mumps-rubella, 85.1% for the varicella zoster virus, 85.1% for the meningococcus C conjugate, 84.3% for the pneumococcus conjugate and 58.9% for the bacillus Calmette-Guérin vaccine. Immunisation rates in youths were 64.4% for DTaP-IPV, 26.8% for the tetravalent meningococcus conjugate vaccine and 54.1% for the human papilloma virus vaccine. In addition, 30.1% received the 23-valent pneumococcal polysaccharide vaccine and 45.6% received annual influenza vaccines. Complete, up-to-date immunisation rates fell from 61.4% at 12 months of age to 14.5% at six and 12 years. All vaccines experienced delays. Most parents believed vaccines were necessary to protect their child's health. CONCLUSION: Our study of children with CF found immunisation gaps with no catch-up immunisations and these need to be administered at follow-up visits.

The role of basophil activation test in allergic bronchopulmonary aspergillosis and Aspergillus fumigatus sensitization in cystic fibrosis patients.

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) and Aspergillus fumigatus sensitization (AFS) are quite often observed in cystic fibrosis (CF) patients. The aim of this study was to evaluate the use of basophil activation test (BAT) in these manifestations of hypersensitivity reactions. METHODS: BAT (CD63 and CD203c) was performed for 56 CF patients (17 ABPA, 24 AFS and 15 non-AFS). A receiver operating characteristic (ROC) curve analysis and a survival analysis were performed. RESULTS: Both markers significantly contributed in ABPA diagnosis (P value<0.001 for both). Twelve AFS patients fulfilled the criteria for ABPA diagnosis during the follow-up period. The median time to ABPA diagnosis was 9months for patients whose values were over the best cutoffs (P value<0.001 for both). CONCLUSIONS: BAT could be considered as an additional criterion for ABPA diagnosis in CF as well as a potential marker for the monitoring of patients with AFS.

Candida albicans chronic colonisation in cystic fibrosis may be associated with inhaled antibiotics.

Candida albicans is increasingly recognised as a coloniser of the respiratory tract in cystic fibrosis (CF) patients. Yet, the potential role, if any, of the micro-organism in the progress of the disease remains unclear. In this study, we investigated the association between inhaled antibiotics and C. albicans chronic colonisation in patients with CF. A cohort of 121 CF patients born from 1988 to 1996 was, respectively, studied. The medical records of each patient were reviewed from the first time they attended the CF Centre until the occurrence of C. albicans chronic colonisation or their last visit for the year 2010. Chronic colonisation was defined as the presence of C. albicans in more than 50% of cultures in a given year. A number of possible confounders were included in the multivariate logistic regression analysis to identify an independent association between inhaled antibiotics and C. albicans chronic colonisation. Fifty-four (44.6%) of the 121 patients enrolled in the study developed chronic colonisation by the micro-organism. Multivariate logistic regression analysis determined the independent effect of inhaled antibiotic treatment on the odds of chronic colonisation (OR 1.112, 95% CI [1.007-1.229], P = 0.036). Candida albicans chronic colonisation may be associated with the duration of inhaled antibiotic treatment.

Time constant of inspiratory muscle relaxation in cystic fibrosis.

BACKGROUND: Patients with cystic fibrosis (CF) are at increased risk of inspiratory muscle fatigue and respiratory failure. The time constant (τ) of the inspiratory muscle relaxation is a simple bedside test of muscle fatigue. We have compared patients with CF and healthy controls regarding τ and hypothesized that it is negatively associated with severity of lower airway obstruction. METHODS: For this cross-sectional study, τ after maximal inspiration and spirometric indices (forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC)) were measured. RESULTS: Fifty-three CF patients (median age 14 y (interquartile range: 11-19.5)) and 53 age- and sex-matched healthy control subjects (14 y (11-19.5)) were recruited. Application of a general linear model revealed that health status (CF vs. non-CF) had a significant effect on τ (P < 0.001), but age group and the interaction of age group with health status did not have significant effects on τ (P = 0.10 and P = 0.71, respectively). Participants with CF had significantly higher τ (253 (188-406)) than control subjects (117 (81-185)) (P < 0.001) and τ was negatively related to FEV1 (r = -0.205; P = 0.031) and FVC (r = -0.294; P = 0.002). CONCLUSION: Patients with CF have higher τ than healthy controls but the correlation of τ with expiratory flow function is modest.

Inhaled corticosteroids and Aspergillus fumigatus isolation in cystic fibrosis.

Aspergillus fumigatus isolation in cultures from respiratory specimens of patients with cystic fibrosis (CF) is quite common; however, the role of A. fumigatus as a pathogen and whether its presence is associated with progression of pulmonary disease remain unclear. We investigated the association between inhaled corticosteroids and the recovery of A. fumigatus by performing a retrospective cohort study of CF patients born between 1988 and 1996. The patients' medical records from their first visit to the CF Center until December 2010 were reviewed. Outcomes were the occurrence of A. fumigatus first isolation, chronic colonization, or the last visit at the CF Center. A number of possible confounders were included in the multivariate logistic regression analysis in order to identify an independent association between inhaled corticosteroids and colonization status. A total of 121 patients were included in the study. Thirty-nine patients (32.2%) had at least one positive culture and 14 (11.6%) developed chronic colonization. Multivariate logistic regression analysis was used to determine the independent effect of inhaled corticosteroids on the odds of first isolation (odds ratio [OR], 1.165; 95% confidence interval [CI], 1.015-1.337; P = 0.029) and chronic colonization (OR, 1.180; 95% CI, 1.029-1.353; P = 0.018). In conclusion, A. fumigatus first isolation and chronic colonization are associated with the duration of inhaled corticosteroid treatment.

Psychosocial distress and functioning of Greek youth with cystic fibrosis: a cross-sectional study.

BACKGROUND: To assess psychosocial functioning and distress of children and adolescents with cystic fibrosis compared to healthy controls. METHODS: Thirty-six patients with cystic fibrosis aged 8-18 years (24 boys, mean age ± SD: 11.5 ± 2.6 years) and 31 sex- and age-matched healthy control subjects (18 boys, mean age ± SD: 12 ± 2.5 years) were enrolled in the study. In order to assess the self-esteem, social adjustment, and family functioning of these young people, the Culture-free Self-esteem Inventory, the Social Adjustment Scale-Self-Report, and the Family Assessment Device were administered. Emotional/ behavioral problems were assessed through the Youth Self Report and the Child Behavior Checklist given to both the subjects and their parents. RESULTS: No significant differences were found for self-esteem between the two study groups. Regarding social adjustment, children with cystic fibrosis reported significantly worse friendship and overall adjustment (P < 0.05). Moreover, no difference was found in the levels of family functioning between the two groups. No significant differences between the groups were found in emotional/ behavioral problems from the self-reports. On the contrary, parents of children with cystic fibrosis reported significantly higher levels of withdrawal/ depression, thought problems, and delinquent behavior (P ≤ 0.01) as compared to controls. CONCLUSIONS: Children and adolescents with cystic fibrosis appear to be a psychosocially vulnerable group. A biopsychosocial approach should emphasize the assessment and treatment of the psychosocial distress of these patients alongside multiple somatic treatments.

Chronic Pseudomonas aeruginosa infection and respiratory muscle impairment in cystic fibrosis.

BACKGROUND: Chronic infection with Pseudomonas aeruginosa in patients with cystic fibrosis (CF) is associated with increased morbidity. Chronic infection can cause limb and respiratory muscle compromise. Respiratory muscle function can be assessed via maximal inspiratory pressure (PImax), maximal expiratory pressure (PEmax), and the pressure-time index of the respiratory muscles (PTImus). We studied the effect of chronic P. aeruginosa infection on respiratory muscle function in patients with CF. METHODS: This cross-sectional study assessed PImax, PEmax, PTImus, FEV1, FVC, maximum expiratory flow during the middle half of the FVC maneuver, body mass index, and upper arm muscle area in 122 subjects with CF, in 4 subgroups matched for age and sex at different stages of P. aeruginosa infection, according to the Leeds criteria. We compared respiratory muscle function in the subgroups according to P. aeruginosa infection state. RESULTS: Median PImax was significantly lower in CF subjects with chronic P. aeruginosa infection (PImax = 62 cm H2O), compared to subjects who were never infected (PImax = 86 cm H2O, P = .02), free of infection (PImax = 74 cm H2O, P = .01), or intermittently infected (PImax = 72 cm H2O, P = .02). Median PTImus was significantly increased in CF subjects with chronic P. aeruginosa infection (PTImus = .142), compared to subjects who were free of infection (PTImus = .102, P = .006). Median upper-arm muscle area was significantly lower in CF subjects with chronic P. aeruginosa infection (upper-arm muscle area = 2,219 mm(2)), compared to subjects who were never infected (2,754 mm(2), P = .03), free of infection (2,678 mm(2), P = .01), or intermittently infected (2,603 mm(2), P = .04). Multivariate logistic regression revealed P. aeruginosa state of infection as a significant determinant of PTImus (P = .03) independently of sex, upper-arm muscle area, and FEV1. CONCLUSIONS: CF subjects with chronic P. aeruginosa infection exhibited impaired respiratory muscle function and decreased inspiratory muscle strength, and chronic P. aeruginosa infection independently impacts respiratory muscle function in subjects with CF.

Aerobic exercise and respiratory muscle strength in patients with cystic fibrosis.

BACKGROUND: The beneficial role of exercise in maintaining health in patients with cystic fibrosis (CF) is well described. Few data exist on the effect of exercise on respiratory muscle function in patients with CF. Our objective was to compare respiratory muscle function indices in CF patients that regularly exercise with those CF patients that do not. METHODS: This cross-sectional study assessed nutrition, pulmonary function and respiratory muscle function in 37 CF patients that undertook regular aerobic exercise and in a control group matched for age and gender which consisted of 44 CF patients that did not undertake regular exercise. Respiratory muscle function in CF was assessed by maximal inspiratory pressure (Pimax), maximal expiratory pressure (Pemax) and pressure-time index of the respiratory muscles (PTImus). RESULTS: Median Pimax and Pemax were significantly higher in the exercise group compared to the control group (92 vs. 63 cm H2O and 94 vs. 64 cm H2O respectively). PTImus was significantly lower in the exercise group compared to the control group (0.089 vs. 0.121). Upper arm muscle area (UAMA) and mid-arm muscle circumference were significantly increased in the exercise group compared to the control group (2608 vs. 2178 mm2 and 23 vs. 21 cm respectively). UAMA was significantly related to Pimax in the exercising group. CONCLUSIONS: These results suggest that CF patients that undertake regular aerobic exercise maintain higher indices of respiratory muscle strength and lower PTImus values, while increased UAMA values in exercising patients highlight the importance of muscular competence in respiratory muscle function in this population.

Maximum rate of pressure development and maximal relaxation rate of respiratory muscles in patients with cystic fibrosis.

BACKGROUND: Respiratory muscle function in patients with cystic fibrosis (CF) has been studied by measurement of maximal inspiratory pressure (P(Imax)), maximal expiratory pressure (P(Emax)), and the pressure-time index of the respiratory muscles (PTI(mus)). The maximum rate of pressure development (MRPD) during P(Imax) (MRPD-P(Imax)), MRPD during P(Emax) (MRPD-P(Emax)), maximal relaxation rate (MRR) during P(Imax) (MRR-P(imax)), and MRR during P(Emax) (MRR-P(Emax)) have not been studied in CF. Our aim was to study MRPD and MRR and investigate their possible application as accessory indices of respiratory muscle function in patients with CF. METHODS: FEVY, FVC, and maximal expiratory flow between 25% and 75% of vital capacity, body mass index (BMI), upper arm muscle area, P(imax), P(Emax), PTI(mus), MRPD-P(Imax), MRPD-P(Emax), MRR-P(imax), and MRR-P(Emax) were assessed in 123 CF patients and in a control group of 123 healthy subjects matched for age and sex. RESULTS: MRR-P(Emax) was significantly increased and MRPD-P(Emax) was significantly decreased in the CF patients, compared to the healthy controls. In the CF patients MRR-P(Imax) was significantly related to PTI(mus) (P = .02), FEV1 (P = .03), FVC (P = .001), BMI (P < .001), and upper arm muscle area (P < .001). In the CF patients, MRPD-P(Imax) and MRPD- P(Emax) were significantly related to upper arm muscle area (P < .001), BMI (P < .001 and P = .01, respectively), P(Imax) (P < .001), and P(Emax) (P < .001). CONCLUSIONS: The CF patients exhibited increased MRR and decreased MRPD during maximal respiratory effort, compared to controls. The differences in MRR-P(imax) and MRPD-P(Imax) between the controls and the complete group of CF patients were not significant. MRPD and MRR were significantly related to nutritional and pulmonary function impairment in CF patients. MRPD strongly correlated to maximal respiratory muscle pressures, and MRR strongly correlated to PTI(mus) in patients with CF. These findings suggest that CF patients are at increased risk of respiratory muscle fatigue. Regular determination of MRPD and MRR may be clinically useful in CF patients and help to initiate inspiratory muscle training and noninvasive ventilation.

Respiratory muscle function in patients with cystic fibrosis.

Respiratory muscle function in patients with cystic fibrosis (CF) can be assessed by measurement of maximal inspiratory pressure (Pimax ), maximal expiratory pressure (Pemax ), and pressure-time index of the respiratory muscles (PTImus ). We investigated the differences in maximal respiratory pressures and PTImus between CF patients with no gross hyperinflation and healthy controls and described the effects of pulmonary function and nutrition impairment on respiratory muscle function in this group of CF patients. Forced expiratory volume in 1 sec (FEV1 ), forced vital capacity (FVC) and maximal expiratory flow between 25% and 75% of VC (MEF25-75 ), body mass index (BMI), upper arm muscle area (UAMA), Pimax , Pemax , and PTImus were assessed in 140 CF patients and in a control group of 140 healthy subjects matched for age and gender. Median Pimax and Pemax were significantly lower in CF patients compared to the controls [Pimax = 74 (57-94) in CF vs. 84 (66-102) in controls, P = 0.009], [Pemax = 71 (50-95) in CF vs. 84 (66-102) in controls, P < 0.001]. Median PTImus in CF patients compared to controls was significantly increased [PTImus = 0.110 (0.076-0.160) in CF vs. 0.094 (0.070-0.137) in controls, P = 0.049] and it was significantly higher in CF patients with impaired pulmonary function. In CF patients, PTImus was significantly negatively related to upper arm muscle area (r = 0.184, P = 0.031). These findings suggest that CF patients with no severe lung disease compared to healthy subjects exhibit impaired respiratory muscle function, while CF patients with impaired pulmonary function and nutrition indices exhibit higher PTImus values.