In persons with multiple sclerosis (MS), the effect of nutrition on exercise performance and fatigue remains unknown. The objective was to determine whether a 3-day diet high in triglycerides (FAT) compared with a 3-day diet high in carbohydrates (CARB) would improve fatigue and exercise performance in persons with MS.A randomized controlled crossover design was incorporated to study FAT versus CARB on submaximal cycling endurance (60% of peak oxygen consumption), substrate utilization, and fatigue in 12 persons with mild-to-moderate MS (Expanded Disability Status Scale score, 2.0-5.0) and 12 age- and sex-matched controls.There were no differences in cycling time between diets in either group (P = .29). The MS group had no changes in fatigue between diets (P = .64); the control group demonstrated increased total mental fatigue after FAT (P = .05). The control group increased carbohydrate oxidation by 24% at rest and 13% during exercise after CARB. Similarly, the control group significantly increased fat oxidation after FAT by 22% at rest and 68% during exercise (P = .01). These changes were not seen in the MS group. Compared with controls, persons with MS oxidized approximately 50% less fat during exercise after FAT (P = .05).Neither CARB nor FAT altered submaximal exercise performance or baseline fatigue in the MS group. The results suggest that persons with MS are unable to adapt to dietary changes and oxidize fatty acids as efficiently as controls.
Abstract Background While often life-saving, treatment for head and neck cancer (HNC) can be debilitating resulting in unplanned hospitalization. Hospitalizations in cancer patients may disrupt treatment and result in poor outcomes. Pre-treatment muscle quality and quantity ascertained through diagnostic imaging may help identify patients at high risk of poor outcomes early. The primary objective of this study was to determine if pre-treatment musculature was associated with all-cause mortality. Methods Patient demographic and clinical characteristics were abstracted from the cancer center electronic database ( n = 403). Musculature was ascertained from pre-treatment CT scans. Propensity score matching was utilized to adjust for confounding bias when comparing patients with and without myosteatosis and with and without low muscle mass (LMM). Overall survival (OS) was evaluated using the Kaplan–Meier method and Cox multivariable analysis. Results A majority of patients were male (81.6%), white (89.6%), with stage IV (41.2%) oropharyngeal cancer (51.1%) treated with definitive radiation and chemotherapy (93.3%). Patients with myosteatosis and those with LMM were more likely to die compared to those with normal musculature (5-yr OS HR 1.55; 95% CI 1.03–2.34; HR 1.58; 95% CI 1.04–2.38). Conclusions Musculature at the time of diagnosis was associated with overall mortality. Diagnostic imaging could be utilized to aid in assessing candidates for interventions targeted at maintaining and increasing muscle reserves.
Respiratory muscle training against resistance (RRMT) increases respiratory muscle strength and endurance as well as underwater swimming endurance. We hypothesized that the latter is a result of RRMT reducing the high energy cost of breathing at depth.Eight subjects breathed air in a hyperbaric chamber at 55 fsw, both before and after RRMT. They rested for 10 minutes, cycled on an ergometer for 10 minutes (100 W), rested for 10 minutes, and then, while still at rest, they voluntarily mimicked the breathing pattern recorded during the exercise (isocapnic simulated exercise ventilation, ISEV).Post-RRMT values of V(E) at rest, exercise and ISEV were not different from those recorded pre-RRMT. Pre-RRMT minute-ventilation (V(E)) during ISEV was not different from the exercise ventilation (49.98 +/- 10.41 vs. 47.74 +/- 8.44 L/minute). The end-tidal PCO2 during ISEV and exercise were not different (44.26 +/- 2.54 vs. 44.49 +/- 4.49 mmHg) or affected by RRMT. Oxygen uptake (VO2) was 0.32 +/- 0.08 L/ minute at rest, 1.78 +/- 0.15 during exercise pre-RRMT, and not different post-RRMT. During ISEV, VO2 decreased significantly from pre-RRMT to post-RRMT (0.46 +/- 0.06 vs. 0.36 +/- 0.11 L/minute). Post-RRMT delta VO2/delta V(E) was significantly lower during ISEV than pre-RRMT (0.0094 +/- 0.0021 L/L vs. 0.0074 +/- 0.0023 L/L).RRMT significantly reduced the energy cost of ventilation, measured as delta VO2/delta V(E) during ISEV, at a depth of 55 fsw. Whether this change was due to reduced work of breathing and/or increased efficiency of the respiratory muscles remains to be determined.
We tested the hypothesis that chronic endurance exercise is associated with the recruitment of four major upper airway muscles (genioglossus, digastric, sternohyoid, and omohyoid) and results in an increased oxidative capacity and a fast-toward-slow shift in myosin heavy chain (MHC) isoforms of these muscles. Female Sprague-Dawley rats (n = 8; 60 days old) performed treadmill exercises for 12 weeks (4 days/week; 90 minutes/day). Age-matched sedentary female rats (n = 10) served as control animals. Training was associated with an increase (p < 0.05) in the activities of both citrate synthase and superoxide dismutase in the digastric and sternohyoid muscles, as well as in the costal diaphragm. Compared with the control animals, Type I MHC content increased (p < 0.05) and Type IIb MHC content decreased (p < 0.05) in the digastric, sternohyoid, and diaphragm muscles of exercised animals. Training did not alter (p > 0.05) MHC phenotype, oxidative capacity, or antioxidant enzyme activity in the omohyoid or genioglossus muscle. These data indicate that endurance exercise training is associated with a fast-to-slow shift in MHC phenotype together with an increase in both oxidative and antioxidant capacity in selected upper airway muscles. It seems possible that this exercise-mediated adaptation is related to the recruitment of these muscles as stabilizers of the upper airway.
Cigarette smoking is an important risk factor in the development of dyspnea. Programs designed to strengthen the respiratory muscles can improve dyspnea in people with or without lung disease. As a first step in understanding the feasibility of offering a respiratory muscle training (RMT) program to people who are seeking help to try to quit smoking, we asked callers who contacted the New York State Quitline about their dyspnea and potential interest in a home-based RMT program. Consecutive callers who contacted the New York State Quitline (n=1019) between 19 May and 9 June 2023 completed the Modified Medical Research Council (mMRC) dyspnea scale and reported their level of interest in RMT. Participants were categorized as: high breathlessness (HB: 0-1), or low breathlessness (LB: 2-4). We examined characteristic differences between participants who reported HB versus LB and examined differences in level of interest in home-based RMT. Those with HB were older [mean (SD): 61.3 (12.5) vs 53.6 (15.0) years, p<0.001], had more cumulative years of smoking [38.8 (15.1) vs 28.8 (15.4) years, p<0.001], smoked more cigarettes per day [19.3 (10.5) vs 17.3 (8.8), p<0.01], reported more disability (p<0.001) and chronic health conditions (78.5% vs 53.9%, p<0.001). Those with HB also expressed greater interest in RMT [7.8 (3.3) vs 6.2 (4.1), p<0.001]. These preliminary findings suggest that about 20% of quitline callers report clinically significant levels of breathlessness and most respondents, regardless of their level of breathlessness, report interest in a home-based RMT program, underscoring a potential opportunity to offer this program along with cessation support.
We sought to assess the associations between nutrition and ambulation, daily activity, quality of life (QOL), and fatigue in individuals with mild-to-moderate disability with multiple sclerosis (MS).This cross-sectional pilot study included 20 ambulatory adult volunteers with MS (14 women and 6 men; mean ± SD age, 57.9 ± 10.2 years; mean ± SD Expanded Disability Status Scale score = 4.1 ± 1.8). Primary outcome variables included dietary assessment and the 6-Minute Walk Test (6MWT). Secondary measures included the Timed 25-Foot Walk test, Timed Up and Go test, daily activity, and three self-report questionnaires: the 12-item Multiple Sclerosis Walking Scale, the 36-item Short Form Health Survey (SF-36), and the Modified Fatigue Impact Scale.Significant correlations were seen between the percentage of diet comprising fats and the 6MWT (r = 0.51, P = .02) and the physical functioning component of the SF-36 (r = 0.47, P = .03). The percentage of carbohydrates was significantly correlated with the 6MWT (r = -0.43, P = .05), daily activity (r = -0.59, P = .005), and the physical functioning component of the SF-36 (r = -0.47, P = .03). Cholesterol, folate, iron, and magnesium were significantly positively correlated with the physical functioning component of the SF-36 and the 6MWT.These findings indicate better ambulation, daily function, and QOL with increased fat intake, decreased carbohydrate intake, and increased intake of the micronutrients cholesterol, folate, iron, and magnesium in people with mild-to-moderate MS. This pilot study highlights the potential impact of diet on function and QOL in MS.
e18597 Background: Head and neck cancer (HNC) is a debilitating disease that affects tens of thousands each year and both the disease and its treatment can cause long-term morbidity. HNC patients with greater physical function at baseline may better withstand both disease and treatment, therefore we hypothesized that baseline physical function is associated with baseline skeletal muscle density (SMD). Methods: A cross-sectional study of existing medical records was conducted. SMD was classified using pre-treatment PET-CT scans and interpreted using Sliceomatic software, and pre-treatment physical function assessed in three ways: hand grip strength, timed up and go, and short physical performance battery. Linear regression models were utilized to assess the association between SMD and each measure of physical function, with adjustment for muscle mass, sex and cancer stage in the hand grip strength model and adjustment for muscle mass and age in both the timed up and go, and short physical performance battery models. Results: The sample of 90 HNC patients, was mostly white, male, former smokers with an average BMI of 28 kg/m2. In adjusted models that included men only, we observed that for every Hounsfield unit increase in SMD there was a 0.08 increase in SPPB score (p=0.005), a 0.31 kg increase in hand grip strength (p=0.04), and a 0.13 second decrease in timed up and go (p=0.0007). In adjusted models that included women only, we observed that for every Hounsfield unit increase in SMD there was a 0.03 decrease in SPPB score (p=0.75), a 0.12 kg increase in hand grip strength (p=0.65), and a 0.01 second increase in timed up and go (p=0.84). Conclusions: Baseline physical function is associated with higher baseline physical SMD. Larger studies involving a more women are needed to replicate these findings and to further examine the potential role of effect modification by both sex and muscle mass.
