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Objectives: This study aimed to provide an overview of prediction models of undiagnosed type 2 diabetes mellitus (U-T2DM) or the incident T2DM (I-T2DM) using the transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD) checklist and the prediction model risk of the bias assessment tool (PROBAST). Data Sources: Both PUBMED and EMBASE databases were searched to guarantee adequate and efficient coverage. Study Selection: Articles published between December 2011 and October 2019 were considered. Data Extraction: For each article, information on model development requirements, discrimination measures, calibration, overall performance, clinical usefulness, overfitting, and risk of bias (ROB) was reported. Results: The median (interquartile range; IQR) number of the 46 study populations for model development was 5711 (1971 - 27426) and 2457 (2060 - 6995) individuals for I-T2DM and U-T2DM, respectively. The most common reported predictors were age and body mass index, and only the Qrisk-2017 study included social factors (e.g., Townsend score). Univariable analysis was reported in 46% of the studies, and the variable selection procedure was not clear in 17.4% of them. Moreover, internal and external validation was reported in 43% the studies, while over 63% of them reported calibration. The median (IQR) of AUC for I-T2DM models was 0.78 (0.74 - 0.82); the corresponding value for studies derived before October 2011 was 0.80 (0.77 - 0.83). The highest discrimination index was reported for Qrisk-2017 with C-statistics of 0.89 for women and 0.87 for men. Low ROB for I-T2DM and U-T2DM was assessed at 18% and 41%, respectively. Conclusions: Among prediction models, an intermediate to poor quality was reassessed in several aspects of model development and validation. Generally, despite its new risk factors or new methodological aspects, the newly developed model did not increase our capability in screening/predicting T2DM, mainly in the analysis part. It was due to the lack of external validation of the prediction models.

Background: Studies on knowledge, attitude, and practice (KAP) can be valuable for public health to help in developing targeted educational programs and assessing the effectiveness of interventional programs. Objectives: This study was designed to determine the level of current knowledge, attitude, and practice (KAP) regarding cardiovascular diseases (CVDs), CVD risk factors and symptoms in adults attending health care centers in Tehran province. Methods: A cross-sectional study was performed using a self-administered questionnaire with score of 0 - 100 on adults aged > 20 years attending ten health care centers in Tehran province, Iran. Descriptive and multivariate logistic regression analyses were used in data analysis. Results: A total of 300 adults (51.3% females) with a mean age of 39.71 ± 12.1 years participated in this study. The median (IQR) score for knowledge about CVD was 91.7 (16.7); approximately 80% of respondents’ awareness was highly satisfactory and hypertension was the commonest identified risk factor followed by obesity. Furthermore, the median (IQR) score for attitude was 89 (18); 70% of respondents had a highly satisfactory attitude about CVD. Regarding physical activity and nutrition/smoking behaviors, just 10.7% and 32% had highly satisfactory behavior, respectively. In the multivariate logistic regression analysis, attending university education and age ≥ 40 years were independent factors of a better level of CVD knowledge; attending university education, and having a family history of chronic disease were independent factors of a better level of CVD attitude. Regarding a higher physical activity behavior, being a man, and for a better nutrition & smoking behavior, attending university education were the only independent factors. Conclusions: Although more than half of the current study participants had high knowledge and attitude about CVD, their behaviors is not satisfactory. Therefore, it is necessary to establish more effective educational interventions aimed at promoting positive health behaviors and explaining to the public that knowledge and action regarding the reduction of risk factors are linked to reduced CVD and mortality.

Background: The burden of chronic kidney disease (CKD) is on the rise worldwide; diabetes and hypertension are mentioned as the main contributors. Objectives: The current study aimed to investigate the multiplicative and additive interaction of diabetes and hypertension in the incidence of CKD. Methods: In this population-based cohort study, 7342 subjects aged 20 years or above (46.8% male) were divided into four groups: no diabetes and hypertension; diabetes and no hypertension; hypertension and no diabetes; and both diabetes and hypertension. The multivariable Cox regression was used to determine the effect of diabetes, hypertension, and their multiplicative interaction on CKD. The following indices were used to determine the additive interaction of diabetes and hypertension: the relative excess risk of interaction, the attributable proportion due to interaction, and the synergism index. Results: Diabetes and hypertension had no significant multiplicative interaction in men (hazard ratio of 0.93, P value: 0.764) and women (hazard ratio of 0.79, P value: 0.198); furthermore, no additive interaction was found in men (relative excess risk due to interaction of 0.79, P value: 0.199; attributable proportion due to interaction of 0.22, P value: 0.130; synergy index of 1.44, P value: 0.183) and women (relative excess risk due to interaction of -0.26, P value: 0.233, attributable proportion due to interaction of -0.21, P value: 0.266; synergy index of 0.48, P value: 0.254). Conclusions: This study demonstrated no synergic effect between diabetes and hypertension on the incidence of CKD.

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.

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.

Background: For addressing the burden of non-communicable diseases and policymaking, the world health organization uses World Bank income group to classify countries. This calcification method might not be optimal. This study aimed to investigate the role of World Bank income group, health expenditure, and cardiometabolic risk factors of countries in explaining the gap between their cardiometabolic mortality. Methods: In total, 190 countries were categorized into four income groups according to the World Bank definition. The energy consumption, health expenditure, and data of sex-specified age-standardized prevalence of obesity, hypercholesterolemia, hypertension, diabetes, smoking, and physical inactivity in 2008 and cardiometabolic mortality in 2012 were used. Multivariable-adjusted mixed-effect linear regression models were applied to relate country-level predictors to their mortality outcomes. Results: While the lowest cardiometabolic mortality was recorded in high-income countries in both genders, the highest rates were recorded in the low-income category for women and in low and middle-income for men. Countries had lower cardiometabolic mortality for women compared to men; however, such a difference was not shown in low-income countries. World Bank income group of countries, per se, explained one-third of the variation in their mortality outcomes while adding health expenditure, energy consumption, and cardiometabolic risk factors increased the explanatory power of the model considerably. Moreover, the more the health expenditure, the weaker the association of prevalence of hypertension with cardiometabolic mortality. Conclusions: Adding countries' health expenditure and/or the prevalence of risk factors to their World Bank income group may contribute to the better explanation of the gap between them in cardiometabolic mortality.

Context: Neonatal mass screening program for congenital hypothyroidism provides the best tool for prevention of its devastating effects on mental development. Despite the overall success of the screening programs in detecting congenital hypothyroidism and eliminating its sequelae and new developments made in the program design, high recall rate and false positive results impose a great challenge worldwide. Lower recall rate and false positive results may properly organize project expenses by reducing the un- necessary repeated laboratory tests, increase physicians and parents’ assurance and cooperation, as well as reduce the psychological effects in families. Evidence Acquisition: In this review, we assessed the recall rate in different programs and its risk factors worldwide. Methods: Publications reporting the results of the CH screening program from 1997 to 2016 focusing on the recall rate have been searched. Results: Recall rates vary from 0.01% to 13.3% in different programs; this wide range may be due to different protocols of screening (use of T4 or TSH or both), different laboratory techniques, site of sample collection, recall cutoff, iodine status, human error, and even CH incidence as affected by social, cultural, and regional factors of the population. Conclusions: It is suggested to implement suitable interventions to reduce the contributing factors by improving the quality of laboratory tests, selecting conservative cut off points, control iodine deficiency, use of iodine free antiseptic during delivery, and use of more specific markers or molecular tests. Applying an age dependent criteria for thyrotropin levels can be helpful in regions with a varied time of discharge after delivery or for preterm babies.

Background High-risk individuals for CHD could be diagnosed by some non-invasive and low-priced techniques such as Minnesota ECG coding and rose angina questionnaire (RQ). Objectives The present study aimed at determining the risk of incident CHD according to ECG and RQ besides diabetes and other metabolic risk factors in our population. Methods Participants comprised of 5431 individuals aged ≥ 30 years within the framework of Tehran lipid and glucose study. Based on their status on history of CHD, ECG, and RQ at baseline, all participants were classified to 5 following groups: (1) History-Rose-ECG- (the reference group); (2) History-Rose+ECG-; (3) History-Rose-ECG+; (4) History-Rose+ECG+; and (5) History+. We used Cox regression model to find the role of ECG and RQ on CHD, independent of other risk factors. Results Overall, 562 CHD events were detected during the median of 10.3 years follow-up. CHD incidence rates were 55.9 and 9.09 cases per 1000 person-year for participants with and without history of CHD, respectively. Hazard ratios (HRs) (95% CIs) were 4.11 (3.27 - 5.11) for History + and 2.18 (1.63 - 2.90), 1.92 (1.47 - 2.51), and 2.48 (1.46 - 4.20) for History-Rose+ECG-, History-Rose-ECG+, and History-Rose+ECG+, respectively. RQ and ECG had the same HRs as high as those for hypertension and hypercholesterolemia; however, diabetes showed statistically and clinically more effects on CVD than RQ and ECG. Conclusions RQ in general and, ECG especially in asymptomatic patients, were good predictors for CHD events in both Iranian males and females; however, their predictive powers were lower than that of diabetes.

Background: Random errors in the measurement of risk factors lead to bias in the exposure-disease association. Objectives: This study aimed to examine the extent of underestimation in the association of total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and triglyceride (TG) with cardiovascular disease (CVDs) in the Tehran Lipid and Glucose Study. Patients and Methods: Of 6327 eligible people in the original cohort followed for about 10 years to detect CVD events, 3063 (1224 men and 1839 women) had replicate measurements for blood lipids. Two regression dilution ratios were calculated by nonparametric and parametric methods, using replicate data from reexaminations three and six years after baseline. Adjusted and unadjusted hazard ratios (HR) were corrected for regression dilution bias. Results: By parametric method, based on reexamination three years after baseline, the strength of real association of usual levels of TC, TG and HDL-C with cardiovascular disease, considering β coefficients of related models, were underestimated about 42%, 51% and 81% in men and 40%, 43% and 62% in women, respectively. Underestimations were relatively independent of age, sex and body mass index. Correction for regression dilution bias led to more than 60% increase in estimated HR for TC adjusted for confounders. Conclusions: Using baseline measurements of lipids led to considerable underestimation in the association of these factors with CVD outcome in TLGS. The underestimation increased with time interval between baseline and follow-up measurements for TC and TG. TC had more attenuation on estimated HR due to stronger relation with CVD risk.