Vitamin D deficiency prevention policies in Iran: a retrospective policy analysis.

Aim: Iran has a higher prevalence of vitamin D deficiency (VDD) than the global level. This study aimed to assess VDD prevention policies in Iran through a policy analysis of agenda setting using the multiple streams framework (MSF). Methods: Using Kingdon's MSF model, this qualitative analytical study performed a policy analysis on vitamin D-related policies in Iran. The policy documents were reviewed, and in-depth interviews were conducted with stakeholders (n = 27) using the framework analysis method. To categorize data and extract the related themes, MAXQDA version 10 was used. Results: According to Kingdon's MSF theory, the problem stream included the high prevalence of VDD among Iranian infants (23.3%), adolescents (76%), and adults (59.1%). The policy stream was identified to focus on preventing programs for non-communicable diseases in the health sector. The political stream indicated that national and international support could provide a political climate for this issue. Conclusion: According to our results, a window of opportunity for policymaking on VDD prevention has opened. However, there are some challenges related to the implementation of these policies. These include the dominance of a treatment-based view rather than a prevention-based approach in the health sector, economic problems, and restricted access to health services due to the outbreak of coronavirus disease 2019 (COVID-19). To strengthen and implement VDD prevention policies, the stakeholders need support from high-level policymakers.

Melatonin effectiveness in amelioration of oxidative stress and strengthening of antioxidant defense system: Findings from a systematic review and dose-response meta-analysis of controlled clinical trials.

BACKGROUND AND AIM: Oxidative stress is involved in the development of chronic diseases. It has been suggested that melatonin has a protective role against oxidative stress by activation of antioxidant enzymes and scavenging free-radicals. Present study aimed to investigate the effect of melatonin supplementation on oxidative stress and antioxidant biomarkers such as malondialdehyde (MDA), increased total antioxidant capacity (TAC), superoxide dismutase (SOD), and Glutathione peroxidase (GPx). METHODS: Systematic search was performed to identify relevant studies in PubMed/Medline, SCOPUS, Web of Science and Embase databases and Google Scholar up to September 2020. Meta-analysis was conducted using random-effect model. Subgroup analysis and meta-regression was used to identify sources of heterogeneity. The quality of studies was assessed using Cochrane Collaboration's tool. Publication bias was assessed by visual inspection of funnel plot. RESULTS: A total number of 16 eligible articles were included in the meta-analysis. The dosages of melatonin varied between 3 and 400 mg/day, with a duration range between 1.42 and 12 weeks. Melatonin supplementation significantly increased serum levels of TAC [SMD: 1.59; 95% CI: 0.89, 2.29; P < 0.001; (I2 = 93.53%, P < 0.001 No significant effects were observed on MDA [SMD: -3.09; 95% CI: -7.07, 0.89; P = 0.12; (I2 = 99.57%, P < 0.001)], GPx [SMD: 0.86; 95% CI: -3.46, 5.19; P = 0.61; (I2 = 98.17%, P < 0.001)] and SOD levels [SMD: 1.92; 95% CI: -3.57, 7.41; P = 0.35; (I2 = 98.27%, P < 0.001)]. CONCLUSION: Results of the current meta-analysis showed that melatonin supplementation had a significant impact on attenuating of oxidative stress and enhancing antioxidant performance. Melatonin supplementation could be suggested as a safe complementary approach in amelioration of the chronic diseases.

Agenda-setting of tobacco control policy in Iran: a retrospective policy analysis study.

BACKGROUND: The prevalence of tobacco use, especially hookah, has increased in Iran In recent years, particularly among young people and women, and the age of onset of use has decreased. Tobacco use is the fourth leading risk factor for non-communicable diseases in Iran. These issues cause concerns in the country and led to the present study on tobacco control agenda-setting in Iran over a 30-year timeframe. METHODS: We conducted this retrospective analytical study to investigate process analysis in Iran using Kingdon's multiple-streams framework (MSF). We collected the data using semi-structured interviews with key informants (n = 36) and reviewing policy documents (n > 100). Then, we analyzed the policy documents and in-depth interviews using the document and framework analysis method. We used MAXQDA 11 software to classify and analyze the data. RESULTS: Iran's accession to the Framework Convention on Tobacco Control (FCTC) opened a window of opportunity for tobacco control. The policy window opens when all three streams have already been developed. The adoption of the comprehensive law on the national control and campaign against tobacco in the Islamic Consultative Assembly in 2006 is a turning point in tobacco control activities in Iran. CONCLUSIONS: The tobacco control agenda-setting process in Iran was broadly consistent with MSF. The FCTC strengthened the comprehensive plan for national control of tobacco as a policy stream. However, there are several challenges in developing effective policies for tobacco control in the Iranian setting.

Investigation of the clinical efficacy of Zn supplementation in improvement of oxidative stress parameters: A systematic review and dose-response meta-analysis of controlled clinical trials.

BACKGROUND/OBJECTIVES: Clinical efficacy of zinc (Zn) supplementation in the improvement of oxidative stress biomarkers has been investigated in some clinical trial studies. The purpose of the current dose-response meta-analysis is to systematically aggregate and evaluate all related studies to highlight the possible effect of Zn supplementation on oxidative stress. METHODS: Systematic search was performed on Scopus, PubMed/Medline, Web of Science and Embase up to 31 December 2020. The random effect method was used to perform pooled analysis. Possible sources of heterogeneity were found using subgroup analysis and meta-regression. In the presence of publication bias, trim and fill analysis was performed to adjust the results. Non-linear relationship between effect size and variables was investigated by performing dose-response analysis. The quality of included studies was assessed using Cochrane Collaboration's tool. RESULTS: Pooled-analysis of 18 studies showed that Zn supplementation improved MDA and Hcys levels (SMD = -1.53 µmol/L; 95% CI: -2.22, -0.85; P < .001 and SMD = -0.62 µmol/L; 95% CI: -1.08, -0.15; P < .001, respectively). There was no significant effect of Zn supplementation on TBARS (SMD = -0.59 µmol/l; 95% CI: -1.31, 0.13; P = .108). Zn had maximum reducing effect on MDA in <40 mg/day dosage. CONCLUSION: Zn supplementation reduces MDA and Hcys levels, but not TBARS level. Supplementation with Zn <40 mg/day has an optimum effect on MDA level. Zn supplementation could be considered clinically as a beneficial approach in amending oxidative stress.

Clinical efficacy of zinc supplementation in improving antioxidant defense system: A comprehensive systematic review and time-response meta-analysis of controlled clinical trials.

Oxidative stress is a contributing factor to many chronic diseases. It has been investigated that zinc (Zn) may enhance the antioxidant defense. The current dose-response and time-response meta-analysis aims to determine the efficacy of Zn supplementation in improving antioxidant defense. Scopus, PubMed/Medline, Web of Science, and Embase databases were searched systematically up to December 30, 2020. Meta-analysis was performed on human controlled clinical trials using random effects method. To find any source of heterogeneity, subgroup analysis and meta-regression were performed. Trim and fill analysis was used for adjusting the publication bias. To find any non-linear relationship between variables and effect size, dose-response and time-response analyses were performed. Cochrane Collaboration's tool was used for evaluating the quality assessment. A total of 23 controlled clinical trials were analyzed. The range of Zn supplementation duration in various studies was within 4-24 weeks. Zn supplementation did not have beneficial effects on glutathione peroxidase (GPx) activity (SMD = -0.34 U/g; 95% CI: -0.93, 0.25; P = 0.258). There were significant increasing effects of Zn supplementation on glutathione (GSH) (SMD = 1.28 µmol/l; 95% CI: 0.42, 2.14; P = 0.003) and total antioxidant capacity (TAC) levels (SMD = 1.39 mmol/l; 95% CI: 0.44, 2.35; P = 0.004). Zn had ameliorative effects on superoxide dismutase (SOD) activity after elimination of publication bias (SMD: 0.84 U/g; 95% CI: 0.12, 1.56, P < 0.05). Zn could also elevate GSH and TAC levels, plus SOD activity after modifying the publication bias. Finally, Zn had no significant effect on GPx activity.