Advances in Care and Outcomes for Children with Cystic Fibrosis.

The landscape of care for children with cystic fibrosis (CF), a genetic disorder of chloride transport with multisystem manifestations including inspissated mucus, recurrent sinopulmonary infections, obstructive lung disease, and exocrine pancreatic insufficiency, is rapidly changing. Early diagnosis via newborn screening enabling timely nutritional support, chronic therapies to improve mucociliary clearance, and prompt treatment of pulmonary infections have improved overall outcomes in children with CF. More widespread availability of novel cystic fibrosis transmembrane conductance regulator modulator therapies for children continues to revolutionize pediatric CF care.However, significant challenges exist to optimize care and outcomes for all children with CF.

Habitually wearing high heels may improve user walking economy in any footwear.

The habitual use of high-heeled footwear may structurally remodel user leg muscle tendons, thereby altering their functional capabilities. High heels set users' ankles in relatively plantarflexed positions, causing calf muscle tendons to operate at relatively short lengths. Habitually operating muscle tendons at relatively short lengths induces structural remodeling that theoretically affects muscle metabolism. Because structural changes occur within the body, the user's locomotor metabolism may change in any footwear condition (e.g., conventional shoes, barefoot). Here, we studied the influence of habitual high-heel use on users' leg muscle-tendon structure and metabolism during walking in flat-soled footwear. We tested eight participants before and after 14 wk of agreeing to wear high heels as their daily shoes. Overall, participants who wore high heels >1,500 steps per day, experienced a 9% decrease in their net metabolic power during walking in flat-soled footwear (d = 1.66, P ≤ 0.049), whereas participants who took <1,000 daily steps in high heels did not (d = 0.44; P = 0.524). Across participants, for every 1,000 daily steps in high heels, net metabolic power during walking in flat-soled footwear decreased 5.3% (r = -0.73; P = 0.040). Metabolic findings were partially explained (r2 = 0.43; P = 0.478) by trending shorter medial gastrocnemius fascicle lengths (d = 0.500, P = 0.327) and increased Achilles tendon stiffness (d = 2.889, P = 0.088). The high-heel intervention did not alter user walking stride kinematics in flat-soled footwear (d ≤ 0.567, P ≥ 0.387). While our limited dataset is unable to establish the mechanisms underlying the high-heel-induced walking economy improvement, it appears that prescribing specific footwear use can be implemented to alter user muscle-tendon properties and augment their function in any shoes.NEW & NOTEWORTHY Habitually wearing high-heeled footwear structurally remodels leg muscle tendons and improves user walking economy, regardless of worn attire.

The effects of plantarflexor weakness and reduced tendon stiffness with aging on gait stability.

Falls among older adults are a costly public health concern. Such falls can be precipitated by balance disturbances, after which a recovery strategy requiring rapid, high force outputs is necessary. Sarcopenia among older adults likely diminishes their ability to produce the forces necessary to arrest gait instability. Age-related changes to tendon stiffness may also delay muscle stretch and afferent feedback and decrease force transmission, worsening fall outcomes. However, the association between muscle strength, tendon stiffness, and gait instability is not well established. Given the ankle's proximity to the onset of many walking balance disturbances, we examined the relation between both plantarflexor strength and Achilles tendon stiffness with walking-related instability during perturbed gait in older and younger adults-the latter quantified herein using margins of stability and whole-body angular momentum including the application of treadmill-induced slip perturbations. Older and younger adults did not differ in plantarflexor strength, but Achilles tendon stiffness was lower in older adults. Among older adults, plantarflexor weakness associated with greater whole-body angular momentum following treadmill-induced slip perturbations. Weaker older adults also appeared to walk and recover from treadmill-induced slip perturbations with more caution. This study highlights the role of plantarflexor strength and Achilles tendon stiffness in regulating lateral gait stability in older adults, which may be targets for training protocols seeking to minimize fall risk and injury severity.

A Data-Driven Approach to Estimate Human Center of Mass State During Perturbed Locomotion Using Simulated Wearable Sensors.

Center of mass (COM) state, specifically in a local reference frame (i.e., relative to center of pressure), is an important variable for controlling and quantifying bipedal locomotion. However, this metric is not easily attainable in real time during human locomotion experiments. This information could be valuable when controlling wearable robotic exoskeletons, specifically for stability augmentation where knowledge of COM state could enable step placement planners similar to bipedal robots. Here, we explored the ability of simulated wearable sensor-driven models to rapidly estimate COM state during steady state and perturbed walking, spanning delayed estimates (i.e., estimating past state) to anticipated estimates (i.e., estimating future state). We used various simulated inertial measurement unit (IMU) sensor configurations typically found on lower limb exoskeletons and a temporal convolutional network (TCN) model throughout this analysis. We found comparable COM estimation capabilities across hip, knee, and ankle exoskeleton sensor configurations, where device type did not significantly influence error. We also found that anticipating COM state during perturbations induced a significant increase in error proportional to anticipation time. Delaying COM state estimates significantly increased accuracy for velocity estimates but not position estimates. All tested conditions resulted in models with R2 > 0.85, with a majority resulting in R2 > 0.95, emphasizing the viability of this approach. Broadly, this preliminary work using simulated IMUs supports the efficacy of wearable sensor-driven deep learning approaches to provide real-time COM state estimates for lower limb exoskeleton control or other wearable sensor-based applications, such as mobile data collection or use in real-time biofeedback.

Safety and Pharmacokinetics Following Oral or Intravenous Lefamulin in Adults With Cystic Fibrosis.

PURPOSE: Methicillin-resistant Staphylococcus aureus infections are increasing in prevalence in patients with cystic fibrosis (CF) and are associated with worsening lung function and increased mortality. Lefamulin is a pleuromutilin antimicrobial approved to treat community-acquired bacterial pneumonia based on potent in vitro activity and clinical efficacy. This Phase I, open-label, randomized crossover study assessed the safety and pharmacokinetic profile of oral and intravenous (IV) lefamulin in adults with CF. METHODS: The study comprised 2 dosing periods in which adults with CF (N = 13) received a single dose of lefamulin via a 150-mg IV infusion or 600-mg immediate-release orally administered tablet, separated by a 4- to 7-day washout period. Pharmacokinetic and safety parameters were assessed after lefamulin treatment. FINDINGS: Single doses of lefamulin administered via oral tablet or IV infusion resulted in comparable drug exposure, and sputum analysis suggested rapid penetration of lefamulin into the lung. Comparison of the present results with those obtained from prior single-dose studies of healthy volunteers indicate no meaningful difference in the pharmacokinetic properties of lefamulin in patients with CF. Treatment-emergent adverse events were consistent with previous reports, and the majority were mild in severity. IMPLICATIONS: These results show similar lefamulin pharmacokinetic and safety profiles between patients with CF and healthy volunteers receiving the same oral and IV doses, suggesting no need for lefamulin dose adjustment in patients with CF and indicating the potential of lefamulin as therapy for lung infections in patients with CF. CLINICALTRIALS: gov identifier: NCT05225805.

Continuous glucose monitoring and advanced glycation endproducts for prediction of clinical outcomes and development of cystic fibrosis-related diabetes in adults with CF.

Introductions: Cystic fibrosis-related diabetes (CFRD) is associated with pulmonary decline, compromised nutritional status, and earlier mortality. Onset is often insidious, so screening for early detection of glycemic abnormalities is important. Continuous glucose monitoring (CGM) has been validated in people with CF and has been shown to detect early glycemic variability otherwise missed on 2-hour oral glucose tolerance testing (OGTT). We previously reported that CGM measures of hyperglycemia and glycemic variability are superior to hemoglobin A1c (HbA1c) in distinguishing those with and without CFRD. However, little is known about the long-term predictive value of CGM measures of glycemia for both the development of CFRD and their effect on key clinical outcomes such as weight maintenance and pulmonary function. In addition, there have been no studies investigating advanced glycation endproducts (AGE) assessed by skin autofluorescence in people with CF. Methods: In this prospective observational study, CGM and HbA1c were measured at 2 to 3 time points 3 months apart in 77 adults with CF. Participants who did not have CFRD at the time of enrollment underwent OGTT at the baseline visit, and all participants had AGE readings at baseline. Follow up data including anthropometric measures, pulmonary function and CFRD status were collected by review of medical records 1- and 2-years after the baseline visits. We applied multivariable linear regression models correlating glycemic measures to change in key clinical outcomes (weight, BMI, FEV1) accounting for age, gender and elexacaftor/tezacaftor/ivacaftor (ETI) use. We also conducted logistic regression analyses comparing baseline glycemic data to development of CFRD during the 2-year follow up period. Results: Of the 77 participants, 25 had pre-existing CFRD at the time of enrollment, and six participants were diagnosed with CFRD by the OGTT performed at the baseline visit. When adjusting for age, gender, and ETI use, multiple CGM measures correlated with weight and BMI decline after one year but not after two years. CGM and HbA1c at baseline did not predict decline in FEV1 (p>0.05 for all). In the 46 participants without a diagnosis of CFRD at baseline, two participants were diagnosed with CFRD over the following two years, but CGM measures at baseline did not predict progression to CFRD. Baseline AGE values were higher in individuals with CFRD and correlated with multiple measures of dysglycemia (HbA1c, AG, SD, CV, TIR, % time >140, >180, >250) as well as weight. AGE values also correlated with FEV1 decline at year 1 and weight decline at year 1 and year 2. Conclusions: Several key CGM measures of hyperglycemia and glycemic variability were predictive of future decline in weight and BMI over one year in this population of adults with CF with and without CFRD. None of the baseline glycemic variables predicted progression to CFRD over 2 years. To our knowledge, this is the first report correlating AGE levels with key clinical and glycemic measures in CF. Limitations of these analyses include the small number of participants who developed CFRD (n=2) during the follow up period and the initiation of ETI by many participants, affecting their trajectory in weight and pulmonary function. These results provide additional data supporting the potential role for CGM in identifying clinically significant dysglycemia in CF. Future studies are needed to investigate CGM as a diagnostic and screening tool for CFRD and to understand the implications of AGE measures in this patient population.

An emotional journey: caregiver experiences with gastrostomy tube decision-making for children with cystic fibrosis.

BACKGROUND: Nutritional challenges are common in early CF care and stressful for caregivers of children with CF (cwCF) to navigate. Gastrostomy tube (G-tube) placement can improve weight gain, however the decision to proceed with placement is personalized and preference-sensitive. Little is known about the experiences of caregivers of cwCF and the G-tube decision-making process. OBJECTIVES: The present study used a qualitative approach to explore the perceptions and experiences of caregivers of cwCF with G-tube introductions and recommendations, as well as factors influencing G-tube decision-making. METHODS: Caregivers of cwCF aged ≤ 10 years completed audio-taped, semi-structured interviews describing their experiences with G-tube placement discussions. Interviews were transcribed and two independent researchers coded the transcripts and conducted content and thematic analysis using an inductive approach. RESULTS: Participants included 43 caregivers, 84 % were mothers (36/43). CwCF had a mean age of 4 years (SD=2.6), 84 % were White (36/43), and 60 % reported weights below <50th percentile (26/43). All caregivers knew about G-tubes, 44 % (19/43) were recommended a G-tube and 35 % (15/43) had a G-tube placed. Major findings included descriptions of the stages of G-tube decision-making from a heads up, to the game plan, to making a first difficult decision and finally living with the decision to pursue G-tube placement. CONCLUSION: G-tube decision-making is an emotional and personalized journey for caregivers of cwCF. Efforts to explore the values and priorities of caregivers is imperative to supporting families making difficult decisions in CF care.

Development and preliminary validation of the personalized cystic fibrosis medication questionnaire (PCF-MQ).

BACKGROUND: A personalized approach to assessing medication knowledge may identify opportunities for education to support self-management of cystic fibrosis (CF). This project describes the development, scoring, and preliminary validity of the Personalized CF Medication Questionnaire (PCF-MQ), designed to assess knowledge of prescribed CF medication purpose, administration, and dose and frequency. METHODS: Participants completed the PCF-MQ, the Knowledge of Disease Management (KDM-CF), and the Cystic Fibrosis-Medication Beliefs Questionnaire (CF-MBQ). Prescribed regimens were abstracted from medical records. Eligibility criteria were age 12 years and older, diagnosed with CF, and prescribed a CF medication. Statistical analyses were conducted using R software. Spearman rho was used to test correlations between measures. RESULTS: Sixty people with CF (pwCF) were enrolled; three people reported a regimen that substantially deviated from the medical record and were excluded from the analyses. The mean (SD) age was 20.2 (7.3) years, 54 % were female, and 74 % had a FEV1pp ≥70 %. The mean (SD) PCF-MQ total score was 77.8 (12.3) and knowledge scores ranged from a low of 58.3 for levalbuterol to 100 for ivacaftor. The PCF-MQ total score correlated with the KDM total score and subscales (Spearman Rho= 0.32-0.59, p < 0.05) and was not correlated with the CF-MBQ subscales (p > 0.05)). CONCLUSIONS: The PCF-MQ was correlated with another measure of general CF knowledge, but not health beliefs; because of the small sample size, this should be considered preliminary evidence of its validity. Advantages over existing CF knowledge measures include its practicality for use to help assess pwCF's knowledge about their prescribed regimen.

Cross-Cutting mHealth Behavior Change Techniques to Support Treatment Adherence and Self-Management of Complex Medical Conditions: Systematic Review.

Background: Mobile health (mHealth) interventions have immense potential to support disease self-management for people with complex medical conditions following treatment regimens that involve taking medicine and other self-management activities. However, there is no consensus on what discrete behavior change techniques (BCTs) should be used in an effective adherence and self-management-promoting mHealth solution for any chronic illness. Reviewing the extant literature to identify effective, cross-cutting BCTs in mHealth interventions for adherence and self-management promotion could help accelerate the development, evaluation, and dissemination of behavior change interventions with potential generalizability across complex medical conditions. Objective: This study aimed to identify cross-cutting, mHealth-based BCTs to incorporate into effective mHealth adherence and self-management interventions for people with complex medical conditions, by systematically reviewing the literature across chronic medical conditions with similar adherence and self-management demands. Methods: A registered systematic review was conducted to identify published evaluations of mHealth adherence and self-management interventions for chronic medical conditions with complex adherence and self-management demands. The methodological characteristics and BCTs in each study were extracted using a standard data collection form. Results: A total of 122 studies were reviewed; the majority involved people with type 2 diabetes (28/122, 23%), asthma (27/122, 22%), and type 1 diabetes (19/122, 16%). mHealth interventions rated as having a positive outcome on adherence and self-management used more BCTs (mean 4.95, SD 2.56) than interventions with no impact on outcomes (mean 3.57, SD 1.95) or those that used >1 outcome measure or analytic approach (mean 3.90, SD 1.93; P=.02). The following BCTs were associated with positive outcomes: self-monitoring outcomes of behavior (39/59, 66%), feedback on outcomes of behavior (34/59, 58%), self-monitoring of behavior (34/59, 58%), feedback on behavior (29/59, 49%), credible source (24/59, 41%), and goal setting (behavior; 14/59, 24%). In adult-only samples, prompts and cues were associated with positive outcomes (34/45, 76%). In adolescent and young adult samples, information about health consequences (1/4, 25%), problem-solving (1/4, 25%), and material reward (behavior; 2/4, 50%) were associated with positive outcomes. In interventions explicitly targeting medicine taking, prompts and cues (25/33, 76%) and credible source (13/33, 39%) were associated with positive outcomes. In interventions focused on self-management and other adherence targets, instruction on how to perform the behavior (8/26, 31%), goal setting (behavior; 8/26, 31%), and action planning (5/26, 19%) were associated with positive outcomes. Conclusions: To support adherence and self-management in people with complex medical conditions, mHealth tools should purposefully incorporate effective and developmentally appropriate BCTs. A cross-cutting approach to BCT selection could accelerate the development of much-needed mHealth interventions for target populations, although mHealth intervention developers should continue to consider the unique needs of the target population when designing these tools.

Impact of Discontinuing Both Hypertonic Saline and Dornase Alfa After Elexacaftor/Tezacaftor/Ivacaftor in Cystic Fibrosis.

Rationale Evaluating approaches to reduce treatment burden is a research priority among people with CF (pwCF) on highly effective modulators including elexacaftor/tezacaftor/ivacaftor (ETI). Objective To evaluate the impact of discontinuing both hypertonic saline (HS) and dornase alfa (DA) versus continuing both therapies among a subgroup of participants in the SIMPLIFY study who sequentially participated in trials evaluating the independent clinical effects of discontinuing HS and DA. Methods SIMPLIFY participants ≥12 years old on ETI and comprising a subgroup using both HS and DA at study entry were randomized to the HS or DA trial, and then randomized 1:1 to continue or discontinue the applicable therapy for 6 weeks. After completion of the first trial, eligible participants could enroll in the second trial beginning with a 2-week run in. Study outcomes were compared across the duration of SIMPLIFY participation between a cohort remaining on both therapies during SIMPLIFY versus a cohort that sequentially discontinued both as a result of trial randomizations. Multivariable regression models were used to estimate treatment differences, adjusted for time between trials, trial order, baseline age, sex at birth and percent predicted forced expiratory volume in one second (ppFEV1) at study entry. Results There were 43 participants who discontinued both therapies by the end of SIMPLIFY and 63 who remained on both, with overall average ppFEV1 at study entry 96.7% and average duration of follow up from beginning of the first trial to completion of the second trial 3.9 months, including time between trials. No clinically meaningful difference in the change in ppFEV1 from baseline to completion of the second trial was observed between those who discontinued versus remained on both therapies (difference: 0.22% Off-On, 95% CI: -1.60,2.03). Changes in LCI2.5, patient reported, and safety outcomes were also comparable. Patient reported treatment burden, as measured by a CFQ-R subscale, significantly decreased in those discontinuing both therapies. Conclusions SIMPLIFY participants who sequentially discontinued both HS and DA experienced no meaningful changes in clinical outcomes and reported decreased treatment burden as compared to those who remained on both therapies. These data continue to inform a new era of post-modulator care of pwCF.