The Tehran Lipid and Glucose Study (TLGS) as the first Community –based large-scale long-term cohort study in I.R.Iran was designed in 1998 and initiated in 1999
To study the incidence of non-communicable diseases and the association between different exposures and outcomes.
Nearly 27,500 people (7,146 households) aged ≥3 years living in District 13 under coverage by three health centers, the Leylatolghadr (7,858), Mohammadian (8,932), and Salavati (10,761) centers, where their health records are available.
Sampling method and sample size
The sample size was determined to be 14,280 considering the following items:
Using cluster random sampling, samples were selected as follows:
Lists of all households selected were prepared and their addresses were determined.
All individuals were invited for interviews and medical examinations to the TLGS unit. Social workers first familiarized them at home with the study objectives and invited them to participate in the study at the second visit; they were asked to sign a written consent and bring it to the TLGS unit following the first visit. At TLGS unit they underwent:
Each interview was conducted by means of a structured questionnaire to collect demographic data such as personal, educational, occupational, medical, and residential details.
In this stage, trained physicians collected data on the medical history, blood pressure, peripheral pulse, and thyroid exam. Trained technicians obtained anthropometrical data such as height, weight, hip, and waist sizes. ECG was taken from those aged 30 years and over.
Blood samples were drawn after 10-12 hours of fasting and the glucose tolerance test (2hPG) was performed in those aged 20 years and over.
After admission and documentation of personal characteristics and determination of a computer code, a 10-ml sample of venous blood was collected. The samples were kept for one and half hours in normal conditions of the lab. The samples were then centrifuged to separate the sera; all the tests were done daily and some samples (four micro-tubes) were stored in –70C temperature for future studies.
Follow up Methods
Active fallow-up every 3 years to repeat all measurements. Up to now, 6 examinations have been conducted. – Active follow up annually for hospitalized events and death. Up to know, 18 years of follow-up have been completed.
Demographic, behavioral (e.g. nutrition, physical activity and smoking), medical history, family history, biological (e.g. anthropometric, blood pressure, pulse rate), biochemical (e.g. serum levels of glucose, lipid profile and kidney, liver and thyroid function tests) and genetic factors.
NCDs events especially cardiovascular diseases, diabetes and other metabolic disorders and cancer. Up to Mar 2016 for any death and hospitalization and up to Mar 2017 for all measurements (Phase 6 of the TLGS) including self-reported physician diagnosis, drug history, and diagnoses based on physical exams and lab measurements, e.g. hypertension and diabetes.
About The Tehran Lipid and Glucose Study (TLGS)
RATIONALE AND DESIGN Papers
TLGS was designed as the first Community –based large scale long term cohort study in I.R.Iran
Phase I was conducted between February 1999 and August 2001.
Phase II was conducted between September 2001 and …
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No.24, Aarabi St, Yaman St, Velenjak, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Postal Code: 1985717413, P.O Box: 19395-4763