Association between Vitamin D Level and Muscle Strength in Patients Undergoing Hemodialysis

Serum 25-Hydroxyvitamin D Level Is Negatively Associated with Fatigue in Elderly Maintenance Hemodialysis Patients

INTRODUCTION

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is frequently observed in maintenance hemodialysis (MHD) patients and is associated with fracture, muscle weakness, malnutrition, etc.; however, relationships of CKD-MBD markers and fatigue are not well established.

METHODS

This was a cross-sectional study including 244 MHD patients (89 elders) from July to September 2021 in the First Affiliated Hospital of Shandong First Medical University. CKD-MBD markers and other clinical data were collected from medical records. Fatigue in the past week was measured by Standardized Outcomes in Nephrology-Hemodialysis (SONG-HD) fatigue measure; fatigue at the end of hemodialysis was measured by numeric rating scale (NRS). Spearman correlation, linear regression, and robust linear regression were.

RESULTS

In all MHD patients, lg[25(OH)D] (nmol/L) was negatively correlated with SONG-HD score (β = -1.503, 95% CI: -2.826 to 0.18, p = 0.026) and NRS score (β = -1.532, p = 0.04) in multiple regression models adjusting for sex, age, and all CKD-MBD characters; but no correlations were found on univariate regression or in other multiple regression models. Interaction effects between age ≥65 years and lg(25[OH]D [nmol/L]) in terms of fatigue scores were significant based on multiple linear regressions (SONG-HD score β = -3.613, p for interaction = 0.006; NRS score β = -3.943, p for interaction = 0.008). Compared with non-elderly patients, elderly patients were with higher ACCI scores (7 [6, 8] vs. 4 [3, 5], p < 0.001), higher SONG-HD scores (3 [2, 6] vs. 2 [1, 3], p < 0.001), higher NRS score (4 [2, 7] vs. 3 [1, 5], p < 0.001), lower serum phosphate levels (1.65 [1.29, 2.10] vs. 1.87 [1.55, 2.26] mmol/L, p = 0.002), and lower serum iPTH levels (160.6 [90.46, 306.45] vs. 282.2 [139, 445.7] pg/mL, p < 0.001). There were no differences in serum calcium, alkaline serum, or 25(OH)D levels between the two groups. In elderly patients, lg[25(OH)D] was negatively correlated with SONG-HD score (β = -3.323, p = 0.010) and NRS score (β = -3.521, p = 0.006) on univariate linear regressions. Following adjustment for sex, age, and all CKD-MBD characters, lg[25(OH)D] was negatively correlated with SONG-HD scores (multiple linear regression β = -4.012, p = 0.004; multiple robust regression β = -4.012, p = 0.003) or NRS scores (multiple linear regression β = -4.104, p = 0.002; multiple robust regression β = -4.104, p = 0.001). There were no significant correlations between fatigue scores and other CKD-MBD markers (calcium, phosphate, lgiPTH, alkaline phosphatase) in elderly MHD patients, on either univariate linear regressions or multiple regressions.

CONCLUSION

Serum 25(OH)D level is negatively associated with fatigue in elderly MHD patients.

Association of serum 25-hydroxy vitamin D with gait speed and handgrip strength in patients on hemodialysis

BACKGROUND

Muscle dysfunction is prevalent in dialysis patients. Gait speed and handgrip strength are simple and reliable methods of assessing muscle function. Numerous observational studies have linked 25-hydroxy vitamin D[25(OH)D] status with gait speed and handgrip strength in populations without kidney diseases. This study aimed to evaluate the potential associations of 25(OH)D status with gait speed and handgrip strength in patients on hemodialysis.

METHODS

In this observational cross-sectional study, demographic data, biological data, and dialysis parameters were collected. Gait speed and handgrip strength were measured. Multiple linear regression and logistic regression analysis were used to investigate the relationship of 25(OH)D status with gait speed and handgrip strength after adjusting for potential confounders.

RESULTS

Overall, a total of 118 participants undergoing hemodialysis were included. Seventy-one (60.2%) participants were male. The median 25(OH)D status in participants was 11.58 (interquartile range: 8.51 to 15.41) ng/ml. When controlling for age, gender, dialysis vintage, and other confounders with a p-value < 0.15 in univariate analyses, 25(OH)D was significantly positively associated with gait speed (β = 0.16, 95% CI 0.05 to 0.28, p = 0.006) and handgrip strength (β = 3.83, 95% CI 1.09 to 6.56, p = 0.007).

CONCLUSION

Our study showed that 25(OH)D status seemed to be associated with gait speed and handgrip strength in patients on hemodialysis. However, these results were not robust. The relationships between 25(OH)D status and gait speed and handgrip should be further explored.

Impedance-derived phase angle is associated with muscle mass, strength, quality of life, and clinical outcomes in maintenance hemodialysis patients

INTRODUCTION

We aimed to evaluate the association between the phase angle and muscle mass, muscle strength, physical performance tests, quality-of-life scales, mood scales, or patient and hospitalization-free survival rates in hemodialysis (HD) patients.

METHODS

We included 83 HD patients. The patients were divided into tertiles based on phase angle value. The phase angle was measured using a bioimpedance analysis machine. Thigh muscle area per height squared (TMA/Ht2), handgrip strength (HGS), nutritional indicators, physical performance, quality-of-life, depression or anxiety status, and the presence of hospitalization or death regardless of cause were evaluated.

RESULTS

In our study, no significant differences were observed in the serum albumin level and body mass index according to tertiles of phase angle. The phase angle tertiles were associated with TMA/Ht2 and HGS. The phase angle was also associated with physical performance measurements and depression or anxiety status. Subgroup analyses according to sex, age, and diabetes mellitus showed similar trends to those of the total cohort. Furthermore, the hospitalization-free survival rate and patient survival rate were favorable in patients with high values for the phase angle.

CONCLUSION

The present study demonstrated that the phase angle is associated with muscle mass, strength, physical performance, quality-of-life scale, and hospitalization-free survival in maintenance HD patients.

Vitamin D and skeletal muscle: A narrative review focusing on chronic kidney disease and dialysis

Morphological, molecular, and physiological effects of vitamin D on skeletal muscle have been analyzed both in animals and humans. Vitamin D may be a potential therapeutic for increasing muscle mass and function. The presence of vitamin D receptors in skeletal muscle cells is already established. However, there is still need for more evidence about the effect of vitamin D on muscle. Some studies have associated vitamin D and skeletal muscle in chronic kidney disease (CKD) patients; most of these studies enrolled hemodialysis patients. FGF-23 and Klotho were recently described in mineral and bone disorders in CKD, resulting in reductions in calcitriol levels. Therefore, both Klotho and FGF-23 may play a role in muscle loss in CKD, which is related to morbidity and mortality risk. Therefore, this article presents a narrative review, aiming to discuss the available information associating skeletal muscle and vitamin D, highlighting the results in CKD and dialysis patients.