Effect of Peripheral and Respiratory Muscle Training on the Functional Capacity of Hemodialysis Patients

Figures & data

Table 1.  Demographic and clinical data of the patients on HD.

	RMT (n = 11)	PMT (n = 14)	C (n = 14)	p
Age (years)	43 (13.8)^†	48.9 (10.1)	51.9 (11.6)	0.18
Gender (males), n (%)	8 (73)	7 (50)	8 (57)	0.60
Etiology of CKD, n (%)				0.82
SAH	4 (36.4)	5 (35.7)	5 (35.7)
DM	4 (36.4)	4 (28.6)	5 (35.7)
CGN	3 (27.2)	2 (14.4)	3 (21.5)
Others	0 (0)	3 (21.4)	1 (7.1)
BMI (kg/m^2)	22.2 (4.2)^†	23.1 (2.6)	24.1 (3.6)	0.42
Number of comorbidities	2.3 (0.8)	2.4 (0.9)	2.8 (0.4)	0.216
Erythropoietin dose (U/kg/week)	200.4 (19.2)	203.5 (23.7)	199.9 (20.2)	0.23
Baseline dry weight (kg)	59.2 (15.6)	64.1 (11.7)	62.6 (11.8)	0.64
Time on HD (months)	60 (24–132)^‡	54 (10.7–120)	54 (12–78)	0.757
Length of HD session (h)	3.9 (0.2) ^†	3.9 (0.2)	3.9 (0.4)	0.98
Blood flow rate (mL/min)	331.8 (25.2)	335.7 (23.4)	330.0 (33.7)	0.86
Dialysate flow rate (mL/min)	663.6 (80.9)	671.4 (72.6)	642.9 (93.8)	0.64
Prescribed UF rate (L)	2.9 (1.7–4.4)	2.4 (1.4–3.3)	2.9 (2.6–4.0)	0.45
Δ Weight during the session (kg)	−2.1 (−3.9 to −1.4)	−2.2 (−3.1 to −1.2)	−2.0 (−3.8 to −1.5)	0.764

Notes: HD, hemodialysis; RMT, respiratory muscle training group; PMT, peripheral muscle training group; C, control group; CKD, chronic kidney disease; SAH, systemic arterial hypertension; DM, diabetes mellitus; CGN, chronic glomerulonephritis; BMI, body mass index; UF, ultrafiltration.

^†Mean (standard deviation).

^‡Median and interquartile range.

Table 2.  Respiratory and peripheral functional variables before and after the muscle training.

	RMT (n = 11)	PMT (n = 14)	C (n = 14)	p
Baseline PImax (cmH2O)	−64.9 (26.8)^†	−55.2 (32.3)	−70.0 (22.4)	0.36
Post-intervention PImax (cmH2O)	−87.4 (24.7)*	−65 (30.7)**	−64.6 (25.3)**	<0.001
Δ PImax (cmH2O)	22.5 (3.2)^‡*	9.1 (2.9)**	−4.9 (2.8)***	<0.001
Δ% of predicted PImax	21.5 (3.3)*	9 (3)**	−5.1 (3)***	<0.001
Baseline PEmax (cmH2O)	79.7 (27.1)	73.3 (28.4)	94.12 (42.8)	0.27
Post-intervention PEmax (cmH2O)	91.4 (35.4)*	79.7 (33.1)*,**	75.3 (29.7)**	0.02
Δ PEmax (cmH2O)	10.8 (6.6)*	3.7 (5.9)*,**	−15.6 (5.9)**	0.01
Δ% of predicted PEmax	6 (5.3)*	2.5 (4.7)*,**	−12.4 (4.9)**	0.03
Baseline FVC (L)	2.8 (0.7)	2.7 (0.8)	3.0 (0.9)	0.65
Post-intervention FVC (L)	3.4 (1.1)	3.4 (1.8)	2.7 (1.1)	0.58
Δ FVC (L)	0.5 (0.2)*	0.6 (0.2)*	−0.2 (0.2)**	0.00
Δ% of predicted FVC	2.2 (5.7)	6.1 (5)	10.1 (5)	0.57
Baseline 6MWT (m)	454.1 (95.8)	444.6 (75.3)	406.7 (117.6)	0.43
Post-intervention 6MWT (m)	519 (103.8)*	475 (74.1)**	407 (116.7)***	<0.001
Δ 6MWT (m)	65.5 (9)*	30.8 (8)**	−0.5 (8.1)***	<0.001
Δ% of predicted 6MWT	10.1 (1.4)*	5.1 (1.3)**	−0.1 (1.3)***	<0.001

Notes: RMT, respiratory muscle training group; PMT, peripheral muscle training group; C, control group; PI_max, maximal inspiratory pressure; PE_max, maximal expiratory pressure; FVC, forced vital capacity; 6MWT, six-minute walk test.

^†Mean (standard deviation).

^‡Estimated mean (standard errors) of the covariance analyses of delta values (Δ) corrected by baseline values.

*, **^{, or} *** means followed by different symbols are statistically different (p < 0.05).

Table 3.  Biochemical and inflammatory parameters before and after muscle training of patients on HD.

	RMT (n = 11)	PMT (n = 14)	C (n = 14)	p
Baseline hemoglobin (g/dL)	10.8 (1.4)^†	10.5 (1.8)	10.7 (1.3)	0.91
Δ Hemoglobin (g/dL)	2.3 (0.4)*^,†	0.6 (0.4)**	0.5 (0.4)**	0.007
Baseline creatinine (mg/dL)	11.5 (2.7)*	12.2 (2.8)*	7.7 (3.7)**	0.01
Baseline urea (mg/dL)	194.1 (51.1)	155 (51.7)	172.3 (48.5)	0.17
Δ Urea (mg/dL)	4.5 (13)*	10.5 (11.5)*	−3.5 (11.2)*	0.68
Baseline potassium (mEq/L)	6.0 (1.1)	5.5 (0.9)	5.6 (0.9)	0.44
Δ Potassium (mEq/L)	−0.5 (0.2)*	−0.5 (0.2)*	0.6 (0.2)**	0.001
Baseline phosphorus (mg/dL)	6.9 (2.7)	6.5 (1.5)	5.9 (1.6)	0.40
Δ Phosphorus (mg/dL)	−0.5 (0.2)*	−0.4 (0.2)*	0.6 (0.2)**	0.001
Baseline albumin (mg/dL)	3.2 (0.3)	3.3 (0.5)	3.4 (0.3)	0.18
Δ Albumin (mg/dL)	0.1 (0.1)*	0.1 (0.1)*,**	−0.2 (0.1)**	0.02
Baseline hsCRP (mg/L)	9.5 (3.6–25.6)^§	3.6 (1.8–13.4)	4.1 (0.5–7.6)	0.42
Δ hsCRP (mg/L)	−6.1 (−18.7 to −0.4)*,^¶	−2.2 (−8.6 to −0.4)*	0.7 (−0.7 to −6.6)**	0.01

Notes: Biochemical parameters: serum levels. HD, hemodialysis; RMT, respiratory muscle training group; PMT, peripheral muscle training group; C, control group; hsCRP, high sensitivity C-reactive protein.

^†Mean (standard deviation).

^‡Estimated mean ± standard error of the covariance analyses of delta values (Δ) corrected by baseline values.

^§Median and interquartile range.

^¶Analysis of Δ hsCRP was made by ranks corrected by baseline values and expressed by the medians (without correction). *, **^{, or} *** means followed by different symbols are statistically different (p < 0.05).

Figure 1 . Median of C-reactive protein (mg/L) at baseline and after ten weeks of muscle training in respiratory and peripheral training and in control groups (Δ RMT vs. Δ C, p = 0.001; Δ PMT vs. Δ C, p = 0.03).

Figure 2 . Improvement in quality of life domains after ten weeks of muscle training in respiratory and peripheral training and in control groups.

Table 4.  Effect size of muscle training on functional and biochemical variables.

	RMT (n = 11)	PMT (n = 14)
Δ PImax	2.68 (1.43–3.52)^†	1.48 (0.54–2.19)
Δ PEmax	1.17 (0.24–1.93)	1.05 (0.19–1.75)
Δ FVC	1.32 (0.36–2.08)	1.26 (0.36–1.97)
Δ6MWT	1.94 (0.86–2.73)	1.08 (1.78–0.91)
Δ Hemoglobin (g/dL)	1.02 (0.11–1.78)	0.12 (−0.63–0.85)
Δ Albumin (mg/dL)	1.54 (0.54–2.30)	0.84 (0.00–1.54)
Δ Potassium (mEq/L)	−1.58 (−2.35 to −0.57)	−1.21 (−1.92 to −0.32)
Δ Phosphorus (mg/dL)	−1.58 (−2.35 to −0.57)	−1.21 (−1.92 to −0.32)

Notes: RMT, respiratory muscle training group; PMT, peripheral muscle training group; C, control group; PI_max, maximal inspiratory pressure; PE_max, maximal expiratory pressure; FVC, forced vital capacity; 6MWT, six-minute walk test.

^†Effect size (confidence interval, 95%).