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.

Maternal serum irisin levels in normotensive and preeclamptic pregnancies: a systematic review and meta-analysis.

BACKGROUND: Altered irisin levels have been reported in pregnancy-associated disorders, such as preeclampsia. OBJECTIVE: A systematic review and meta-analysis were conducted to evaluate the changes in maternal circulatory irisin levels in preeclampsia as compared to normotensive healthy pregnant controls. METHODS: Relevant studies were identified by searching PubMed and other databases. Random-effects model was used to obtain standardized mean differences (SMDs) and its 95% confidence intervals (CIs). The sub-group meta-regression analyses were conducted to explore heterogeneity. The presence of publication bias and the study robustness was tested using funnel plot and sensitivity analyses, respectively. RESULTS: This meta-analysis finally included 14 observations from eight studies. Compared with controls, preeclampsia patients showed significantly decreased serum irisin levels (SMD: -1.13; 95% CI: -1.63 to -0.62, p < .0001). The sub-group analysis showed that this decrease in irisin is regardless of body mass index (BMI) and gestational age of preeclampsia patients. The meta-regression analysis indicated that blood pressure is significantly associated with the observed results. There was no significant publication bias as indicated by the funnel plot analysis followed by Begg's (p = .35) and Egger's tests (p = .39). The sensitivity analysis indicated that no single study had a significant influence on the overall outcome, suggesting the robustness of this meta-analysis. CONCLUSIONS: This meta-analysis showed significantly decreased maternal serum irisin level in preeclampsia patients as compared to normotensive pregnant women. This study highlights the need for future studies evaluating the diagnostic utilities and associations of irisin with the fetal and neonatal outcomes in preeclampsia.

Maternal adropin levels in patients with gestational diabetes mellitus: a systematic review and meta-analysis.

BACKGROUND: Adropin is a regulatory protein with potential implications in energy homeostasis, glucose regulation, and insulin resistance. AIM: The aim of this meta-analysis was to compare the maternal serum/plasma adropin levels between gestational diabetes mellitus (GDM) patients and non-GDM controls. METHODS: Relevant studies were retrieved by online database and manual searching. The standardized mean differences (SMDs) with 95% confidence intervals (CIs) were obtained by a random-effects meta-analysis. A one-study leave-out sensitivity analysis and trimester-wise subgroup analysis were performed. RESULTS: A total of eight observations were included in this meta-analysis. The results based on random-effects meta-analysis indicated that adropin levels were significantly increased in GDM patients as compared to non-GDM controls (SMD = 2.41, 95% CI = 0.52-4.29, p= .01). The sensitivity analysis indicated that no single study had significantly influenced the overall outcome. CONCLUSIONS: The results indicate that maternal serum/plasma adropin concentrations were significantly higher in GDM patients as compared to non-GDM controls suggesting the potential associations of adropin in GDM. Despite this, further studies are needed to investigate the mechanistic, diagnostic and prognostic roles of trimester-wise adropin levels in GDM and associated fetal outcomes.

Effect of metformin intervention on circulating irisin levels in polycystic ovary syndrome: a systematic review and collaborative meta-analysis.

BACKGROUND: Irisin is an adipo-myokine with potential implications in metabolic disorders such as polycystic ovary syndrome (PCOS). Despite of a strong evidence showing increased irisin level in PCOS, there is no conclusive evidence on the effect of metformin intervention on circulatory irisin in PCOS. AIM: The aim of this meta-analysis was to compare the circulatory (serum/plasma) irisin levels before and after metformin intervention in subjects with PCOS. METHODS: Relevant studies were retrieved by online database and manual searching. The standardized mean differences (SMDs) with 95% confidence intervals (CIs) were obtained by a random-effects meta-analysis. A one-study leave-out sensitivity analysis was conducted to validate the overall obtained results. RESULTS: A total of five observations were included in this meta-analysis. The results based on random effects meta-analysis indicated that irisin levels were significantly decreased after metformin intervention as compared to the baseline pretreatment levels in PCOS (SMD: -1.00, 95% CI: -1.60 to -0.41, Z: 3.29, p = .001). The sensitivity analysis leaving-out a particular observation at a time and repeating the meta-analysis validated the robustness of the overall finding suggesting the significant effect of metformin treatment on irisin levels in PCOS. CONCLUSION: Circulating irisin levels were significantly decreased upon metformin intervention in PCOS patients. The higher pretreatment irisin levels in PCOS may recede once the altered metabolic state is restored upon metformin intervention. Well-designed randomized trials with large sample sizes are warranted to further substantiate the reported evidence reported and to establish the possible mechanisms.

Adropin levels and its associations as a fat-burning hormone in patients with polycystic ovary syndrome: a correlational meta-analysis.

AIMS: Adropin is a peptide hormone with potential implications in patients with polycystic ovary syndrome (PCOS). The aim of this meta-analysis was to compare the circulating (serum/plasma) and follicular fluid adropin levels between human PCOS patients and non-PCOS controls. METHODS: Relevant studies were retrieved by online database and manual searching. The standardized mean differences (SMDs) with 95% confidence intervals (CIs) were obtained by a random-effects meta-analysis. Meta-analysis of correlations was performed for the associations of adropin with anthropometric, lipid, insulin resistance and hormonal covariates. The funnel plot analysis with Begg's and Egger's tests was used for publication bias. RESULTS: A total of 9 studies were included in this meta-analysis. The results indicated that the adropin levels were significantly decreased in PCOS patients as compared to non-PCOS controls (SMD = -1.87, 95% CI = -2.55 to -1.18, p < .0001). This decrease was more evident in overweight PCOS patients than their normoweight counterparts (SMD = -0.55, 95% CI = -0.80 to -0.30, p < .0001). A one-study leave-out sensitivity analysis indicated that no single study had a significant influence on the overall outcome, suggesting the robustness of this meta-analysis. There were significant associations of decreased adropin levels with the body mass index, dyslipidemia and insulin resistance in PCOS. CONCLUSION: Adropin levels are significantly reduced in PCOS patients compared to controls, and this decrease was more evident in overweight PCOS patients.

Diabetes and COVID-19: A pooled analysis related to disease severity and mortality.

Globally, COVID-19 has become a major concern for the diabetic community. We conducted a pooled analysis and constructed a forest plot for the association between diabetes and COVID-19 progression in 47 studies. A random effects meta-analysis (Mantel-Haenszel method) was conducted to estimate the outcomes effect size as odds ratios (OR) and 95% confidence intervals (CI) using Review Manager Software version 5.3. COVID-19 patients with diabetes have a significantly higher risk of disease severity (OR=2.20, 95% CI=1.69-2.86, p<0.00001) and associated mortality outcomes (OR=2.52, 95% CI=1.93-3.30, p=<0.00001).

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.