COVID-19 and vitamin D (Co-VIVID study): a systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: Vitamin D levels have been reported to be associated with COVID-19 susceptibility, severity, and mortality events. We performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the use of vitamin D intervention on COVID-19 outcomes. AREAS COVERED: Literature search was conducted using PubMed, Cochrane library, and ClinicalTrials.gov databases. We included RCTs reporting the use of vitamin D intervention to control/placebo group in COVID-19. The study was registered at PROSPERO: CRD42021271461. EXPERT OPINION: A total of 6 RCTs with 551 COVID-19 patients were included. The overall collective evidence pooling all the outcomes across all RCTs indicated the beneficial use of vitamin D intervention in COVID-19 (relative risk, RR = 0.60, 95% CI 0.40 to 0.92, Z = 2.33, p = 0.02, I2 = 48%). The rates of RT-CR positivity were significantly decreased in the intervention group as compared to the non-vitamin D groups (RR = 0.46, 95% CI 0.24 to 0.89, Z = 2.31, p = 0.02, I2 = 0%). Conclusively, COVID-19 patients supplemented with vitamin D are more likely to demonstrate fewer rates of ICU admission, mortality events, and RT-PCR positivity.

Decreased circulatory levels of Vitamin D in Vitiligo: a meta-analysis

Abstract Background: The serum Vitamin D status in patients with vitiligo is ambiguous when compared to controls. A systematic review and updated meta-analysis were conducted to evaluate the association between Vitamin D and vitiligo. Methods: Relevant studies were identified by searching PubMed and other databases. The random effects model was used to obtain standardized mean differences and pooled correlation coefficients. Meta-regression and sub-group analyses were conducted to explore heterogeneity. The presence of publication bias and the study robustness were tested using funnel plot and sensitivity analyses, respectively. Results: This meta-analysis finally included 31 studies. Compared with controls, vitiligo patients showed significantly decreased serum Vitamin D levels (standardized mean difference = −1.03; p < 0.0001). The sub-group analysis showed that vitiligo patients with indoor/urban work had a significantly lower Vitamin D level when compared to their outdoor/rural counterparts (standardized mean differences = −0.45; p = 0.03). The sensitivity analysis indicated that no single study had a significant influence on the overall outcome, suggesting the robustness of this meta-analysis. Study limitations: Varied sample sizes and heterogeneous study populations from different countries are the limitations of this study. However, the between-study heterogeneity has been addressed by the random-effects model with meta-regression and sensitivity analyses. Conclusions: This meta-analysis showed significantly decreased Vitamin D level in vitiligo, and its association with indoor/outdoor type of work of vitiligo patients. This study highlights the need to assess Vitamin D status for improving its level in vitiligo.

Decreased circulatory levels of Vitamin D in Vitiligo (ViViD Study): a meta-analysis

Abstract Background: The serum Vitamin D status in patients with vitiligo is ambiguous when compared to controls. A systematic review and updated meta-analysis were conducted to evaluate the association between Vitamin D and vitiligo. Methods: Relevant studies were identified by searching PubMed and other databases. The random effects model was used to obtain standardized mean differences and pooled correlation coefficients. Meta-regression and sub-group analyses were conducted to explore heterogeneity. The presence of publication bias and the study robustness were tested using funnel plot and sensitivity analyses, respectively. Results: This meta-analysis finally included 31 studies. Compared with controls, vitiligo patients showed significantly decreased serum Vitamin D levels (standardized mean difference = −1.03; p < 0.0001). The sub-group analysis showed that vitiligo patients with indoor/urban work had a significantly lower Vitamin D level when compared to their outdoor/rural counterparts (standardized mean differences = −0.45; p = 0.03). The sensitivity analysis indicated that no single study had a significant influence on the overall outcome, suggesting the robustness of this meta-analysis. Study limitations: Varied sample sizes and heterogeneous study populations from different countries are the limitations of this study. However, the between-study heterogeneity has been addressed by the random-effects model with meta-regression and sensitivity analyses. Conclusions: This meta-analysis showed significantly decreased Vitamin D level in vitiligo, and its association with indoor/outdoor type of work of vitiligo patients. This study highlights the need to assess Vitamin D status for improving its level in vitiligo.

Decreased circulatory levels of Vitamin D in Vitiligo: a meta-analysis.

BACKGROUND: The serum Vitamin D status in patients with vitiligo is ambiguous when compared to controls. A systematic review and updated meta-analysis were conducted to evaluate the association between Vitamin D and vitiligo. METHODS: Relevant studies were identified by searching PubMed and other databases. The random effects model was used to obtain standardized mean differences and pooled correlation coefficients. Meta-regression and sub-group analyses were conducted to explore heterogeneity. The presence of publication bias and the study robustness were tested using funnel plot and sensitivity analyses, respectively. RESULTS: This meta-analysis finally included 31 studies. Compared with controls, vitiligo patients showed significantly decreased serum Vitamin D levels (standardized mean difference = -1.03; p < 0.0001). The sub-group analysis showed that vitiligo patients with indoor/urban work had a significantly lower Vitamin D level when compared to their outdoor/rural counterparts (standardized mean differences = -0.45; p = 0.03). The sensitivity analysis indicated that no single study had a significant influence on the overall outcome, suggesting the robustness of this meta-analysis. STUDY LIMITATIONS: Varied sample sizes and heterogeneous study populations from different countries are the limitations of this study. However, the between-study heterogeneity has been addressed by the random-effects model with meta-regression and sensitivity analyses. CONCLUSIONS: This meta-analysis showed significantly decreased Vitamin D level in vitiligo, and its association with indoor/outdoor type of work of vitiligo patients. This study highlights the need to assess Vitamin D status for improving its level in vitiligo.

Higher skin autofluorescence detection using AGE-Reader™ technology as a measure of increased tissue accumulation of advanced glycation end products in dialysis patients with diabetes: a meta-analysis.

This meta-analysis was conducted to compare skin autofluorescence (SAF) levels as a measure of advanced glycation end products (AGEs) accumulation between diabetic and non-diabetic dialysis patients. Relevant studies were identified primarily by searching PubMed/MEDLINE and other online databases and manual searching of cross-references. Random-effects model was used to obtain standardized mean differences (SMD) as a summary statistic. Heterogeneity was tested with meta-regression and sub-group analyses. Publication bias and robustness of this meta-analysis were tested using funnel plot and sensitivity analyses. A total of 11 reports comparing SAF between diabetic and non-diabetic dialysis patients were finally included in this meta-analysis. Dialysis patients with diabetes showed significantly higher circulatory SAF levels than their non-diabetic counterparts (SMD = 0.39; P < 0.0001). The difference was more evident in hemodialysis modality (SMD = 0.40; P < 0.0001). A one-study leave-out sensitivity analysis validated the robustness of this meta-analysis. The presence of diabetes in dialysis patients is associated with increased AGEs accumulation reflected through SAF measurements using a novel and non-invasive AGE-Reader™ technology. Our findings are in support of considering anti-AGE therapeutic strategies in addition to standard glycemic management in dialysis patients with diabetes.

The association of non-invasive skin autofluorescence measurements with cardiovascular and all-cause mortality in hemodialysis patients: a meta-analysis.

BACKGROUND: This systematic review and meta-analysis were aimed to study the association of tissue accumulation of advanced glycation end products (AGEs) measured as skin autofluorescence (SAF) with cardiovascular disease (CVD), cardiovascular mortality (CVM) and all-cause mortality (ACM) in hemodialysis (HD) patients. METHODS: All major databases were searched for relevant studies reporting SAF in dialysis patients. Data for meta-analyses were extracted in the form of odds ratios (OR) and/or hazard ratios (HR) and the pooled overall outcomes were computed for the association of SAF with CVD, CVM, ACM in HD patients using either fixed or random effects meta-analysis based on the between-study heterogeneity. The sensitivity and meta-regression analyses were performed. RESULTS: We included nine studies in this meta-analysis. The SAF levels were associated with higher risk for cardiovascular morbidity (pooled OR = 2.59, Z = 2.30, P = 0.02), cardiovascular (pooled HR = 3.03, Z = 3.13, P = 0.002) and overall mortalities (pooled HR = 2.23, Z = 6.30, P < 0.001) in HD patients. CONCLUSION: In HD patients, the novel and non-invasive measurement of tissue AGEs as SAF levels could be useful for risk estimating the cardiovascular and all-cause mortalities.