ABSTRACT
OBJECTIVES@#Cigarette smoking is an established, strong, and modifiable risk factor for coronary heart disease (CHD). However, little research has investigated CHD risk in former smokers who continue to be exposed to others’ cigarette smoke (former & secondhand smokers). @*METHODS@#In the Tehran Lipid and Glucose Study, a prospective population-based cohort (n=20,069) was followed up for a median period of 14.6 years. A subset of 8,050 participants of 30 years of age and older was analyzed, with first CHD events as the study outcome. Participants were categorized as never, former, current, secondhand, and former & secondhand smokers. Data on smoking intensity (cigarette/d) were also collected. A Cox proportional hazards regression model was applied to estimate the risk of CHD, taking into account the main potential confounders. @*RESULTS@#The mean age of participants was 46.10 ±11.38 years, and they experienced 1,118 first CHD events (with most CHD cases in former smokers) during the follow-up period. The risk of CHD was highest in current smokers, followed in order by former & secondhand, former, and secondhand smokers (hazard ratio [HR], 1.99; 95% confidence interval [CI], 1.65 to 2.39; HR, 1.55; 95% CI, 1.15 to 2.08; HR, 1.39; 95% CI, 1.12 to 1.72; HR, 1.27; 95% CI, 1.07 to 1.51, respectively), compared to never smokers. The risk of CHD increased with smoking intensity, which has been proposed as a preferable measure of smoking, indicating a dose-response pattern. @*CONCLUSIONS@#The elevated risk of CHD in former & secondhand smokers was a noteworthy finding, with possible implications for health policy; however, further research is needed.
ABSTRACT
OBJECTIVES@#Cigarette smoking is an established, strong, and modifiable risk factor for coronary heart disease (CHD). However, little research has investigated CHD risk in former smokers who continue to be exposed to others’ cigarette smoke (former & secondhand smokers). @*METHODS@#In the Tehran Lipid and Glucose Study, a prospective population-based cohort (n=20,069) was followed up for a median period of 14.6 years. A subset of 8,050 participants of 30 years of age and older was analyzed, with first CHD events as the study outcome. Participants were categorized as never, former, current, secondhand, and former & secondhand smokers. Data on smoking intensity (cigarette/d) were also collected. A Cox proportional hazards regression model was applied to estimate the risk of CHD, taking into account the main potential confounders. @*RESULTS@#The mean age of participants was 46.10 ±11.38 years, and they experienced 1,118 first CHD events (with most CHD cases in former smokers) during the follow-up period. The risk of CHD was highest in current smokers, followed in order by former & secondhand, former, and secondhand smokers (hazard ratio [HR], 1.99; 95% confidence interval [CI], 1.65 to 2.39; HR, 1.55; 95% CI, 1.15 to 2.08; HR, 1.39; 95% CI, 1.12 to 1.72; HR, 1.27; 95% CI, 1.07 to 1.51, respectively), compared to never smokers. The risk of CHD increased with smoking intensity, which has been proposed as a preferable measure of smoking, indicating a dose-response pattern. @*CONCLUSIONS@#The elevated risk of CHD in former & secondhand smokers was a noteworthy finding, with possible implications for health policy; however, further research is needed.
ABSTRACT
PURPOSE: This study aimed to evaluate the effect of field-of-view (FOV) size on the gray values derived from conebeam computed tomography (CBCT) compared with the Hounsfield unit values from multidetector computed tomography (MDCT) scans as the gold standard. MATERIALS AND METHODS: A radiographic phantom was designed with 4 acrylic cylinders. One cylinder was filled with distilled water, and the other 3 were filled with 3 types of bone substitute: namely, Nanobone, Cenobone, and Cerabone. The phantom was scanned with 2 CBCT systems using 2 different FOV sizes, and 1 MDCT system was used as the gold standard. The mean gray values (MGVs) of each cylinder were calculated in each imaging protocol. RESULTS: In both CBCT systems, significant differences were noted in the MGVs of all materials between the 2 FOV sizes (P < .05) except for Cerabone in the Cranex3D system. Significant differences were found in the MGVs of each material compared with the others in both FOV sizes for each CBCT system. No significant difference was seen between the Cranex3D CBCT system and the MDCT system in the MGVs of bone substitutes on images obtained with a small FOV. CONCLUSION: The size of the FOV significantly changed the MGVs of all bone substitutes, except for Cerabone in the Cranex3D system. Both CBCT systems had the ability to distinguish the 3 types of bone substitutes based on a comparison of their MGVs. The Cranex3D CBCT system used with a small FOV had a significant correlation with MDCT results.
Subject(s)
Bone Density , Bone Substitutes , Cone-Beam Computed Tomography , Multidetector Computed Tomography , Phantoms, Imaging , WaterABSTRACT
Context: Tehran Lipid and Glucose Study [TLGS], a longitudinal family based cohort study, is the oldest and largest longitudinal family based study in Iran, aimed at investigating effects of environmental, social and biological factors on the health of Tehranians over time. Considering the importance of genetic studies in this aspect, here we present a summary of the important genetic findings, and the potentiality of their contributions to future related projects
Evidence Acquisition: for all related studies during the past 20 years the search sources were all prominent search engines such as PubMed, Scopus, and Google Scholar with the most proper Medical Subject Headings [MeSH]
Results: this review summarizes associations of 6 binary phenotypes and 17 quantitative traits with genetic markers in 26 genes. Of the 47 genetic markers, studied most were related to cardio metabolic risk factors. Results of heritability and linkage analysis were also collected and the highest heritability was found to be related to HDL-C [0.5]
Conclusion: considering the opportunity provided by large-scale cohort studies to investigate molecular effects of genetic variants on causality and different omics' data, genetic studies conducted on TLGS population have had a remarkable success in identifying genetic variants that facilitating a unique genetic database on Iranian populations. The results of genome wide association studies in this population are currently facilitating investigations to define the Iranian genetic differences with other population
ABSTRACT
Metabolic syndrome is a complex trait and its prevalence is 32% in Iranian population. The present study was conducted to find chromosomal area locus of HDL-C, triglycerides and waist with microsatellites and multivariate two level Haseman-Elston regressions in Iranian families with metabolic syndrome. 91 Iranian families [493 people] with at least one member with metabolic syndrome were selected from database of TLGS. We performed the Fragment Analysis technique to reproduce 12 different pieces from 4 chromosomal areas and to identify loci related to metabolic syndrome; both single and multi variable two level Haseman-Elston regression methods were used for traits of triglycerides, high-density lipoprotein and waist. We performed three single variable models, three double variable models and one triple variable model of these traits. 91 Iranian familes included 493 people, 234 males and 259 females. In single variable models: genetic linkage of HDL-C was significant with D11S1998 marker; genetic linkage of triglycerides was significant with Dl IS 1934 and D12S1632 markers. In double variable models genetic linkage of HDL-C and triglyceride, HDL-C and waist was significant with Dl IS 1998 marker and the genetic linkage of HDL-C and triglyceride, triglyceride and waist was significant with D8S1743 and D11S934 marker. In triple variable model genetic linkage of HDL-C, triglyceride and waist was significant with D8S1743 marker. These results showed when a trait is common in different models; the linked markers of them are also common. We concluded that the multivariate methods can detect linked loci of mixed disease better than single variable models and these results are useful for more future studies in Iranian population