Association Between Insulin Resistance Indices and Liver Function Parameters Among Women With Polycystic Ovary Syndrome.

OBJECTIVE: This study aimed to investigate whether polycystic ovary syndrome (PCOS) status changes the association between insulin resistance (IR) indices and liver function parameters among women. METHODS: This is a cross-sectional, population-based study. We selected 1101 subjects aged ≥20 years from participants of Tehran Lipid and Glucose Study (TLGS). All of them had known the status of PCOS, and all variables were related to the IR indices and liver function parameters. The main outcome measures were TG/HDL-C and triglyceride-glucose (TyG) and liver function parameters (hepatic steatosis index [HSI], alanine transaminase [ALT] and aspartate transaminase [AST]). RESULT: In the present study, there was no significant difference between the PCOS and the non-PCOS regarding the presence of liver function abnormalities. A model adjusted by age and BMI showed that the upper tertile of TyG index was positively associated with high AST (OR = 3.04 [95% CI: 1.20-7.68], p < 0.05), high ALT (4.76 [3.07-7.36], p < 0.05) and high HSI (8.44 [1.82-39.17], p < 0.05). Although the history of diabetes had a positive impact on elevated AST (1.66 [1.15, 2.40], p < 0.05), the third tertile of TG/HDL-C was associated with increased odds of elevated ALT (3.35 [2.21-5.06]) and HSI (6.55 [1.17-36.46]), whereas the second tertile of TG/HDL-C (OR = 2.65, CI 95%: 1.74-4.03) was also positively associated with elevated ALT. PCOS had no significant association with elevated liver function tests. CONCLUSION: The highest tertile of TyG index and the TG/HDL-C ratio as a surrogate of IR might play a role in detecting abnormalities of liver function parameters among women. However, PCOS status cannot change the association between IR and liver dysfunction.

Prevalence and metabolic determinants of abnormal alanine aminotransferase: A cross-sectional study of Iranian adults, 2018-2022.

BACKGROUND: Alanine aminotransferase (ALT) is an enzyme whose activity became the principal biomarker for liver disease. In the current study, we aimed to determine the prevalence of abnormal ALT, as a surrogate of nonalcoholic fatty liver disease (NAFLD) and its associated determinants using different criteria among Tehranian subjects between 2018 and 2022. METHODS: This is a cross-sectional study on 5676 Tehranian individuals aged 20-70 years. The weighted prevalence of abnormal ALT was calculated using both the National Health and Nutrition Examination Survey in the United States (US-NHANCE; ALT ≥30 U/L for females and ≥40 U/L for males) and the American College of Gastroenterology (ACG) guideline (ALT >25 U/L for females, and >33 U/L for males) thresholds. Moreover, uni/multivariable logistic regression analysis was performed to find the determinants of abnormal ALT. RESULTS: The weighted prevalence of abnormal ALT was 12.8% (7.6% females and 18% males) and 22.5% (17.7% females and 27.3% males) based on US-NHANCE and ACG criteria, respectively. Our results showed every decade increase in age decreased the risk of abnormal ALT by 32%. We also found that generally male gender, being overweight/obese, central adiposity, TG ≥6.9 mmol/L, non-HDL-C ≥3.37 mmol/L, lipid-lowering medications, pre-diabetes/T2DM were associated with abnormal ALT using different cutoff points. Moreover, among men resting tachycardia (≥90 beats per min), hypertension, and females past-smoker were also found as other determinants of abnormal ALT. CONCLUSION: High prevalence of abnormal ALT among non-elderly Iranian adults, especially among men, necessitates immediate multifaceted strategies by policymakers to prevent potential complications caused by NAFLD.

The association between arterial hypertension and menarcheal age.

OBJECTIVE: Menarche, as a milestone of puberty, may have a long-term effect on health. The present study investigated the association of age at menarche with the incidence of arterial hypertension. STUDY DESIGN: A total of 4747 post-menarcheal participants of the Tehran Lipid and Glucose Study who met the eligibility criteria were selected. Demographic, lifestyle, reproductive, and anthropometric data, as well as risk factors for cardiovascular diseases, were collected. Participants were classified according to their age at menarche: group I: ≤11 years, group II: 12-15 years, and group III: ≥16 years. MAIN OUTCOME MEASURES: A Cox proportional hazards regression model was used to estimate the associations between age at menarche and arterial hypertension outcomes. The generalized estimating equation models were used to compare the trend of changes in systolic and diastolic blood pressure between the three groups. RESULTS: The mean age of participants at baseline was 33.9 (13.0). At the end of the study, 1261 (26.6 %) participants had arterial hypertension. Women in group III had a 2.04-fold higher risk of arterial hypertension than those in group II. The mean changes in systolic and diastolic blood pressure were 29 % (95 % CI: 0.02-0.57) and 16 % (95 % CI: 0.00-0.38) higher for women in group III compared with group II. CONCLUSIONS: Late menarche could be a risk factor for arterial hypertension, so it is necessary to pay more attention to age at menarche in cardiovascular risk assessment programs.

Active and Passive Smoking in Adults Undergoing a Long-Term Multi-Setting Healthy Lifestyle Education: Tehran Lipid and Glucose Study.

We aimed to investigate the effects of a multi-setting lifestyle education on men's cigarette, hookah, and passive smoking, and women's passive smoking, in Iran. Data of Tehran Lipid and Glucose Study (TLGS) were used. TLGS started in 1999 with every-3-year follow-ups. Multi-stage cluster random sampling was used to recruit participants under the coverage of three health centers. One health center implemented multi-setting lifestyle education at school, family, and community setting. Our analytic sample for generalized estimating equation was restricted to 1322 and 3593 adults (respectively as intervention and control) who were followed for 15.8 years. Intervention reduced the odds of men's cigarette smoking by 27%. The estimated mean cigarettes/day was 1.58 lower in intervention men. The intervention reduced the odds of men's hookah use by 42% in short term. Intervention women had 33% lower odds of passive smoking. Lifestyle education with community outreach can help achieve pragmatic tobacco control goals.

Adults' perceived health promotion needs in the prediabetes stage: a meta-synthesis study.

Introduction: One of the methods to promote pre-diabetic patients' adherence to preventive behaviors and improving their lifestyle is to pay attention to their needs in the designed educational programs. Therefore, this study was conducted with the aim of identifying the needs of individuals with prediabetes. Methodology: Three databases, including ISI/Web of Sciences, PubMed, Scopus were searched without time limitation until August 2022. The quality of the included studies was assessed using the Critical Appraisal Skills Programme tool. This study was reported according to the Enhancing Transparency in Reporting the Synthesis of Qualitative Research guidelines and to achieve the research goal, Sandelowski and Barroso's seven-step meta-synthesis method (2007) was used. Thematic synthesis was used to analyses the data. Results: Out of the 1934 studies obtained, 34 studies were finally examined and 805 codes were recorded based on the extracted data. Through synthesizing and analyzing the primary studies, 8 main themes were extracted regarding individuals' needs in the prediabetes stage: Information needs, Cultural needs, psychological needs, Social support needs, Education needs, Financial needs, Service needs and Skill needs. Discussion and Conclusions: The perceived needs and their types in each of the dimensions in detail can be a proper guide for designing educational programs and various interventions to control the prediabetes condition, leading to a reduction in the prevalence of type 2 diabetes in the society.

The Long-Term Effectiveness of a Multisetting Lifestyle Intervention on Tobacco-Related Habits in Adolescent Boys and Girls: Tehran Lipid and Glucose Study.

BACKGROUND: This study assesses the long-term effectiveness of a lifestyle intervention on cigarette, passive, and hookah smoking in adolescent boys and girls. METHODS: One thousand one hundred and fifty-nine adolescent participants of Tehran Lipid and Glucose Study (TLGS) (2001-2004) were followed for 12 years. Participants in the intervention area received lifestyle interventions in family, schools, and community settings, with the largest part implemented in schools. After excluding those with missing baseline parental data (n = 66), complete parental data of 1093 adolescents was used for cluster analysis. Families were classified as low- and high-risk. Two hundred and ninety-six individuals who did not complete intervention/follow-ups were excluded, GEE was performed on 797 adolescents (369 boys, 192 intervention) to assess the intervention effect on tobacco-related habits. RESULTS: Adolescents' mean baseline age was 15.21 ± 1.95. Those living in high-risk families were more at risk of cigarette, passive, and hookah smoking. Intervention decreased odds of cigarette and passive smoking by 38% and 57%, respectively. Intervention did not reduce hookah smoking in adolescents. After sex-specific analysis, the intervention reduced current cigarette smoking by 40% only in boys and passive smoking in both sexes. CONCLUSIONS: Targeting lifestyle behaviors in school-aged adolescents and their families reduces cigarette smoking in boys and protects both sexes from secondhand smoke.

Improvement of glycemic indices by a hypocaloric legume-based DASH diet in adults with type 2 diabetes: a randomized controlled trial.

PURPOSE: The current study aimed to investigate the effects of legumes inclusion in the hypocaloric dietary approaches to stop hypertension (DASH) diet on fasting plasma glucose (FPG) and cardiometabolic risk factors in overweight and obese patients with type 2 diabetes over 16 weeks. Also, the modulatory effects of rs7903146 variant in the transcription factor 7 like 2 (TCF7L2) gene that is associated with the risk of diabetes, were assessed on these cardiometabolic risk factors. METHODS: This study was a randomized controlled trial. Three-hundred participants, aged 30-65 years, whose TCF7L2 rs7903146 genotype was determined, were studied. The participants were randomly assigned to receive either the hypocaloric DASH diet or a hypocaloric legume-based DASH diet. The primary outcome was the difference in FPG change from baseline until the 16-week follow-up between the two dietary interventions. The secondary outcomes were differences in insulin resistance and lipid profile changes between the dietary intervention diets. RESULTS: A reduction in FPG, insulin, homeostatic model assessment for insulin resistance (HOMA-IR), triglyceride, total cholesterol, and low-density lipoprotein cholesterol (LDL-C) was observed at week 16 in both hypocaloric dietary interventions. Compared to the DASH diet, the legume-based DASH diet decreased the FPG and HOMA-IR. There is no interaction between rs7903146 and intervention diets on glycemic parameters. CONCLUSION: The DASH diet, enrich in legumes, could improve the glycemic parameters in participants with type 2 diabetes, regardless of having rs7903146 risk or non-risk allele. REGISTRATION NUMBER OF CLINICAL TRIAL: Iranian Registry of Clinical Trials (IRCT) (code: IRCT20090203001640N17).

Impact of Polycystic Ovary Syndrome on Silent Coronary Artery Disease and Cardiovascular Events; A Long-term Population-based Cohort Study.

BACKGROUND: The existing data regarding the impact of Polycystic Ovary Syndrome (PCOS) on the risk of developing cardiovascular disease (CVD) are conflicting. AIM: To explore the effect of PCOS status on the occurrence of silent coronary artery disease (CAD)/CVD. METHODS: A total of 1591 women without CVD at baseline, aged 18-45 years, including 356 PCOS patients (defined by the Rotterdam criteria) and 1235 eumenorrheic non-hirsute women without polycystic ovarian morphology (controls), were selected from the Tehran Lipid and Glucose Study (TLGS). The median follow-up was 15.4 years, and most participants were in their late reproductive years at the end of the study. Silent CAD and CVD outcomes in PCOS and control groups were compared according to the multivariable-adjusted hazard ratios (HRs) and cumulative hazard functions. RESULTS: There was no difference in CVD risk factors between the PCOS and control groups. After controlling for confounders, PCOS status did not increase the risk of silent CAD (HR: 0.96, 95% CI 0.86-1.08). Regardless of PCOS status, women with a history of silent CAD showed 2.25 times higher CVD events than those without this history (95% CI 1.63-3.10). PCOS status reduced the CVD incidence by 42%, independently of silent CAD or traditional risk factors (HR: 0.58, 95% CI 0.35-0.98). CONCLUSIONS: Whereas silent CAD, regardless of PCOS, accelerated CVD, PCOS preserved it, most likely due to a combination of protective factors, including the endocrine pattern in the late reproductive period, environmental/social elements, and recruiting additional counseling and lifestyle modifications.

Sex Differences in Cumulative Exposure to Metabolic Risk Factors Before Hypertension Onset: The Cohort of the Tehran Lipid and Glucose Study.

Background Previous studies have shown a sex difference in the association between hypertension and cardiovascular disease; however, the precise mechanism remains unclear. Because there are strong associations between metabolic risk factors (MRFs) and hypertension, a sex-specific analysis of MRFs before hypertension onset could offer new insights and expand our understanding of sex differences in cardiovascular disease. We evaluated cumulative exposure to major MRFs and rate of change of those factors, including body mass index, waist circumference, systolic blood pressure, diastolic blood pressure, fasting plasma glucose, total cholesterol, triglycerides, and high-density lipoprotein cholesterol among individuals who did and did not develop hypertension at follow-up. Methods and Results We included 5374 participants (2191 men) initially without hypertension with age range of 20-50 years at baseline who participated in the Tehran Lipid and Glucose Study, and had been examined at least 3 times during the study period (1999-2018). In both sexes, the cumulative exposure to all MRFs (except for fasting plasma glucose and high-density lipoprotein cholesterol in men) were higher in those who developed hypertension, compared with those who did not develop hypertension. However, women experienced greater cumulative exposure to major MRFs, compared with their male counterparts. Also, they experienced a faster increase in waist circumference, systolic blood pressure, diastolic blood pressure, and high-density lipoprotein cholesterol than men. Furthermore, rapid increase in systolic blood pressure began earlier in women than men, at the age of 30 years. We also found that those men who developed hypertension experienced unfavorable change in major MRFs during young adulthood (<50 years of age). Conclusions Women exhibited more metabolic disturbances than men before onset of hypertension, which may explain the stronger impact of hypertension for major types of cardiovascular disease in women, compared with men.

The Role of Metabolic Syndrome and its Components in Incident Fracture: A 15-Year Follow-Up Among the Iranian Population.

CONTEXT: The relationship between metabolic syndrome (MetS) and the risk of fracture is a matter of debate. OBJECTIVE: This work aimed to determine the impact of MetS and its components on the risk of hospitalized fractures, during a median follow-up of 15.9 years. METHODS: A total of 7,520 participants (4,068 women) 30 years or older entered the study. Multivariable Cox proportional hazards regression were applied for data analysis. RESULTS: The prevalence of MetS was 40.0% and 40.4% in men and women, respectively. During the follow-up, hospitalized fracture was observed in 305 cases (men = 152). The multivariable hazard ratio (HR) and 95% confidence interval (CI) of MetS for incident fracture for men and women was 0.72 (0.49-1.05, P = .08) and 1.38 (0.96-1.98, P = .08), respectively. In the fully adjusted model, high fasting plasma glucose (FPG) among men tended to be associated with a lower risk of fracture [0.67 (0.44-1.02, P = .06)]; among women, high waist circumference (WC) was associated with a greater risk [2.40 (1.55-3.73)]. Among the population 50 years and older in the pooled sample, MetS was not accompanied by the risk of fracture, but high WC was associated with a higher risk [1.58 (1.07-2.33)]. For incident hip/pelvic fracture, abdominal obesity-but not MetS per se-was also a strong and independent risk factor. CONCLUSION: A significant sex difference in the association between MetS and its components with incident fracture was observed. Women with central adiposity were at increased risk of hospitalized fracture, whereas men with high FPG were at decreased risk.

The Cigarette Smoking Initiation and Continuation in Adolescents Undergoing a Long-Term Behavioral Intervention.

INTRODUCTION: Targeting adolescents' smoking reduces its burden on health systems. We investigated the effects of the first multidisciplinary community-based lifestyle intervention in the Eastern Mediterranean region, on smoking initiation, continuation, and risk of current smoking in Iranian adolescents. METHODS: The current analyses were conducted on 945 nonsmoker adolescents (12-18 years) who participated in Phase II of Tehran Lipid and Glucose Study (TLGS) and were examined four times in 12 years. The lifestyle intervention including school-based and public programs was implemented, focusing on all components of healthy lifestyle. Using a two-step cluster analysis, families were classified as high and low risk, based on parental risk factors of adolescents' smoking. Participants who failed to complete all the follow-ups (n = 99) and those with missing smoking data were excluded. Subsequently, 872 adolescents (538 control, 334 intervention) were included in the Cox model on smoking initiation, and 674 adolescents (414 control, 260 intervention) were included in the logistic regression on smoking status. RESULTS: Mean age of adolescents was 15.08 ± 1.94 years at baseline. The hazard of the smoking initiation was significantly lower in the intervention (hazard ratio = 0.71, 95% confidence interval: 0.51-0.99; p = .044) compared with control group. At the end of the fourth follow-up, intervention reduced the odds of current cigarette smoking by 29%. Within the intervention group, the high-risk cluster was at a 35% lower risk of initiating smoking and had 37% lower odds of becoming a current smoker. However, the intervention could not make a difference in preventing those who initiated smoking from maintaining it during the follow-ups. CONCLUSIONS: Our results demonstrate that lifestyle modification programs targeting at-risk populations could reduce risk of smoking initiation and current smoking in adolescents in long term. IMPLICATIONS: Experiencing cigarette smoking at the critical period of adolescence could result in adulthood habitual smoking. Therefore, identifying adolescents who are more at risk of smoking initiation and implementing targeted interventions are of great importance in public health. Our findings highlight the long-term effectiveness of a multidisciplinary community-based behavioral intervention on forming smoking behaviors in adolescents. The current intervention was successful in reducing smoking uptake in adolescents living in high-risk families.

Role of Air Pollution and rs10830963 Polymorphism on the Incidence of Type 2 Diabetes: Tehran Cardiometabolic Genetic Study.

Diabetes mellitus (DM) is considered one of the leading health issues that are egregiously threatening human life throughout the world. Several epidemiological studies have examined the relationship of a particular matter < 10 µm (PM10) exposure and with type 2 diabetes mellitus (T2DM) prevalence and incidence. Accordingly, the current study is a study investigating the independent influence of air pollution (AP) and rs10830963 on the incidence of T2DM. A total number of 2428 adults over 20 years of age participated in a prospective cohort (TCGS) during a 9-year follow-up phase. The concentration of AP was measured, and the obtained values were considered the mean level in three previous years since the exposure concentration took the people living in that location. The COX regression model was employed to determine the influence of AP and rs10830963 on the incidence of T2DM in adjustment with covariate factors. Among the 392 T2DM, 230 cases (58.7%) were female diabetics, and 162 (41.3%) were male diabetics. According to the multivariable-adjusted model, exposure to PM10 (per 10 µm/m3), associated with the risk of T2DM, although just a borderline (p = 0.07) was found in the multivariable model (HR; 1.50, 95% CI; 1-2.32). The rs10830963 was directly associated with the incidence of diabetes, and the GG genotype increased the T2DM rate by 113% (more than two times) (HR; 2.134, 95% CI; 1.42-3.21, p ≤ 0.001) and GC increased it by 65% (HR; 1.65, 95% CI; 1.24-2.21, p ≤ 0.001). Long-term exposure to PM10 was associated with an increased risk of diabetes. Thus, it is suggested that the individuals with variant rs10830963 genotypes fall within a group susceptible to an increased risk of T2DM arising from AP.

The First Cigarette Smoking Experience and Future Smoking Behaviors Among Adolescents with Different Parental Risk: a Longitudinal Analysis in an Urban Iranian Population.

BACKGROUND: Longitudinal research among Iranian adolescent smoking is limited. The current study aimed to investigate (1) the first smoking experience (FSE) and future smoking behaviors of adolescents with different parental risk factors and (2) the association between age of the FSE and future smoking behaviors over a 12-year follow-up. METHOD: Based on Tehran Lipid and Glucose Study (TLGS) database, 1487 adolescents (12-18 years) with complete baseline parental data were recruited. Using two-step cluster analysis, families were classified as either high or low risk; these were based on parental risk factors including age, education, employment, and smoking status. Participants were examined four times in 12 years and their data were used for survival analysis. After exclusion of 24 cases who were smokers at baseline, Cox proportional hazard modeling was used to evaluate the effect of parental clusters on the FSE in 1463 nonsmoking adolescents who completed all prospective follow-ups. Logistic regression analysis was used to examine the effect of the age of FSE on future smoking behaviors. RESULTS: The mean age of adolescents was 14.63 ± 2.07 years at baseline. Adolescents in the high-risk cluster group were 49% more likely to try smoking for their first time, and 55% more likely to smoke in the future. Compared with girls, boys had 83% higher chance of trying their first cigarette. Moreover, 1-year delay in the FSE resulted in 25% reduction in the probability of smoking in the future. CONCLUSION: The findings show that compared with adolescents living in low-risk families, teenagers living in high-risk families are at greater risk of smoking at an earlier age; therefore, this group could benefit from gender- and culture specific preventive interventions.

Impact of secondhand smoke exposure in former smokers on their subsequent risk of coronary heart disease: evidence from the population-based cohort of the Tehran Lipid and Glucose Study.

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.

Sex-specific initiation rates of tobacco smoking and its determinants among adults from a Middle Eastern population: a cohort study.

OBJECTIVES: To assess the initiation rate and determinants of tobacco smoking among adults. METHODS: In the Tehran Lipid and Glucose Study, a population-based cohort from Iran, 6101 participants ≥ 18 years old who had never smoked tobacco at baseline (phase II: 2002-2006) were followed until phase VI (2015-2018). Sex-specific initiation rates per 1000 person-years for self-reported tobacco smoking and hazard ratios (HR) for its potential determinants (using Cox proportional hazards models) were calculated. RESULTS: The age- and sex-adjusted smoking initiation rate was 13.77 [95% confidence interval (CI) 12.59-14.94] per 1000 person-years, of which 78% was attributed to water pipe use. Initiation rate was remarkably higher among men [19.1 (16.9-21.2)] than women [8.3 (7.4-9.2)] and declined in older age-groups. Among both genders, being married was protective [men: HR 0.67 (CI 95% 0.48-0.92); women: 0.58 (0.45-0.74)], while intermediate-level education (compared with high level) [men: 1.61 (1.14-2.26); women: 1.33 (0.95-1.84, p value = 0.092)] and passive smoking [men: 1.76 (1.36-2.28); women: 1.82 (1.42-2.33)] increased the risk. Educational intervention decreased the risk among women [0.74 (0.58-0.94)]. CONCLUSIONS: The majority of adult smoking initiators started smoking with water pipe. The initiation rate was remarkably higher in men and younger age-groups. Passive smoking, being single and lower education were risk factors. Educational intervention was protective among women.

Smoking habits and incidence of cardiovascular diseases in men and women: findings of a 12 year follow up among an urban Eastern-Mediterranean population.

BACKGROUND: Despite the strong association of smoking with cardiovascular disease (CVD) and cerebral stroke, the consequences of smoking have not been elucidated among Iranian populations. This study aimed to assess sex-specific incidence of CVDs among an urban Iranian population with different smoking habits. METHODS: Participants were recruited from the Tehran Lipid and Glucose Study (TLGS). Data on socio-demographic features and smoking habits from a sample of 10,400 individuals (4378 men and 6022 women), aged ≥20 years without prior CVD history were analyzed. Participants were followed up for 12 years for incidence of CVD/CHD events. Men were categorized in six groups, including never-, passive, ex-, passive and ex-, occasional and daily smokers. Women were categorized in three groups, i.e. never smokers, passive smokers and ever smokers. Using cox regression model, adjusted hazard ratios (HRs) of incident CVD/CHD were calculated for each group, given never smokers as the reference. RESULTS: In men, HR of CVD was 1.13 (95%CI: 0.80-1.59) in passive smokers, 1.23 (95%CI: 0.91-1.66) in ex-smokers, 1.46 (95%CI: 0.90-2.36) in passive and ex-smokers, 2.33 (95%CI: 1.25-4.33) in occasional smokers and 2.05 (95%CI: 1.57-2.67) in daily smokers. In smokers of ≥21 cigarettes/day, HR of CVD was 3.79 (95%CI: 2.25-6.37), with less risk observed in those who smoked lesser numbers of cigarettes/day. Quitters of ≥15 years were almost risk free. In women, none of the HRs of CVD/CHD were significant. CONCLUSION: An increased risk of incidence of CVD/CHD was found in current male smokers. To confirm and further elaborate these findings, more data of sex-specific studies are required from culturally diverse urban and rural areas of Iran.

Reference Values for Serum Lipid Profiles in Iranian Adults: Tehran Lipid and Glucose Study.

BACKGROUND: Lipid abnormalities are major risk factors for cardiovascular diseases. In addition to age and sex, other variables can affect serum lipid levels, warranting the determination of population-specific reference values. This study aimed to determine age- and sex-specific reference values for serum total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), and triglycerides (TG) in healthy Tehranian adults. METHODS: TC, TG, and HDL-C were measured using the enzymatic colorimetric method and the Friedewald equation (LDL-C = TC - HDL-C - TG/5) was used to calculate LDL-C concentrations in individuals with TG <400 mg/dL. After applying the exclusion criteria, 1147 participants (548 men and 599 women) aged ≥20 years were included. For determining reference values, the International Federation of Clinical Chemistry guidelines (non-parametric method) and the robust method were used for sample sizes ≥120 and <120, respectively. RESULTS: Reference values for serum TC, LDL-C, HDL-C, and TG were 121.0-261.0, 54.1-175.2, 30.9-71.9, and 46.9-301.2 mg/ dL in men and 117.8-235.9, 49.9-160.9, 36.0-83.9, and 38.1-184.2 mg/dL in women, respectively. All parameters except HDL-C were higher in men than women and showed an increasing trend with age. CONCLUSION: Reference values for serum TC, LDL-C, HDL-C, and TG in healthy Tehranian adults were determined, and these values could provide the basis for better decision making in both prevention and clinical settings.

Long-Term Effectiveness of a Lifestyle Intervention: A Pragmatic Community Trial to Prevent Metabolic Syndrome.

INTRODUCTION: The purpose of this study is to evaluate the long-term effectiveness of a community-based lifestyle education on primary prevention of metabolic syndrome in a middle-income country. STUDY DESIGN: This study followed 3,180 individuals free of metabolic syndrome who were under the coverage of three health centers in Tehran from 1999 until 2015. They were undergoing triennial examinations resulting in four re-exams. People in one of three areas received interventions consisting of family-, school-, and community-based educational programs, including a face-to-face educational session at baseline. Data were analyzed considering the incidence of metabolic syndrome at each re-exam and also repeated-measure analysis including all re-exams together. Weighting was considered to correct selection bias because of loss to follow-up. Data were analyzed in 2017. RESULTS: After 3 years, 149 of 852 participants in the intervention and 471 of 2,328 people in control area developed metabolic syndrome at first re-exam resulting in a RR of 0.78 (95% CI=0.67, 0.92). The difference between groups remained unchanged up to the 6-year follow-up (RR=0.79, 95% CI=0.66, 0.93, at second re-exam), but disappeared during the third and fourth re-exams (RR=1.04, 95% CI=0.91, 1.18 and RR=1.03, 95% CI=0.91, 1.16, respectively). Marginal models for longitudinal data showed a significant interaction between intervention and time of re-exams. Further analyses showed that the effect of the intervention might have been rooted in improvement of lipid profile and glucose level. CONCLUSIONS: In a middle-income country, face-to-face educational sessions followed by a long-term maintenance community-level educational program could reduce the risk of metabolic syndrome for up to 6 years. A booster face-to-face session is recommended to retain this preventive effect. TRIAL REGISTRATION: This study is registered at Iran Registry for Clinical Trials (http://irct.ir) IRCT138705301058N1.

Tobacco Smoking: Findings from 20 Years of the Tehran Lipid and Glucose Study.

CONTEXT: Smoking is a global public health priority and accurate data of the local population is essential to improve the health policies against its use. Hence, this study aimed to summarize the important findings available on the prevalence of smoking and its association with non-communicable diseases, documented by one of the largest prospective community-based studies of Iran. EVIDENCE ACQUISITION: All articles derived from the Tehran Lipid and Glucose Study (TLGS) in the last two decades, from the earliest publications until 30 January 2018 were reviewed for their findings on tobacco smoking. RESULTS: The prevalence of smoking in non-diabetic adults ≥ 20 years increased between baseline (phase I, 1999 - 2001) and follow-up (phase V, 2008 - 2011) from 25.5% to 35.4% among men and from 3.4% to 6.8% among women. In TLGS adolescents (10 - 18 years) water pipe use increased between 2003 and 2005 from 35.5% to 40.9% among boys and from 19.7% to 26.1% among girls. Regarding health hazards, smoking in men was associated with increased risk of combined impaired fasting glucose/impaired glucose tolerance [hazard ratio (HR) 1.69; confidence interval (CI) 95% 1.15 - 2.48] and hypertension (HR 1.26; CI 95% 0.98 - 1.63). Moreover, men, even smoking less than 10 cigarettes per day, were at increased risk for cardiovascular diseases by HR 2.12 (CI 95% 1.14 - 3.95). For women, the risk of chronic kidney disease dramatically increased 5.74-fold (CI 95% 2.71 - 12.15) among smokers. In the whole population, smoking contributed to 7.7% of all-cause mortality with HR 1.75 (CI 95% 1.38 - 2.22). Other health aspects of tobacco smoke, including its impact on metabolic status, thyroid function, female reproductive system and life style have also been reviewed. CONCLUSION: Considering hazards of smoking, there is the urgency for more effective preventive measures in Iran; emphasizing the need for further local studies on the hazards of smoking with special attention to women and adolescents and the independent hazards of water pipe use.

Outcomes of a Longitudinal Population-based Cohort Study and Pragmatic Community Trial: Findings from 20 Years of the Tehran Lipid and Glucose Study.

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.