ABSTRACT
In the late 1990s the non-communicable diseases were becoming increasingly more prevalent and a significant proportion of evidence in this regard had originated from industrialized "Western" countries. This had led to a landscape where most national and local health decisions regarding non-communicable diseases [NCDs] were informed by data generated elsewhere. Iran, as a large country in the Middle East was no exception and was going through significant population growth and urban development at the time. An initiative by the Iranian National Scientific Research Council funded an idea that was aimed at delineating the local epidemiology of NCDs and their risk factors in a manner that was unprecedented. The result was Tehran Lipid and Glucose Study [TLGS], the first and longest running cohort of its sort in Iran. Initial data out of TLGS reported the characteristics of 15005 people aged over 3 years in a representative population of Tehranians. Additionally, distribution and prevalence of cardiovascular risk factors among the study population were characterized. This population was selected through a multistage stratified cluster random sampling technique from the population of district 13 in Tehran. In addition, TLGS gave rise to a great deal of important and highly effective initial findings on national cut-off points for various variables, information about nutrition, hypertension, dyslipoproteinemia, and metabolic syndrome. TLGS also generated information about metabolic health indicators among children and adolescents. Here we present a brief overview of rationale, design, and initial findings of TLGS
ABSTRACT
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
Context: the Tehran lipid and glucose study [TLGS] is one of the oldest population-based longitudinal cohort studies, providing knowledge about the incidence and risk factors of some non-communicable diseases [NCDs] in West Asia which hitherto was relatively scarce. We reviewed the methods and results related to the outcome measurements of this study
Evidence Acquisition: we reviewed all the TLGS papers which reported the incidence of NCDs
Results: the TLGS was initiated in 1999 - 2001 on a population in district no. 13 of Tehran with the same age distribution of the overall Tehran population and with a middle socioeconomic status. Totally, 15005 individuals, aged >/= 3 years, participated in the first examination; reexaminations were conducted in a triennial manner and 3550 individuals were added in the second examination. All participants were also followed up annually and asked about any medical event leading to hospitalization or death. A part of participants was assigned to an educational program for lifestyle modification. High incidence of cardiovascular disease [CVD], premature CVD, diabetes and hypertension [around 19, 6, 10 and 31 in men and 11, 5, 11 and 29 in women per 1000 person-year, respectively] besides the high incidence of pre-diabetes and pre-hypertension [around 46 and 76 in men and 37 and 49 in women per 1000 person-year, respectively] showed a worrying situation. Fortunately, the results of the community interventions were promising with around 20% reduction in the risk of metabolic syndrome up to six years
Conclusions: these precise detections of different outcomes in the TLGS provided valuable evidences for prediction and prevention of NCDs in Iran with some novelties in the middle-income countries in the world. The Tehran thyroid study [TTS] and the Tehran cardiometabolic genetic study [TCGS], conducted in the framework of the TLGS, are among few studies aiming to determine the natural course of thyroid function and to identify patterns of genetic polymorphisms related to cardiometabolic outcomes, respectively
ABSTRACT
Tehran Lipid and Glucose Study [TLGS], an epidemiological study of non-communicable disease with 20 years follow up in a developing country in nutrition transition is a unique study in 15000 family based individuals, 3 - 75 years of age in a part of large city of Tehran. The success rate of recruitment for 20 years, intervention for lifestyle change, and thyroid, reproduction and cardiometabolic genetic studies derived from TLGS have paved suitable path towards precision medicine. In this review, baseline findings and changes of risk factors for the development of NCD including body weight, nutrition, physical activity, blood pressure, tobacco smoking, serum glucose and serum lipids as well as metabolic syndrome, chronic kidney disease, quality of life and biochemical findings in TLGS cohort have been summarized. The results of community based intervention for lifestyle change caused decreases in the prevalence of metabolic syndrome and the incidence of diabetes. It is concluded that TLGS has served as a model for other cohort studies in Iran and the region; it has helped to mobilize scientists in developing countries; it has established locally needed definitions of NCD variables; has served as a model for cohort studies in developing countries in nutrition transition with all socioeconomic constraints and has helped manpower education and development of local CVD risk scores for implementation of NCD management
ABSTRACT
Thyroid cancer, the most common endocrine malignancy worldwide, originates from follicular epithelial cells. It is classified as a well-differentiated thyroid carcinoma [WDTC] -follicular [FTC] and papillary types [PTC]-, poorly differentiated thyroid carcinomas [PDTC], anaplastic thyroid carcinoma [ATC], and parafollicular calcitoninproducing cells include medullary thyroid carcinoma [MTC]. "Epigenetic" refers to the study of heritable changes in gene expression that occur without any alteration in the pattern of the primary DNA sequence. Growing evidence shows that epigenetic changes play important roles in thyroid carcinomas and, together with genetic changes, lead to tumorigenesis. Epigenetic silencing of various genes specific for thyroid differentiation have been detected in thyroid tumors. These changes in tumor-promoting and tumorsuppressor genes also contribute to the dysregulation of thyrocyte growth and other aspects of tumorigenesis. However, at present, no promising treatment is available for advanced thyroid cancer, which is unresponsive to radioiodine. Biologically targeted therapies for advanced thyroid carcinomas have been proposed based on the recognition of main oncogenic mutations. In this review we discuss the most frequent epigenetic variations in different types of thyroid cancer, epigenetic strategies for treating this carcinoma, and experimental data and clinical trials, particularly those that use deacetylase inhibitors and demethylating agents