Effect of Thyroxin Treatment on Carotid Intima-Media Thickness (CIMT) Reduction in Patients with Subclinical Hypothyroidism (SCH): a Meta-Analysis of Clinical Trials.

AIM: Research shows that subclinical hypothyroidism (SCH) is related to an increased carotid intima-media thickness (CIMT), a surrogate marker of subclinical cardiovascular disease (CVD). It is controversial whether or not SCH should be treated to reduce CVD morbidity and mortality. This meta-analysis aimed to determine whether SCH is associated with an increase in CIMT as compared to Euthyroidism (EU) and whether thyroxin (T4) treatment in SCH can reverse the change in CIMT. METHODS: Two independent reviewers conducted an extensive database research up to December 2016. A total of 12 clinical trials discussed the effect of Thyroxin on CIMT values at pre- and post-treatment in subjects with SCH. RESULTS: CIMT was significantly higher among SCH (n=280) as compared to EU controls (n=263) at baseline; the pooled weighted mean difference (WMD) of CIMT was 0.44 mm [95% confidence interval (CI) 0.14, 0.74], p=0.004; I2=65%. After treatment with thyroxin in subjects with SCH (n=314), there was a statistically significant decrease in CIMT from pre- to post-treatment; the pooled WMD of CIMT decrease was [WMD －0.32; 95% CI (－0.47, －0.16), p=＜0.0001; I2=2%], and it was no longer different from EU controls [WMD 0.13 mm; 95% CI (－0.04, 0.30); p=0.14; I2=27%]. The total cholesterol (TC), triglycerides (TG), and low-density lipoprotein (LDL) were higher in SCH as compared to EU controls and decreased significantly after treatment with thyroxin. CONCLUSION: This meta-analysis shows that thyroxin therapy in subjects with SCH significantly decreases CIMT and improves lipid profile, modifiable CVD risk factors. Thyroid hormone replacement in subjects with SCH may play a role in slowing down or preventing the progression of atherosclerosis.

Association Between Coronary Artery Disease and MicroRNA: Literature Review and Clinical Perspective.

BACKGROUND: Until recently, circulating micro-RNAs (miRNAs) have attracted major interest as novel biomarkers for the early diagnosis of coronary artery disease (CAD). This review article summarizes the available evidence on the correlation of micro-RNAs with both the clinical and subclinical coronary artery disease and highlights the necessity for exploring miRNAs as a potential diagnostic and prognostic biomarker of early CAD in an adult population. METHODS: A systematic literature analysis and retrieval online systems Public/Publisher MEDLINE/ Excerpta Medica Database /Medical Literature Analysis and Retrieval System Online,(PUBMED/EMBASE/MEDLINE) search were conducted for relevant information. Search was limited to the articles published in English language and conducted on humans, January 2000 onwards. We excluded studies of heart surgery, coronary artery bypass grafting (CABG), angioplasty and heart transplant. Eighteen studies met the inclusion criteria. RESULTS: Seven out of 18 studies were multivariate, i.e. adjusted for age, gender, body mass index (BMI), smoking, hypertension, diabetes, and blood lipid profiles, while the remaining twelve studies were univariate analysis. Different sources of miRNAs were used, i.e. plasma/serum, microparticles, whole blood, platelets, blood mononuclear intimal and endothelial progenitor cells were investigated. Fourteen out of 18 studies showed up-regulation of different miRNA in CAD patients and in vulnerable plaque disease. Four out of 18 studies showed both the up-regulation and down-regulation of miRNA in the population, while only three studies showed down-regulation of miRNA. Various sources and types of miRNA were used in each study. CONCLUSION: This review gives an extensive overview of up-regulation and down-regulation of miRNA in CAD and non-CAD patients. The pattern of miRNA regulation with respect to CAD/non-CAD study subjects varies across individual studies and different parameters, which could be the possible reason for this aberrancy. We suggest further trials be conducted in future for highlighting the role of miRNA in CAD, which may improve both the diagnostic and therapeutic approaches to stratifying CAD burden in the general population.