Growth and long-term lung function in cystic fibrosis: a longitudinal study of patients diagnosed by neonatal screening

Endocrine Complications of Cystic Fibrosis

Endocrine comorbidities have become increasingly important medical considerations as improving cystic fibrosis (CF) care increases life expectancy. Although the underlying pathophysiology of CF-related diabetes remains elusive, the use of novel technologies and therapeutics seeks to improve both CF-related outcomes and quality of life. Improvements in the overall health of those with CF have tempered concerns about pubertal delay and short stature; however, other comorbidities such as hypogonadism and bone disease are increasingly recognized. Following the introduction of highly effective modulator therapies there are many lessons to be learned about their long-term impact on endocrine comorbidities.

Trends in Growth and Maturation in Children with Cystic Fibrosis Throughout Nine Decades

Since cystic fibrosis (CF) was first described in 1938, there have been many discoveries and innovations in the field, each having a profound impact on survival, growth and quality of life. For example, the introduction of enteric-coated pancreatic enzyme microspheres increased fat absorption and improved nutritional status. Early detection of CF through newborn screening facilitated prompt nutritional intervention for infants at high risk of malnutrition. Use of anti-pseudomonal therapy, such as inhaled tobramycin, increased weight gain and pulmonary function in addition to reducing pulmonary exacerbations. Similarly, DNAse and hypertonic saline improved pulmonary function and reduced exacerbations. The identification of the CFTR gene and its protein product were fundamental in understanding the pathophysiology of CF and paved the way for advances in both diagnosis and management. In fact, CFTR modulator therapies have revolutionized the care for individuals with CF. Here, we examine the impact of these interventions on the nutritional status, growth and pubertal maturation of children and adolescents with CF.

Evaluation of growth hormone deficiency in children with cystic fibrosis

Background:

Due to chronic respiratory and gastrointestinal problems, growth failure is a common issue in patients with cystic fibrosis (CF). The present study aimed to investigate the prevalence of growth hormone deficiency (GHD) in CF children with stable gastrointestinal and respiratory conditions.

Materials and Methods:

In this study, the growth indicators of all 4–16-year-old children referred to two CF clinics were monitored over 3 years. Children without severe gastrointestinal or pulmonary symptoms with weight <3% percentile or whose height increase were two standard deviations below their expected height growth over 6 months were selected for the growth hormone (GH) stimulation test by clonidine and L-dopa test. Some of the children without CF, who were also referred for height growth disorders and matched the CF group, were considered the control group. They underwent the GH stimulation test, and the results were compared.

Results:

From 150 patients with CF, growth failure was observed in 24 patients with stable gastrointestinal and respiratory conditions; in 10 of them, the GH stimulation test was deficient. The prevalence of GHD was 6.6% in CF patients. In the control group of 30 children without CF, but with growth failure, the GH was deficient in nine cases, implying no significant difference with the case group (P = 0.37).

Conclusion:

In our study, the prevalence of GHD was 6.6% in CF patients, whereas the prevalence GHD in the normal population of childhood is <1%. Therefore, further studies should be designed to investigate the cause of GHD in CF patients.

Most Short Children with Cystic Fibrosis Do Not Catch Up by Adulthood

Poor linear growth is common in children with cystic fibrosis (CF) and predicts pulmonary status and mortality. Growth impairment develops in infancy, prior to pulmonary decline and despite aggressive nutritional measures. We hypothesized that growth restriction during early childhood in CF is associated with reduced adult height. We used the Cystic Fibrosis Foundation (CFF) patient registry to identify CF adults between 2011 and 2015 (ages 18–19 y, n = 3655) and had height for age (HFA) records between ages 2 and 4 y. We found that only 26% CF adults were ≥median HFA and 25% were <10th percentile. Between 2 and 4 years, those with height < 10th percentile had increased odds of being <10th percentile in adulthood compared to children ≥ 10th percentile (OR = 7.7). Of HFA measured between the 10th and 25th percentiles at ages 2–4, 58% were <25th percentile as adults. Only 13% between the 10th and 25th percentile HFA at age 2–4 years were >50th percentile as adults. Maximum height between ages 2 and 4 highly correlated with adult height. These results demonstrate that low early childhood CF height correlates with height in adulthood. Since linear growth correlates with lung growth, identifying both risk factors and interventions for growth failure (nutritional support, confounders of clinical care, and potential endocrine involvement) could lead to improved overall health.

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.

A new era for people with cystic fibrosis

Cystic fibrosis is the most prevalent inherited disease caused by a defect in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The impaired electrolyte homeostasis caused by the mutated or absent protein leads to symptoms in multiple organ systems. However, the pulmonary manifestation with chronic infections and eventually respiratory failure remains the most important threat. Until one decade ago, only symptomatic treatment was available. However, since 2012, different combinations of CFTR modulators are available for people with cystic fibrosis (pwCF) that carry different mutations. The advent of these drugs has impressively changed life expectancy and quality of life in people with cystic fibrosis and raised new challenges regarding long-term complications and tapering of conventional therapies.Conclusion: In this review, we provide an update on the latest developments around diagnostics, treatment, and prognosis of pwCF. What is Known: • Cystic fibrosis is an incurable and life-shortening disease asking for life-long symptomatic treatment. • Three combination CFTR modulating drugs has gained marked approval over the last 10 years. What is New: • The emerge of new (modulating) therapies contribute to the increasing life expectancy. • A high unmet need to develop new therapies for people with CF who cannot access or benefit from these drugs remains. This review gives an update on the current status.

Growth failure and treatment in cystic fibrosis

Poor growth has long been a characteristic feature of cystic fibrosis (CF) and is significantly linked to lung function and overall health status. Improvements in pulmonary and nutrition care for patients with cystic fibrosis (CF) have resulted in better growth outcomes; however, height gains have not paralleled the improvements in weight in children with CF, and patients with more severe CF mutations remain significantly more affected. Many factors affect the growth hormone-IGF-1 axis and the growth plate of the long bones, including the chronic inflammatory state associated with CF. There are also increasing data on the direct effects of CFTR on bone and implications for CFTR modulators in attaining optimal growth. Treatments aimed at improving growth in CF are also reviewed here.

Pilot study for cystic fibrosis neonatal screening: the Cuban experience

Background In Cuba, no screening program for cystic fibrosis (CF) has been implemented yet. The ultramicro enzyme-linked immunosorbent assay (UMELISA)® TIR NEONATAL has been developed for the measurement of immunoreactive trypsin (IRT) in dried blood spots on filter paper. The analytical performance of the kit was evaluated in the national network of laboratories. Methods Newborn dried blood samples (DBS) were evaluated in 16 laboratories. An IRT/IRT/DNA protocol was followed using a cut-off value of 50 ng/mL. The mean, median and percentiles of the distribution were calculated and a two-sample t-test with unequal variance was used for statistical analysis. Influence of perinatal factors on IRT levels was analyzed. Results From January to June 2018, 6470 newborns were studied, obtaining a mean IRT value of 12.09 ng/mL (ranging 0-358 ng/mL) and a median of 8.99 ng/mL. Fifty-two samples (0.78%) were above the cut-off level and 16 samples (0.24%) were elevated in the re-screening process. One of them was confirmed positive by molecular biology (phe508del/c.3120 + 1G > A), constituting the first newborn screened and diagnosed early in Cuba. Second DBS samples were collected on average at 14 days and processed in the laboratory at 16 days of birth. Significant differences were observed (p < 0.05) when evaluating the influence of gender, birth weight (BW) and gestational age (GA) on the IRT values. Lower IRT concentrations were found in samples processed after 10 days of collection. Conclusions The performance of UMELISA® TIR NEONATAL in the laboratories has been satisfactory; hence CF newborn screening (NBS) was extended throughout the country from January 2019.

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 ± 3.9 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 ± 1.08), followed by WHO (0.17 ± 1.14) and IOTF (0.35 ± 1.05) (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.

Phenotype of children with inconclusive cystic fibrosis diagnosis after newborn screening

OBJECTIVE

To characterize the phenotypic expression of children with conductance regulator-related metabolic syndrome (CRMS)/cystic fibrosis screen positive inconclusive diagnosis (CFSPID) designation after positive newborn screening, reassign labeling if applicable and better define these children's prognosis.

METHODS

A multicenter cohort with CRMS/CFSPID designation was matched with cystic fibrosis (CF)-diagnosed cohort. Cohorts were prospectively compared on baseline characteristics, cumulative data and when they reached 6 to 7 years at endpoint assessment.

RESULTS

Compared to infants with CF (n = 63), the CRMS/CFSPID cohort (n = 63) had initially lower immunoreactive trypsinogen (IRT) and sweat chloride (SC) values, delayed visits, less symptoms, and better nutritional status; during follow-up, they had fewer hospitalizations, Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus identification, CF comorbidities, and treatment burden. At endpoint assessment, they presented a milder pulmonary phenotype on Brody computed tomography scores (0.0[0.0; 2.0] vs 13[2.0; 31.0]; P < .0001, respectively), Wisconsin and Brasfield chest radiograph scores, pulmonary function tests, and improved nutritional status. Among the inconclusive CF diagnosis cohort, 28 cases (44%) converted to CF diagnosis based on genotype (44%), SC (28%) or both (28%); yet, comparing those with or without final CF diagnosis, we found no differences, possibly related to their young age and mild degree of lung disease. In the total cohort, we found significant associations between Brody scores and IRT, SC values, genotype, Wisconsin and Brasfield score and spirometry.

CONCLUSIONS

The matched CRMS/CFSPID and CF cohorts showed differences in outcomes. By a mean age of 7.6 years, a high proportion of the CRMS/CFSPID cohort converted to CF. Our results highlight that monitoring at CF clinics until at least 6 years is needed as well as further studies.

Rapid early increase in BMI is associated with impaired longitudinal growth in children with cystic fibrosis

BACKGROUND

We aimed to assess whether final height in children with cystic fibrosis (CF) is affected by body mass index (BMI), BMI increase, pulmonary function, and cystic fibrosis-related diabetes (CFRD).

STUDY DESIGN

A longitudinal, retrospective study was performed in a cohort of 57 patients with CF (30 boys, 27 girls) born between 1997 and 2001. Height and weight were recorded annually from ages 0.5 to 10 years and biannually up to the age of 18. Measurements were converted to height-for-age-adjusted-for-target-height (HFA-TH) and BMI-for-age z-scores. Analyses were performed using the independent t tests and the Pearson's correlation.

RESULTS

For both boys and girls, HFA-TH and BMI-for-age z-scores were significantly lower in the first year of life, these scores increased rapidly until the age of 11 and 8 years, respectively. In boys, HFA-TH z-scores declined during puberty, with subsequently significantly impaired final height (z-score, -0.56, n = 30, standard deviation [SD] = 0.81, P = 0.001). In girls, HFA-TH z-scores briefly declined after the age of 8 years, but then increased to a z-score of -0.21 (n = 27, SD = 0.87) at age 18, which is not significantly lower than the national average (P = 0.22). Pulmonary function and the presence of CFRD were not associated with final height. However, rapid BMI increase between ages 1 and 6 was negatively associated with final height in boys (n = 29, r =-0.420; P = 0.023) and girls (n = 25, r =-0.466; P = 0.019).

CONCLUSIONS

In boys and girls, early BMI increase was associated with impaired final height. We suggest that early childhood serves as a "window" in which nutritional variations may program subsequent growth. Further refinement of nutritional strategies could be needed.

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.

Nutritional Status in the First 2 Years of Life in Cystic Fibrosis Diagnosed by Newborn Screening

OBJECTIVE

To evaluate nutritional status and associated factors in a cystic fibrosis (CF) cohort diagnosed by newborn screening and followed up to month 24.

METHODS

A prospective longitudinal multicenter study assessing nutritional status according to pancreatic status, feeding modalities, prescriptions, pulmonary outcome, and biological nutritional parameters.

RESULTS

One hundred and five infants were recruited and 99 completed the study. Nutritional care management prevented undernutrition and stunting in those with exocrine pancreatic sufficiency (EPS), but affected (13/87) 15% and (21/86) 24%, respectively, of infants with exocrine pancreatic insufficiency (EPI). The logistic regression model found a positive association between both weight and length z scores "at risk" at month 24, and initial pulmonary symptoms (odds ratio [OR] 0.06, P < 0.01 and OR 0.08, P < 0.01, respectively); these symptoms were less frequent when age at first visit was earlier than 1.2 months (33% vs 67%, P = 0.02); stunting was also associated with high-calorie density intake and Staphylococcus aureus (OR 0.05, P = 0.01 and OR 0.17, P < 0.01). Pulmonary outcome did not differ according to pancreatic status; breast-feeding for at least 3 months delayed first acquisition of Pseudomonas aeruginosa. Despite sodium and fat-soluble vitamin supplementation, half of both cohorts had low urinary sodium output and half of the EPI cohort had low vitamin D levels.

CONCLUSIONS

Our data shed light on the fact that stunting was more frequent than undernutrition, while both parameters involved only patients with pancreatic insufficiency. Modalities of feeding were not associated with nutritional status; breast-feeding may provide some protection against acquisition of P aeruginosa.

S737F is a new CFTR mutation typical of patients originally from the Tuscany region in Italy

Background

An increasing number of patients have been described as having a number of Cystic Fibrosis Transmembrane conductance Regulator (CFTR) variants for which it lacks a clear genotype–phenotype correlation. We assesses the clinical features of patients bearing the S737F (p.Ser737Phe) CFTR missense variant and evaluated the residual function of CFTR protein on nasal epithelial cells (NEC).

Methods

A retrospective database was performed from individuals homozygous or compound heterozygous for the S737F variant followed in the Cystic Fibrosis (CF) Centre of Florence. We performed a nasal brushing in cooperating patients and compared the results with those of patients followed in the pediatric CF Centre of Naples.

Results

9/295 (3%) subjects carrying at least S737F CFTR variant on one allele were identified. Patients were diagnosed in 7/9 cases by newborn screening and in two cases for dehydration with hypochloremic metabolic alkalosis; at diagnosis sweat chloride levels (SCL) were in the pathological range in only one case. After a mean follow up of 8,6 years (range 0,5–15,8), SCL were in the pathological range in 8/9 cases (mean age at CF diagnosis: 1,5 years), all patients were pancreatic sufficiency and respiratory function was normal. The gating activity on NEC was 15.6% and 12.7% in two patients compound heterozygous for W1282X and DelE22_24, while it was ranged between 6,2% and 9,8% in CF patients.

Conclusions

S737F is a CFTR mutation associated to hypochloremic alkalosis in childhood, mild CF phenotype in teenage years and a residual function of CFTR protein.

Reduced bone length, growth plate thickness, bone content, and IGF-I as a model for poor growth in the CFTR-deficient rat

Background

Reduced growth and osteopenia are common in individuals with cystic fibrosis (CF). Additionally, improved weight and height are associated with better lung function and overall health in the disease. Mechanisms for this reduction in growth are not understood. We utilized a new CFTR knockout rat to evaluate growth in young CF animals, via femur length, microarchitecture of bone and growth plate, as well as serum IGF-I concentrations.

Methods

Femur length was measured in wild-type (WT) and SD-CFTR^tm1sage (Cftr-/-) rats, as a surrogate marker for growth. Quantitative bone parameters in Cftr-/- and WT rats were measured by micro computed tomography (micro-CT). Bone histomorphometry and cartilaginous growth plates were analyzed. Serum IGF-I concentrations were also compared.

Results

Femur length was reduced in both Cftr-/- male and female rats compared to WT. Multiple parameters of bone microarchitecture (of both trabecular and cortical bone) were adversely affected in Cftr-/- rats. There was a reduction in overall growth plate thichkness in both male and female Cftr-/- rats, as well as hypertrophic zone thickness and mean hypertrophic cell volume in male rats, indicating abnormal growth characteristics at the plate. Serum IGF-I concentrations were severely reduced in Cftr-/- rats compared to WT littermates.

Conclusions

Despite absence of overt lung or pancreatic disease, reduced growth and bone content were readily detected in young Cftr-/- rats. Reduced size of the growth plate and decreased IGF-I concentrations suggest the mechanistic basis for this phenotype. These findings appear to be intrinsic to the CFTR deficient state and independent of significant clinical confounders, providing substantive evidence for the importance of CFTR on maintinaing normal bone growth.

Improved Growth Patterns in Cystic Fibrosis Mice after Loss of Histone Deacetylase 6

Growth failure in cystic fibrosis (CF) patients has been well-documented and shown to correlate with poorer disease outcomes. This observation is also true in CF animal models, including mouse, pig, rat, and ferret. The etiology underlying growth deficits is unknown, and our previous work demonstrated reduced tubulin acetylation in CF cell models and tissue that is correctable by inhibition of histone deacetylase-6 (HDAC6). Here, we hypothesize that loss of HDAC6 will improve growth phenotype in a CF mouse model. Hdac6 knockout mice were crossed with F508del (CF) mice to generate F508del/Hdac6 (CF/HDA) mice. Growth, fat deposits, survival, and bioelectric measurements were analyzed. CF/HDA mice displayed improvements in length and weight with no correction of CFTR function. Mechanistically, Igf1 levels likely account for increased length and improvements in fertility. Weight gain is attributed to increased fat deposits potentially mediated by increased adipocyte differentiation. CF-related growth deficits can be improved via inhibition of HDAC6, further implicating it as a potential therapeutic target for CF.

Optimization of the French cystic fibrosis newborn screening programme by a centralized tracking process

Objectives To evaluate the French cystic fibrosis newborn screening algorithm, based on data tracked by a centralized monitoring process, from 2002 to 2014. The programme aimed to attain European Standards in terms of positive predictive value, sensitivity, the ratio of screen positive patients diagnosed with cystic fibrosis to infants who screen positive but with inconclusive diagnosis (CFSPID), and time to diagnosis. Methods Retrospective analysis of programme performance, compliance with the algorithm, and changes in screening strategy. Results Modifications in the flow chart protocol improved the positive predictive value to 0.31 while maintaining the sensitivity at 0.95. Among infants diagnosed with cystic fibrosis, or identified as CFSPID, sweat test results were obtained for 94%, and two mutations were identified after exhaustive screening for the gene, when applicable, in 99.6%. The rate of pending diagnosis was very low (0.5%). The ratio of infants with cystic fibrosis:CFSPID was 6.3:1. Age at initial visit at the CF centre was ≤ 35 days, respectively, in 53%/26%. Conclusion Performances were in agreement with European standards, but timeliness of initial visit needed improvement. Our data complement an accumulating body of evidence demonstrating that attention must be paid to such ethical considerations as limiting carrier detection and inconclusive diagnosis. Newborn screening programmes should have a rigorous centralized monitoring process to warrant adjustments for improving performance to attain consensus guidelines.

Growth in Prepubertal Children With Cystic Fibrosis Treated With Ivacaftor

BACKGROUND AND OBJECTIVES

Cystic fibrosis (CF) is known for its impact on the lung and pancreas of individuals; however, impaired growth is also a common complication. We hypothesized that targeting the biological defect in the CF transmembrane conductance regulator (CFTR) protein may affect growth outcomes.

METHODS

In this post hoc analysis, we assessed linear growth and weight in 83 children (aged 6-11 years) enrolled in 2 clinical trials, the longitudinal-observation GOAL study and the placebo-controlled ENVISION study, to evaluate the effects of ivacaftor, a CFTR potentiator. We calculated height and weight z scores and height and weight growth velocities (GVs).

RESULTS

In ivacaftor-treated children in GOAL, height and weight z scores increased significantly from baseline to 6 months (increases of 0.1 [P < .05] and 0.26 [P < .0001], respectively); height GV increased significantly from 3 to 6 months (2.10-cm/year increase; P < .01). In ivacaftor-treated children in ENVISION, height and weight z scores increased significantly from baseline to 48 weeks (increases of 0.17 [P < .001] and 0.35 [P < .001], respectively). Height and weight GVs from baseline to 48 weeks were also significantly higher with ivacaftor than with placebo (differences of 1.08 cm/year [P < .05] and 3.11 kg/year [P < .001], respectively).

CONCLUSIONS

Ivacaftor treatment in prepubescent children may help to address short stature and altered GV in children with CF; results from these analyses support the existence of an intrinsic defect in the growth of children with CF that may be ameliorated by CFTR modulation.

Cystic fibrosis: a clinical view

Cystic fibrosis (CF), a monogenic disease caused by mutations in the CFTR gene on chromosome 7, is complex and greatly variable in clinical expression. Airways, pancreas, male genital system, intestine, liver, bone, and kidney are involved. The lack of CFTR or its impaired function causes fat malabsorption and chronic pulmonary infections leading to bronchiectasis and progressive lung damage. Previously considered lethal in infancy and childhood, CF has now attained median survivals of 50 years of age, mainly thanks to the early diagnosis through neonatal screening, recognition of mild forms, and an aggressive therapeutic attitude. Classical treatment includes pancreatic enzyme replacement, respiratory physiotherapy, mucolitics, and aggressive antibiotic therapy. A significant proportion of patients with severe symptoms still requires lung or, less frequently, liver transplantation. The great number of mutations and their diverse effects on the CFTR protein account only partially for CF clinical variability, and modifier genes have a role in modulating the clinical expression of the disease. Despite the increasing understanding of CFTR functioning, several aspects of CF need still to be clarified, e.g., the worse outcome in females, the risk of malignancies, the pathophysiology, and best treatment of comorbidities, such as CF-related diabetes or CF-related bone disorder. Research is focusing on new drugs restoring CFTR function, some already available and with good clinical impact, others showing promising preliminary results that need to be confirmed in phase III clinical trials.

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

Objective:

To review the literature addressing the relationship of growth and nutritional parameters with pulmonary function in pediatric patients with cystic fibrosis.

Data source:

A collection of articles published in the last 15 years in English, Portuguese and Spanish was made by research in electronic databases - PubMed, Cochrane, Medline, Lilacs and Scielo - using the keywords cystic fibrosis, growth, nutrition, pulmonary function in varied combinations. Articles that addressed the long term association of growth and nutritional parameters, with an emphasis on growth, with pulmonary disease in cystic fibrosis, were included, and we excluded those that addressing only the relationship between nutritional parameters and cystic fibrosis and those in which the aim was to describe the disease.

Data synthesis:

Seven studies were included, with a total of 12,455 patients. Six studies reported relationship between growth parameters and lung function, including one study addressing the association of growth parameters, solely, with lung function, and all the seven studies reported relationship between nutritional parameters and lung function.

Conclusions:

The review suggests that the severity of the lung disease, determined by spirometry, is associated with body growth and nutritional status in cystic fibrosis. Thus, the intervention in these parameters can lead to the better prognosis and life expectancy for cystic fibrosis patients.

Pubertal Height Growth and Adult Height in Cystic Fibrosis After Newborn Screening

BACKGROUND

To examine long-term growth benefit of newborn screening (NBS), adolescent peak height velocity (PHV), and adult height were compared between the screened (diagnosed early via NBS) and the control (identified generally by symptoms) in the Wisconsin Randomized Clinical Trial.

METHODS

Data from 107 children born in 1985-1994 and followed through 2012 were analyzed. PHV was estimated by a semiparametric growth curve model and compared with Tanner reference.

RESULTS

Meconium ileus (MI; n = 25) was associated with the worst pubertal growth and adult height, including 1 child who did not experience apparent PHV; children with pancreatic sufficiency (n = 18) achieved the best growth (normal PHV and adult height). In children with pancreatic insufficiency without meconium ileus (n = 64), the subgroup most likely to benefit from NBS, screened children had similar PHV but better adult height compared with controls. Specifically, in boys, the screened group (n = 22) achieved normal PHV (9.5 cm at 13.5 years); the control group (n = 19) had similar onset age (13.6 years) but 0.6-cm lower magnitude (P = .08). In girls, the screened group (n = 10) had somewhat later (12.5 years vs 11.7 years, P = .12) and lower PHV (7.3 cm vs 7.9 cm, P = .33) than the controls (n = 13), coinciding with later menarche (13.6 years vs 12.2 years, P = .10). Adult height was taller in the screened than the control (50th vs 29th percentile, P = .02), even after adjusted for genetic potential (32nd vs15th percentile, P = .006). Differences in adult height were primarily attributable to NBS and better prepubertal growth.

CONCLUSIONS

Early linear growth benefits of NBS were sustained through puberty, leading to better adult height in cystic fibrosis.

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

OBJECTIVE

To review the literature addressing the relationship of growth and nutritional parameters with pulmonary function in pediatric patients with cystic fibrosis.

DATA SOURCE

A collection of articles published in the last 15 years in English, Portuguese and Spanish was made by research in electronic databases - PubMed, Cochrane, Medline, Lilacs and Scielo - using the keywords cystic fibrosis, growth, nutrition, pulmonary function in varied combinations. Articles that addressed the long term association of growth and nutritional parameters, with an emphasis on growth, with pulmonary disease in cystic fibrosis, were included, and we excluded those that addressing only the relationship between nutritional parameters and cystic fibrosis and those in which the aim was to describe the disease.

DATA SYNTHESIS

Seven studies were included, with a total of 12,455 patients. Six studies reported relationship between growth parameters and lung function, including one study addressing the association of growth parameters, solely, with lung function, and all the seven studies reported relationship between nutritional parameters and lung function.

CONCLUSIONS

The review suggests that the severity of the lung disease, determined by spirometry, is associated with body growth and nutritional status in cystic fibrosis. Thus, the intervention in these parameters can lead to the better prognosis and life expectancy for cystic fibrosis patients.

Growth and the Growth Hormone-Insulin Like Growth Factor 1 Axis in Children With Chronic Inflammation: Current Evidence, Gaps in Knowledge, and Future Directions

Growth failure is frequently encountered in children with chronic inflammatory conditions like juvenile idiopathic arthritis, inflammatory bowel disease, and cystic fibrosis. Delayed puberty and attenuated pubertal growth spurt are often seen during adolescence. The underlying inflammatory state mediated by proinflammatory cytokines, prolonged use of glucocorticoid, and suboptimal nutrition contribute to growth failure and pubertal abnormalities. These factors can impair growth by their effects on the GH-IGF axis and also directly at the level of the growth plate via alterations in chondrogenesis and local growth factor signaling. Recent studies on the impact of cytokines and glucocorticoid on the growth plate further advanced our understanding of growth failure in chronic disease and provided a biological rationale of growth promotion. Targeting cytokines using biological therapy may lead to improvement of growth in some of these children, but approximately one-third continue to grow slowly. There is increasing evidence that the use of relatively high-dose recombinant human GH may lead to partial catch-up growth in chronic inflammatory conditions, although long-term follow-up data are currently limited. In this review, we comprehensively review the growth abnormalities in children with juvenile idiopathic arthritis, inflammatory bowel disease, and cystic fibrosis, systemic abnormalities of the GH-IGF axis, and growth plate perturbations. We also systematically reviewed all the current published studies of recombinant human GH in these conditions and discussed the role of recombinant human IGF-1.

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

BACKGROUND

Cystic fibrosis is an inherited condition causing disease most noticeably in the lungs, digestive tract and pancreas. People with cystic fibrosis often have malnutrition and growth delay. Adequate nutritional supplementation does not improve growth optimally and hence an anabolic agent, recombinant growth hormone, has been proposed as a potential intervention.

OBJECTIVES

To evaluate the effectiveness and safety of recombinant human growth hormone therapy in improving lung function, quality of life and clinical status of children and young adults with cystic fibrosis.

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: 11 February 2015.We conducted a search of relevant endocrine journals and proceedings of the Endocrinology Society meetings using Scopus and Proceedings First. Date of latest search: 04 March 2015.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of all preparations of recombinant growth hormone 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 cystic fibrosis (by sweat test or genetic testing).

DATA COLLECTION AND ANALYSIS

Two authors independently screened papers, extracted trial details and assessed their risk of bias.

MAIN RESULTS

Four controlled trials were included in this review (with 161 participants in total), each with an unclear risk of bias. Analysis of data obtained from these trials shows improvement in height for all comparisons, but improvements in weight and lean tissue mass were only reported in the comparison of standard dose recombinant growth hormone versus no treatment. One study showed moderate improvement at one time point in one parameter of pulmonary function tests, forced vital capacity (per cent predicted) when comparing standard dose recombinant growth hormone and no treatment, but there was no consistent benefit in lung function across all studies. Little evidence was found for improvement in quality of life. An improvement in fasting blood glucose levels was reported when comparing rhGH to placebo only. Exercise capacity improved in participants receiving standard dose recombinant growth hormone versus no treatment, but not for any other comparison. There is insufficient evidence to conclude any changes in hospitalisations, antibiotic use or significant adverse effects.

AUTHORS' CONCLUSIONS

Recombinant growth hormone therapy is effective in improving the intermediate outcomes in height, weight and lean tissue mass when compared with no treatment. One measure of pulmonary function test showed moderate improvement at a single time point, but no consistent benefit was seen across all studies. No significant changes in quality of life, clinical status or side-effects were observed in this review. Long-term, well-designed randomised controlled trials of recombinant growth hormone therapy in people with cystic fibrosis are required prior to evaluation of human growth hormone treatment for routine use.

Glucose tolerance affects pubertal growth and final height of children with cystic fibrosis

There are few data about the impact of cystic fibrosis-related diabetes (CFRD) on growth. We analyzed 17 children with cystic fibrosis (CF) presenting with newly diagnosed CFRD during puberty, in comparison with a matched control group of 52 CF children with normal glucose tolerance (NGT). Anthropometric evaluation showed that body mass index at CFRD diagnosis was significantly reduced in children with CFRD, in comparison with children with NGT (CFRD: -0.48 ± 1.08 vs. NGT: 0.2 ± 0.99; P=0.01), and the same difference remained evident at the end of follow up (CFRD: -0.49 ± 0.95 vs. NGT: 0.13 ± 0.89; P=0.04). Height standard deviation score (SDS) at baseline was slightly but not significantly lower in CFRD children (CFRD: -0.71 ± 0.83 vs. NGT: -0.25 ± 1.08; P=0.08), while final height SDS was significantly reduced (CFRD: -1.61 ± 1.12 vs. NGT: -0.61 ± 1.15; P=0.003). Mean final height SDS of the whole group was lower than mean target height SDS (final height SDS: -0.86 ± 1.2 vs. target height SDS: -0.3 ± 0.85; P<0.001). Target adjusted final height was lower in CFRD children, although the difference between CFRD and NGT children did not reach statistical significance (CFRD: -0.8 ± 1.03 vs. NGT: -0.47 ± 0.9; P=0.09). Pubertal growth and final height are negatively affected by CFRD. Intensive insulin treatment does not appear to be effective in normalizing growth, even when treatment is started early in the course of the disease, before the onset of clinical deterioration.

[Factors impacting the growth and nutritional status of cystic fibrosis patients younger than 10 years of age who did not undergo neonatal screening]

OBJECTIVE

The aim of this study was to evaluate by clinical and laboratory parameters how cystic fibrosis (CF) affects growth and nutritional status of children who were undergoing CF treatment but did not receive newborn screening.

METHODS

A historical cohort study of 52 CF patients younger than 10 years of age were followed in a reference center in Campinas, Southeast Brazil. Anthropometric measurements were abstracted from medical records until March/2010, when neonatal screening program was implemented. Between September/2009 and March/2010, parental height of the 52 CF patients were also measured.

RESULTS

Regarding nutritional status, four patients had Z-scores ≤ -2 for height/age (H/A) and body mass index/age (BMI/A). The following variables were associated with improved H/A ratio: fewer hospitalizations, longer time from first appointment to diagnosis, longer time from birth to diagnosis and later onset of respiratory disease. Forced vital capacity [FVC(%)], forced expiratory flow between 25-75% of FVC [FEF25-75(%)], forced expiratory volume in the first second [FEV1(%)], gestational age, birth weight and early respiratory symptoms were associated with IMC/A.

CONCLUSIONS

Greater number of hospitalizations, diagnosis delay and early onset of respiratory disease had a negative impact on growth. Lower spirometric values, lower gestational age, lower birth weight, and early onset of respiratory symptoms had negative impact on nutritional status. Malnutrition was observed in 7.7% of cases, but 23% of children had nutritional risk.

The relationship between body growth and pulmonary function in children with cystic fibrosis

AIM

To measure the weight and height of children with cystic fibrosis (CF) from 2 to 10 years of age and to investigate the relationship between these parameters and forced expiratory volume in 1 sec (FEV1) beginning at 6 years of age.

METHODS

Weight and height were expressed as z-scores for weight-for-age (WFA), height-for-age (HFA), height-adjusted-for-target-height (HFA/TH) and weight-for-height (WFH). The children were categorised as having a z-score ≥0, between 0 and -1, or <-1 based on z-scores at 2 years of age. The cross-sectional and longitudinal relationships between FEV1 and WFA, HFA, HFA/TH and WFH were determined and the predictive value of these parameters for FEV1.

RESULTS

We enrolled 156 CF children. Their mean weight and height were below the average for the healthy population. Both WFA and WFH increased with age (primarily before the age of 6), while the reduction in HFA and HFA/TH persisted. Importantly, the yearly decline in FEV1 was significantly slowed [by 1.8 and 1.9% for each unit increase in WFA and WFH (p < 0.015)] in children who gained weight.

CONCLUSION

CF patients aged 2 to 10 years have long-term impaired growth. Nevertheless, weight gain slowed the decline in FEV1 in these patients.

Screening for cystic fibrosis: what every NP should know

In a chronic childhood disease such as cystic fibrosis, it is important for nurse practitioners to be knowledgeable about the disease process, methods of mutation identification, and diagnostic criteria. Multiple studies have shown improved prognosis for patients diagnosed early.

Pubertal height velocity and associations with prepubertal and adult heights in cystic fibrosis

OBJECTIVES

To test the hypothesis that pubertal peak height velocity (PHV) in cystic fibrosis (CF) has improved and is influenced by prepubertal growth and genetic potential.

STUDY DESIGN

PHV from 1862 children born in 1984-87 and documented in the 1986-2008 US CF Foundation Registry was determined by statistical modeling and classified into normal, delayed (2-SD > average age), attenuated (magnitude <5th percentile), or both delayed and attenuated (D&A). Genetic potential for height was estimated by parental stature.

RESULTS

PHV averaged 8.4 cm/year at age 14.0 years in boys and 7.0 cm/year at age 12.1 years in girls, ∼6-month delay and ∼15% reduction compared with healthy children. PHV was normal in 60%, delayed in 9%, attenuated in 21%, and D&A in 5%. Patients with delayed PHV reached similar adult height percentile (boys: 34th, girls: 46th) to those with normal PHV (boys: 33rd, girls: 34th); both were significantly taller than the attenuated (boys: 11th, girls: 19th) and D&A PHV subgroups (boys: 8th, girls: 14th). Pancreatic-sufficient patients had taller prepubertal and adult heights but similar PHV compared with pancreatic-insufficient or meconium ileus patients. Adjusting for genetic potential reduced adult height percentiles more in boys (from 25th to 16th) than girls (from 28th to 24th). Height at age 7 years, PHV age and magnitude, and parental stature significantly predicted adult height.

CONCLUSIONS

Pubertal PHV has improved in children with CF born after mid-1980s compared with older cohorts but remains below normal. Suboptimal prepubertal and pubertal growth led to adult height below genetic potential in CF.

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

BACKGROUND

Cystic fibrosis is an inherited condition causing disease most noticeably in the lungs, digestive tract and pancreas. People with cystic fibrosis often have malnutrition and growth delay. Adequate nutritional supplementation does not improve growth optimally and hence an anabolic agent, recombinant growth hormone, has been proposed as a potential intervention.

OBJECTIVES

To evaluate the effectiveness and safety of recombinant human growth hormone therapy in improving lung function, quality of life and clinical status of children and young adults with cystic fibrosis.

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: 15 May 2013.We conducted a search of relevant endocrine journals and proceedings of the Endocrinology Society meetings using Scopus and Proceedings First. Date of latest search: 15 March 2012.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of all preparations of recombinant growth hormone 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 cystic fibrosis (by sweat test or genetic testing).

DATA COLLECTION AND ANALYSIS

Two authors independently screened papers, extracted trial details and assessed their risk of bias.

MAIN RESULTS

Four controlled trials were included in this review (with 161 participants in total), each with an unclear risk of bias. Analysis of data obtained from these trials shows improvement in height for all comparisons, but improvements in weight and lean tissue mass were only reported in the comparison of standard dose recombinant growth hormone versus no treatment. There is moderate improvement in one parameter of pulmonary function tests, functional vital capacity (per cent predicted) when comparing standard dose recombinant growth hormone and no treatment. Little evidence was found for improvement in quality of life. An improvement in fasting blood glucose levels was reported when comparing rhGH to placebo only. Exercise capacity improved in participants receiving standard dose recombinant growth hormone versus no treatment, but not for any other comparison. There is insufficient evidence to conclude any changes in hospitalisations, antibiotic use or significant adverse effects.

AUTHORS' CONCLUSIONS

Recombinant growth hormone therapy is effective in improving the intermediate outcomes in height, weight and lean tissue mass when compared with no treatment. One measure of pulmonary function test showed moderate improvement. No significant changes in quality of life, clinical status or side-effects were observed in this review. Long-term, well-designed randomised controlled trials of recombinant growth hormone therapy in patients with cystic fibrosis are required prior to evaluation of human growth hormone treatment for routine use in patients.

Better nutritional status in early childhood is associated with improved clinical outcomes and survival in patients with cystic fibrosis

OBJECTIVES

To evaluate the relationship between nutritional status early in life and the timing and velocity of height growth, lung function, complications of cystic fibrosis, and survival.

STUDY DESIGN

Prospective, observational study using data from the Cystic Fibrosis Foundation Registry (US) for patients born between 1989 and 1992 (n = 3142).

RESULTS

Weight-for-age percentile (WAP) at 4 years of age was positively associated with height-for-age percentiles throughout childhood. Age 4 years WAP >10% was associated with better lung function from 6-18 years of age. In boys and girls with current WAP >50%, peak pubertal height velocities approximated but remained lower than that of the healthy reference population. By age 18 years, patients with an age 4 years WAP >50% suffered fewer acute pulmonary exacerbations, spent fewer days in the hospital, and had lower rates of impaired glucose tolerance or diabetes. Patients attaining higher age 4 years WAP and height-for-age percentiles had a survival advantage throughout childhood.

CONCLUSION

For the population studied, greater weight at age 4 years is associated with greater height, better pulmonary function, fewer complications of cystic fibrosis, and better survival through age 18 years. Furthermore, greater weight-for-age in the peripubertal period is associated on average with improved tempo and timing of pubertal height growth.

Growth retardation and reduced growth hormone secretion in cystic fibrosis. Clinical observations from three CF centers

OBJECTIVE

Growth delay in cystic fibrosis is frequent and is usually the result of several interacting causes. It most often derives from severe respiratory impairment and severe malabsorption. There are however patients whose clinical condition is not severe enough to be held accountable for this phenomenon. We aimed at describing patients who showed growth delay, who were not affected by severe pulmonary disease or malabsorption and who, when tested, showed a reduced GH secretion after stimulation with conventional agents. We noticed a disproportionately large prevalence of growth hormone (GH) release deficit (GHRD) in pediatric cystic fibrosis (CF) patients.

PATIENTS AND METHODS

We examined all patients under our care in the period 2006-11, who were older than 5 and younger than 16 years old. We focussed on those who fell below the 3rd height percentile, or whose growth during the previous 18 months faltered by >2SD, and who did not present clinical conditions that could reasonably explain their failure to thrive. These patients were subjected to standard GH provocative tests.

RESULTS

Out of 285 who matched the age criterion, 33 patients also matched the height percentile criterion. While 15/33 suffered clinical conditions that could reasonably explain their failure to thrive, 18/33 underwent GH release provocative tests and 12/18 showed a release deficit.

CONCLUSIONS

We conclude that impaired GH secretion is more frequent among CF patients compared to the prevalence of GH deficiency in the general population and that GH release impairment may be an independent cause of growth delay in CF. Our findings are in agreement with recent studies that have described low GH levels in CF piglets and in neonates with CF [1].

A multi-center controlled trial of growth hormone treatment in children with cystic fibrosis

OBJECTIVES

We evaluated safety and efficacy of recombinant human growth hormone (rhGH) for improving growth, lean body mass (LBM), pulmonary function, and exercise tolerance in children with cystic fibrosis (CF) and growth restriction.

STUDY DESIGN

Multicenter, open-label, controlled clinical trial comparing outcomes in prepubertal children <14 years with CF, randomized in a 1:1 ratio to receive daily rhGH (Nutropin AQ) or no treatment (control) for 12 months, followed by a 6-month observation (month 18). Safety was monitored at each visit, including assessments of glucose tolerance.

RESULTS

Sixty-eight subjects were randomized (control n = 32; rhGH n = 36). Mean height standard deviation score (SDS) in the rhGH group increased by 0.5 ± 0.4 at 12 months (mean ± SD, P < 0.001); the control group height SDS remained unchanged. Weight increased by 3.8 ± 1.8 versus 2.8 ± 1.5 kg, (mean ± SD, P = 0.0356) and LBM increased by 3.8 ± 1.8 versus 2.1 ± 1.4 kg (P = 0.0002) in the rhGH group versus controls, respectively. Forced vital capacity increased by 325 ± 319 in the rhGH group compared with 178 ± 152 ml in controls (mean ± SD, P = 0.032). Forced expiratory volume in 1 sec improved in both groups with a significant difference between groups after adjustment for baseline severity (LS mean ± SE: rhGH, 224 ± 37, vs. controls, 108 ± 40 ml; P = 0.04). There was no difference between groups in exercise tolerance (6-min walk distance) at 1 year. Changes in glucose tolerance for the two groups were similar over the 12-month study period, with three subjects developing IGT and one CFRD in each group. One rhGH-treated patient developed increased intracranial pressure.

CONCLUSIONS

Treatment with rhGH in prepubertal children with CF was effective in promoting growth, weight, LBM, lung volume, and lung flows, and had an acceptable safety profile.

CREON (Pancrelipase Delayed-Release Capsules) for the treatment of exocrine pancreatic insufficiency

Exocrine pancreatic insufficiency (EPI) is associated with conditions including cystic fibrosis (CF), chronic pancreatitis (CP), and pancreatic surgery (PS). The symptoms include maldigestion, malnutrition, weight loss, flatulence, and steatorrhea. Pancreatic enzyme replacement therapy (PERT) is the standard treatment for EPI; it is regulated in many countries and most recently in the USA following a US FDA mandate for all PERT manufacturers to submit new drug applications. Pancrelipase delayed-release capsules (CREON®, Abbott, Marietta, GA, USA) have been available in Europe since 1984 and in the USA since 1987; a new formulation was the first PERT to gain approval in the USA in 2009. The efficacy and safety of CREON have been demonstrated in double-blind, randomized, placebo-controlled trials in patients with CF aged ≥7 years and in patients with CP or post-PS. The data consistently demonstrate significantly better fat and nitrogen absorption with CREON versus placebo, and improvements in clinical symptoms, stool frequency, and body weight. Additionally, efficacy and safety of CREON have been shown in open-label studies in young children with CF (aged 1 month to 6 years), with control of fat malabsorption and control of clinical symptoms. The most commonly reported adverse events (AEs) with PERT are gastrointestinal disorders and allergic skin reactions. In clinical studies, CREON was well tolerated with very few withdrawals due to AEs and a low frequency of AEs judged treatment related, regardless of patient age. To further support the known safety profile of PERT, all manufacturers are required to investigate risk factors for fibrosing colonopathy, a rare gastrointestinal complication of CF, and the theoretical risk of viral transmission from porcine-derived PERT products. Together, the clinical study data and wealth of clinical experience suggest that CREON is effective and safe in patients with EPI regardless of etiology, with a very favorable risk-benefit profile.

Nutritional considerations in patients with cystic fibrosis

Nutritional status is strongly associated with pulmonary function and survival in cystic fibrosis patients. Attainment of a normal growth pattern in childhood and maintenance of adequate nutritional status in adulthood represent major goals of multidisciplinary cystic fibrosis centers. International guidelines on energy intake requirements, pancreatic enzyme-replacement therapy and fat-soluble vitamin supplementation are of utmost importance in daily practice. The present review summarizes the most up-to-date information on early nutritional management in newly diagnosed patients and evaluates the benefits of aggressive nutritional support, assessment of nutritional status, recommendations for nutrition-related management in pancreatic-insufficient patients and the possible therapeutic impact of fat intake modulation upon inflammatory status.

Growth in children with cystic fibrosis-related diabetes

Cystic fibrosis-related diabetes (CFRD) is associated with a shortened life expectancy and greater deterioration in lung function than in CF patients with normal glucose metabolism. There are few published data on how CFRD affects growth in childhood. We carried out a retrospective case controlled study of growth and lung function in 34 children with CFRD attending three specialist centers in London. We found that for the 2 years leading to CFRD diagnosis (at a mean age of 13.1 years), the mean height velocity was significantly less compared to controls: 4.9 (standard deviation-SD 1.6) cm/year vs. 6.0 (SD 1.9) cm/year (P = 0.005). For the 2 years following diagnosis, height velocity remained significantly lower (3.4 (SD 2.2) cm/year vs. 4.4 (SD 2.2) cm/year, P = 0.02). Mean FEV(1) was reduced prior to diagnosis and at diagnosis, but was similar to controls 2 years after diagnosis. This study highlights the compromise in height velocity and lung function that occurs prior to diagnosis of CFRD in children with CF, and a reduction in height velocity should be considered an indicator of impaired glucose metabolism. It would be useful to know whether early treatment with insulin can help promote catch up growth.