Effects of Calcium and Vitamin D Co-supplementation on the Lipid Profile: A Systematic Review and Meta-analysis.

PURPOSE: Calcium and vitamin D co-supplementation is common and widely used, but randomized, controlled trials (RCTs) have yielded inconclusive results concerning its impact on the serum lipid profile. METHODS: A comprehensive literature search of Medline, Web of Science, Scopus, Embase, Cochrane Central Register of Controlled Trials, and clinical trial registry databases was conducted to identify placebo-controlled RCTs that were published through September 2020 and that evaluated the impact of calcium and vitamin D co-supplementation on total cholesterol (TC), triglycerides (TGs), low- and very-low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol (HDL-C). Standardized mean differences (SMDs) were pooled using random-effects meta-analysis models. FINDINGS: Thirteen studies in a total of 2304 participants met the inclusion criteria. Calcium and vitamin D co-supplementation was associated with significant reductions in both TC (SMD, -0.81; 95% CI, -1.35 to -0.27; I2 = 94.6%) and TGs (SMD, -0.50; 95% CI, -0.91 to -0.08; I2 = 91.5%), and with a significant increase in HDL-C (SMD, 1.22; 95% CI, 0.60 to 1.83; I2 = 95.4%). However, calcium and vitamin D co-supplementation were not found to be associated with significantly decreased low-density lipoprotein cholesterol (SMD, -0.39; 95% CI, -0.78 to 0.01; I2 = 90.1%) or very-low-density lipoprotein cholesterol (SMD, -0.01; 95% CI, -0.70 to 0.69; I2 = 82.3%). IMPLICATIONS: The findings from the present systematic review and meta-analysis suggest that calcium and vitamin D co-supplementation has a beneficial effect on TC, TG, and HDL-C. Larger-scale, well-designed RCTs are needed to clarify the effect of calcium and vitamin D co-supplementation on all lipid-profile components.

Effects of body weight regain on leptin levels: A systematic review and meta-analysis.

BACKGROUND: There are different changes observed before and after diet therapy, and also after weight regain. However, there is not sufficient information regarding weight regain and hormonal changes. PURPOSE: The purpose of this study was to review the connection between weight regain and leptin concentration levels. METHODS: MEDLINE, SCOPUS, Web of Science, and the Cochrane Library were searched for interventional articles published from January 1, 1980, to June 30, 2020. Randomized clinical trials with parallel or cross over design assessing leptin concentrations at the baseline and at the end of study were reviewed. Two independent reviewers extracted data related to study design, year of publication, country, age, gender, body mass index (BMI), duration of the following up period and mean ± SD of other intended variables. RESULTS: Four articles were included, published between 2004 and 2016. Three of them were conducted in the US and one of them in Netherland. Sample size of the studies ranged between 25 and 148 participants. The range of following up period was from13 to 48 weeks. The age range of participants was from 34 to 44 years. Our analysis shows that weight regain could reduce leptin levels, but this change is not statistically significant. CONCLUSION: This review suggests that weight regain may induce a non-significant reduction in leptin level. However, the limited number and great heterogeneity between the included studies may affect the presented results and there are still need to well-designed, large population studies to determine the relationship between weight regain and leptin levels.

Sumac fruit supplementation improve glycemic parameters in patients with metabolic syndrome and related disorders: A systematic review and meta-analysis.

BACKGROUND: Metabolic syndrome (MetS) is the one of the main causes of mortality worldwide. Several randomized controlled trials (RCTs) have revealed the beneficial effects of sumac (Rhus coriaria) on cardiometabolic risk factors. However, the entirety of the evidence has yet to be summarized in a systematic review. OBJECTIVE: The aim of this systematic review and meta-analysis was to evaluate the effects of sumac on several cardiometabolic risk factors in patients with MetS and related disorders. METHODS: We reviewed Medline, Scopus, Web of Science and Cochrane CENTRAL for RCTs published from inception to December 2020 evaluating the impact of sumac in adults with MetS or related disorders. Outcome measures included anthropometric measures, glycemic indices, blood lipids, blood pressure and liver enzymes. Pooled effect sizes were reported as standard mean differences (SMDs) and 95% confidence intervals (CIs). Trials were pooled using a random effects model. RESULTS: Nine studies enrolling 526 participants met the inclusion criteria for this meta-analysis. Our results indicate that sumac intake significantly decrease fasting blood sugar (FBS) (SMD: -0.28; 95% CI: -0.54, -0.02; I2 = 00.0%), insulin (SMD: -0.67; 95% CI: -0.99, -0.36; I2 = 03.7%), and insulin resistance (measured through the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)) (SMD: -0.79; 95% CI: -1.24, -0.34; I2 = 50.1%). Sumac intake did not have a significant impact on weight, body mass index (BMI), waist circumference (WC), hip circumference (HC), waist to hip ratio (WHR), HbA1c, total cholesterol (TC), triglycerides (TG), high density lipoproteins (HDL), low density lipoprotein (LDL), systolic blood pressure (SBP), diastolic blood pressure (DBP), aspartate transaminase (AST) and alanine transaminase (ALT). CONCLUSION: Sumac, as an adjuvant therapy, may decrease serum levels of FBS, insulin and HOMA-IR. However, due to high heterogeneity in the included studies, these findings must be interpreted with great caution. Larger, well-designed placebo-controlled clinical trials are still needed to further evaluate the capacity of sumac as a complementary treatment to control MetS risk factors.