Delayed puberty in girls with cystic fibrosis despite good clinical status

Factors associated with pubertal growth outcomes in cystic fibrosis: Early Growth and Puberty in CF

BACKGROUND

Pubertal delays in children with cystic fibrosis (CF) have historically been common. It is unclear to what degree puberty is affected in the new era of CF care or the role of early nutritional status. We hypothesized that more favorable early growth trajectories are associated with improved pubertal growth outcomes.

METHODS

We used data from the United States CF Foundation Patient Registry to analyze associations between early weight-for-length/body mass index (WFL-BMI) growth trajectories and pubertal outcomes, using peak height velocity (PHV) and age at PHV (APHV) as proxy measures for puberty in addition to adult height (defined as height at age 18 years). Our analysis consisted of shape invariant mixed modeling and multivariable linear regression.

RESULTS

Our sample consisted of 9,186 people with CF aged 18 to 21 years between 2010-2019. APHV was earliest and PHV/adult height were highest in those with WFL-BMI always >50th percentile from 0-6 years. However, there was no difference after adjusting for key covariates. Receiving CF transmembrane conductance regulator (CFTR) modulator therapy in childhood was associated with being taller at 18 years, by 0.92 cm in males (p=0.048) and 1.02 cm in females (p=0.010) in adjusted models. Higher height z-score at 2 years was associated with improved APHV and PHV for males and improved adult height for both males and females (p<0.001) in adjusted models.

CONCLUSIONS

Early height, but not early WFL-BMI trajectories, may be associated with pubertal growth outcomes. CFTR modulator therapy shows the potential to improve pubertal growth outcomes, but further research is necessary.

Auxological and Endocrinological Features in Children and Adolescents with Cystic Fibrosis

Cystic fibrosis (CF) is a multisystem autosomal recessive disease caused by mutations that lead to deficient or dysfunctional CF transmembrane conductance regulator (CFTR) proteins. Patients typically present malnutrition resulting from the malabsorption of fundamental nutrients and recurring lung infections, with a progressive worsening of the respiratory function. For these reasons, the clinical management of CF requires a multidisciplinary team. From an endocrinological point of view, patients often present major complications, such as diabetes, bone disease, thyroid disorders, delayed growth and puberty, hypogonadism and infertility, which negatively affect their quality of life and, in some cases, significantly reduce life expectancy. These complications can arise as a direct result of CFTR dysfunction and/or as a consequence of a deterioration in the function of the organs affected. The objective of this review is to analyze all the possible endocrinological complications that can occur in patients with CF by evaluating the most recent papers in the literature.

Optimizing sexual and reproductive health across the lifespan in people with cystic fibrosis

With improved therapies, people with cystic fibrosis are living longer and healthier lives and increasingly have questions surrounding their sexual and reproductive health. This article will summarize the important issues of which providers should be aware during the lifespan of people with cystic fibrosis, including puberty, adulthood, and menopause. A wide range of sexual and reproductive health topics are addressed such as puberty, transgender and gender nonbinary identities, contraception, sexually transmitted infections, hypogonadism, sexual functioning, cyclical hemoptysis, and urinary incontinence. We discuss gaps in knowledge and current evidence as well as management strategies to optimize care. Our goal is to support providers to enable them to give comprehensive care throughout the lifespan of people with cystic fibrosis.

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.

The Prognosis of ART Is Not Altered in Cystic Fibrosis Women: A Case-Report Study

RESEARCH QUESTION

Unlike in men, a very limited number of studies were focused on the specificity of ART management of cystic fibrosis (CF) in women. The purpose of this study was to determine the causes of infertility in patients, the appropriate ART treatment, and their prognosis in terms of pregnancy.

DESIGN

We conducted a multicentre analytical case-control study including CF women who were age-matched to non-CF women. We reported the causes of infertility, the ART management type and pregnancy outcomes.

RESULTS

17 cases were compared to 34 controls. There was no significant difference between the groups concerning cause infertility. There was a non-statistically significant trend with a lower antral follicle count in CF compared to controls (19.5 versus 26.8, p=0.08). IUI seemed to be as successful as IVF/ICSI in CF as opposed to controls where the IVF/ICSI was the most effective (in CF group for HCG >100 UI/L: 38.8% vs. 36.8%, p=0.4175). There were more embryos obtained in CF than in controls (3.1 versus 1.6, p=0.02). The number of oocytes and embryos obtained and pregnancy outcomes remained similar between DF508 homozygous group and others CFTR mutations group. The results of ART procedures and pregnancy evolution were not influenced by FEV1.

CONCLUSION

In absence of any other pathology, IUI may be first option for CF women. If insemination fails, IVF with a low dose of gonadotropins may be more appropriate to prevent the risk of hyperstimulation syndrome. FEV1 and genetic do not seem to be contributing factors in the prognosis of ART.

Gynecologic health care for females with cystic fibrosis

•

Females with CF may have cyclic lung symptoms, yeast infections, and urinary incontinence.

•

Contraception is safe, but comorbidities should be considered in method selection.

•

Females with CF have reduced fertility, though the etiology is unknown.

•

Females with CF underutilize basic preventive gynecologic services.

As females with cystic fibrosis (CF) increasingly reach their reproductive years, gynecologic issues have become an important area of clinical care and research. First, females with CF may have disease-specific gynecologic problems, including cyclic pulmonary symptoms, vaginal yeast infections, and urinary incontinence. Next, contraceptive methods are thought to be overall safe and effective, however further research is needed to confirm this and to understand the lower rates of uptake among females with CF compared to the general population. Further, females with CF have reduced fertility, although the etiology of this is unknown and under investigation. While assisted reproductive technologies may help achieve pregnancy, decision-making around parenthood remains complex. Finally, while patients and providers agree on the importance of sexual and reproductive health care, females with CF underutilize basic preventive services such as cervical cancer screening, and better approaches are needed to bridge the gap with gynecology. In this review, we discuss the current state of gynecologic care for females with CF, as well as clinical and research opportunities for improvement.

Ultrasound findings of pubertal development in girls with cystic fibrosis and their association with clinical outcomes and Tanner staging

OBJECTIVE

Patients with cystic fibrosis (CF) have a high incidence of pubertal and growth delay. In girls with CF, pubertal delay has an important psychological impact. Still, only a few studies have explored the occurrence of pubertal delay in girls with CF. The aims of this study were to compare the pubertal development of girls with CF compared with healthy controls regarding Tanner staging and pelvic ultrasound and, in girls with CF, correlate the findings with those of spirometry, body mass index, Shwachman-Kulczycki score (SKS), and genotyping.

METHODS

This was a cross-sectional, case-control study including 35 girls with CF aged 6-17 years and following up at the Pediatric Pulmonology Outpatient Clinic of a tertiary hospital. These patients were compared with 59 healthy controls who had undergone pelvic ultrasound as part of another study conducted by the same group. Girls with CF were consecutively enrolled in the study during their annual routine check-up visit. Data collected in the CF group included spirometry and anthropometric results, SKS values, bone age, occurrence of current cystic fibrosis-related diabetes (CFRD) and Pseudomonas aeruginosa colonization, history of meconium ileus, genotype, ultrasound parameters, and Tanner stage.

RESULTS

Pelvic ultrasound findings and Tanner stage reflected less pubertal development in girls with CF compared with healthy controls. Pubertal stage in patients with CF who presented CFRD (3.17 ± 1.16), had chronic colonization by Pseudomonas aeruginosa (3.10 ± 1.10), or were homozygous for the F508del mutation (1.91 ± 1.30) was more delayed than in controls (3.41 ± 1.41). Tanner stage correlated with age at menarche, bone age, and anthropometric and ultrasound data.

CONCLUSION

Girls with CF presented a delay in pubertal development evaluated by Tanner stage and ultrasound parameters, which was more evident in the presence of comorbidities.

Challenges Faced by Women with Cystic Fibrosis

Women with cystic fibrosis (CF) face several unaddressed concerns related to their health. These areas of concern include explanations and guidance on a sex disparity in outcomes, timing of puberty, effects of contraception, prevalence of infertility and impact of pregnancy, and prevention of urinary incontinence and osteoporosis. These understudied topics leave women with numerous unanswered questions about how to manage sexual and reproductive health in the setting of CF. Because people with CF are living longer and healthier lives, there is an increasing awareness of these important aspects of care and multiple ongoing studies to address these understudied topics.

Delayed age at menarche in chronic respiratory diseases

OBJECTIVE

Age at menarche (AAM) is an important indicator of physiological development in women, and delayed AAM has been associated with chronic illnesses. We investigated predictive factors at diagnosis that influence AAM in adolescents with chronic respiratory diseases.

STUDY DESIGN

AAM was assessed in 1207 northern Italian female aged 11-24 (1062 healthy, 98 with asthma and 47 with cystic fibrosis [CF]). AAM was defined by recall and status quo methods. We studied anthropometric data, metabolic status, diagnosis parameters, presence of irregular menses. Clinical data of subjects with chronic respiratory illness were compared with that of healthy adolescents.

RESULTS

Mean AAM for healthy adolescents was 12.49 ± 1.2 years. Mother's AAM was positively associated with that of their daughters (P < .001). BMI was negatively correlated with AAM (P < .001). 69% of healthy adolescents referred regular menses. AAM in the different groups was 12.79 ± 3.0 years for patients with asthma (P < .05 vs healthy) and 13.24 ± 1.44 years for adolescents with CF (P < .0001 vs healthy). In the asthmatic group, 57% of the patients referred regular menses, and no significant differences were found between AAM and control of the disease (ACT test). In the CF group, no correlation was found between the type of CFTR mutation or FEV1% and AAM. 53% of the patients with CF referred regular menses.

CONCLUSIONS

AAM in patients with CF and asthma was significantly higher than in healthy adolescents, and menses abnormalities were observed in the last two groups. Inflammation influences the reproductive function in chronic respiratory disease.

Prevention of osteoporosis in cystic fibrosis

PURPOSE OF REVIEW

The increased life span of patients with cystic fibrosis has lead to the detection of new complications. Osteopenia is present in up to 50% of adult patients with cystic fibrosis, and osteoporosis in 10-34% and can cause a difficult management problem.

RECENT FINDINGS

In children, defects in bone health become apparent generally at adolescence because of suboptimall bone peak mass achievement. Malnutrition, inflammation, vitamin D and vitamin K deficiency, altered sex hormone production, glucocorticoid therapy, and physical inactivity potentiate poor bone health.

SUMMARY

Monitoring bone mineral density and preventive care of osteoporosis are necessary from childhood to minimize cystic fibrosis-related bone disease in adult cystic fibrosis patients.

Oral ethinyl estradiol treatment in women with cystic fibrosis is associated with lower bone mineral density

Objective

The purpose of this study was to determine whether estrogen supplementation primarily from oral contraceptive pills compared to no estrogen supplementation is associated with differences in mean bone mineral density (BMD) measured by DXA in a cross-sectional study of women with cystic fibrosis (CF).

Methods

In this cross-sectional study of women with CF followed at a single center, we analyzed 49 women with CF ages 18–50 years with a documented DXA. BMD of women with CF taking estrogen supplementation was compared to BMD of women with CF not taking estrogen supplementation.

Results

Twelve women with CF were taking estrogen supplementation with mean dose of 23.3 mcg/day (SD 6.9 mcg/day) of ethinyl estradiol. There were no statistically significant differences between demographics of the 12 women with CF taking estrogen supplementation compared to the 37 women with CF not taking estrogen supplementation. Women taking estrogen had lower mean lumbar spine Z-score: −0.7 ± 0.7, compared to women not taking estrogen, Z-score: −0.04 ± 1.0 (p-value 0.046). Women taking estrogen had lower mean BMD at the lumbar spine: 0.952 ± 0.086 g/cm², compared to women not taking estrogen: 1.023 ± 0.105 g/cm² (p-value 0.038). Similar trends were seen at the total hip and femoral neck.

Conclusion

Low-dose estrogen supplementation in premenopausal women with CF was associated with lower BMD compared to no estrogen supplementation in a similar group of premenopausal young women with CF. Future studies are needed to investigate the optimal formulation, route of administration, and dose to accrue and preserve bone mass in premenopausal women with CF.

Exercise Physiology Across the Lifespan in Cystic Fibrosis

Cystic fibrosis (CF), a severe life-limiting disease, is associated with multi-organ pathologies that contribute to a reduced exercise capacity. At present, the impact of, and interaction between, disease progression and other age-related physiological changes in CF on exercise capacity from child- to adult-hood is poorly understood. Indeed, the influences of disease progression and aging are inherently linked, leading to increasingly complex interactions. Thus, when interpreting age-related differences in exercise tolerance and devising exercise-based therapies for those with CF, it is critical to consider age-specific factors. Specifically, changes in lung function, chronic airway colonization by increasingly pathogenic and drug-resistant bacteria, the frequency and severity of pulmonary exacerbations, endocrine comorbidities, nutrition-related factors, and CFTR (cystic fibrosis transmembrane conductance regulator protein) modulator therapy, duration, and age of onset are important to consider. Accounting for how these factors ultimately influence the ability to exercise is central to understanding exercise impairments in individuals with CF, especially as the expected lifespan with CF continues to increase with advancements in therapies. Further studies are required that account for these factors and the changing landscape of CF in order to better understand how the evolution of CF disease impacts exercise (in)tolerance across the lifespan and thereby identify appropriate intervention targets and strategies.

Delayed Puberty-Phenotypic Diversity, Molecular Genetic Mechanisms, and Recent Discoveries

This review presents a comprehensive discussion of the clinical condition of delayed puberty, a common presentation to the pediatric endocrinologist, which may present both diagnostic and prognostic challenges. Our understanding of the genetic control of pubertal timing has advanced thanks to active investigation in this field over the last two decades, but it remains in large part a fascinating and mysterious conundrum. The phenotype of delayed puberty is associated with adult health risks and common etiologies, and there is evidence for polygenic control of pubertal timing in the general population, sex-specificity, and epigenetic modulation. Moreover, much has been learned from comprehension of monogenic and digenic etiologies of pubertal delay and associated disorders and, in recent years, knowledge of oligogenic inheritance in conditions of GnRH deficiency. Recently there have been several novel discoveries in the field of self-limited delayed puberty, encompassing exciting developments linking this condition to both GnRH neuronal biology and metabolism and body mass. These data together highlight the fascinating heterogeneity of disorders underlying this phenotype and point to areas of future research where impactful developments can be made.

Inspiration for the Future: The Role of Inspiratory Muscle Training in Cystic Fibrosis

Cystic fibrosis (CF) is an inherited, multi-system, life-limiting disease characterized by a progressive decline in lung function, which accounts for the majority of CF-related morbidity and mortality. Inspiratory muscle training (IMT) has been proposed as a rehabilitative strategy to treat respiratory impairments associated with CF. However, despite evidence of therapeutic benefits in healthy and other clinical populations, the routine application of IMT in CF can neither be supported nor refuted due to the paucity of methodologically rigorous research. Specifically, the interpretation of available studies regarding the efficacy of IMT in CF is hampered by methodological threats to internal and external validity. As such, it is important to highlight the inherent risk of bias that differences in patient characteristics, IMT protocols, and outcome measurements present when synthesizing this literature prior to making final clinical judgments. Future studies are required to identify the characteristics of individuals who may respond to IMT and determine whether the controlled application of IMT can elicit meaningful improvements in physiological and patient-centered clinical outcomes. Given the equivocal evidence regarding its efficacy, IMT should be utilized on a case-by-case basis with sound clinical reasoning, rather than simply dismissed, until a rigorous evidence-based consensus has been reached.

Pubertal abnormalities in adolescents with chronic disease

Pubertal disorders in the context of chronic disease especially in those with chronic inflammatory disorders or those requiring prolonged periods of treatment with glucocorticoid are common reasons for referral to the paediatric endocrine clinic. Disorders of puberty are also common in adolescents with disability requiring management by paediatric endocrinologists. In these adolescents, impaired skeletal development is also observed and this can be associated with fragility fractures. Chronic inflammation, glucocorticoid and sub-optimal nutrition all impact on the hypothalamic-pituitary gonadal axis, and can also impact on skeletal development locally by their effects on the growth plate and bone. Addressing pubertal disorders is important to ensure adolescents with chronic disease are matched with their peers, promote adequate bone mass accrual and linear growth. Careful discussion with primary clinicians, the young person and the family is needed when instituting endocrine therapies to address puberty and manage bone health.

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.

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.

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.

Diagnosis and treatment of endocrine comorbidities in patients with cystic fibrosis

PURPOSE OF REVIEW

The aim of this review is to provide an update on various relevant endocrine aspects of care in adolescents and adults with cystic fibrosis.

RECENT FINDINGS

As life expectancy in cystic fibrosis has continuously improved, endocrine complications have become more apparent. The common endocrine complications include cystic fibrosis related diabetes, cystic fibrosis related bone disease, vitamin D deficiency and poor growth and pubertal development. Thyroid and adrenal disorders have also been reported, although the prevalence appears to be less common.

SUMMARY

Endocrine diseases are an increasingly recognized complication that has a significant impact on the overall health of individuals with cystic fibrosis. This review summarizes the updated screening and management of endocrine diseases in the cystic fibrosis population.

Effects of puberty on cystic fibrosis related pulmonary exacerbations in women versus men

BACKGROUND

Epidemiologic data from studies of airway diseases, such as asthma, chronic obstructive pulmonary disease, and cystic fibrosis indicate a gender disparity where women have worse outcomes. The explanation for this is largely unknown. We hypothesize that female sex hormones play a role in this gender disparity, predisposing women to more exacerbations and decreased lung function post-puberty.

OBJECTIVE

In Cystic Fibrosis, to determine if puberty marks a point of increasing exacerbations and decreasing lung function in women relative to men.

METHODS

Using the United States Cystic Fibrosis Foundation Patient Registry, we used linear regression to compare lung function and rate of pulmonary exacerbations in men versus women before and after puberty.

RESULTS

Of 5,137 subjects who met inclusion criteria, 2,689 were male and 2,448 were female. Average age of puberty was found to be 13.2 ± 2.2 years in men and 11.2 ± 2.0 years of age in women. Percent predicted FEV1 pre- and post-puberty were no different between males versus females (P = 0.44 pre-puberty and P = 0.16 post-puberty). In contrast, women had a significantly higher rate of pulmonary exacerbations post-puberty than men (1.17 ± 1.35 exacerbations per year in women versus 0.95 ± 1.27 in men; P < 0.001) despite controlling for morphometrics, co-morbidities, and microbiologic variables.

CONCLUSION

After puberty, the rate of pulmonary exacerbations increased in adolescent women relative to men with cystic fibrosis, supporting a role for sex hormones in the disease process. Further understanding of the mechanisms that modulate sex hormone receptors in airway disease may serve as future targets for therapy.

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.

Menarche in pediatric patients with Crohn's disease

BACKGROUND AND AIMS

The timing of menarche in Crohn's disease (CD) is poorly described. Our objectives were to study age at menarche onset in CD, and factors associated with this.

METHODS

We compared the age at menarche of 34 CD patients with that for 545 controls, using data in the National Health and Nutrition Examination Survey (NHANES).

RESULTS

Mean chronological age (CA) of CD patients (15.6 years) did not differ from that of the NHANES cohort (15.7 years; P = 0.91). The median CA at menarche (13.9 years) in CD was older than in the NHANES sample (12.0 years) (P < 0.00005). In CD patients, the cumulative incidence of menarche was 10 % at CA 12 years, 51 % at CA 14 years, and 100 % at CA 16 years. Sixty-eight percent reached menarche by bone age (BA) 13.5 years and 100 % by BA greater than 14.0 years. Menarche occurred earliest in South Asians, followed by East Asians, and then Caucasians (P = 0.02).

CONCLUSIONS

CA at menarche is delayed in CD compared with the NHANES cohort. BA at menarche in CD is similar to BA at menarche reported for healthy children. CA at menarche in CD differs by race. If menarche has not occurred by BA greater than 14.0 years, endocrinology referral should be considered.

[Endocrine complications of cystic fibrosis in childhood]

Since the 20 last years, the median age of survival has dramatically improved in children suffering from cystic fibrosis and complications such as growth retardation, pubertal delay and low bone mineral density are now more often than not observed in affected adolescents. The severity of the disease and the poor nutritional status due to pancreatic insufficiency and malabsorption are commonly implicated but recent data suggest that the disease could also play a role though the alteration of the chlore chanel (CFTR). Furthermore an increase prevalence of glucose intolerance and diabetes due to the progressive β cells destruction is observed in these children that make the life sometimes difficult for these adolescents already affected by an heavy chronic disease. The monitoring of the children should thus now become pluridisciplinary and include regular clinical evaluation of height and pubertal status, mineral bone density by DEXA and OGTT every two years since 10 years of age. Therefore, in addition to the standard treatment of cystic fibrosis is now added the vitamin D supplementation, the subcutaneous insulin therapy and may be the growth hormone that could be a new therapeutic demonstrating beneficial effects in these chronic disease. However further studies need to be performed to improve the management of these new endocrine complications more and more frequent in children and adolescents suffering from cystic fibrosis.

Impaired CFTR-dependent amplification of FSH-stimulated estrogen production in cystic fibrosis and PCOS

CONTEXT

Estrogens play important roles in a wide range of physiological and pathological processes, and their biosynthesis is profoundly influenced by FSH that regulates the rate-limiting enzyme aromatase-converting estrogens from androgens. Abnormal estrogen levels are often seen in diseases such as ovarian disorders in polycystic ovarian syndrome (PCOS), an endocrine disorder affecting 5-10% of women of reproductive age, and cystic fibrosis (CF), a common genetic disease caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR).

OBJECTIVES

We undertook the present study to investigate the mechanism underlying these ovarian disorders, which is not well understood.

RESULTS

FSH-stimulated cAMP-responsive element binding protein phosphorylation, aromatase expression, and estradiol production are found to be enhanced by HCO3- and a HCO3- sensor, the soluble adenylyl cyclase, which could be significantly reduced by CFTR inhibition or in ovaries or granulosa cells of cftr knockout/ΔF508 mutant mice. CFTR expression is found positively correlated with aromatase expression in human granulosa cells, supporting its role in regulating estrogen production in humans. Reduced CFTR and aromatase expression is also found in PCOS rodent models and human patients.

CONCLUSIONS

CFTR regulates ovarian estrogen biosynthesis by amplifying the FSH-stimulated signal via the nuclear soluble adenylyl cyclase. The present findings suggest that defective CFTR-dependent regulation of estrogen production may underlie the ovarian disorders seen in CF and PCOS.

Cystic fibrosis growth retardation is not correlated with loss of Cftr in the intestinal epithelium

Maldigestion due to exocrine pancreatic insufficiency leads to intestinal malabsorption and consequent malnutrition, a mechanism proposed to cause growth retardation associated with cystic fibrosis (CF). However, although enzyme replacement therapy combined with increased caloric intake improves weight gain, the effect on stature is not significant, suggesting that growth retardation has a more complex etiology. Mouse models of CF support this, since these animals do not experience exocrine pancreatic insufficiency yet are growth impaired. Cftr absence from the intestinal epithelium has been suggested as a primary source of growth retardation in CF mice, a concept we directly tested by generating mouse models with Cftr selectively inactivated or restored in intestinal epithelium. The relationship between growth and functional characteristics of the intestines, including transepithelial electrophysiology, incidence of intestinal obstruction, and histopathology, were assessed. Absence of Cftr exclusively from intestinal epithelium resulted in loss of cAMP-stimulated short-circuit current, goblet cell hyperplasia, and occurrence of intestinal obstructions but only slight and transient impaired growth. In contrast, specifically restoring Cftr to the intestinal epithelium resulted in restoration of ion transport and completely protected against obstruction and histopathological anomalies, but growth was indistinguishable from CF mice. These results indicate that absence of Cftr in the intestinal epithelium is an important contributor to the intestinal obstruction phenotype in CF but does not correlate with the observed growth reduction in CF.

Cystic fibrosis Δf508 mutation screening in Brazilian women with altered fertility

Cystic Fibrosis (CF) is an autosomal recessive disease, caused by mutations in the Cystic Fibrosis Transmembrane Regulator gene (CFTR). The most frequent mutation in CF is ΔF508. The disease is clinically characterized by elevated concentrations of sweat chlorides and abnormally thick mucus. It affects organs such as lung, pancreas, gastrointestinal and reproductive tract. Women with CF commonly present delayed puberty and amenorrhea due to malnutrition. Our objective was to screen the presence of ΔF508 mutation in 24 women with altered fertility. Nine of these women presented reduced fertility without a known cause, four showed polycystic ovaries and two had early menopause. One woman with early menopause was a carrier of the ΔF508 mutation. Our study demonstrates that it is possible that the frequency of CF mutations among patients with altered fertility may be higher than expected. Previous data showed that fibrocystic women can show reduced fertility, maternal mortality associated with pregnancy and increased incidence of spontaneous abortion. We therefore recommend that women with reduced fertility undertake genetic tests for a better evaluation of pregnancy risks and clinical monitoring.

Contraception, communication and counseling for sexuality and reproductive health in adolescents and young adults with CF

With survival now into the fourth decade and rapid growth of the adolescent and adult population of people with cystic fibrosis CF sexual and reproductive health issues are integral to the management of adolescents and adults with CF. Education and counseling for sexual health related issues must be included in the daily routine of CF care. With advances in genetic counseling, contraception, assisted reproductive technology and collaborative management adolescents and young adults with CF realizing their sexual and reproductive potentials safely and realistically can be possible .

CYSTIC FIBROSIS – A GUIDE FOR CLINICIANS IN REPRODUCTIVE AND OBSTETRIC MEDICINE

Cystic Fibrosis (CF) is the most common life-shortening recessive genetic disease in the UK. Far from being a condition managed exclusively by paediatricians with sufferers dying in early childhood, CF is now a condition in which adults outnumber children with the condition, and the death of a child in a paediatric centre is rare. As increasing numbers of young people grow up relatively healthy it is unsurprising they begin to ask about relationships, sex, fertility and the possibility of having a child. This paper briefly describes the genetics, pathophysiology and clinical features of CF with an emphasis on how it pertains to female reproduction. The management of women with CF considering having a baby including contraception, preparation for pregnancy, the pregnancy itself, delivery and the post natal period will be discussed. Contraindications to pregnancy, method of termination, and pregnancy after transplantation will also be considered. Much of the detailed management is given in the European Guidelines for the Management of Pregnancy in Women with CF on which this paper is based.

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.

Update on cystic fibrosis-related bone disease: a special focus on children

A high prevalence of low bone mineralization is documented in adult patients with cystic fibrosis (CF). Osteopenia is present in up to 85% of adult patients and osteoporosis in 10% to 34%. In children, study results are discordant probably because of comparisons to different control populations and corrections for bone size in growing children. Malnutrition, inflammation, vitamin D and vitamin K deficiency, altered sex hormone production, glucocorticoid therapy, and physical inactivity are well known risk factors for poor bone health. Puberty is a critical period for bone mineralization and requires a careful follow-up to achieve optimal bone peak mass. Strategies for optimizing bone health, such as monitoring bone mineral density (BMD) and providing preventive care are necessary from childhood through adolescence to minimize CF-related bone disease in adult CF patients.

Murine model for cystic fibrosis bone disease demonstrates osteopenia and sex-related differences in bone formation

As the incidence of cystic fibrosis (CF) bone disease is increasing, we analyzed CF transmembrane conductance regulator (CFTR) deficient mice (CF mice) to gain pathogenic insights. In these studies comparing adult (14 wk) CF and C57BL/6J mice, both bone length and total area were decreased in CF mice. Metaphyseal trabecular and cortical density were also decreased, as well as diaphyseal cortical and total density. Trabecular bone volume was diminished in CF mice. Female CF mice revealed decreased trabecular width and number compared with C57BL/6J, whereas males demonstrated no difference in trabecular number. Female CF mice had reduced mineralizing surface and bone formation rates. Conversely, male CF mice had increased mineralizing surface, mineral apposition, and bone formation rates compared with C57BL/6J males. Bone formation rate was greater in males compared with female CF mice. Smaller bones with decreased density in CF, despite absent differences in osteoblast and osteoclast surfaces, suggest CF transmembrane conductance regulator influences bone cell activity rather than number. Differences in bone formation rate in CF mice are suggestive of inadequate bone formation in females but increased bone formation in males. This proanabolic observation in male CF mice is consistent with other clinical sex differences in CF.

Cystic fibrosis and estrogens: a perfect storm

Irreversible destruction and widening of the airways due to acquired infections or genetic mutations as well as those of unknown cause are more severe in females. Differences between male and female anatomy, behavior, and hormonal state have been proposed to explain the increased incidence and severity in females with airway disease such as cystic fibrosis (CF); however, a mechanism to explain a sex-related difference has remained elusive. In this issue of the JCI, Coakley et al. report that elevations in the major estrogen hormone in humans--17beta-estradiol--reduce Ca2+-activated Cl- secretion by airway epithelial cells in culture, thereby disrupting ion and water balance (see the related article beginning on page 4025). They measure a similar diminution of nasal epithelial Ca2+-activated Cl- secretion in women with CF during the menstrual cycle phase at which 17beta-estradiol level is at its highest. These data suggest that for about one week of a four-week menstrual cycle, women with CF will have a reduced ability to efficiently clear airway secretions, the buildup of which is a hallmark of CF. The authors suggest that these data warrant the testing of antiestrogen therapy in females with CF and propose an alternative avenue for CF therapeutic development.

Deficits in bone mineral content in children and adolescents with cystic fibrosis are related to height deficits

Despite reports of decreased bone density, children with mild to moderate cystic fibrosis (CF)-associated pulmonary disease do not have increased fracture rates. Short stature and delayed puberty complicate interpretations of bone mineral status in many children with chronic diseases. This study sought to characterize bone mineral content (BMC) in children with CF and determine its relationship to growth, body composition, and disease severity. Dual-energy X-ray absorptiometry measurements of whole body BMC (WB-BMC), spine BMC (Sp-BMC), and lean body mass (LBM) were converted to Z-scores in 82 CF and 322 healthy children. Effects of growth, body composition, and CF-disease characteristics on BMC were determined using linear regression. Children with CF had lower weight, height (HT), BMI, and LBM-Z. Females with CF had lower (p<0.001) WB-BMC-Z (-1.1+/-1.1) and Sp-BMC-Z (-0.9+/-1.1) than controls. Following adjustment for height standard deviation score (HT-Z), deficits were absent. Males with CF had lower (p<0.001) WB-BMC-Z (-1.3+/-0.9) and Sp-BMC-Z (-0.9+/-1.3). Following adjustment for HT-Z, WB-BMC-Z deficits were attenuated and Sp-BMC-Z deficits absent. HT-Z, LBM-Z, and pulmonary function had independent effects on WB-BMC-Z and Sp-BMC-Z. BMC deficits are related to altered body size, reduced LBM, and pulmonary function in children with CF. Interventions targeting improved growth, muscle mass, and pulmonary function may benefit bone health in CF.

Growth and nutritional status in children and adolescents with cystic fibrosis

BACKGROUND

Growth retardation, delayed puberty and malnutrition are frequently observed in children suffering from cystic fibrosis.

AIM

The aim of this study was to estimate growth and nutritional status in children with cystic fibrosis on the basis of body proportions and body mass index.

SUBJECTS AND METHODS

Anthropometric data were collected from the medical histories of 62 patients treated in three cystic fibrosis treatment centers in Poland. Anthropometric parameters were expressed in terms of standard deviations away from age-specific and sex-specific reference means reported for the population of Poland. Two-way analysis of variance was used to determine whether the type of cystic fibrosis transmembrane conductance regulator (CFTR) mutation is correlated with age at the time of diagnosis and with body proportions.

RESULTS

The type of mutation was significantly correlated with height, weight and transverse chest width. Growth retardation was greater in subjects diagnosed before they were 3 years old than in subjects diagnosed later. The children had infantile body proportions. Their legs were short and their trunks were long in comparison to their height. Almost 40% of the subjects suffered from malnourishment.

CONCLUSION

Further study is needed to determine how growth in children with cystic fibrosis is affected by clinical practice and socio-economic factors.

Infertility in females with cystic fibrosis is multifactorial: evidence from mouse models

Infertility is commonly associated with cystic fibrosis (CF). Although infertility in men with CF has been thoroughly investigated, the infertility observed in women with CF has not been well studied. To investigate female infertility associated with CF, we used two independently derived mouse models of CF. Both of these models displayed decreased fertility characterized by a reduction in litter number and litter size. Our findings suggest that much of the reduced fertility in these mice originates from decreased fertilization due to inadequate sperm transport within the female reproductive tract. However, our data indicate that additional reproductive phenotypes in the CF female mice also contribute to the reduced fertility including small ovarian and uterine size, aberrant estrous cycles, and decreased oocyte ovulation rates. These data, along with previous work demonstrating that the gene mutated in CF, the cystic fibrosis transmembrane conductance regulator (CFTR), is normally expressed in tissues vital to reproduction, raises the possibility that CFTR may have a direct effect on fertility. If so, CFTR may also play an important role in normal female fertility within the general population.

Low bone mineral density in young children with cystic fibrosis

RATIONALE

Low bone mineral density (BMD) is a frequent problem for adult patients with cystic fibrosis (CF). Only limited information is available for young patients.

OBJECTIVES

The aim of this study was to evaluate BMD of children with CF younger than 6 years.

METHODS

BMD was measured at the lumbar spine (LS) after adjustment for height, sex, and pubertal status in 25 children with CF younger than 6 years, 53 prepubertal children aged 6 to 10 years, and 36 adolescents aged 11 to 18 years. Nutritional status, body composition, pulmonary disease severity, corticosteroid usage, dietary calcium, caloric intake, and vitamin D status were evaluated as potential correlates of BMD.

MEASUREMENTS AND MAIN RESULTS

The mean LS z score in the youngest group was significantly lower than normal (-0.96; SEM, 0.3). It did not differ significantly from that of children aged 6 to 10 years (-0.91; SEM, 0.2) or adolescents (-1.4; SEM, 0.2). LS z score was positively correlated with fat-free mass in multiple regression analysis. LS z score was less than -1 in 34% of the patients with mild pulmonary disease and normal nutritional status.

CONCLUSIONS

These data suggest that the origin of CF bone disease in early childhood may be independent of nutritional status or disease severity.

Nutritional intake and status in children with cystic fibrosis: does age matter?

OBJECTIVES

To determine whether nutritional intake and status vary with age in children with cystic fibrosis (CF).

METHODS

Case-control study examining differences in nutritional parameters and intakes in 58 children with CF recruited from a regional centre (2000-2001) and 45 controls. Participants were divided into age groups of 5-8 years, 9-12 years and 13-16 years. Weight, height, body mass index and standard deviation scores were recorded. A 4-day food diary (51 CF, 31 controls) was calculated for macronutrients and micronutrients.

RESULTS

Energy intakes (%EAR) increased with age (112%, 115% and 116%, respectively) and were significantly higher in children with CF than controls. Lower weight and growth trends were observed in children ages 5 to 8 years (NS). Weight gain and growth was normal in children with CF ages 9 to 12 years but declined at 13 to 16 years (weight z score -0.85 vs 0.68 P = 0.003, height z score -0.54 vs 0.53 P = 0.002, body mass index z score -0.72 vs 0.41 P = 0.03). Lung function was the most significant predictor of nutritional status at 9 to 12 years (r2 = 0.37, P = 0.006) and 13 to 16 years (r2 = 0.31, P = 0.01), but was not significant in children ages 5 to 8 years.

CONCLUSION

Energy intakes increased with age in children with CF and exceeded that of healthy peers in all age groups. Weight gain and growth equaled that of healthy peers at 9 to 12 years but was suboptimal at 5 to 8 years and dramatically declines at 13 to 16 years. Energy intakes were unable to meet the clinical demands of children in these age groups. Both remain vulnerable and require greater nutritional targeting.

Growth hormone treatment improves growth and clinical status in prepubertal children with cystic fibrosis: results of a multicenter randomized controlled trial

CONTEXT

This multicenter, randomized, controlled, crossover trial of prepubertal children with cystic fibrosis (CF) tests the hypotheses that recombinant human GH (rhGH) treatment 1) improves height, weight, lean mass, and bone content irrespective of baseline measures; 2) improves clinical status and quality of life; and 3) has continued effect after cessation after 1 yr of treatment.

METHODS

Sixty-one prepubertal subjects (<or=25th percentile for height and weight) were randomized into two groups: daily rhGH treatment or no treatment groups for 1 yr. In yr 2, treatments were crossed over. Outcome measures included serial standardized height and weight, number of hospitalizations and antibiotic courses, random blood glucose levels, lean mass, bone mineral content, pulmonary function, nutritional intake, and CF quality of life questionnaires.

RESULTS

Groups were similar at baseline and prepubertal during the entire study. After 1 yr, GH showed significantly greater gain in height, weight, lean mass, and bone mineral content. Gain in height was similar regardless of baseline. There were fewer hospitalizations in the rhGH-treated group and improvement in CF quality of life questionnaires measures of weight and body image. There was no difference in pulmonary function between groups. Results were similar in those treated with rhGH the second year. After cessation of rhGH treatment, there was sustained effect for increased height and weight velocity, as well as accrual of bone mineral.

CONCLUSION

rhGH therapy improves height and weight, decreases the number of hospitalizations, and improves quality of life in prepubertal children with CF. These effects are sustained after rhGH is discontinued.

The cystic fibrosis transmembrane conductance regulator (Cftr) modulates the timing of puberty in mice

BACKGROUND

Delayed puberty is common among individuals with cystic fibrosis (CF) and is usually attributed to chronic disease and/or poor nutrition. However, it has recently been recognised that pubertal delay can occur even in the setting of good nutritional and clinical status. This finding, along with evidence that Cftr is expressed in rat brain, human hypothalamus, and a gonadotropin releasing hormone secreting cell line, raises the possibility that some of the pubertal delay in CF could stem directly from alterations in Cftr function that affect the hypothalamic-pituitary-gonadal axis.

METHODS

To examine this hypothesis, we investigated pubertal timing (as assessed by vaginal opening (VO)) in a mouse model of CF (Cftr(tm1Unc)) engineered to produce a truncated Cftr mRNA and referred to as S489X. Homozygous knockout, heterozygote, and wild type (WT) female mice were examined.

RESULTS

As expected, the S489X-/S489X- knockout mice, which have chronic inflammation and gastrointestinal disease, grew more slowly and had later onset of puberty than WT animals. We anticipated that the S489X-/S489X+ heterozygotes, which have no clinical CF phenotype, might display an intermediate timing of puberty. Surprisingly, however, these mice had earlier VO than WT. These findings were confirmed in a second, independent model of CF engineered to generate the deltaF508 mutation in mice. Again, the homozygotes displayed later pubertal timing, while the heterozygotes displayed earlier VO than the WT animals.

CONCLUSIONS

These data provide further evidence that Cftr can directly modulate the reproductive endocrine axis and raise the possibility that heterozygote mutation carriers may have a reproductive advantage.