The Association of Grip Strength, Body Mass Index, and Lung Function in Youth with Cystic Fibrosis

Remote endpoints for clinical trials in cystic fibrosis: Report from the U.S. CF foundation remote endpoints task force

The COVID-19 pandemic necessitated a rapid shift in clinical research to perform virtual visits and remote endpoint assessments, providing a key opportunity to optimize the use of remote endpoints for clinical trials in cystic fibrosis. The use of remote endpoints could allow more diverse participation in clinical trials while minimizing participant burden but must be robustly evaluated to ensure adequate performance and feasibility. In response, the Cystic Fibrosis Foundation convened the Remote Endpoint Task Force (Supplemental Table 1), a multidisciplinary group of CF researchers with remote endpoint expertise and community members tasked to better understand the current and future use of remote endpoints for clinical research. Here, we describe the current use of remote endpoints in CF clinical research, address key unanswered questions regarding their use and feasibility, and discuss the next steps to determine clinical trial readiness.

Association of handgrip strength with nutritional status and clinical outcomes in hospitalized pediatric patients

BACKGROUND & AIMS

Malnutrition in children and adolescents is prevalent at hospital admission and the incidence increases with length of stay. Malnourished patients have loss of muscle mass and strength, compromising their functionality. Handgrip strength (HGS) is a nutritional marker understudied in pediatrics although it is capable of detecting nutritional deprivation before changes in body composition are observed. Therefore, this study aimed to evaluate the association between reduced HGS at hospital admission, compromised nutritional status and worse clinical outcomes of pediatric patients.

METHODS

Cohort study conducted with patients aged 6-18 years admitted to a pediatric ward. Nutritional status was assessed in the first 48 h of hospital admission using the z-score of height for age (H/A) and body mass index for age (BMI/A), percentile of mid-arm muscle circumference for age (MAMC/A) and the pediatric global subjective nutritional assessment (SGNA). HGS was measured using a digital dynamometer and considered reduced when the maximum value of three measurements was below the 5th percentile for sex and age. The clinical outcomes analyzed were length of hospital stay and frequency of readmission within 3 months after hospital discharge.

RESULTS

A total of 135 patients were evaluated (median age 10.9 years, 55.6% male) and 17.8% had reduced HGS. Patients with reduced HGS had lower H/A z-score (-0.50 vs 0.22, p = 0.012) and a higher frequency of reduced MAMC when compared to those with normal HGS (8% vs 13%, p = 0.007). Reduced HGS was not associated with malnutrition (OR = 0.63; 95%CI 0.23-1.77), prolonged hospital stay (OR = 1.89; 95%CI 0.72-4.92) or readmission to hospital 3 months after hospital discharge (OR = 1.82; 95%CI 0.67-4.93), in a model adjusted for the clinical condition.

CONCLUSION

Reduced HGS was not a predictor of malnutrition and clinical outcomes. However, it was associated with lower H/A Z-score and MAMC/A percentile values and can be used as a complementary measure in the nutritional status assessment of hospitalized pediatric patients.

Muscle Wasting among Hospitalized Children: A Narrative Review of the Feasibility and Accuracy of Diagnostic Methods

Muscle wasting is associated with a worse quality of life and increased morbidity and mortality among hospitalized children, especially those with chronic diseases. This review was conducted to summarize the data available on the most feasible and accurate diagnostic methods for detecting muscle wasting among hospitalized children, especially to review the evidence of the accuracy and feasibility of conducting assessments using handgrip strength (HGS). Many diagnostic methods are used in hospital settings to assess muscle wasting, by evaluating either muscle mass or strength, with evidentiary support for assessing muscle mass provided using ultrasonography, magnetic resonance imaging, computed tomography, dual-energy X-ray, bioelectrical impedance analysis, and anthropometry measurements. Currently, the most common diagnostic method used to detect muscle strength loss is the handheld dynamometer. Studies support using HGS among healthy and hospitalized children to assess the overall nutritional status and especially muscle function. However, almost all of these studies have been conducted in hospital settings and recruited children with different chronic diseases using a small sample size. More longitudinal cohort studies with large sample sizes are needed to assess the accuracy and feasibility of using HGS among hospitalized children.

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.

Association of Body Mass Index With Clinical Outcomes in Patients With Cystic Fibrosis: A Systematic Review and Meta-analysis

IMPORTANCE

The prevalence of overweight (body mass index [BMI] = 25-29.9 [calculated as weight in kilograms divided by height in meters squared]) and obesity (BMI ≥30) is increasing among patients with cystic fibrosis (CF). However, it is unclear whether there is a benefit associated with increasing weight compared with the reference range (ie, normal) in CF.

OBJECTIVE

To evaluate the association of altered BMI or body composition and clinical outcomes in patients with CF.

DATA SOURCES

For this systematic review and meta-analysis, the literature search was conducted November 2, 2020, of 3 databases: MEDLINE (via PubMed), Embase, and Cochrane Central Register of Controlled Trials.

STUDY SELECTION

Patients older than 2 years diagnosed with CF with altered body composition or BMI were compared with patients having the measured parameters within the reference ranges. Records were selected by title, abstract, and full text; disagreements were resolved by consensus. Cohort studies and conference abstracts were eligible; articles with no original data and case reports were excluded.

DATA EXTRACTION AND SYNTHESIS

Two authors independently extracted data, which were validated by a third author. Studies containing insufficient poolable numerical data were included in the qualitative analysis. A random-effects model was applied in all analyses.

MAIN OUTCOMES AND MEASURES

Pulmonary function, exocrine pancreatic insufficiency (PI), and CF-related diabetes (CFRD) were investigated as primary outcomes. Odds ratios (ORs) or weighted mean differences (WMDs) with 95% CIs were calculated. The hypothesis was formulated before data collection.

RESULTS

Of 10 524 records identified, 61 met the selection criteria and were included in the qualitative analysis. Of these, 17 studies were included in the quantitative synthesis. Altogether, 9114 patients were included in the systematic review and meta-analysis. Overweight (WMD, -8.36%; 95% CI, -12.74% to -3.97%) and obesity (WMD, -12.06%; 95% CI, -23.91% to -0.22%) were associated with higher forced expiratory volume in the first second of expiration compared with normal weight. The odds for CFRD and PI were more likely in patients of normal weight (OR, 1.49; 95% CI, 1.10 to 2.00) than in those who were overweight (OR, 4.40; 95% CI, 3.00 to 6.45). High heterogeneity was shown in the analysis of pulmonary function (I2 = 46.7%-85.9%).

CONCLUSIONS AND RELEVANCE

The findings of this systematic review and meta-analysis suggest that the currently recommended target BMI in patients with CF should be reconsidered. Studies with long-term follow-up are necessary to assess the possible adverse effects of higher BMI or higher fat mass in patients with CF.

Handgrip Strength: Associations with Clinical Variables, Body Composition, and Bone Mineral Density in Adults with Cystic Fibrosis

Background: Loss of fat-free mass (FFM) is associated with an increase in morbidity and mortality in cystic fibrosis (CF) patients. Handgrip strength (HGS) measures muscle function and may be associated with clinical parameters with prognostic value. Our objectives were to evaluate muscle strength through HGS in CF patients and to determine if there are any associations with respiratory clinical variables, FFM, and bone mineral density (BMD). Methods: A cross-sectional study conducted in clinically stable patients. We evaluated muscle function through HGS, respiratory function—forced expiratory volume in 1 s (FEV1) (%), forced vital capacity (FVC) (%), bronchorrhea, annual exacerbations, and body composition (FFM and FFM index, FFMI: fat-free mass in kg/height in m²) and Bone Mineral Density (BMD) through densitometry (DXA). Results: The study included 53 CF patients (58.5% females, mean age 28.3 ± 8.1, body mass index (BMI) 21.7 ± 3.4). The mean values for dynamometry were 40.2 ± 8.1 kg in males and 23.1 ± 7.0 kg in women, being 20.8% below the 10th percentile. Patients with lower muscle strength showed significantly more exacerbations and lower FEV1% and FVC%, as well as lower BMI, worse BMD (g/cm²), T-score, and Z-score. A significant and positive correlation was found between the mean and maximum dynamometry values and age, FVC%, BMI, FFMI, FFM (kg), and BMD. Conclusions: For adults with CF, HGS is a practical tool for assessment of health status. Low values reflect poor nutritional status and are associated with poor respiratory function, low fat-free mass and low bone mineral density.

Handgrip strength as a surrogate marker of lean mass and risk of malnutrition in paediatric patients

BACKGROUND & AIMS

The use of handgrip strength (HGS) as a proxy of nutritional status in sick children has not been studied. This study created HGS centile charts in healthy children and explored the utility of HGS z-scores as markers of body composition and screening of malnutrition risk in sick children.

METHODS

Data from 535 healthy children aged 5-16 years were used for the development of HGS centiles adjusted either for age or height. In 595 sick children, relationships between HGS z-scores with body composition, malnutrition risk (Paediatric Yorkhill Malnutrition Score-PYMS), length of hospital stay (LOS) and biomarkers of disease severity were explored. The use of HGS z-score to identify sick children in need of further dietetic assessment was investigated.

RESULTS

Children scoring at high malnutrition risk with PYMS had lower HGS z-scores for age (by 0.51 SD, p < 0.001) and height (by 0.46 SD, p = 0.001) than those who scored low. A HGS z-score at cut-offs of -0.81 SD and -1.2 SD for age and height, respectively, was predictive of need for dietetic intervention in sick children with sensitivity of 79% and 70% and specificity of 56% and 69%, respectively. HGS z-scores were predictive of fat free mass (FFM) in sick and healthy (all p < 0.001) children, while fat mass was not. HGS z-scores were inversely related with plasma CRP (rho, age: -0.21; height: -0.23, both p = 0.001). HGS was not predictive of LOS.

CONCLUSION

HGS is predictive of FFM, could compliment assessment of malnutrition risk, and may help identify children for further dietetic intervention on admission to hospital.

Assessing the Utility of an Outpatient Exercise Program for Children With Cystic Fibrosis: A Quality Improvement Project

Children with cystic fibrosis (CF) (cwCF) suffer from inadequate weight gain, failure to thrive, and muscle weakness. The latter may be secondary to disuse atrophy (muscle wasting or reduction in muscle size associated with reduced physical activity and inflammation). Handgrip strength (HGS) is a reliable surrogate for muscle strength and lean body mass. Data from our CF center have shown an association between low HGS and forced expiratory volume in 1 s (FEV₁) in cwCF. High-intensity interval training (HIIT) improves physical strength. Therefore, we devised a project to assess implementing a HIIT exercise program in the home setting, in order to improve physical strength in cwCF with HGS ≤ 50th percentile. Patients were instructed to complete 3-5 sessions of HIIT exercises per week. Wilcoxon matched-pairs signed-rank tests were used to compare HGS, FEV₁, and body mass index (BMI) percentile at baseline and at a follow-up clinic visit. Follow-up was limited due to the COVID pandemic. Adherence to the HIIT regimen was poor. A total of twenty-nine cwCF participated in the program. However, a total of 13 individuals reported some form of moderate activity at follow-up and therefore constituted our final study population. There was a statistically significant increase in absolute grip strength (AGS) and FEV₁ for these individuals. Even though the home HIIT protocol was not followed, the project demonstrated that moderate physical activity in cwCF can lead to significant improvement in HGS and overall physical strength.