Association Between Fat-Free Mass and Pulmonary Function in Patients With Cystic Fibrosis: A Narrative Review

Pulmonary function and body composition parameters of children with cystic fibrosis from a hight complexity institution between 2015 and 2018

BACKGROUND

An adequate nutritional status in patients with cystic fibrosis correlates with higher survival and better pulmonary function. Body mass index (BMI) is an anthropometric indicator with independent association with pulmonary function, and it can hide alterations of nutritional status in cystic fibrosis.

OBJECTIVE

To determine the relationship of lung function with BMI and body composition parameters in children with cystic fibrosis in a Hight Complexity institution between 2015 and 2018.

MATERIALS AND METHODS

It was an observational study with analytical, cross-sectional, and retrospective scope, including 33 patients between 5 and 17 years old. Spearman's test was applied to evaluate correlation of FEV1 (forced expiratory volume in first second) with BMI and five body composition parameters by bioelectrical impedance using InbodyS10 equipment. Statistical significance was considered with p < 0.05.

RESULTS

Positive correlation was obtained between FEV1 and appendicular skeletal muscle mass between lung function and percentage of fat-free mass (p = 0.006) and phase angle (p = 0.001). Percent fat mass had a negative correlation with FEV1 (p = 0.007). BMI and fat free mass index did not correlate with lung function (p = 0.085).

CONCLUSIONS

Appendicular skeletal muscle mass correlated better than BMI with lung function in children with cystic fibrosis. It is recommended to perform anthropometric follow-up by BMI complemented with body composition study in children with cystic fibrosis. Analyses with larger populations are required to standardize its use.

Combined Fat Mass and Fat-free Mass Indices and Lung Function Among Japanese Population: The Tohoku Medical Megabank Community-based Cohort Study

BACKGROUND

Although fat mass index (FMI) and fat-free mass index (FFMI) affect lung function, FMI and FFMI are not independent of each other, since FMI and FFMI were calculated as fat mass and fat-free mass divided by height squared, respectively. We aimed to examine the association of combined FMI and FFMI with lung function.

METHODS

In this cross-sectional study, lung function was evaluated using forced expiratory volume at 1 s (FEV1) and forced vital capacity (FVC) measured using spirometry. Both FMI and FFMI were classified into sex-specific quartiles (16 groups). Analysis of covariance was used to assess the associations of combined FMI and FFMI with lung function. The trend test was conducted by stratifying the FMI and FFMI, scoring the categories from 1-4 (lowest-highest), and entering the number as a continuous term in the regression model.

RESULTS

This study included 3,736 men and 8,821 women aged ≥20 years living in Miyagi Prefecture, Japan. The mean FEV1 was 3.0 (standard deviation [SD], 0.7) L for men and 2.3 (SD, 0.5) L for women. The mean FVC was 3.8 (SD, 0.7) L for men and 2.8 (SD, 0.5) L for women. FMI was inversely associated with lung function among all FFMI subgroups in both sexes. Conversely, FFMI was positively associated with lung function in all FMI subgroups in both sexes.

CONCLUSION

Higher FMI was associated with lower lung function independent of FFMI; higher FFMI was associated with higher lung function independent of FMI. Reducing FMI and maintaining FFMI might be important for respiratory health.

Effects of a remotely supervised resistance training program on muscle strength and body composition in adults with cystic fibrosis: Randomized controlled trial

INTRODUCTION

Among the limited studies on physical exercise interventions in adults with cystic fibrosis (CF), few have specifically addressed the improvement of peripheral muscle strength and body fat-free mass. The aim of this study was to examine the impacts of a remotely supervised, individualized 8-week resistance training program of moderate to high intensity on strength and body composition in these subjects.

METHODS

This was a randomized controlled trial performed in adults with CF. The exercise group (EX) performed three 1-h resistance training sessions per week over 8 weeks. The control group (CON) followed the physical activity recommendations of their physician. The main outcomes were muscle strength and body composition, with secondary measures including pulmonary function and quality of life. Two-way repeated measures analysis was used.

RESULTS

In 23 participants (age 32.13 ± 7.72 years), the intervention showed a significant beneficial effect on leg press strength, with a large effect size, both in absolute (p = 0.011;η p 2 $$ {\eta}_{\mathrm{p}}^2 $$  = 0.281) and relative (p = 0.007;η p 2 $$ {\eta}_{\mathrm{p}}^2 $$  = 0.310) terms. Large intervention effects were observed on total fat mass (p < 0.001;η p 2 $$ {\eta}_{\mathrm{p}}^2 $$  = 0.415), body adiposity index (p < 0.001;η p 2 $$ {\eta}_{\mathrm{p}}^2 $$  = 0.436), and fat mass index (p < 0.001;η p 2 $$ {\eta}_{\mathrm{p}}^2 $$  = 0.445), all showing reduction in the EX group. In addition, significant large size effects were detected on total fat-free mass (p = 0.046;η p 2 $$ {\eta}_{\mathrm{p}}^2 $$  = 0.177), trunk fat-free mass (p = 0.039;η p 2 $$ {\eta}_{\mathrm{p}}^2 $$  = 0.188), and fat-free mass index (p = 0.048;η p 2 $$ {\eta}_{\mathrm{p}}^2 $$  = 0.174), all favoring exercise. No significant effects were observed on pulmonary function and quality of life.

CONCLUSIONS

An 8-week remotely supervised resistance training program, with moderate to high intensity, effectively improved lower limb muscle strength and body composition.

Effects of insulin therapy optimization with sensor augmented pumps on glycemic control and body composition in people with cystic fibrosis-related diabetes

Objective

Cystic fibrosis (CF)-related diabetes (CFRD) resulting from partial-to-complete insulin deficiency occurs in 40-50% of adults with CF. In people with CFRD, poor glycemic control leads to a catabolic state that may aggravate CF-induced nutritional impairment and loss of muscle mass. Sensor augmented pump (SAP) therapy may improve glycemic control as compared to multiple daily injection (MDI) therapy.

Research design and methods

This non-randomized clinical trial was aimed at evaluating the effects of insulin therapy optimization with SAP therapy, combined with a structured educational program, on glycemic control and body composition in individuals with insulin-requiring CFRD. Of 46 participants who were offered to switch from MDI to SAP therapy, 20 accepted and 26 continued the MDI therapy. Baseline demographic and clinical characteristics were balanced between groups using a propensity score-based overlap weighting procedure and weighted mixed-effects regression models were used to estimate changes in study outcomes.

Results

After 24 months changes in HbA1c were: -1.1% (-12.1 mmol/mol) (95% CI: -1.5; -0.8) and -0.1% (-1 mmol/mol) (95% CI: -0.5; 0.3) in the SAP and MDI therapy group, respectively, with a between-group difference of -1.0 (-10 mmol/mol) (-1.5; -0.5). SAP therapy was also associated with a decrease in mean glucose (between group difference: -32 mg/dL; 95% CI: -44; -20) and an increase in TIR (between group difference: 19.3%; 95% CI 13.9; 24.7) and in fat-free mass (between group difference: +5.5 Kg, 95% CI: 3.2; 7.8).

Conclusion

Therapy optimization with SAP led to a significant improvement in glycemic control, which was associated with an increase in fat-free mass.

Current and Future Therapeutic Approaches of Exocrine Pancreatic Insufficiency in Children with Cystic Fibrosis in the Era of Personalized Medicine

This review presents current updates of pancreatic enzyme replacement therapy in children with cystic fibrosis based on literature published in the last decade and some special considerations regarding pancreatic enzyme replacement therapy in the era of new therapies, such as cystic fibrosis transmembrane conductance regulator modulator therapies. Few articles evaluate the efficacy of pancreatic enzyme replacement therapy in the pediatric population, and most studies also included children and adults with cystic fibrosis. Approximately 85% of cystic fibrosis patients have exocrine pancreatic insufficiency and need pancreatic enzyme replacement therapy. Fecal elastase is the most commonly used diagnostic test for exocrine pancreatic insufficiency, although this value can fluctuate over time. While it is used as a diagnostic test, it cannot be used for monitoring the effectiveness of pancreatic enzyme replacement therapy and for adjusting doses. Pancreatic enzyme replacement therapy, the actual treatment for exocrine pancreatic insufficiency, is essential in children with cystic fibrosis to prevent malabsorption and malnutrition and needs to be urgently initiated. This therapy presents many considerations for physicians, patients, and their families, including types and timing of administration, dose monitoring, and therapy failures. Based on clinical trials, pancreatic enzyme replacement therapy is considered effective and well-tolerated in children with cystic fibrosis. An important key point in cystic fibrosis treatment is the recent hypothesis that cystic fibrosis transmembrane conductance regulator modulators could improve pancreatic function, further studies being essential. Pancreatic enzyme replacement therapy is addressed a complication of the disease (exocrine pancreatic insufficiency), while modulators target the defective cystic fibrosis transmembrane conductance regulator protein. Exocrine pancreatic insufficiency in cystic fibrosis remains an active area of research in this era of cystic fibrosis transmembrane conductance regulator modulator therapies. This new therapy could represent an example of personalized medicine in cystic fibrosis patients, with each class of modulators being addressed to patients with specific genetic mutations.

Updates in Nutrition Management of Cystic Fibrosis in the Highly Effective Modulator Era

Attainment and maintenance of good nutrition has been an important aspect of management in cystic fibrosis (CF) for decades. In the era of highly effective modulator therapy for CF, the quality of the nutrients we recommend is increasingly important. Our therapy must support our patients' health for many years beyond what we previously thought. Preventing cardiovascular disease, reducing hyperlipidemia, and optimizing lean body mass for active, longer lives now join the long-standing goal of promoting lung function through nutrition. This chapter summarizes recent developments in nutrition in people with CF, with an eye to the evolution of our practice.

Usefulness of Muscle Ultrasonography in the Nutritional Assessment of Adult Patients with Cystic Fibrosis

Background: Muscle ultrasonography of the quadriceps rectus femoris (QRF) is a technique on the rise in the assessment of muscle mass in application of nutritional assessment. The aim of the present study is to assess the usefulness of muscle ultrasonography in patients with cystic fibrosis, comparing the results with other body composition techniques such as anthropometry, bioelectrical impedance analysis (BIA), dual-energy X-ray absorptiometry (DXA), and handgrip strength (HGS). At the same time, we intend to assess the possible association with the nutritional and respiratory status. Methods: This was a prospective observational study in adult patients with cystic fibrosis in a clinically stable situation. Muscle ultrasonography of the QRF was performed, and the results were compared with other measures of body composition: anthropometry, BIA, and DXA. HGS was used to assess muscle function. Respiratory parameters were collected, and nutritional status was assessed using Global Leadership Initiative on Malnutrition (GLIM) criteria. Results: A total of 48 patients were included, with a mean age of 34.1 ± 8.8 years. In total, 24 patients were men, and 24 patients were women. Mean BMI was 22.5 ± 3.8 kg/m2. Mean muscular area rectus anterior (MARA) was 4.09 ± 1.5 cm2, and mean muscular circumference rectus was 8.86 ± 1.61 cm. A positive correlation was observed between the MARA and fat-free mass index (FFMI) determined by anthropometry (r = 0.747; p < 0.001), BIA (r = 0.780; p < 0.001), and DXA (r = 0.678; p < 0.001), as well as muscle function (HGS: r = 0.790; p < 0.001) and respiratory parameters (FEV1; r = 0.445, p = 0.005; FVC: r = 0.376, p = 0.02; FEV1/FVC: r = 0.344, p = 0.037). A total of 25 patients (52.1%) were diagnosed with malnutrition according to GLIM criteria. Differences were observed when comparing the MARA based on the diagnosis of malnutrition (4.75 ± 1.65 cm2 in normo-nourished vs. 3.37 ± 1.04 in malnourished; p = 0.014). Conclusions: In adults with cystic fibrosis, the measurements collected by muscle ultrasound of the QRF correlate adequately with body composition techniques such as anthropometry, BIA, DXA, and handgrip strength. Muscle ultrasound measurements, particularly the MARA, are related to the nutritional status and respiratory function of these patients.

Body functions and structure, activity, and participation limitations of adult cystic fibrosis patients under the international classification of functioning, disability, and health framework

Objective: There is no study in the literature evaluating impairments and functional limitations in adults with cystic fibrosis (CF) under the framework of the International Classification of Functioning, Disability, and Health (ICF). To evaluate the adults with CF using ICF model. Methods: Twenty-three adults with CF and 23 age-sex matched healthy individuals included in this cross-sectional study. The participants evaluated according to the selected items for domain b, domain s, and domain d from the Obstructive Pulmonary Diseases (OPD) Comprehensive Core Set. The body composition, pulmonary functions, respiratory and peripheral muscle strength/endurance tests and anxiety/depression level were evaluated for domain b and s. For domain d, the Incremental Shuttle Walk Test (ISWT) and Short Form-36 (SF-36) Health Survey were used. Results: The fat-free mass (p = .044), pulmonary functions (p < .05), respiratory muscle endurance (p = .010), absolute and %quadriceps muscle strength (p = .001, p = .025, respectively), number of sit-ups (p = .020), walking speed (p = .035), ISWT and ISWT% distance (p < .001) and peak oxygen consumption (p < .001) were significantly lower in adults with CF compared to healthy individuals (p < .05). There were only significant differences in SF-36 physical functioning and role physical subdimension scores between groups (p = .009, p = .045 respectively). Conclusions: The ICF framework is applicable to comprehensively evaluate limitations of adults with CF among rehabilitation professionals. Especially age, respiratory function, respiratory muscle strength and endurance, dyspnea perception, peripheral muscle endurance were related to activity and participation limitation.

Exercise intolerance in cystic fibrosis-the role of CFTR modulator therapies

Exercise intolerance is common in people with CF (pwCF), but not universal among all individuals. While associated with disease prognosis, exercise intolerance is not simply a reflection of the degree of lung disease. In people with severe CF, respiratory limitations may contribute more significantly to impaired exercise capacity than in those with mild-moderate CF. At all levels of disease severity, there are peripheral factors e.g., abnormal macro- and micro-vascular function that impair blood flow and reduce oxygen extraction, and mitochondrial defects that diminish metabolic efficiency. We discuss advances in understanding the central and peripheral mechanisms underlying exercise intolerance in pwCF. Exploring both the central and peripheral factors that contribute to exercise intolerance in CF can help inform the development of new therapeutic targets, as well as help define prognostic criteria.

25-Hydroxy vitamin D and body composition are associated with pulmonary function in non-cystic fibrosis bronchiectasis: A cross-sectional study

BACKGROUND

Previous studies have emphasized the effects of vitamin D on the lung function of cystic fibrosis (CF) adult patients. The main aim of the present study sought to determine the association between circulating 25-hydroxyvitamin D (25-OH D) concentration and clinical outcomes in non-cystic fibrosis (non-CF) bronchiectasis subjects. Secondary, we assessed the possible relationship between body composition and respiratory dysfunction in these patients.

MATERIALS AND METHODS

Sixty-two non-CF bronchiectasis patients (24 male/38 female), aged 18-72, were recruited in this cross-sectional study. Anthropometric indices, lung function tests, and bronchiectasis severity valuations were determined. Body composition, including Mid-arm muscle circumference (MAMC, cm) was calculated using triceps skinfold (TSF,mm) and mid-arm circumference (MAC,cm) under the reference formula. Then serum 25-hydroxyvitamin D concentration and C-reactive protein level were measured. The correlation between vitamin D level and pulmonary function and disease exacerbation tests was primarily assessed. Additionally, we evaluated the correlation between body composition and lung function tests.

RESULTS

Circulating 25-hydroxyvitamin D status positively was correlated with lung function tests, including FEV₁ (r = 0.30, p value = 0.035) and FVC (r = 0.36, p value = 0.011), and also be associated with the extent of pulmonary involvement (r = -0.34, p value = 0.03). There was a significant negative correlation between percentage body fat and respiratory function, FEV₁/FVC ratio (r = -0.43, p value < 0.001). In contrast, there was a strong correlation between skeletal muscle mass and pulmonary function tests (r = 0.26, p value = 0.04).

CONCLUSION

There is a positive association between low 25-hydroxyvitamin D status and lung dysfunction in participants with non-CF bronchiectasis. The pulmonary dysfunction also correlated with more percentage body fat and low skeletal muscle mass in these patients. Therefore, the evaluation of body composition and serum vitamin D are suggested in the disease management of the patients with non-CF bronchiectasis. However, these associations should be interpreted with caution due to the likelihood of reverse causation. More high-quality prospective studies are warranted to confirm our observations and determine the mechanisms underlying these findings.

Assessment of body composition in cystic fibrosis: agreement between skinfold measurement and densitometry

INTRODUCTION

few studies have evaluated body composition (BC) through different techniques, and the degree of agreement between them in adults with cystic fibrosis (CF).

OBJECTIVES

to describe BC using techniques to assess nutritional status and to test their concordance in CF.

METHODS

a cross-sectional study in CF patients in a clinically stable situation. Nutritional assessment was performed using skinfold measurement (SM) and densitometry (DXA). Fat-free mass index (FFMI) was also determined. The diagnosis of malnutrition was established if body mass index (BMI) < 18.5 kg/m2. Fat-free mass (FFM) malnutrition was diagnosed when FFMI was < 17 kg/m2 in males and < 15 kg/m2 in females (FFMI: fat-free mass in kg/height in m2).

RESULTS

forty-one patients were studied (twenty-two females, 53.7 %); median age was 29.8 (interquartile range, 20.9-33.7); BMI was 21.6 (19.8-23.0). Only four (9.8 %) patients had a BMI < 18.5. By DXA, FFM (kg) results were: median, 52.8 (47.8-56.9) with FFMI of 17.9 (16.7-19.3) in males and 36.7 (33.1-38.9) in females, FFMI of 14.7 (14.2-15.8). Twenty (48.6 %) patients presented FFM malnutrition, with 16.7 % of males and 59.1 % of females being affected. By SM, the FFMI was 18.7 (17.2-20.0) in males and 14.9 (14.2-15.8) in females; moreover, sixteen (39.1 %) patients presented malnutrition of FFM, with 20.8 % of males and 61.8 % of females being affected. For FFM (kg), a high concordance was obtained between SM and DXA (intraclass correlation coefficient of 0.950); likewise when they were compared by applying the ESPEN criteria for FFM malnutrition. However, when the techniques were compared to classify malnutrition according to FFMI, the kappa coefficient was only moderate (k = 0.440). The mean difference between FFM by DXA and SM was +1.44 ± 0.62 kg in favor of SM, with greater dispersion as FFM increased.

CONCLUSIONS

the prevalence of FFM malnutrition is high in adult CF patients, despite a normal BMI, especially in females. Notwithstanding the good statistical agreement between SM and DXA, concordance was moderate. Therefore, DXA remains the technique of choice, and SM may be used when the former is not available.

Arm muscle area for the longitudinal assessment of nutritional status in paediatric patients with cystic fibrosis - A single centre experience

BACKGROUND

In cystic fibrosis, adequate nutrition contributes to good long-term prognosis. A body mass index (BMI) at or above the 50th percentile for age and sex in all children has been recommended. As researchers have described a depletion of fat-free mass despite normal BMI, longitudinal studies using more sensitive nutritional parameters are warranted. We evaluated anthropometric measurements in an attempt to identify early indicators of deteriorating nutritional status in our paediatric cohort.

METHODS

We analysed datasets from children and adolescents between 2 and 17.9 years with at least two entries for triceps skinfold thickness and upper arm circumference in our patient database between January 1995 and December 2018. Arm muscle area (AMA) was calculated, and all values were expressed as z-scores from CDC growth charts.

RESULTS

A total of 4,862 encounters from 161 paediatric patients (78 girls) were available, representing a median number of 28 visits during a median follow-up of 8.1 years per patient. Linear mixed effects models revealed relatively stable courses for weight, height, BMI and skinfold thickness up to adulthood. AMA was the only parameter which declined slightly (r = -0.036), particularly in boys. Kaplan-Meier-analyses showed that AMA was the earliest parameter to decrease below -1 z-score between 6 and 18 years.

CONCLUSIONS

The present data suggest that compared with weight or BMI, AMA could serve as an earlier indicator of a deteriorating nutritional status. The benefit of assessing skinfold thickness and arm circumference routinely and calculating AMA from these measurements should be evaluated in large, prospective, multi-centre studies.

Cystic fibrosis

Cystic fibrosis is a monogenic disease considered to affect at least 100 000 people worldwide. Mutations in CFTR, the gene encoding the epithelial ion channel that normally transports chloride and bicarbonate, lead to impaired mucus hydration and clearance. Classical cystic fibrosis is thus characterised by chronic pulmonary infection and inflammation, pancreatic exocrine insufficiency, male infertility, and might include several comorbidities such as cystic fibrosis-related diabetes or cystic fibrosis liver disease. This autosomal recessive disease is diagnosed in many regions following newborn screening, whereas in other regions, diagnosis is based on a group of recognised multiorgan clinical manifestations, raised sweat chloride concentrations, or CFTR mutations. Disease that is less easily diagnosed, and in some cases affecting only one organ, can be seen in the context of gene variants leading to residual protein function. Management strategies, including augmenting mucociliary clearance and aggressively treating infections, have gradually improved life expectancy for people with cystic fibrosis. However, restoration of CFTR function via new small molecule modulator drugs is transforming the disease for many patients. Clinical trial pipelines are actively exploring many other approaches, which will be increasingly needed as survival improves and as the population of adults with cystic fibrosis increases. Here, we present the current understanding of CFTR mutations, protein function, and disease pathophysiology, consider strengths and limitations of current management strategies, and look to the future of multidisciplinary care for those with cystic fibrosis.

Changes in handgrip strength in children with cystic fibrosis compared to children without cystic fibrosis

BACKGROUND & AIMS

Cystic Fibrosis (CF) may impact nutritional status. Handgrip strength (HGS) may be used for nutrition assessment. The objective of the study was to evaluate changes in HGS over time in children with CF compared to children without CF. A secondary purpose was to analyze the relationship of clinical characteristics of CF with HGS.

METHODS

A prospective, longitudinal study was conducted. The non-CF group (n = 76) was recruited from a school and the CF group (n = 75) from an accredited CF center. Height, weight, mid-upper arm circumference, triceps skinfold, and HGS were measured at baseline and approximately three and six months in both groups. Data for pulmonary function, nutrition risk, enteral supplementation, CF transmembrane conductance regulator modulator, steroids, antibiotics, vitamin levels, CF related diabetes (CFRD), and recent hospitalization were collected for the CF group. A mixed model determined the difference in the change in HGS between the CF group and the non-CF group. For all analyses, p=<0.05 was significant.

RESULTS

The rate of change in HGS z-score in the CF-group (0.18 ± 0.05) versus the non-CF group (0.06 ± 0.06) was not significant (p = 0.15). Initial mean dominant HGS z-score was significantly lower (p = 0.02) in those with vitamin D deficiency (-1.35 ± 0.09) versus those without (-1.02 ± 0.11). HGS z-score significantly (p = 0.02) decreased over time in children with CFRD (-0.19 ± 0.22) versus children without CFRD (0.32 ± 0.14), p = 0.02.

CONCLUSION

Serial measurements of HGS may help detect changes in muscle function related to CFRD and vitamin D deficiency. Further investigation is warranted to elucidate HGS's role in nutrition assessment of children with CF.

Oral Nutritional Supplements in Adults with Cystic Fibrosis: Effects on Intake, Levels of Fat-Soluble Vitamins, and Bone Remodeling Biomarkers

Background: The use of oral nutritional supplements (ONS) is common practice in patients suffering from cystic fibrosis (CF). We aimed to describe the rate of ONS use to assess their contribution to dietary intake and to determine if they are associated with respiratory status, body composition, muscle strength, bone mineral density (BMD), bone remodeling biomarkers, and plasmatic levels of vitamins. Methods: Cross-sectional study. Patients were clinically stable adults recruited from the CF unit. A 4-day prospective dietary questionnaire was conducted; in addition to respiratory variables, body composition, and BMD (through densitometry, DXA), muscle strength (JAMAR dynamometer), fat-soluble vitamins, and bone remodeling biomarkers (vitamins A, D, and E; osteocalcin, OC; undercarboxylated osteocalcin, ucOC; degradation of the C-terminal telopeptides of type I collagen, CTX; and receptor activator of nuclear factor-kappaB ligand, RANKL) were also evaluated. Results: The study included 59 subjects with CF (57.6% female, mean age 29.3 ± 9.4 years, and BMI 22.0 ± 3.6 kg/m²). In this study, 22% (13) patients were taking ONS and presented, compared with those not taking them, significantly more total and mild exacerbations and lower BMI; moreover, they showed a significantly higher total daily calorie intake in addition to a higher consumption of carbohydrates, proteins, and lipids per kg of body weight, omega-3 fatty acids, and vitamins A, D, and E. Vitamin E plasmatic levels were significantly higher in the group on ONS, as was the case with RANKL; finally, a lower rate of vitamin D deficiency was also found. Conclusions: ONS were used by patients with worse respiratory and nutritional statuses and their use was associated with a higher intake of macro- and micronutrients and with better plasmatic levels of fat-soluble vitamins.

Growth, Body Composition, and Lung Function in Prepubertal Children with Cystic Fibrosis Diagnosed by Newborn Screening

BACKGROUND

Children with cystic fibrosis (CF) are at risk of altered body composition (BC). Newborn screening (NBS) may lead to improved BC outcomes. We investigated BC and its relationship with lung function in prepubertal children diagnosed with CF by NBS. Secondary aims explored predictors of fat-free mass (FFM) and lung function.

METHODS

Thirty-seven screened (non-meconium ileus) children with CF (20 boys) born 2007-2012 had a dual-energy x-ray absorptiometry scan at 5-8 years to determine whole-body (WB) and appendicular BC. Anthropometry was performed and routine spirometry recorded. Results were converted to z-scores, height-adjusted (fat mass index [FMI] and FFM index [FFMI]) and compared with population mean values. Predictors of forced expiratory volume in 1 second (FEV₁ ) were assessed using linear regression.

RESULTS

Height, body mass index (BMI), and FEV₁ were within normal limits, however, weight and BC were significantly low compared with reference data (weight, P = .03; WB FMI, P = .001; WB FFMI, P = .009). Gender differences were detected, with lower appendicular BC in boys and lower weight, BMI, and BC in girls. The association between FEV₁ and WB FFMI (r = 0.38; P = .02) was stronger than with BMI (r = 0.29; P = .08). WB FFMI was the only significant predictor of FEV₁ in a multivariable model (95% CI, 0.11-0.99; P = .016).

CONCLUSION

In this NBS CF population, gender differences in growth and BC were apparent despite preserved lung function. These results support BC assessment in prepubertal children, particularly girls, with an opportunity to direct interventions to optimize FFM.

Triage for Malnutrition Risk among Pediatric and Adolescent Outpatients with Cystic Fibrosis, Using a Disease-Specific Tool

Malnutrition prevails in considerable proportions of children with Cystic Fibrosis (CF), and is often associated with adverse outcomes. For this, routine screening for malnutrition is pivotal. In the present cross-sectional study, we aimed to assess the risk for malnutrition in pediatric outpatients with CF. A total of 76 outpatients (44 girls, 11.9 ± 3.9 years old, 39.5% adolescents) were recruited and anthropometric, clinical, dietary and respiratory measures were collected. All outpatients were screened for malnutrition risk with a validated disease-specific instrument. Most children exhibited a low risk for malnutrition (78.9%), whereas none of the participants were characterized as having a high malnutrition risk. In the total sample, malnutrition risk was positively associated with age (r = 0.369, p = 0.001), and inversely related to the body mass index (r = −0.684, p < 0.001), height z-score (r = −0.264, p = 0.021), and forced expiratory volume (FEV₁%, r = −0.616, p < 0.001). Those classified as having a low malnutrition risk were younger (p = 0.004), heavier (p < 0.001) and taller (p = 0.009) than their counterparts with a moderate risk. On the other hand, patients in the moderate risk group were more likely pubertal (p = 0.034), with a reduced mid-upper arm fat area (p = 0.011), and worse pulmonary function (p < 0.001). Interestingly, none of the children attaining ideal body weight were classified as having a moderate malnutrition. risk, whereas 37.5% of the patients allocated at the moderate risk group exhibited physiological lung function. In this cohort of outpatients with CF that were predominantly well-nourished and attained physiological lung function, malnutrition risk was identified only in small proportions of the sample. Our data support that patients that are older, pubertal, or have diminished fat mass are at greater risk for malnutrition.