Incidence and predictors of early adulthood pre-diabetes/type 2 diabetes, among Iranian adolescents: the Tehran Lipid and Glucose Study

Stuttering in adolescence and the risk for dysglycemia in early adulthood

AIMS

To investigate the association between stuttering during adolescence and the onset of dysglycemia (prediabetes or type 2 diabetes) in early adulthood among men and women.

MATERIALS AND METHODS

This cohort study included Maccabi Health Services members assessed for mandatory military service at ages 16-19 during 1990-2019 and followed until 31 December 2020. Stuttering status was recorded in the baseline medical evaluation. Incident cases of dysglycemia were identified systematically using prediabetes and diabetes registries. Cox proportional hazard models were applied for men and women separately, adjusting for sociodemographics and medical status.

RESULTS

The study cohort comprised 866,304 individuals (55% men; 0.21% with stuttering) followed for a total of 12,696,250 person-years. During the study period, 7.6% (n = 36,603) of men and 9.0% (n = 34,723) of women were diagnosed with dysglycemia. The mean ages at diagnosis were 34 and 32 years for men and women, respectively. Women with stuttering exhibited the highest dysglycemia incidence rate (102.3 per 10,000 person-years) compared with the other groups (61.4, 69.0, and 51.9 per 10,000 person-years for women without stuttering, men with stuttering, and men without stuttering, respectively). For both men and women, those with stuttering showed an increased risk of being diagnosed with dysglycemia compared with those without (adjusted hazard ratios 1.18 [1.01-1.38] and 1.61 [1.15-2.26], respectively). The associations persisted in extensive sub-analyses.

CONCLUSIONS

Stuttering in adolescence is associated with a higher risk of dysglycemia in early adulthood for men and women. Screening and targeted prevention in this population, especially women, may be beneficial.

Tracking correlations and predictors of plasma glucose in young adulthood: A comprehensive analysis from adolescence to young adulthood in TLGS study

AIMS

We investigated the tracking correlations between fasting plasma glucose (FPG) in adolescence with both FPG and 2-hour post-load glucose (2 h-PG) in adulthood, and identified the predictors of FPG and 2 h-PG in young adulthood using traditional risk factors during adolescence and adulthood.

METHODS

We included 2188 participants (1033 male) from the Tehran lipid and glucose study within the age ranges 11-18 and 19-40 years during 1999-2018. The area under the curve (AUC) was computed using the growth curve models, and predictors were identified by the linear regression model.

RESULTS

The partial correlation between AUCs of FPG in adolescence and adulthood was 0.37 (P < 0.001). The correlation between AUCs of FPG in adolescence and 2 h-PG in adulthood was 0.17 (P < 0.001). The AUC of FPG was a significant positive predictor for both FPG and 2 h-PG in young adulthood. Other predictors of adult FPG included sex, as well as BMI and the ratio of triglycerides to HDL-cholesterol during both adolescence and adulthood.

CONCLUSIONS

Tracking correlation was observed for FPG, suggesting that monitoring and managing risk factors in adolescence may have implications for future glucose metabolism in young adulthood.

Youth-onset type 2 diabetes mellitus: an urgent challenge

The incidence and prevalence of youth-onset type 2 diabetes mellitus (T2DM) and its complications are increasing worldwide. Youth-onset T2DM has been reported in all racial and ethnic groups, but Indigenous peoples and people of colour are disproportionately affected. People with youth-onset T2DM often have a more aggressive clinical course than those with adult-onset T2DM or those with type 1 diabetes mellitus. Moreover, the available treatment options for children and adolescents with T2DM are more limited than for adult patients. Intermediate complications of youth-onset T2DM, such as increased albuminuria, often develop in late childhood or early adulthood, and end-stage complications, including kidney failure, develop in mid-life. The increasing frequency, earlier onset and greater severity of childhood obesity in the past 50 years together with increasingly sedentary lifestyles and an increasing frequency of intrauterine exposure to diabetes are important drivers of the epidemic of youth-onset T2DM. The particularly high risk of the disease in historically disadvantaged populations suggests an important contribution of social and environmental factors, including limited access to high-quality health care, healthy food choices and opportunities for physical activity as well as exposure to stressors including systemic racism and environmental pollutants. Understanding the mechanisms that underlie the development and aggressive clinical course of youth-onset T2DM is key to identifying successful prevention and management strategies.

Efficacy of ixekizumab in patients with moderate-to-severe plaque psoriasis and prediabetes or type 2 diabetes

Objective

Patients with psoriasis have an increased prevalence of type 2 diabetes when compared to the general population. Research suggests that type 2 diabetes (T2D) as well as obesity may have an impact on patients' response to treatment. This post-hoc analysis reports the efficacy of ixekizumab in treating moderate-to-severe psoriasis in patients with prediabetes or T2D.

Method and materials

UNCOVER-1, UNCOVER-2, and UNCOVER-3 were three Phase 3, multicenter, randomized, double-blind, placebo-controlled trials that evaluated the efficacy and safety of ixekizumab in adult patients with moderate-to-severe psoriasis. Patients were aged ≥18 years with chronic moderate-to-severe psoriasis (defined as ≥10% body surface area affected, static Physician Global Assessment ≥3, and Psoriasis Area and Severity Index [PASI] ≥12 at screening and baseline) who were candidates for phototherapy or systemic therapy. UNCOVER-1, UNCOVER-2, and UNCOVER-3 participants received ixekizumab as per label (that is, an initial dose of two subcutaneous injections [160 mg in total] at Week 0, followed by 80 mg every 2 weeks through Week 12 and 80 mg every 4 weeks thereafter through Week 60).

Results

The proportions of patients with prediabetes, T2D and normoglycemia that achieved PASI75, PASI90, and PASI100 at Week 60 were similar. Results suggest that patients with T2D were slower to achieve PASI100 than patients with prediabetes or those with normoglycemia. Ixekizumab had no effect on any metabolic markers in patients receiving the treatment.

Conclusions

Despite the higher rate of obesity and extreme obesity in patients with prediabetes and T2D, ixekizumab was an efficacious treatment in treating patients with psoriasis.

Worldwide estimates of incidence of type 2 diabetes in children and adolescents in 2021

AIMS

We aimed to conduct a systematic review of published studies on the incidence of type 2 diabetes in children and adolescents aged under 20 years and provide worldwide incidence estimates for 2021.

METHODS

We used MEDLINE and EMBASE to identify studies reporting type 2 diabetes incidence in children and adolescents published between Jan 2000 and April 2021. We used a negative binomial regression model to develop a prediction equation to estimate incidence rates from country characteristics. We applied the resulting incidence predictions to country population data to estimate numbers of incident cases in children and adolescents by International Diabetes Federation (IDF) region and World Bank income classification group.

RESULTS

We estimate that there are approximately 41,600 new cases of diagnosed type 2 diabetes among children and adolescents in 2021 worldwide. Around 30% and 40% of the worldwide total incident cases are in IDF Western Pacific region and in World Bank upper-middle-income countries, respectively. The three countries with the highest estimated number of incident cases are China, India, and United States of America.

CONCLUSIONS

The number of newly diagnosed type 2 diabetes in children and adolescents is substantial. More reliable data are needed to track the incidence of type 2 diabetes in children and adolescents.

Epidemiology of type 2 diabetes in the Middle East and North Africa: Challenges and call for action

Type 2 diabetes continues to be a serious and highly prevalent public health problem worldwide. In 2019, the highest prevalence of diabetes in the world at 12.2%, with its associated morbidity and mortality, was found in the Middle East and North Africa region. In addition to a genetic predisposition in its population, evidence suggests that obesity, physical inactivity, urbanization, and poor nutritional habits have contributed to the high prevalence of diabetes and prediabetes in the region. These risk factors have also led to an earlier onset of type 2 diabetes among children and adolescents, negatively affecting the productive years of the youth and their quality of life. Furthermore, efforts to control the rising prevalence of diabetes and its complications have been challenged and complicated by the political instability and armed conflict in some countries of the region and the recent coronavirus disease 2019. Broad strategies, coupled with targeted interventions at the regional, national, and community levels are needed to address and curb the spread of this public health crisis.

Adolescent metabolic syndrome and its components associations with incidence of type 2 diabetes in early adulthood: Tehran lipid and glucose study

AIM

To investigate the association of youth metabolic syndrome (MetS) and its components, individually and in combination with early adulthood incident type 2 diabetes (T2DM).

METHODS

A total of 2798 adolescents aged 11-19 years enrolled in the study. At baseline, MetS, its components including blood pressure (BP), waist circumference (WC), triglycerides (TGs), fasting plasma glucose, and low HDL-C, and different combinations of MetS components were defined. After a mean 11.3 years of follow-up, T2DM was determined. Multivariable Cox proportional hazard regression analysis adjusted for age, sex, family history of T2DM, and adult BMI was used for data analysis. The hazard ratio (HR) and 95% confidence interval (CI) were reported.

RESULTS

During the follow-up, 44 incidents T2DM were developed. Among different individual components, only high WC [HR = 2.63, 95% CI (1.39-4.97)] and high TGs [HR = 1.82, 95% CI (1.00-3.34)] remained as significant predictors only in the age and sex adjusted model. Regarding combinations of MetS components, 'high TGs and high WC' [HR = 2.70, 95% CI (1.27-5.77)], 'high BP and high WC' [HR = 2.52, 95% CI (1.00-6.33)], 'high TGs and high BP' [HR = 2.27, 95% CI (1.02-5.05)] as well as MetS per se [HR = 2.82, 95% CI (1.41-5.64)] had a significant relationship with incident T2DM in the multivariable adjusted model. Among different confounders, being female and having family history of T2DM were consistently associated with higher risk of T2DM, in different combinations of MetS components.

CONCLUSIONS

Adolescence MetS and some combinations of MetS components predicted early adulthood T2DM. Thus, adolescents, particularly female ones, with combinations of MetS components as well as those with family history of T2DM could be targeted for lifestyle intervention.

Incidence and Predictors of Dysglycemia and Regression to Normoglycemia in Indian Adolescents and Young Adults: 10-Year Follow-Up of the ORANGE Study

Background: The prevalence of diabetes in youth is increasing worldwide in parallel with the obesity epidemic. This study aimed to determine the incidence rates of dysglycemia (diabetes or prediabetes) and evaluate the predictors of its progression or regression to normal glucose tolerance (NGT) in a cohort of children and adolescents studied in Chennai, South India. Methods: A longitudinal follow-up of the Obesity Reduction and Awareness of Noncommunicable Diseases through Group Education (ORANGE) cohort was performed after a median of 7.1 years (n = 845; 5928 person-years of follow-up). To determine their diabetes status at follow-up, participants underwent an oral glucose tolerance test (n = 811 with NGT and 34 with prediabetes at baseline), excluding those with diabetes at baseline. Incidence rates for dysglycemia were reported per 1000 person-years of follow-up. Cox proportional hazards model was used to estimate the predictors of progression and regression. Results: Out of 811 individuals with NGT at baseline, 115 developed dysglycemia giving an incidence rate of 20.2 per 1000 person-years (95% confidence interval: 16.8-24.2). Among those with prediabetes at baseline, 70.6% of the individuals converted to NGT and the remaining 29.4% either got converted to diabetes or remained as prediabetes. Higher age, body mass index, fasting plasma glucose, 2-hour plasma glucose (2-h PG), positive family history of diabetes, and systolic blood pressure (BP) were independent predictors of incident dysglycemia, whereas lower age, waist circumference, 2-h PG, systolic BP, and triglycerides predicted regression to normoglycemia. Conclusions: This study highlights the growing burden of dysglycemia in Asian Indian youth and emphasizes the need for targeted preventive actions.

An Early-Onset Subgroup of Type 2 Diabetes: A Multigenerational, Prospective Analysis in the Framingham Heart Study

OBJECTIVE

To assess the relation of type 2 diabetes occurring earlier (age <55 years) versus later in life to the risk of cardiovascular death and to diabetes in offspring.

RESEARCH DESIGN AND METHODS

In the Framingham Heart Study, a community-based prospective cohort study, glycemic status was ascertained at serial examinations over six decades among 5,571 first- and second-generation participants with mortality data and 2,123 second-generation participants who initially did not have diabetes with data on parental diabetes status. We assessed cause of death in a case (cardiovascular death)-control (noncardiovascular death) design and incident diabetes in offspring in relation to parental early-onset diabetes.

RESULTS

Among the participants in two generations (N = 5,571), there were 1,822 cardiovascular deaths (including 961 coronary deaths). The odds of cardiovascular versus noncardiovascular death increased with decreasing age of diabetes onset (P < 0.001 trend). Compared with never developing diabetes, early-onset diabetes conferred a 1.81-fold odds (95% CI 1.10-2.97, P = 0.02) of cardiovascular death and 1.75-fold odds (0.96-3.21, P = 0.07) of coronary death, whereas later-onset diabetes was not associated with greater risk for either (P = 0.09 for cardiovascular death; P = 0.51 for coronary death). In second-generation participants, having a parent with early-onset diabetes increased diabetes risk by 3.24-fold (1.73-6.07), whereas having one or both parents with late-onset diabetes increased diabetes risk by 2.19-fold (1.50-3.19).

CONCLUSIONS

Our findings provide evidence for a diabetes subgroup with an early onset, a stronger association with cardiovascular death, and higher transgenerational transmission.

Glucocorticoid induced diabetes and lipid profiles disorders amongst lymphoid malignancy survivors

BACKGROUND AND AIMS

Hyperglycemia and glucose test abnormalities are problems during the treatment of patients with lymphoid malignancy, caused by corticosteroid therapy. However, its long-term complications or risk of developing diabetes are not available.

METHODS

Two hundred patients with lymphoid hematologic malignancy were recruited and followed up for median of 47 months. The underlying hematologic malignancy includes Hodgkin's disease (HD), Non-Hodgkin's Lymphoma (NHL), Chronic Lymphocytic Leukemia(CLL), Multiple Myeloma (MM) and Acute Lymphocytic Leukemia (ALL). Fasting blood sugar, glucose tolerance test and lipid profiles were measured before each chemotherapy cycle and every 3 months after. This study was designed to evaluate patients for long-term follow up of glucose tests abnormalities.

RESULTS

The mean age of the non-diabetic patients was significantly lower than that of diabetics and patients with fasting glucose disorder (p < 0.001). The prevalence of diabetes and impaired FBS and GTT was higher in NHL (9%), CLL (6.5%) and MM (1.5%), respectively. For lipid profiles, the highest levels of cholesterol and triglycerides were observed in multiple myeloma and the lowest in Hodgkin's lymphoma (P:0.004).

CONCLUSIONS

The most important factor for steroid-induced diabetes is age, which was more prevalent with age increase (P < 0.001). Glucocorticoid-induced diabetes is common in multiple myeloma and then in chronic lymphocytic leukemia and non-Hodgkin's lymphoma in comparison with Hodgkin's lymphoma and acute lymphoblastic leukemia.

Prevalence of autoantibodies in type 1 diabetes mellitus pediatrics in Mazandaran, North of Iran

Objectives Type 1 diabetes is an autoimmune disease. Its most important immunologic markers are pancreatic beta-cell autoantibodies. This study aimed to determine diabetes mellitus antibodies frequency among children and adolescents with type 1 diabetes. Methods This descriptive study evaluated the frequency of four diabetes autoantibodies (glutamic acid decarboxylase 65 autoantibodies [GADA], islet cell autoantibodies [ICA], insulin autoantibodies [IAA], tyrosine phosphatase-like insulinoma antigen-2 antibodies [IA-2A]) and their serum level in children and adolescents diagnosed with type 1 diabetes mellitus at the diabetes department of Bou-Ali-Sina Hospital and Baghban Clinic, Sari, Iran, from March 2012 to March 2018. The relationship between the level of different antibodies and age, gender, and diabetes duration were determined. A two-sided p value less than 0.05 indicated statistical significance. Results One hundred forty-two eligible patient records were screened. The average age at diabetes diagnosis was 4.2 ± 4.4 years. The median duration of diabetes was 34.0 (12.7-69.7) months. 53.5% of patients were female, and 81.7% of them had at least one positive autoantibody, and ICA in 66.2%, GADA in 56.3%, IA-2A in 40.1%, and IAA in 21.8% were positive. The type of the autoantibodies and their serum level was similar between females and males but there was a higher rate of positive autoantibodies in females. The level of IA-2A and ICA were in positive and weak correlation with age at diagnosis. Conclusions More than 80% of pediatric and adolescent patients with type 1 diabetes were autoantibody-positive. ICA and GADA were the most frequently detected autoantibodies. The presence of antibodies was significantly higher in females.

Severity of the metabolic syndrome as a predictor of prediabetes and type 2 diabetes in first degree relatives of type 2 diabetic patients: A 15-year prospective cohort study

BACKGROUND

Type 2 diabetes mellitus (T2DM) has high morbidity and mortality worldwide, therefore there is of paramount importance to identify the risk factors in the populations at risk early in the course of illness. A strong correlation between severity of metabolic syndrome (MetS) and HbA1c, fasting insulin and insulin resistance has been reported. Accordingly, the MetS severity score (or MestS Z-score) can potentially be used to predict the risk of T2DM progression over time.

AIM

To evaluate the association the of MestS Z-score in first degree relatives (FDRs) of T2DM with the risk of prediabetes and type 2 diabetes in future.

METHODS

A prospective open cohort study was conducted between 2003-2018. At baseline, the sample comprised of 1766 FDRs of patients with T2DM who had a normal glucose tolerance test. Relative risk (RR) and 95% confidence interval were calculated based on logistic regression. The receiver-operator characteristic analysis and area under the curve based on MetS Z-score were used to evaluate the risk of prediabetes and diabetes among the FDR population.

RESULTS

Baseline MetS Z-scores were associated with the its latest values (P < 0.0001). Compared with individuals who were T2DM free at the end of follow up, those who developed T2DM had higher MetS Z-score at baseline (P < 0.001). In multivariable logistic regression analyses for every unit elevation in MetS Z-score at the baseline, the RR for developing future T2DM and prediabetes was (RR = 1.94, RR = 3.84), (RR = 1.5, RR = 2.17) in total population and female group, respectively (P < 0.05). The associations remained significant after adjusting the potential confounding variables. A cut off value of 0.97 and 0.94 was defined in the receiver-operator characteristic curve based on the MetS Z-score for differentiating female patients with diabetes and prediabetes from the normal population, respectively.

CONCLUSION

The MetS Z-score was associated with an increased risk of future T2DM. Appropriate interventions at earlier stages for preventing and attenuating MetS effects may be considered as an effective strategy for FDR as at-risk population.

The role of childhood BMI in predicting early adulthood dysglycemia: Tehran lipid and glucose study

BACKGROUND AND AIM

Increased adiposity is associated with insulin resistance and glycemic disturbances. We aimed to determine whether childhood overweight or obesity are independent factors in predicting adulthood dysglycemia (prediabetes or type 2 diabetes).

METHODS AND RESULTS

In this population-based cohort study, 1290 normoglycemic subjects aged 3-11 years were followed for incidence of dysglycemia. Cox-proportional hazard models were employed to evaluate the association of obesity and overweight with incidence of dysglycemia by adjustments for age, sex, parental risk factors and baseline individual risk factors. The participants, with a mean age of 7.7 ± 2.5 years, were followed for a median of 14.9 years. During follow up, 158 subjects developed dysglycemia (18 type 2 diabetes, 140 prediabetes), contributing to a total cumulative incidence of 24.7%. The unadjusted HR for developing adult dysglycemia were 1.6 (95% CI; 1.0-2.4) and 1.7 (95% CI; 1.0-3.0) in overweight and obese children, respectively. Further adjustments for age, sex, parental risk factors and baseline individual risk factors changed the results in both overweight and obese children.

CONCLUSION

These findings show that overweight or obesity in childhood have no independent role for developing adulthood dysglycemia.

Impaired fasting glucose prevalence surge among Iranian adolescents in a decade: The Tehran Lipid and Glucose Study

PURPOSE

Impaired fasting glucose (IFG) is associated with incident diabetes, cardiovascular risk, and markers of atherosclerosis in early adulthood. We aimed to explore the 10-year change in IFG prevalence among adolescent participants of the Tehran Lipid and Glucose Study, a population-based study from Iran.

METHODS

For our study, we used data on fasting plasma glucose (FPG), anthropometric, and demographic information of 11 to 19-year-old adolescents in study periods I (1999-2005; 1415 boys, 1583 girls) and II (2011-2014; 477 boys, 469 girls). Sex-adjusted and sex-stratified multivariable logistic regression models were used to assess the relationship of the study period (reference: study period I) with IFG.

RESULTS

The prevalence of IFG, general obesity, and central obesity increased from 7%, 13.3%, and 18.8% in study period I to 16.6%, 24%, and 37.4% in study period II; while a favorable trend was seen for blood pressure, triglycerides, and high-density lipoprotein cholesterol. In the fully adjusted model, being older (age group 15-19 vs 11-14 years) and female sex were associated with lower risk. Being overweight and obese increased the risk by risk ratios (confidence interval) of 1.57 (1.17-2.11) and 1.63 (1.15-2.30), respectively. Central adiposity did not remain as an independent risk factor. Nevertheless, study period persisted as a significant factor despite all adjustments [2.20 (1.81-2.68)]. Results in the sex-stratified models were generally the same.

CONCLUSION

Our results demonstrated that the over 2-fold rise in IFG prevalence among adolescents was not solely dependent on general and central obesity.

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.

Strategy for early identification of prediabetes in lean populations: New insight from a prospective Chinese twin cohort of children and young adults

AIMS

To identify certain subgroups in young and lean populations, who may be at a high risk of developing prediabetes/diabetes, which is not captured by current BMI-based screening algorithms.

METHODS

Incidence of prediabetes/diabetes was assessed using oral glucose tolerance tests among 1859 children and 1073 young adults from a prospective Chinese twin cohort.

RESULTS

Over a 6-year follow-up, 507 (27.3%) children and 293 (27.3%) adults developed prediabetes/diabetes. Of the 800 incidents, 737(92.1%) and 644(80.5%) were lean at baseline and follow-up, respectively. Baseline fasting glucose in the top tertile of the normal range was associated with an increased risk of prediabetes/diabetes: odds ratio, 1.85 (95% CI 1.32-2.59) and 3.29 (95%CI 2.10-5.17) among normal weight and underweight children, respectively, and 2.74 (95% CI 1.78-4.23) and 3.08 (95% CI 1.69-5.58) among normal weight and overweight/obese adults, respectively, compared with the low tertile of fasting glucose.

CONCLUSIONS

We showed that majority incident cases of prediabetes/diabetes were not overweight/obese (at baseline), who would have been missed by traditional screening algorithm emphasizing overweight/obesity. Our findings revealed that an upper end of normal fasting glucose was a simple and robust predictor of future higher risk of prediabetes/diabetes in this young and lean population.

Diabetes Mellitus: Findings from 20 Years of the Tehran Lipid and Glucose Study

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.

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.