Association of growth and nutritional parameters with pulmonary function in cystic fibrosis: a literature review

Recombinant growth hormone therapy for cystic fibrosis in children and young adults

BACKGROUND

Cystic fibrosis (CF) is an inherited condition causing disease most noticeably in the lungs, digestive tract and pancreas. People with CF often have malnutrition and growth delay. Adequate nutritional supplementation does not improve growth optimally and hence an anabolic agent, recombinant human growth hormone (rhGH), has been proposed as a potential intervention. This is an update of a previously published review.

OBJECTIVES

To evaluate the effectiveness and safety of rhGH therapy in improving lung function, quality of life and clinical status of children and young adults with CF.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Date of latest search: 12 January 2021. We also searched ongoing trials registers: clinicaltrials.gov from the United States - date of latest search 19 Jun 2021; WHO International Clinical Trials Registry Platform (ICTRP) - date of latest search 05 March 2018 (not available in 2021).  We conducted a search of relevant endocrine journals and proceedings of the Endocrinology Society meetings using Web of Science, Scopus and Proceedings First. Date of latest search: 21 Jun 2021.  SELECTION CRITERIA: Randomised and quasi-randomised controlled trials of all preparations of rhGH compared to either no treatment, or placebo, or each other at any dose (high-dose and low-dose) or route and for any duration, in children or young adults (aged up to 25 years) diagnosed with CF (by sweat test or genetic testing).

DATA COLLECTION AND ANALYSIS

Two authors independently screened papers, extracted trial details and assessed their risk of bias. We assessed the quality of the evidence using the GRADE system.

MAIN RESULTS

We included eight trials (291 participants, aged between five and 23 years) in the current version of the review. Seven trials compared standard-dose rhGH (approximately 0.3 mg/kg/week) to no treatment and one three-arm trial (63 participants) compared placebo, standard-dose rhGH (0.3 mg/kg/week) and high-dose rhGH (0.5 mg/kg/week). Six trials lasted for one year and two trials for six months. We found that rhGH treatment may improve some of the pulmonary function outcomes, but there was no difference between standard and high-dose levels (low-certainty evidence, limited by inconsistency across the trials, small number of participants and short duration of therapy). The trials show evidence of improvement in the anthropometric parameters (height, weight and lean body mass) with rhGH therapy, again no differences between dose levels. We found improvement in height for all comparisons (very low- to low-certainty evidence), but improvements in weight and lean body mass were only reported for standard-dose rhGH versus no treatment (very low-certainty evidence). There is some evidence indicating a change in the level of fasting blood glucose with rhGH therapy, however, it did not cross the clinical threshold for diagnosis of diabetes in the trials of short duration (low-certainty evidence). There is low- to very low-certainty evidence for improvement of pulmonary exacerbations with no further significant adverse effects, but this is limited by the short duration of trials and the small number of participants. One small trial provided inconsistent evidence on improvement in quality of life (very low-certainty evidence). There is limited evidence from three trials in improvements in exercise capacity (low-certainty evidence). None of the trials have systematically compared the expense of therapy on overall healthcare costs.

AUTHORS' CONCLUSIONS

When compared with no treatment, rhGH therapy is effective in improving the intermediate outcomes in height, weight and lean body mass. Some measures of pulmonary function showed moderate improvement, but no consistent benefit was seen across all trials. The significant change in blood glucose levels, although not causing diabetes, emphasizes the need for careful monitoring of this adverse effect with therapy in a population predisposed to CF-related diabetes. No significant changes in quality of life, clinical status or side-effects were observed in this review due to the small number of participants. Long-term, well-designed randomised controlled trials of rhGH in individuals with CF are required prior to routine clinical use of rhGH in CF.

Effect of malnutrition in infants with cystic fibrosis in India: An underestimated danger

Aims

To assess the clinical profile and nutritional status of infants with cystic fibrosis (CF) and track their nutritional outcomes with treatment.

Materials and Methods

This retrospective study was conducted in a tertiary-care institute in South India. Demographic and clinical information were collected. The nutritional status and treatment outcome was assessed by Z-scores for weight-for-age (WAZ), length-for-age (LAZ), and weight-for-length (WLZ) at diagnosis and follow-up.

Results

Nineteen infants with CF had mean follow-up duration of 9.7 ± 8.7 months. There was a mean delay of 2.9 ± 2.1 months from symptom onset to diagnosis, by which time infants were severely malnourished (mean WAZ -4.68 ± 1.8). Pneumonia, summer dehydration with electrolyte abnormalities (42.1%), and a combination of anemia, hypoalbuminemia, and malnutrition (42.1%) were the predominant features. Significant weight loss had been recorded in undiagnosed infants by second month of life before symptom onset. At follow-up, there was a remarkable improvement in WAZ (P 0.001), but not LAZ and WLZ. There was a high mortality rate of 37% in these infants.

Conclusions

Malnutrition is a significant morbidity in infants with CF in India. There was significant improvement of WAZ with treatment, but it lagged behind the recommended targets. There is an opportunity for identification of CF infants at the time of vaccination at six and ten weeks of age, by the primary care physician and pediatrician. Screening of young infants having failure to thrive in the immunization clinic may be a strategy for early diagnosis of infants with severe CF phenotype.

Novel therapeutic approaches for the management of cystic fibrosis

Cystic fibrosis (CF) is a genetic condition characterised by the build-up of thick, sticky mucus that can damage many of the body's organs. It is a life-long disease that results in a shortened life expectancy, often due to the progression of advanced lung disease. Treatment has previously targeted the downstream symptoms such as diminished mucus clearance and recurrent infection. More recently, significant advances have been made in treating the cause of the disease by targeting the faulty gene responsible. Hope for the development of potential therapies lies with ongoing research into new pharmacological agents and gene therapy. This review gives an overview of CF, and summarises the current evidence regarding the disease management and upcoming strategies aimed at treating or potentially curing this condition.

A comparative study of the pancreas in pediatric patients with cystic fibrosis and healthy children using two-dimensional shear wave elastography

PURPOSE

To compare sonographic parameters of the pancreas between healthy children and pediatric cystic fibrosis (CF) patients with pancreatic involvement using shear wave elastography (SWE) and to investigate the efficacy of SWE in the diagnosis of pancreatic involvement in pediatric CF patients.

METHODS

The pancreas was evaluated in 38 patients with CF and 38 healthy children using conventional B-mode ultrasonography (US) and two-dimensional (2D)-SWE.

RESULTS

The pancreatic 2D-SWE values of the CF group were significantly lower than those of the healthy control group (1.01 ± 0.16 vs. 1.31 ± 0.01 m/s for the head, 1.03 ± 0.05 vs. 1.28 ± 0.08 m/s for the pancreatic body, and 1.02 ± 0.05 vs. 1.30 ± 0.10 m/s for the tail; p < 0.005 for all the comparisons). When the threshold values were obtained for the pancreatic head, body, and tail segments for the differentiation of the CF patients and healthy controls, the sensitivity of the test was determined as 81.5%, 76.3%, and 73.3%, respectively, and the specificity as 97.3%, 100%, and 100%, respectively. When the patients were divided into two groups based on the presence of B-mode US characteristics (homogeneity, sharp demarcation, and hyperechoic pancreas), there was a significant difference in the 2D-SWE values of the pancreatic head between the patients with and the patients without these characteristics (p = 0.048 for homogeneity, p = 0.021 for sharp demarcation, and p = 0.006 for hyperechoic pancreas).

CONCLUSION

The measurement of 2D-SWE values was found to be an easily applicable non-invasive test with high sensitivity and specificity for the demonstration of changes in the pancreas of pediatric CF patients.

Recombinant growth hormone therapy for cystic fibrosis in children and young adults

BACKGROUND

Cystic fibrosis (CF) is an inherited condition causing disease most noticeably in the lungs, digestive tract and pancreas. People with CF often have malnutrition and growth delay. Adequate nutritional supplementation does not improve growth optimally and hence an anabolic agent, recombinant human growth hormone (rhGH), has been proposed as a potential intervention. This is an update of a previously published review.

OBJECTIVES

To evaluate the effectiveness and safety of rhGH therapy in improving lung function, quality of life and clinical status of children and young adults with CF.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Date of latest search: 22 October 2018.We also searched ongoing trials registers in clinicaltrials.gov from the United States and WHO International Clinical Trials Registry Platform (ICTRP). Date of latest search: 05 March 2018.We conducted a search of relevant endocrine journals and proceedings of the Endocrinology Society meetings using Web of Science, Scopus and Proceedings First. Date of latest search: 04 March 2018.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of all preparations of rhGH compared to either no treatment, or placebo, or each other at any dose (high-dose and low-dose) or route and for any duration, in children or young adults (aged up to 25 years) diagnosed with CF (by sweat test or genetic testing).

DATA COLLECTION AND ANALYSIS

Two authors independently screened papers, extracted trial details and assessed their risk of bias. We assessed the quality of the evidence using the GRADE system.

MAIN RESULTS

We included eight trials (291 participants, aged between five and 23 years) in this revision of the review. Seven trials compared standard-dose rhGH (approximately 0.3 mg/kg/week) to no treatment and one three-arm trial (63 participants) compared placebo, standard-dose rhGH (0.3 mg/kg/week) and high-dose rhGH (0.5 mg/kg/week). Six trials lasted for one year and two trials for six months. We found that rhGH treatment may improve some of the pulmonary function outcomes but there was no difference between standard and high-dose levels (low-quality evidence, limited by inconsistency across the trials, small number of participants and short duration of therapy). The trials show evidence of improvement in the anthropometric parameters (height, weight and lean body mass) with rhGH therapy, again no differences between dose levels. We found improvement in height for all comparisons (very low- to low quality evidence), but improvements in weight and lean body mass were only reported for standard-dose rhGH versus no treatment (very low-quality evidence). There is some evidence indicating a change in the level of fasting blood glucose with rhGH therapy, however, it did not cross the clinical threshold for diagnosis of diabetes in the trials of short duration (low-quality evidence). There is low- to very low-quality evidence for improvement of pulmonary exacerbations with no further significant adverse effects, but this is limited by the short duration of trials and the small number of participants. One small trial provided inconsistent evidence on improvement in quality of life (very low-quality evidence). There is limited evidence from three trials in improvements in exercise capacity (low-quality evidence). None of the trials have systematically compared the expense of therapy on overall healthcare costs.

AUTHORS' CONCLUSIONS

When compared with no treatment, rhGH therapy is effective in improving the intermediate outcomes in height, weight and lean body mass. Some measures of pulmonary function showed moderate improvement, but no consistent benefit was seen across all trials. The significant change in blood glucose levels, although not causing diabetes, emphasizes the need for careful monitoring of this adverse effect with therapy in a population predisposed to CF-related diabetes. No significant changes in quality of life, clinical status or side-effects were observed in this review due to the small number of participants. Long-term, well-designed randomised controlled trials of rhGH in individuals with CF are required prior to routine clinical use of rhGH in CF.

The importance of data issues when comparing cystic fibrosis registry outcomes between countries: Are annual review FEV1 in the UK only collected when subjects are well?

RATIONALE, AIMS AND OBJECTIVE

Cross-country comparisons of cystic fibrosis (CF) outcomes can potentially identify variation in care but are dependent on data quality. An important assumption is that the UK annual review FEV₁ is only collected during periods of clinical stability. If this assumption does not hold, results of FEV₁ comparisons may be biased in favour of registries with encounter-based FEV₁ . We aimed to test the assumption that CF annual reviews in the UK are only performed during periods of clinical stability.

METHOD

Prospective encounter-based data collected in Sheffield (n = 174) was used to establish whether annual review FEV₁ were always collected during periods of clinical stability and to determine the group-level discrepancy between annual review vs best FEV₁ . We then went on to quantify the group-level discrepancy between annual review and best annual FEV₁ readings within the UK registry (n = 2995) to determine if the differences observed in Sheffield also apply to the wider UK data.

RESULTS

Sheffield results showed a group-level discrepancy between best and annual review FEV₁ of -2.5% (95% CI -3.95% to -1.2%) for annual reviews performed during periods of clinical stability (n = 50). The group-level discrepancy is larger at -8.0% (95% CI -11.2% to -4.9%) among annual reviews performed during periods of clinical instability (n = 13). Therefore, the magnitude of this group-level discrepancy is a surrogate for the proportion of clinically stable annual reviews-smaller discrepancy indicates a higher proportion of clinically stable annual reviews and vice versa. The overall group-level discrepancy in the UK registry (-5.6%, 95% CI -5.9 to -5.4%) was similar to Sheffield (-6.1%, 95% CI -7.1 to -5.1%). Around 20% of the clinician reviewed, annual reviews in Sheffield were performed during periods of clinically instability.

CONCLUSIONS

Annual review FEV₁ underestimates lung health of adults with CF in the UK and may bias cross-country comparisons.