The interaction of aging with serum 25(OH)D and 1,25(OH)2 D status on muscle strength

Vitamin D level as a predictor of dysmobility syndrome with type 2 diabetes

Dysmobility Syndrome (DMS), is a combination, that is analogous to the approach taken with metabolic syndrome, The diagnosis of DMS is complex. So this study aimed to explore the relationship between 25-(OH) Vit D with Dysmobility Syndrome (DMS)in type 2 diabetes mellitus(T2DM) patients. This is a cross-sectional study, including 330 patients (67.0 ± 8.8 years old) with T2DM who were admitted to the Qinhuangdao First Hospital from October 2020 to February 2022. Selected independent variables include grip strength, six-meter gait speed, level of 25-(OH) vitamin D, and bone mineral density (BMD) measured by Dual-energy X-ray (DXA). DMS includes six conditions: osteoporosis, low muscle mass, low muscle strength, slow gait speed, occurrences of falls in the past year ≥ 1, and obesity, having three or more of these conditions were diagnosed with DMS. Patients were classified based on DMS. The detection rate of DMS in patients with T2DM was 25.5%. The proportion of vitamin deficiency is 67.9% in patients with T2DM. The 25-(OH) Vit D deficiency was defined based on the 25th percentile into two groups; < 36.2 nmol/L. The vitamin D levels in Group DMS were significantly lower than that in Group Non-DMS (41.74 ± 14.60 vs. 47.19 ± 13.01, P < 0.05). After adjusting confounder factors including sex, age, vitamin D levels, HbA1c, ALB, HDLC, eGFR, diabetes microvascular complications and macrovascular, there was an independent association between risk of DMS and age (OR value = 1.160, 95% CI 1.091-1.234, P = 0.000), HbA1c(OR value = 1.262, 95% CI 1.046-1.532, P = 0.015), and vitamin D deficiency (< 36.2 nmol/L) (OR value = 2.990, 95% CI 1.284-6.964, P = 0.011). Our findings suggest that low levels of vitamin D are a predictor of DMS in middle-aged and elderly patients with poor control of type 2 diabetes.

Effect of vitamin D monotherapy on indices of sarcopenia in community-dwelling older adults: a systematic review and meta-analysis

BACKGROUND

Vitamin D supplementation is proposed as a potentially effective nutritional intervention to mitigate the risk of sarcopenia. The aim of this systematic review and meta-analysis was to investigate the impact of vitamin D supplementation monotherapy on indices of sarcopenia in community-dwelling older adults.

METHODS

A comprehensive search of the literature was conducted in PubMed, Web of Science, Scopus, and Cochrane Library. Eligible randomized controlled trials (RCTs) compared the effect of vitamin D supplementation (as monotherapy) with placebo on indices of sarcopenia in older (>50 years) adults. Using the random effects inverse-variance model, we calculated the mean difference (MD) in handgrip strength (HGS), short physical performance battery (SPPB), timed up and go (TUG), and appendicular lean mass (ALM) between groups. We also calculated the standardized mean difference (SMD) in general muscle strength and general physical performance (composite plot of all muscle strength and physical performance outcomes, respectively) between groups.

RESULTS

Ten RCTs were included in the meta-analysis. A significant decrease in SPPB scores was observed with vitamin D supplementation compared with placebo (MD: -0.23; 95% CI -0.40 to -0.06; I²  = 0%; P = 0.007). Vitamin D supplementation conferred no effect on HGS (MD: -0.07 kg; 95% CI -0.70 to 0.55; I²  = 51%, P = 0.82), TUG (MD: 0.07 s; 95% CI -0.08 to 0.22; I²  = 0%, P = 0.35), ALM (MD: 0.06 kg/m² ; 95% CI: -0.32 to 0.44; I²  = 73%, P = 0.77), general muscle strength (SMD: -0.01; 95% CI -0.17 to 0.15; I²  = 42%, P = 0.90), or general physical performance (SMD: -0.02; 95% CI -0.23 to 0.18; I²  = 71%, P = 0.83).

CONCLUSIONS

Vitamin D supplementation did not improve any sarcopenia indices in community-dwelling older adults and may compromise some aspects of physical performance. Future studies are warranted to investigate the impact of vitamin D supplementation on individual indices of SPPB, including mobility and balance, in older adults.