Vitamin D protects against depression: Evidence from an umbrella meta-analysis on interventional and observational meta-analyses.

Meta-analyses of interventional and observational studies investigating the efficacy and the relationship between vitamin D and depression provided inconsistent results. The current umbrella meta-analysis was conducted to assess the available evidence and provide a conclusive outcome in this regard. The following international databases were systematically searched till March 2022: PubMed, Scopus, Embase, Web of Science, and Google Scholar. Random-effects model was carried out to calculate the pooled point estimates and their respective 95 % confidence intervals (CI). Ten meta-analyses of randomised controlled trials (RCTs) revealed significant reduction in depression symptoms comparing participants on vitmain D supplements to those on placebo (Pooled standardised mean difference: - 0.40; 95 % CI: - 0.60, - 0.21, p < 0.01: I2 = 89.1 %, p < 0.01). Four meta-analyses of cohort studies (with one having two subgroups) revealed that participants with lower levels of serum vitamin D were at increased odds of depression than those with higher levels of serum vitamin D (Pooled odds ratio: 1.60; 95 % CI: 1.08, 2.36, p < 0.01; I2 = 91.3 %, p < 0.01). The present umbrella meta-analysis confirms the potential benefits of vitamin D supplementation and higher serum vitamin D levels in reducing the development and symptoms of depression.

Cinnamon, an effective anti-obesity agent: Evidence from an umbrella meta-analysis.

The evidence provided by meta-analyses on the beneficial impacts of cinnamon supplementation on anthropometric indices are still conflicting. Present study's aim was to evaluate the effects of cinnamon on obesity indices by an umbrella meta-analysis. The electronic databases including Web of Science, PubMed, EMBASE, Scopus were systematically searched up to March 2021. Data for the effects of cinnamon on anthropometric indices were collected from the meta-analyses. An umbrella meta-analysis was carried out using a random-effects model. The pooled effects of 7 meta-analyses showed that cinnamon supplementation significantly reduced body weight (ES: -0.67 kg; 95% CI: -0.99, -0.35, p Ë‚ .001), body mass index (ES: -0.45 kg/m2 ; 95% CI: -0.57, -0.33, p Ë‚ .001) in comparison to control group. However, the effects of cinnamon on waist circumference (ES: -1.05 cm; 95% CI: -2.26, 0.15, p = .087) were not considerable. According to results, cinnamon could be suggested as a complementary weight loss agent. Favorable results were obtained at a dose of ≥3 g/day. In this study, a comprehensive study was performed on meta-analyses performed on the effect of cinnamon on anthropometric indices. This study could be considered as a final conclusion about the effect of cinnamon on anthropometric indices. The results of this study showed that supplementation with cinnamon significantly reduces BMI and body weight. The impacts were greater in doses of ≥3 g/day and in PCOS patients. PRACTICAL APPLICATIONS: In this study, a comprehensive study was performed on meta-analyses performed on the effect of cinnamon on anthropometric indices. This study could be considered as a final conclusion about the effect of cinnamon on anthropometric indices. The results of this study showed that supplementation with cinnamon significantly reduces BMI and body weight. The impacts were greater in doses of ≥3 g/day and in PCOS patients.

Relationship between the levels of serum fibroblast growth factor 19 and metabolic factors in obese and normal weight subjects with and without type 2 diabetes mellitus: a case-control study.

OBJECTIVES: Fibroblast growth factor 19 (FGF-19) is a metabolic regulating factor with an anti-diabetic effect. This study aimed to evaluate FGF-19 in patients with type 2 diabetes mellitus (T2DM) and its relationship with some metabolic risk factors. METHODS: In this case-control study, 80 diabetic patients and 80 non-diabetic individuals were divided into two subgroups based on body mass index (BMI): obese people (BMI≥30) and participants with normal weight (25>BMI≥18.5). Furthermore, stratified analysis by gender was also performed. The metabolic factors were measured and compared in all groups. The relationship between FGF-19 and the measured items was investigated in each group. RESULTS: The FGF-19 levels did not show a significant difference between groups. The serum levels of FGF-19 were negatively associated with some metabolic items, such as BMI, low-density lipoprotein (LDL), total cholesterol (TC) (p<0.01), and LDL/high-density lipoprotein (HDL) ratio (p=0.02) only in the healthy group with normal weight. According to the gender-based classification of individuals, FGF-19 showed a significant inverse relationship with BMI, weight (WT), waist circumference (WC), and hip circumference (HC) (p<0.05) in diabetic men; besides, FGF-19 in non-diabetic women had a significant negative association with TC, LDL, and LDL/HDL ratio (p<0.05). CONCLUSIONS: The levels of FGF-19 were negatively correlated to WT, BMI, WC and HC in diabetic males. More studies are needed to warrant these results.