Serum Selenium Levels and Lipid Profile: A Systematic Review and Meta-analysis of Observational Studies.

Selenium is a trace element with pivotal roles in metabolic processes. Studies suggested that selenium deficiency could lead to impaired lipid profiles. However, inconsistent results have been reported regarding the association between serum selenium concentrations and lipid profile (triglycerides, LDL, HDL, VLDL, and total cholesterol). Thus, we aimed to review the correlation between them. A systematic literature search was conducted in PubMed, Embase, Web of Science, Scopus, and Google Scholar until 31 December 2023. The relevant correlation coefficients were used as desired effect sizes to assess the correlation between selenium level and lipid profile. Among 8291 records found in the primary search, 47 and 34 articles were included in the systematic review and meta-analysis, respectively. All included studies were observational investigations and had acceptable quality. Our results failed to reach strong evidence supporting the correlation between serum selenium level and lipid profiles, except for HDL, which showed a weak correlation among both adults (r = 0.1 [0.03:0.17]; I2 = 71%) and pediatrics (r = 0.08 [0.03:0.14]; I2 = 38%). Subgroup analyses based on gender did not reveal a significant or strong correlation with selenium levels (except for total cholesterol in males (r = 0.12 [0.01:0.22]; I2 = 52%)). The results did not change after the sensitivity analysis. Although some previous studies have suggested that selenium deficiency could lead to impaired lipid profile, the findings of this study indicate no strong correlation between serum selenium levels and lipid profile.

Dynamic changes of serum trace elements following cardiac surgery: A systematic review and meta-analysis.

BACKGROUND: Cardiac surgeries are known to induce an inflammatory response. Besides, dietary factors such as trace elements contribute to promoting cardiovascular health by maintaining oxidative balance. Here we systematically review the literature about alterations in serum concentrations of zinc (Zn), copper (Cu), and selenium (Se) in response to cardiac surgeries. METHODS: A systematic search was performed on databases until the end of December 2022. Studies assessing the changes of mentioned elements in adult patients undergoing cardiac surgery were included. Changes in the means and standard deviations of the elements before and after the cardiac surgery were utilized as desired effect sizes. RESULTS: Among 1252 records found in the primary search, 23 and 21 articles were included in the systematic review and meta-analysis respectively. Seventeen studies evaluated the changes in serum Zn and Cu levels, and fifteen studies assessed Se levels. According to the results of quantitative analysis, Zn, Cu, and Se concentrations, one day after the surgery were significantly lower than preoperative values (WMD for Zn: 4.64 µmol/L [3.57-5.72], WMD for Cu: 1.62 µmol/L [0.52-2.72], and WMD for Se: 0.1 µmol/L [0.03-0.16]). The concentration of trace elements recovered gradually during the first-week post-operation and reached preoperative levels or even higher. CONCLUSION: Serum trace elements dropped significantly soon after the cardiac surgery, but they reached their baseline levels mostly during the first week after the surgery. Future studies are warranted to elucidate the impact of alterations in serum concentration of trace elements on the outcomes and complications of open-heart surgeries.

The prevalence of positive thyroid autoantibodies in patients with subacute thyroiditis: a systematic review and meta-analysis.

PURPOSE: Subacute thyroiditis (SAT) is a transient inflammatory disorder of the thyroid gland with a possible viral etiology. We conducted this study to estimate the pooled prevalence of thyroid autoantibodies in SAT patients. This question arose due to the varying reports on the positivity rates of thyroid autoantibodies among SAT patients. METHODS: We searched PubMed, Embase, Scopus, and Web of Science from their inception until March 25th, 2023. Observational studies reporting the positivity rate of thyroid autoantibodies for more than ten patients were included. We used the Joanna Briggs Institute's (JBI) critical appraisal checklist to assess the quality of the included studies. Pooled prevalence estimates with 95% confidence intervals were calculated using the random effects model. Subgroup analyses were performed to find sources of heterogeneity. RESULTS: Out of 1373 identified records, 32 studies involving 2348 SAT patients were included in our study. Thyroglobulin antibody (TgAb) and thyroid peroxidase antibody (TPOAb) were positive in 22.8% and 12.2% of patients, respectively. The Study design, mean erythrocyte sedimentation rate and mean thyroid-stimulating hormone of patients were identified as sources of heterogeneity. As our secondary objectives, we found a recurrence rate of 14.7% and permanent hypothyroidism in 11.6% of patients. CONCLUSION: The results of our study revealed a low TPOAb positivity rate in SAT patients, consistent with its non-autoimmune etiology. The TgAb positivity rate in SAT patients was higher than that of the general population, possibly explained by the transient release of thyroglobulin into the bloodstream during the thyrotoxic phase, leading to subsequent TgAb production. Furthermore, our findings demonstrate a notable recurrence rate and permanent hypothyroidism among SAT patients, highlighting the importance of ongoing follow-up care.

Prevalence of dysphagia in patients with multiple sclerosis: A systematic review and meta-analysis.

BACKGROUND: Dysphagia is a major disorder observed in patients with multiple sclerosis (MS), yet different prevalence rates are reported for it. Therefore, we designed this study to estimate the pooled prevalence of dysphagia in patients with MS. METHOD: We searched PubMed, Scopus, EMBASE, Web of Science, and gray literature including references from the identified studies, reviews studies, and conference abstracts which were published up to May 2022. Articles that were relevant to our topic and could provide information regarding the prevalence of dysphagia among MS patients were included; however, articles with self-report screening strategies were excluded. RESULTS: The literature search found 997 articles. After eliminating duplicates, 672 articles remained. Two conference abstracts were included for final analysis. A total of 11,266 MS cases and 5047 MS patients with dysphagia were included in the meta-analysis. The overall prevalence of dysphagia across all 54 studies was 44.8 % (95 % CI: [40.4 %-49.2 %]), with a high level of heterogeneity between countries (Q=; I2 = 94.96 %; p < 0.001). CONCLUSION: The results of this systematic review shows that the prevalence of dysphagia in MS patients is 45% which is greatly higher compared to the general population.