@article{RufThomasBrunneretal.2019,
  author    = {Ruf, Katharina and Thomas, Wolfgang and Brunner, Maximilian and Speer, Christian P. and Hebestreit, Helge},
  title     = {Diverging effects of premature birth and bronchopulmonary dysplasia on exercise capacity and physical activity - a case control study},
  series = {Respiratory Research},
  volume    = {20},
  journal   = {Respiratory Research},
  doi       = {10.1186/s12931-019-1238-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202449},
  pages     = {260},
  year      = {2019},
  abstract  = {Background Extreme prematurity has been associated with exercise intolerance and reduced physical activity. We hypothesized that children with bronchopulmonary dysplasia (BPD) would be especially affected based on long-term lung function impairments. Therefore, the objective of this study was to compare exercise capacity and habitual physical activity between children born very and extremely preterm with and without BPD and term-born children. Methods Twenty-two school-aged children (aged 8 to 12 years) born with a gestational age < 32 weeks and a birthweight < 1500 g (9 with moderate or severe BPD (=BPD), 13 without BPD (=No-BPD)) and 15 healthy term-born children (=CONTROL) were included in the study. Physical activity was measured by accelerometry, lung function by spirometry and exercise capacity by an incremental cardiopulmonary exercise test. Results Peak oxygen uptake was reduced in the BPD-group (83 ± 11\%predicted) compared to the No-BPD group (91 ± 8\%predicted) and the CONTROL group (94 ± 9\%predicted). In a general linear model, variance of peak oxygen uptake was significantly explained by BPD status and height but not by prematurity (p < 0.001). Compared to CONTROL, all children born preterm spent significantly more time in sedentary behaviour (BPD 478 ± 50 min, No-BPD 450 ± 52 min, CONTROL 398 ± 56 min, p < 0.05) and less time in moderate-to-vigorous-physical activity (BPD 13 ± 8 min, No-BPD 16 ± 8 min, CONTROL 33 ± 16 min, p < 0.001). Prematurity but not BPD contributed significantly to explained variance in a general linear model of sedentary behaviour and likewise moderate-to-vigorous-physical activity (p < 0.05 and p < 0.001 respectively). Conclusion In our cohort, BPD but not prematurity was associated with a reduced exercise capacity at school-age. However, prematurity regardless of BPD was related to less engagement in physical activity and more time spent in sedentary behaviour. Thus, our findings suggest diverging effects of prematurity and BPD on exercise capacity and physical activity."},
  language  = {en}
}
@article{RufDemerathHebestreitetal.2018,
  author    = {Ruf, Katharina and Demerath, Antonia and Hebestreit, Helge and Kunzmann, Steffen},
  title     = {Is sweat testing for cystic fibrosis feasible in patients with down syndrome?},
  series = {BMC Pulmonary Medicine},
  volume    = {18},
  journal   = {BMC Pulmonary Medicine},
  number    = {8},
  doi       = {10.1186/s12890-018-0580-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-175519},
  year      = {2018},
  abstract  = {Background: Recurrent airway infections are common in patients with Down's syndrome (DS). Hence, ruling out Cystic Fibrosis (CF) in these patients is often required. In the past, the value of sweat testing the gold standard to diagnose CF -has been questioned in DS as false positive results have been reported. However, these reports are based on measurements of sweat osmolality or sodium concentrations, not chloride concentrations. This study analyses sweat secretion rate and chloride concentration in sweat samples of patients with DS in comparison to healthy controls. Methods: We assessed sweat samples in 16 patients with DS and 16 healthy controls regarding sweat secretion rate (SSR) and sweat chloride concentration. Results: All measured chloride concentrations were within the normal range. The chloride concentrations were slightly, but not significantly lower in patients with DS (15,54 mmol/l (±4,47)) compared to healthy controls (18,31 mmol/l (±10,12)). While no gender gap in chloride concentration could be found, chloride concentration increased with age in both groups. Insufficient sweat was collected in 2 females with DS (12.5\% of the study group) but not in an individual of the control group. A significant lower sweat secretion rate was found in the DS group (27,6 μl/30 min (± 12,18)) compared to the control group (42,7 μl/30 min (± 21,22)). In a sub-analysis, female patients produced significantly less sweat (20,8 ± 10,6 μl/30 min) than male patients with DS (36,4 ± 7,8 μl/30 min), which accounts for the difference between patients and controls. Furthermore, while the sweating secretion rate increased with age in the control group, it did not do so in the DS group. Once again this was due to female patients with DS, who did not show a significant increase of sweat secretion rate with age. Conclusions: Sweat chloride concentrations were within the normal range in patients with DS and therefore seem to be a reliable tool for testing for CF in these patients. Interestingly, we found a reduced sweat secretion rate in the DS group. Whether the last one has a functional and clinical counterpart, possibly due to a disturbed thermoregulation in DS patients, requires further investigation.},
  language  = {en}
}
@article{RufFehnBachmannetal.2012,
  author    = {Ruf, Katharina C. and Fehn, Sonja and Bachmann, Mich{\`e}le and Moeller, Alexander and Roht, Kristina and Kriemler, Susi and Hebestreit, Helge},
  title     = {Validation of activity questionnaires in patients with cystic fibrosis by accelerometry and cycle ergometry},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75083},
  year      = {2012},
  abstract  = {Background: The objective of this study was to validate physical activity questionnaires for cystic fibrosis (CF) against accelerometry and cycle ergometry. Methods: 41 patients with CF (12-42 years) completed the Habitual Activity Estimation Scale (HAES), the 7-Day Physical Activity Recall questionnaire (7D-PAR) and the Lipid Research Clinics questionnaire (LRC) and performed an incremental exercise test according to the Godfrey protocol up to volitional fatigue. Time spent in moderate and vigorous physical activity (MVPA) assessed objectively by accelerometry was related to the time spent in the respective activity categories by correlation analyses and calculating intraclass correlation coefficients (ICC). Furthermore, the results of the exercise test were correlated with the results of the questionnaires. Results: Time spent in the categories 'hard','very hard' and 'hard \& very hard' of the 7D-PAR (0.41 < r < 0.56) and 'active' (r = 0.33) of the HAES correlated significantly with MVPA. The activity levels of the LRC were not related to objectively determined physical activity. Significant ICCs were only observed between the 7D-PAR activitiy categories and MVPA (ICC = 0.40-0.44). Only the LRC showed moderate correlations with the exercise test (Wmax: r = 0.46, p = 0.002; VO2peak: r = 0.32, p = 0.041). Conclusions: In conclusion, the activity categories 'hard' and 'very hard' of the 7D-PAR best reflected objectively measured MVPA. Since the association was at most moderate, the 7D-PAR may be selected to describe physical activity within a population. None of the evaluated questionnaires was able to generate valid physical activity data exercise performance data at the individual level. Neither did any of the questionnaires provide a valid assessment of aerobic fitness on an invidual level.},
  subject      = {Medizin},
  language  = {en}
}
@article{RufBeerKoestleretal.2019,
  author    = {Ruf, Katharina and Beer, Meinrad and K{\"o}stler, Herbert and Weng, Andreas Max and Neubauer, Henning and Klein, Alexander and Platek, Kathleen and Roth, Kristina and Beneke, Ralph and Hebestreit, Helge},
  title     = {Size-adjusted muscle power and muscle metabolism in patients with cystic fibrosis are equal to healthy controls - a case control study},
  series = {BMC Pulmonary Medicine},
  volume    = {19},
  journal   = {BMC Pulmonary Medicine},
  doi       = {10.1186/s12890-019-1039-8},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200981},
  pages     = {269},
  year      = {2019},
  abstract  = {Background Skeletal muscle function dysfunction has been reported in patients with cystic fibrosis (CF). Studies so far showed inconclusive data whether reduced exercise capacity is related to intrinsic muscle dysfunction in CF. Methods Twenty patients with CF and 23 age-matched controls completed an incremental cardiopulmonary cycling test. Further, a Wingate anaerobic test to assess muscle power was performed. In addition, all participants completed an incremental knee-extension test with 31P magnetic resonance spectroscopy to assess muscle metabolism (inorganic phosphate (Pi) and phosphocreatinine (PCr) as well as intracellular pH). In the MRI, muscle cross-sectional area of the M. quadriceps (qCSA) was also measured. A subgroup of 15 participants (5 CF, 10 control) additionally completed a continuous high-intensity, high-frequency knee-extension exercise task during 31P magnetic resonance spectroscopy to assess muscle metabolism. Results Patients with CF showed a reduced exercise capacity in the incremental cardiopulmonary cycling test (VO2peak: CF 77.8 ± 16.2\%predicted (36.5 ± 7.4 ml/qCSA/min), control 100.6 ± 18.8\%predicted (49.1 ± 11.4 ml/qCSA/min); p < 0.001), and deficits in anaerobic capacity reflected by the Wingate test (peak power: CF 537 ± 180 W, control 727 ± 186 W; mean power: CF 378 ± 127 W, control 486 ± 126 W; power drop CF 12 ± 5 W, control 8 ± 4 W. all: p < 0.001). In the knee-extension task, patients with CF achieved a significantly lower workload (p < 0.05). However, in a linear model analysing maximal work load of the incremental knee-extension task and results of the Wingate test, respectively, only muscle size and height, but not disease status (CF or not) contributed to explaining variance. In line with this finding, no differences were found in muscle metabolism reflected by intracellular pH and the ratio of Pi/PCr at submaximal stages and peak exercise measured through MRI spectroscopy. Conclusions The lower absolute muscle power in patients with CF compared to controls is exclusively explained by the reduced muscle size in this study. No evidence was found for an intrinsic skeletal muscle dysfunction due to primary alterations of muscle metabolism.},
  language  = {en}
}
@article{RufBadranSiauwetal.2021,
  author    = {Ruf, Katharina and Badran, Alaa and Siauw, C{\´e}line and Haubitz, Imme and Schlegel, Paul-Gerhardt and Hebestreit, Helge and H{\"a}rtel, Christoph and Wiegering, Verena},
  title     = {Does allogeneic stem cell transplantation in survivors of pediatric leukemia impact regular physical activity, pulmonary function, and exercise capacity?},
  series = {Molecular and Cellular Pediatrics},
  volume    = {8},
  journal   = {Molecular and Cellular Pediatrics},
  doi       = {10.1186/s40348-021-00127-7},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265528},
  year      = {2021},
  abstract  = {Background Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has improved survival in high-risk childhood leukemia but is associated with long-term sequelae such as impaired pulmonary function and reduced exercise capacity impacting quality of life. Methods A convenience sample of 17 patients after allo-HSCT (HSCT—12 male, age 15.7±6.7 years, time after HSCT 5.3±2.8 years) underwent pulmonary function testing, echocardiography, and an incremental exercise test on a bike. Physical activity and health-related quality of life were assessed by questionnaires (7-day physical activity recall, PEDS-QL). Seventeen healthy age- and gender-matched controls served as control group (CG) for results of pulmonary function and exercise testing. Results HSCT showed reduced pulmonary function (HSCT vs. CG: FEV1 90.5±14.0 vs. 108.0±8.7\%pred; FVC 88.4±19.3 vs. 107.6±6.9\%pred, DLCO 75.3±23.6 vs. 104.9±12.8\%pred) and exercise capacity (VO2peak 89±30.8\%pred, CG 98±17.5\%pred; Wmax 84±21.7\%pred, CG 115±22.8\%pred), but no relevant cardiac dysfunction and a good quality of life (PEDS-QL mean overall score 83.3±10.7). Differences in peak oxygen uptake between groups were mostly explained by 5 adolescent patients who underwent total body irradiation for conditioning. They showed significantly reduced diffusion capacity and reduced peak oxygen uptake. Patients reported a mean time of inactivity of 777±159min/day, moderate activity of 110±107 min/day, hard activity of 35±36 min/day, and very hard activity of 23±22 min/day. A higher amount of inactivity was associated with a lower peak oxygen uptake (correlation coefficient tau -0.48, p=0.023). Conclusions This pilot study shows that although patients after allo-HSCT reported a good quality of life, regular physical activity and exercise capacity are reduced in survivors of stem cell transplantation, especially in adolescents who are treated with total body irradiation for conditioning. Factors hindering regular physical activity need to be identified and exercise counseling should be part of follow-up visits in these patients.},
  language  = {en}
}
@article{RueeggKriemlerZuercheretal.2017,
  author    = {Rueegg, Corina S. and Kriemler, Susi and Zuercher, Simeon J. and Schindera, Christina and Renner, Andrea and Hebestreit, Helge and Meier, Christian and Eser, Prisca and von der Weid, Nicolas X.},
  title     = {A partially supervised physical activity program for adult and adolescent survivors of childhood cancer (SURfit): study design of a randomized controlled trial [NCT02730767]},
  series = {BMC Cancer},
  volume    = {17},
  journal   = {BMC Cancer},
  doi       = {10.1186/s12885-017-3801-8},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-172497},
  year      = {2017},
  abstract  = {Background: Beyond survival of nowadays >80\%, modern childhood cancer treatment strives to preserve long-term health and quality of life. However, the majority of today's survivors suffer from short- and long-term adverse effects such as cardiovascular and pulmonary diseases, obesity, osteoporosis, fatigue, depression, and reduced physical fitness and quality of life. Regular exercise can play a major role to mitigate or prevent such late-effects. Despite this, there are no data on the effects of regular exercise in childhood cancer survivors from randomized controlled trials (RCTs). \(Primary\) \(outcome\) of the current RCT is therefore the effect of a 12-months exercise program on a composite cardiovascular disease risk score in childhood cancer survivors. \(Secondary\) \(outcomes\) are single cardiovascular disease risk factors, glycaemic control, bone health, body composition, physical fitness, physical activity, quality of life, mental health, fatigue and adverse events (safety). Methods: A total of 150 childhood cancer survivors aged ≥16 years and diagnosed ≥5 years prior to the study are recruited from Swiss paediatric oncology clinics. Following the baseline assessments patients are randomized 1:1 into an intervention and control group. Thereafter, they are seen at month 3, 6 and 12 for follow-up assessments. The intervention group is asked to add ≥2.5 h of intense physical activity/week, including 30 min of strength building and 2 h of aerobic exercises. In addition, they are told to reduce screen time by 25\%. Regular consulting by physiotherapists, individual web-based activity diaries, and pedometer devices are used as motivational tools for the intervention group. The control group is asked to keep their physical activity levels constant. Discussion: The results of this study will show whether a partially supervised exercise intervention can improve cardiovascular disease risk factors, bone health, body composition, physical activity and fitness, fatigue, mental health and quality of life in childhood cancer survivors. If the program will be effective, all relevant information of the SURfit physical activity intervention will be made available to interested clinics that treat and follow-up childhood cancer patients to promote exercise in their patients.},
  language  = {en}
}
@article{RothMauerObingeretal.2010,
  author    = {Roth, Kristina and Mauer, Sonja and Obinger, Matthias and Ruf, Katharina C. and Graf, Christine and Kriemler, Susi and Lenz, Dorothea and Lehmacher, Walter and Hebestreit, Helge},
  title     = {Prevention through Activity in Kindergarten Trial (PAKT): A cluster randomised controlled trial to assess the effects of an activity intervention in preschool children},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-67972},
  year      = {2010},
  abstract  = {Background: Physical activity and motor skills acquisition are of high importance for health-related prevention and a normal development in childhood. However, few intervention studies exist in preschool children focussing on an increase in physical activity and motor skills. Proof of positive effects is available but not consistent. Methods/Design: The design, curriculum, and evaluation strategy of a cluster randomised intervention study in preschool children are described in this manuscript. In the Prevention through Activity in Kindergarten Trial (PAKT), 41 of 131 kindergartens of Wuerzburg and Kitzingen, Germany, were randomised into an intervention and a control group by a random number table stratified for the location of the kindergarten in an urban (more than 20.000 inhabitants) or rural area. The aims of the intervention were to increase physical activity and motor skills in the participating children, and to reduce health risk factors as well as media use. The intervention was designed to involve children, parents and teachers, and lasted one academic year. It contained daily 30-min sessions of physical education in kindergarten based on a holistic pedagogic approach termed the "early psychomotor education". The sessions were instructed by kindergarten teachers under regular supervision by the research team. Parents were actively involved by physical activity homework cards. The kindergarten teachers were trained in workshops and during the supervision. Assessments were performed at baseline, 3-5 months into the intervention, at the end of the intervention and 2-4 months after the intervention. The primary outcomes of the study are increases in physical activity (accelerometry) and in motor skills performance (composite score of obstacle course, standing long jump, balancing on one foot, jumping sidewise to and fro) between baseline and the two assessments during the intervention. Secondary outcomes include decreases in body adiposity (BMI, skin folds), media use (questionnaire), blood pressure, number of accidents and infections (questionnaire), increases in specific motor skills (throwing, balancing, complex motor performance, jumping) and in flexibility. Discussion: If this trial proofs the effectiveness of the multilevel kindergarten based physical activity intervention on preschooler's activity levels and motor skills, the programme will be distributed nationwide in Germany. Trial Registration: ClinicalTrials.gov Identifier: NCT00623844},
  subject      = {Vorschulkind},
  language  = {en}
}
@article{NeubauerWirthRufetal.2012,
  author    = {Neubauer, Henning and Wirth, Clemens and Ruf, Katharina and Hebestreit, Helge and Beer, Meinrad},
  title     = {Acute Muscle Trauma due to Overexercise in an Otherwise Healthy Patient with Cystic Fibrosis},
  series = {Case Reports in Pediatrics},
  volume    = {2012},
  journal   = {Case Reports in Pediatrics},
  number    = {527989},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123967},
  year      = {2012},
  abstract  = {Cystic fibrosis (CF) is one of the most common inherited diseases and is caused by mutations in the CFTR gene. Although the pulmonary and gastrointestinal manifestations of the disease remain in the focus of treatment, recent studies have shown expression of the CFTR gene product in skeletal muscle cells and observed altered intramuscular \(Ca^{2+}\) release dynamics in CFTR-deficient animal models. Physical exercise is beneficial for maintaining fitness and well-being in CF patients and constitutes one aspect of modern multimodal treatment, which has considerably increased life span and reduced morbidity. We report on a case of acute muscle trauma resulting from excessive dumbbell exercise in a young adult with cystic fibrosis and describe clinical, laboratory and imaging characteristics of acute exercise-induced muscle injury.},
  language  = {en}
}
@article{NentwichRufGirschicketal.2019,
  author    = {Nentwich, Julia and Ruf, Katharina and Girschick, Hermann and Holl-Wieden, Annette and Morbach, Henner and Hebestreit, Helge and Hofmann, Christine},
  title     = {Physical activity and health-related quality of life in chronic non-bacterial osteomyelitis},
  series = {Pediatric Rheumatology},
  volume    = {17},
  journal   = {Pediatric Rheumatology},
  doi       = {10.1186/s12969-019-0351-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-323710},
  year      = {2019},
  abstract  = {Background Chronic non-bacterial osteomyelitis (CNO) is an autoinflammatory disorder of the skeletal system of yet unknown etiology. Patients present with local bone pain and inflammation and - to our experience - often suffer from functional impairment with significant disabilities of daily life. The objective of this study was to assess physical activity, fitness and health-related quality of life (HRQOL) in adolescents with established diagnosis of CNO versus healthy controls (HC). Methods 15 patients with CNO and 15 age and gender matched HC aged 13-18 years, completed questionnaires, performed an incremental exercise test with gas exchange measures up to voluntary fatigue and wore an accelerometer over 7 days at home to assess physical activity behavior. Results At the time of assessment, 5 CNO patients were in clinical, one in radiological and 5 in clinical and radiological remission. 7 did not receive any therapy at the time of assessment. The results of the exercise test and of the accelerometry did not show any significant difference between CNO and HC. However, reported sports participation was lower in patients with CNO and PedsQL3.0 and 4.0 showed significant lower values in most of the scores indicating reduced HRQOL. Conclusion Although most CNO patients showed a favorable course of disease without any relevant differences in objective measurements of physical activity and fitness versus HC at the time of assessment, questionnaires revealed perceived limitations. Further studies are needed to measure HRQOL and to validate questionnaires in patients with CNO against objective measures including more participants with a higher level of disease activity.},
  language  = {en}
}
@article{MeyerSchindlerZahneretal.2014,
  author    = {Meyer, Ursina and Schindler, Christian and Zahner, Lukas and Ernst, Dominique and Hebestreit, Helge and van Mechelen, Willem and Brunner-La Rocca, Hans-Peter and Probst-Hensch, Nicole and Puder, Jardena J. and Kriemler, Susi},
  title     = {Long-Term Effect of a School-Based Physical Activity Program (KISS) on Fitness and Adiposity in Children: A Cluster-Randomized Controlled Trial},
  series = {PLOS ONE},
  volume    = {9},
  journal   = {PLOS ONE},
  number    = {2},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0087929},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117436},
  pages     = {e87929},
  year      = {2014},
  abstract  = {Background: School-based intervention studies promoting a healthy lifestyle have shown favorable immediate health effects. However, there is a striking paucity on long-term follow-ups. The aim of this study was therefore to assess the 3 yr-follow-up of a cluster-randomized controlled school-based physical activity program over nine month with beneficial immediate effects on body fat, aerobic fitness and physical activity. Methods and Findings: Initially, 28 classes from 15 elementary schools in Switzerland were grouped into an intervention (16 classes from 9 schools, n = 297 children) and a control arm (12 classes from 6 schools, n = 205 children) after stratification for grade (1st and 5th graders). Three years after the end of the multi-component physical activity program of nine months including daily physical education (i.e. two additional lessons per week on top of three regular lessons), short physical activity breaks during academic lessons, and daily physical activity homework, 289 (58\%) participated in the follow-up. Primary outcome measures included body fat (sum of four skinfolds), aerobic fitness (shuttle run test), physical activity (accelerometry), and quality of life (questionnaires). After adjustment for grade, gender, baseline value and clustering within classes, children in the intervention arm compared with controls had a significantly higher average level of aerobic fitness at follow-up (0.373 z-score units [95\%-CI: 0.157 to 0.59, p = 0.001] corresponding to a shift from the 50th to the 65th percentile between baseline and follow-up), while the immediate beneficial effects on the other primary outcomes were not sustained. Conclusions: Apart from aerobic fitness, beneficial effects seen after one year were not maintained when the intervention was stopped. A continuous intervention seems necessary to maintain overall beneficial health effects as reached at the end of the intervention.},
  language  = {en}
}