ABSTRACT
Context: we summarized findings from Tehran lipid and glucose study [TLGS] about different aspects of type 2 diabetes [T2D] over the span of nearly 2 decades
Evidence Acquisition: a review was undertaken to retrieve papers related to all aspects of T2D from the earliest date available up to January 30, 2018
Results: an annual crude incidence rate of 10 per 1000 person-years of follow-up was found for T2D in adult participants. Overall incidence rate of pre-diabetes/T2D was 36.3 per 1000 person-years or about 1% each year among youth. Diabetes was associated with increased risk of CVD[hazard ratio [HR]: 1.86, 95% confidence interval [95% CI]: 1.57 - 2.27] and mortality [HR: 2.56; 95% CI: 2.08 - 3.16] in the total population. Compared with non-diabetic men and women, their diabetic counterparts survived 1.4 and 0.7 years shorter, respectively, during 15 years of follow-up. Wrist circumference, hyperinsulinaemia, 25-hydroxy vitamin D and increase in alanin aminotranferase provided incremental prognostic information beyond the traditional risk factors for incident T2D in adults. Using decision tree algorithms, a number of high risk groups were found for incident T2D. A probability of 84% was found for incidence of T2D among a group of men with fasting plasma glucose [FPG] > 5.3 mmol/L and waist to height ratio [WHtR] > 0.56, and women with FPG > 5.2 mmol/L and WHtR > 0.56
Conclusions: original TLGS studies have contributed greatly to clarify important evidence regarding the epidemiology and risk factors for T2D among Iranian 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
Background: several studies have emphasized the importance of cardiovascular disease [CVD] prevention. However, there is a dearth of data on the prevention of cardiovascular disease recurrence. The present study was the 1st in Iran to evaluate factors associated with CVD recurrence
Methods: this prospective cohort study was conducted on 483 subjects [> 30 years old] with a history of CVD who participated in the Tehran Lipid and Glucose Study and were followed up for 12 years [1999-2012]. The relationships between the most important established risk factors for CVD and CVD recurrence were evaluated
Results: totally, 258 [53.4%] men and 225[46.5%] women at a mean age of 59.2 +/- 10.7 years were recruited in the study. Our results showed that over the 12-year follow-up, the incidence of a recurrent event [per 100 person-years] was 48.5. Further, after controlling the possible confounding factors, the following variables had a significant relationship with CVD recurrence: age [HR = 1.02; p value = 0. 001], male sex [HR = 1.4; p value = 0.012], smoking [HR = 1.7; p value = 0.004], and increased fasting blood sugar [HR = 2.1; p value = 0.001]
Conclusion: we found that the established variables in the development of CVD [i.e., age, sex, and smoking] played an important role in the risk of CVD recurrence
ABSTRACT
Use of single measurement of risk factors can distort their estimated effects, due to random error in measurements. The aim of this study was to examine the extent of underestimation in the estimated effect of common variables in physical exam i.e. systolic and diastolic blood pressure [SBP, DBP] and body mass index [BMI] on cardiovascular diseases in Tehran Lipid and Glucose Study [TLGS]. A subsample [1167 men and 1786 women] of the original cohort, who had replicate measures of the variables in triennial interval, was used to calculate the regression dilution ratios [RDRs] in men and women. RDRs were determined by parametric and nonparametric methods. Hazard ratios [HR] of risk factors, per one standard deviation change, were corrected for regression dilution bias. The estimated RDRs by parametric method in men and women were 45% and 35% for SBP and 54% and 64% for DBP, respectively. There were 26% and 25% underestimation in HR of SBP and 23% and 33% in HR of DBP in men and women. The corresponding underestimation for BMI was about 8%. RDRs of men and women and in age groups by both methods were fairly similar. They were relatively constant during the 10-year follow-up for SBP and BMI. Using baseline measurements of blood pressure underestimate its real association with CVD events and the estimated HRs. The underestimations are independent of age and sex, and it can be fairly constant in short to moderate time intervals
ABSTRACT
Triglyceride/HDL-cholesterol ratio [TG/HDL-C] has been shown as an indicator for metabolic syndrome [MetS]. This study aimed to detect the role of this ratio to predict coronary heart disease [CHD] outcome in an Iranian men population with high prevalence of MetS. 1824 men >/= 40 years old, free of clinical cardiovascular disease at baseline, were included in the study from February 1999 to August 2001. Serum level of total cholesterol [TC], HDL-C, TG, and risk factors of CHD; including age, systolic blood pressure, diastolic blood pressure, body mass index, diabetes, smoking and family history of cardiovascular diseases were measured at initial phase of study. During a median follow up of 6.5 years until March 2007, a total of 163 new CHD events occurred. According to a Cox proportional hazard modeling, after adjustment for TC and other risk factors, men in the top quartile of TG/HDL-C relative to first quartile had a significant hazard ratio [HR] of 1.85 [95% Cl, 1.07-3.17]. Combined HR for TC and TG/HDL-C [men in the top quartiles of both TC and TG/HDL-C relative to first quartiles] after adjustment for other risk factors was 6.13 [95% Cl, 2.37-15.86]. The evaluation of both TG/HDL-C ratio and TC should be considered for CHD risk prediction in Iranian male population