Effectiveness of a resistance exercise program for lower limbs in chronic renal patients on hemodialysis: A randomized controlled trial

INTRODUCTION

Physical inactivity in hemodialysis patients is associated with increased mortality. The objective of this study was evaluated the effect of an intradialytic resistance exercise program on chronic kidney disease (CKD) patients on hemodialysis.

METHODS

One hundred seven patients were included in the study. They were aged 18-60 years, of both sexes, had undergone hemodialysis treatment for at least 1 year, sedentary. Patients were randomly divided into two groups: stretching (STG) and resistance exercise (REG). Intervention programs were performed for 8 weeks, three times a week. The evaluations were performed before and after the training programs. The primary outcome was functional capacity using the 6-minute walk test (6MWT). Secondary outcomes were peripheral muscle strength, respiratory muscle strength, spirometric respiratory function, and laboratory data.

FINDINGS

Comparisons between groups revealed the following clinically relevant results in favor of REG: lower limb muscle strength (mean difference [MD] = -1.99, 95% confidence interval [CI] = -2.77 to -1.21; d = -0.53), distance walked in the 6MWT (MD = -26.27, 95% CI = -45.40 to -7.14; d = -0.46), creatinine (MD = -1.52, 95% CI = -2.49 to -0.54; d = -0.66), and calcium (MD = -0.44, 95% CI = -0.78 to -0.10; d = -0.49).

DISCUSSION

CKD patients on hemodialysis have reduced functional capacity compared to healthy sedentary individuals. In turn, this reduction appears to be associated with a lower survival rate and affects the performance of their daily living activities. Thus, resistance exercise performed in the intradialytic phase is an effective therapeutic strategy for CKD patients, mainly because it increases functional capacity and lower limb muscle strength.

Protective effects of spirulina against hemato-biochemical alterations, nephrotoxicity, and DNA damage upon lead exposition

The current study was aimed at exploring the protective efficacy of spirulina against the hemato-biochemical alterations and nephrotoxicity induced by lead (Pb). Female rats aged 12 weeks were treated for 4 weeks with Pb (0.344 g kg^-1 bw) associated or not with spirulina (5.3 g kg^-1 bw). Renal damage induced by Pb was related to a severe anemia, increases of oxidative stress-related parameters (thiobarbituric acid reactive substances (TBARS) (+29%), protein carbonyl (PCO) (+66.3%), and advanced oxidation protein product (AOPP) (+110%)), plasma lactate dehydrogenase (LDH) (+80%), creatinine and urea levels in plasma, and uric acid concentration in urine, as well as genotoxic changes (+89.3% and +60% for DNA and mRNA levels, respectively). Conversely, LDH and antioxidant enzyme activities in kidney were decreased, as well as the levels of plasma uric acid, and urinary creatinine and urea levels. Spirulina-supplemented rats exhibited normal peripheral blood and renal parameters and renal histology. It can be suggested that Arthrospira platensis alleviates damages induced by Pb, thanks to its high phenolic content and antioxidant capacity.

Respiratory sympathetic modulation is augmented in chronic kidney disease

Respiratory modulation of sympathetic nerve activity (respSNA) was studied in a hypertensive rodent model of chronic kidney disease (CKD) using Lewis Polycystic Kidney (LPK) rats and Lewis controls. In adult animals under in vivo anaesthetised conditions (n = 8-10/strain), respiratory modulation of splanchnic and renal nerve activity was compared under control conditions, and during peripheral (hypoxia), and central, chemoreceptor (hypercapnia) challenge. RespSNA was increased in the LPK vs. Lewis (area under curve (AUC) splanchnic and renal: 8.7 ± 1.1 vs. 3.5 ± 0.5 and 10.6 ± 1.1 vs. 7.1 ± 0.2 μV.s, respectively, P < 0.05). Hypoxia and hypercapnia increased respSNA in both strains but the magnitude of the response was greater in LPK, particularly in response to hypoxia. In juvenile animals studied using a working heart brainstem preparation (n = 7-10/strain), increased respSNA was evident in the LPK (thoracic SNA, AUC: 0.86 ± 0.1 vs. 0.42 ± 0.1 μV.s, P < 0.05), and activation of peripheral chemoreceptors (NaCN) again drove a larger increase in respSNA in the LPK with no difference in the response to hypercapnia. Amplified respSNA occurs in CKD and may contribute to the development of hypertension.

Clinical study of Shengxuening tablet combined with rHuEPO for the treatment of renal anemia of maintenance hemodialysis patients

The aim of the present study was to investigate the clinical effects of Shengxuening tablet (silkworm excrement) combined with recombinant human erythropoietin (rHuEPO) for the treatment of renal anemia of maintenance hemodialysis (MHD) patients. Seventy-two MHD patients with renal anemia were included in the study and randomly divided into the control (n=34) and observation (n=38) groups. Patients in the control group were treated by hypodermic injection of 100-150 U/(kg·w) rHuEPO and patients in the observation group were treated by rHuEPO + 1.0 g t.i.d. p.o. Shengxuening tablet. The two groups were assisted by conventional treatments including iron, folic acid, vitamin B12 and L-carnitine. After 3 and 6 months, improvement of anemia was compared. After 3 months, the hemoglobin, hematocrit, serum ferritin and transferrin saturation levels of the observation group were significantly higher than those of the control group (p<0.05). In addition, C-reactive protein and superoxide dismutase levels of the observation group were significantly lower than those of the control group (p<0.05). After 6 months, indices of the observation group were ameliorated while the improvement of control group was not obvious, and indices of the observation group were significantly higher than those of the control group (p<0.05). Consumption of rHuEPO in the observation group was significantly less than that of the control group, and the total effective rate was significantly higher than that of the control group (p<0.05). In conclusion, Shengxuening tablet combined with rHuEPO was safe and effective for the treatment of renal anemia of MHD patients.

Abnormalities associated with progressive aortic vascular dysfunction in chronic kidney disease

Increased stiffness of large arteries in chronic kidney disease (CKD) has significant clinical implications. This study investigates the temporal development of thoracic aortic dysfunction in a rodent model of CKD, the Lewis polycystic kidney (LPK) rat. Animals aged 12 and 18 weeks were studied alongside age-matched Lewis controls (total n = 94). LPK rodents had elevated systolic blood pressure, left ventricular hypertrophy and progressively higher plasma creatinine and urea. Relative to Lewis controls, LPK exhibited reduced maximum aortic vasoconstriction (R_max) to noradrenaline at 12 and 18 weeks, and to K⁺ (12 weeks). Sensitivity to noradrenaline was greater in 18-week-old LPK vs. age matched Lewis (effective concentration 50%: 24 × 10⁻⁹ ± 78 × 10⁻¹⁰ vs. 19 × 10⁻⁸ ± 49 × 10⁻⁹, P < 0.05). Endothelium-dependent (acetylcholine) and -independent (sodium nitroprusside) relaxation was diminished in LPK, declining with age (12 vs. 18 weeks R_max: 80 ± 8% vs. 57 ± 9% and 92 ± 6% vs. 70 ± 9%, P < 0.05, respectively) in parallel with the decline in renal function. L-Arginine restored endothelial function in LPK, and L-NAME blunted acetylcholine relaxation in all groups. Impaired nitric oxide synthase (NOS) activity was recovered with L-Arginine plus L-NAME in 12, but not 18-week-old LPK. Aortic calcification was increased in LPK rats, as was collagen I/III, fibronectin and NADPH-oxidase subunit p47 (phox) mRNAs. Overall, our observations indicate that the vascular abnormalities associated with CKD are progressive in nature, being characterized by impaired vascular contraction and relaxation responses, concurrent with the development of endothelial dysfunction, which is likely driven by evolving deficits in NO signaling.