The role of the inspiratory muscle weakness in functional capacity in hemodialysis patients

Abstract

IntroductionInspiratory muscle function may be affected in patients with End-Stage Renal Disease (ESRD), further worsening the functional loss in these individuals. However, the impact of inspiratory muscle weakness (IMW) on the functional capacity (FC) of hemodialysis patients remains unknown. Thus, the present study aimed to evaluate the impact of IMW on FC in ESRD patients undergoing hemodialysis.Materials and methodsESRD patients on hemodialysis treatment for more than six months were evaluated for inspiratory muscle strength and FC. Inspiratory muscle strength was evaluated based on maximal inspiratory pressure (MIP). IMW was defined as MIP values less than 70% of the predicted value. FC was evaluated using the Incremental Shuttle Walk test (ISWT). Patients whose predicted peak oxygen uptake (VO2peak) over the distance walked during the ISWT was less than 16mL/kg/min were considered to have FC impairment. Associations between variables were assessed by linear and logistic regression, with adjustment for age, sex, body mass index (BMI), presence of diabetes and hemoglobin level. Receiver-operating characteristic (ROC) analysis was used to determine different cutoff values of the MIP for normal inspiratory muscle strength and FC.ResultsSixty-five ERSD patients (67.7% male), aged 48.2 (44.5–51.9) years were evaluated. MIP was an independent predictor of the distance walked during the ISWT (R2 = 0.44). IMW was an independent predictor of VO2peak < 16mL/kg/min. (OR = 5.7; p = 0.048) in adjusted logistic regression models. ROC curves showed that the MIP cutoff value of 82cmH2O had a sensitivity of 73.5% and specificity of 93.7% in predicting normal inspiratory strength and a sensitivity and specificity of 76.3% and 70.4%, respectively, in predicting VO2peak ≥ 16mL/kg/min.ConclusionsIMW is associated with reduced FC in hemodialysis patients. Evaluation of the MIP may be important to functional monitoring in clinical practice and can help in the stratification of patients eligible to perform exercise testing.

Relationships between respiratory muscle strength, chest wall expansion, and functional capacity in healthy nonsmokers

“…Our results are in agreement with previous studies reporting the potential relationship between inspiratory muscle strength and functional capacity (Demir et al, 2018;Zeren et al, 2016). Furthermore, it has been reported that respiratory muscle weakness is associated with reduced functional capacity in hemodialysis patients (Figueiredo et al, 2017). What's more, inspiratory muscle training has been shown to produce advantageous effects in terms of increasing respiratory muscle strength and functional capacity (de Medeiros et al, 2017;Saglam et al, 2015).…”

“…Moreover, weakness of inspiratory muscle is correlated with low functional capacity in end-stage renal disease, chronic obstructive pulmonary disease, and heart failure patients (Du et al, 2017;Singer et al, 2011;Yamada et al, 2016). Recent results showed positive association between inspiratory muscle weakness and functional capacity as measured by distance walked during the incremental shuttle-walk test in hemodialysis patients (Figueiredo et al, 2017). Furthermore, it has been showed that an inspiratoty muscle training improved the distance walked in 6 min among patients with stable chronic heart failure and chronic obstructive pulmonary disease (Du et al, 2017;Martínez et al, 2001).…”

Effects of the inspiratory muscle training and aerobic training on respiratory and functional parameters, inflammatory biomarkers, redox status and quality of life in hemodialysis patients: A randomized clinical trial

“…In addition, the increase in MIP after all interventions was greater than the minimal clinically important difference in individuals with chronic respiratory disease. [ 35 ] Considering that the MIP is an independent preditor to functional capacity in hemodialysis patients, [ 9 ] increases of the distance covered during ISWT would be expected. In fact, we also demonstrated the increase in functional capacity after all three interventions.…”

“…In addition, the inspiratory muscle weakness was an independent predictor of functional capacity impairment in this population. [ 9 ] Thus, inspiratory muscle training (IMT) could improve functional capacity in hemodialysis patients. [ 10 ]…”

Short period of high-intensity inspiratory muscle training improves inspiratory muscle strength in patients with chronic kidney disease on hemodialysis: a randomized controlled trial

“…3 Furthermore, functional capacity impairment is one of the most important risk factor for cardiac death in this population which is 10---20 times higher than in the general population. 4 Impairment of CKD patients' functional capacity is associated with uremic myopathy and HD, with both conditions promoting protein breakdown and which can have an effect on the strength and endurance of both inspiratory and peripheral muscles. 5 CKD patients usually demonstrate a reduction of 40---50% in their exercise capacity when compared to healthy individuals.…”