Resistance training and testosterone levels in male patients with chronic kidney disease undergoing dialysis

Role of endocrine factors and stem cells in skeletal muscle regeneration

The process of reconstructing damaged skeletal muscles involves degeneration, inflammatory and immune responses, regeneration and reorganization, which are regulated by a number of immune-endocrine factors affecting muscle cells and satellite cells (SCs). One of these molecules is testosterone (T), which binds to the androgen receptor (AR) to initiate the expression of the muscle isoform of insulin-like growth factor 1 (IGF-1Ec). The interaction between T and IGF-1Ec stimulates the growth and regeneration of skeletal muscles by inhibiting apoptosis, enhancement of SCs proliferation and myoblasts differentiation. As a result of sarcopenia, muscle dystrophy or wasting diseases, the SCs population is significantly reduced. Regular physical exercise attenuates a decrease in SCs count, and thus elevates the regenerative potential of muscles in both young and elderly people. One of the challenges of modern medicine is the application of SCs and extracellular matrix scaffolds in regenerative and molecular medicine, especially in the treatment of degenerative diseases and post-traumatic muscle reconstruction. The aim of the study is to present current information on the molecular and cellular mechanisms of skeletal muscle regenera,tion, the role of testosterone and growth factors in the activation of SCs and the possibility of their therapeutic use in stimulating the reconstruction of damaged muscle fibers.

An Exercise Program for Peritoneal Dialysis Patients in the United States: A Feasibility Study

BACKGROUND

People with end-stage kidney disease receiving peritoneal dialysis (PD) are generally physically inactive and frail. Exercise studies in PD are scarce and currently there are no PD exercise programs in the United States. The primary objective of this study was to test the feasibility of a combined resistance and cardiovascular exercise program for PD patients under the care of a dedicated home dialysis center in the United States.

STUDY DESIGN

Parallel randomized controlled feasibility study.

SETTING & PARTICIPANTS

PD patients were recruited from a single center and randomly assigned to the intervention (exercise; n = 18) or control (nonexercise; n = 18) group.

INTERVENTION

The intervention group received monthly exercise physiologist consultation, exercise prescription (resistance and aerobic exercise program using exercise bands), and 4 exercise support telephone calls over 12 weeks. The control group received standard care.

OUTCOMES

The primary outcome was study feasibility as measured by eligibility rates, recruitment rates, retention rates, adherence rates, adverse events, and sustained exercise rates. Secondary outcome measures were changes in physical function (sit-to-stand test, timed-up-and-go test, and pinch-strength tests) and patient-reported outcome measures.

RESULTS

From a single center with 75 PD patients, 57 (76%) were deemed eligible, resulting in a recruitment rate of 36 (63%) patients. Participants were randomly assigned into 2 groups of 18 (1:1). 10 patients discontinued the study (5 in each arm), resulting in 26 (72%) patients, 13 in each arm, completing the study. 10 of 13 (77%) intervention patients were adherent to the exercise program. A t test analysis of covariance found a difference between the treatment groups for the timed-up-and-go test (P = 0.04) and appetite (P = 0.04). No serious adverse events caused by the exercise program were reported.

LIMITATIONS

Single center, no blinded assessors.

CONCLUSIONS

A resistance and cardiovascular exercise program appears feasible and safe for PD patients. We recommend that providers of PD therapy consider including exercise programs coordinated by exercise professionals to reduce the physical deterioration of PD patients.

FUNDING

None.

TRIAL REGISTRATION

NCT03980795.

Effects of intradialytic resistance exercise on systemic inflammation in maintenance hemodialysis patients with sarcopenia: a randomized controlled trial

PURPOSE

To investigate the effect of intradialytic resistance exercise on inflammation markers and sarcopenia indices in maintenance hemodialysis (MHD) patients with sarcopenia.

METHODS

Forty-one MHD patients with sarcopenia were divided into an intervention group (group E, n = 21) and a control group (group C, n = 20). Group C patients only received routine hemodialysis care, whereas group E patients received progressive intradialytic resistance exercise with high or moderate intensity for 12 weeks at three times per week (using the weight of the lower limbs and elastic ball movement of the upper limb) on the basis of routine hemodialysis care.

RESULTS

After 12 weeks, a significant difference in physical activity status (maximum grip strength, daily pace, and physical activity level), Kt/V, and C-reactive protein was found between groups E and C. Inflammatory factors (interleukin (IL)-6, IL-10, and tumor necrosis factor(TNF)-α) increased or decreased more significantly in group E than in group C.

CONCLUSIONS

This study showed that intradialytic resistance exercise can improve physical activity effectively and reduce microinflammatory reactions even if this simple exercise does not affect the muscle mass in MHD patients with sarcopenia.