Resting heart rate and the risk of incident type 2 diabetes mellitus among non-diabetic and prediabetic Iranian adults: Tehran lipid and glucose study.

BACKGROUND: Resting heart rate (RHR) has been found to be a potential risk factor for developing type 2 diabetes mellitus (T2DM), with a highly significant heterogeneity among previous studies. Therefore, we examined the association of RHR and risk of incident T2DM among non-diabetic and prediabetic adults. METHODS: The study population included 2431 men and 2910 women aged ≥ 20 years without T2DM at baseline (2001-2005). Participants were followed for incident T2DM by about 3-year intervals up to April 2018. The multivariable Cox proportional models were applied to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs). The models were adjusted for age, body mass index, waist circumference, educational level, physical activity, smoking, hypertension, family history of diabetes, triglycerides/ high-density lipoprotein cholesterol ratio, and fasting plasma glucose. RESULTS: During a median follow-up of 12.2 years, 313 men and 375 women developed T2DM. Interestingly, a significant sex-difference was found (all P-values for sex interaction < 0.025). Among men, compared to the first quintile (< 68 bpm: beats per minute), those who had RHR of over 84 bpm were at higher T2DM risk with a HR (95%CI) of 1.69 (1.16-2.47). Furthermore, considering RHR as a continuous variable, an increase of 10 bpm caused 17% significantly higher risk among men with a HR of 1.17 (1.05-1.30). However, among women, there was no significant association between incident T2DM and RHR. Moreover, among prediabetic participants at baseline, the association of RHR and risk of T2DM progression was generally similar to the general population, which means higher RHR increased the risk of T2DM development only among men with a HR of 1.26 (1.09-1.46) for 10 bpm increase. CONCLUSIONS: Among men, being either non-diabetic or prediabetic at baseline, higher RHR can be associated with incident T2DM; however, women didn't show a significant association. Further studies are needed to determine the added value of RHR as a potential modifiable risk factor in screening and risk prediction of incident T2DM.

The clinical value of metabolic syndrome and its components with respect to sudden cardiac death using different definitions: Two decades of follow-up from the Tehran Lipid and Glucose Study.

BACKGROUND: To evaluate the impact of different definitions of metabolic syndrome (MetS) and their components on the risk of sudden cardiac death (SCD) among the Iranian population according to the World Health Organization (WHO), International Diabetes Federation (IDF), Adult Treatment Panel III (ATP III), and Joint Interim Statement (JIS) criteria. METHODS: The study population included a total of 5,079 participants (2,785 women) aged ≥ 40 years, free of cardiovascular disease (CVD) at baseline. Participants were followed for incident SCD annually up to 20 March 2018. Multivariable Cox proportional hazards regression models were applied to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of MetS and its components for incident SCD. RESULTS: The prevalence of MetS ranged from 27.16% to 50.81%, depending on the criteria used. Over a median of 17.9 years of follow-up, 182 SCD events occurred. The WHO, IDF, and JIS definitions were strong predictors of SCD with multivariable-adjusted HRs (95% CI) of 1.68 (1.20-2.35), 1.51 (1.12-2.03), and 1.47 (1.08-1.98), respectively; these associations significantly attenuated after further adjustment for MetS components. MetS by the ATP III definition was not associated with the risk of SCD after controlling for antihypertensive, glucose-lowering, and lipid-lowering medication use. Among the components of MetS, high blood pressure (WHO definition), high waist circumference (using the national cutoff of ≥ 95 cm), and high glucose component by the JIS/IDF definitions remained independent predictors of SCD with HRs of 1.79 (1.29-2.48), 1.46 (1.07-2.00), and 1.52 (1.12-2.05), respectively. CONCLUSIONS: The constellation of MetS, except for when defined with ATP III definition, is a marker for identifying individuals at higher risk for SCD; however, not independent of its components. Among MetS components, abdominal obesity using the population-specific cutoff point, high glucose component (JIS/IDF definitions), and high blood pressure (WHO definition) were independent predictors of SCD.

Association between Wrist Circumference and Risk of Any Fracture in Adults: Findings from 15 Years of Follow-Up in the Tehran Lipid and Glucose Study.

We evaluated whether wrist circumference (WrC), as a novel anthropometric measure, is associated with incidences of any fractures. The study population included 8288 adults (45.3% men) aged ≥30 years, who were followed for incidences of any fractures from 31 January 1999 to 16 March 2016. We used Cox proportional hazard models adjusted for well-known risk factors to evaluate the association of WrC, both as continuous and categorical variables (bottom tertile as reference), with incidences of any fractures and major osteoporotic fractures (MOF). Over 15 years of follow-ups, 348 fractures occurred (men = 162). For a 1 cm increase in WrC, hazard ratios (HRs) were 1.18 (95% CI: 1.03-1.35) for incident any fractures and 1.22 (1.01-1.49) for incident MOF. In addition to WrC, age, female sex, lower BMI, higher WC, current smoking, and usage of steroidal medications were significantly associated with the incidences of any fractures. Moreover, participants in the middle and top tertiles of WrC had a higher risk of incidence for any fractures [HR = 1.62 (1.19-2.20) and 1.70 (1.14-2.55), respectively, p-value for trend = 0.012]. We presented WrC as a strong and independent risk factor for incidences of any fractures that might be considered in the risk prediction of bone fracture in Iranian adults.

Three-year weight change and risk of all-cause, cardiovascular, and cancer mortality among Iranian adults: over a decade of follow-up in the Tehran Lipid and Glucose Study.

BACKGROUND: We investigated the impact of weight change on mortality in a population-based cohort setting. METHODS: We conducted two weight measurements for 5436 participants aged ≥ 30 years with an approximate 3-year interval. Based on their weight change, we categorized participants to: > 5% weight loss, 3-5% weight loss, stable weight (± < 3%), 3-5% weight gain, > 5% weight gain. We followed participants for mortality annually up to March 20th 2018. We applied the multivariable Cox proportional hazard models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of weight change categories for all-cause, cardiovascular (CV), and cancer mortality, considering stable weight as reference. The Cox models was adjusted for age, sex, educational level, body mass index, smoking status, hypertension, hypercholesterolemia, diabetes, and cardiovascular disease (CVD) at baseline. RESULTS: During a median follow-up of 14.4 years, 629 deaths (247 CV and 126 cancer deaths) have occurred. Over 5% weight loss and gain were associated with increased risk of all-cause mortality in multivariable analysis with HRs of 1.47 [95% CI: 1.17-1.85] and 1.27 [1.02-1.57], respectively; however, a 3-5% loss or gain did not alter the risk of all-cause mortality significantly. These significant risks for wight change > 5% were not modified by the presence of diabetes, obesity, and smoking status; however, the unfavorable impact of weight change on mortality events was more prominent in those older than > 65 years (P-value for interaction: 0.042). After excluding those with history of CVD, diabetes, and cancer during the weight measurements period, these associations significantly attenuated (HR: 1.29 [0.89-1.87] for > 5% weight loss and 1.12 [0.84-1.50] for > 5% weight gain). Additionally, a > 5% weight loss was also associated with about 60% higher risk for CV mortality (HR: 1.62 [1.15-2.28]), and a 3-5% weight loss was associated with about 95% higher risk of cancer mortality (HR: 1.95 [1.13-3.38]). CONCLUSIONS: Our findings showed a U-shaped association across weight change categories for all-cause mortality risk with over 5% weight gain and loss causing higher risk. Moreover, weight loss can have adverse impact on CV and cancer mortality events.

Weight change and risk of cardiovascular disease among adults with type 2 diabetes: more than 14 years of follow-up in the Tehran Lipid and Glucose Study.

BACKGROUND: To examine the impact of weight change on incident cardiovascular disease and coronary heart disease (CVD/CHD) among an Iranian population with type 2 diabetes mellitus (T2DM). METHODS: The study population included 763 participants with T2DM aged ≥ 30 years without a history of CVD and cancer at baseline. Two weight measurements done at baseline and about 3 years later. Based on their weight change, they categorized into: > 5% loss, 3-5% loss, stable (± < 3%), 3-5% gain, > 5% gain. Participants were then followed for incident CVD/CHD annually up to 20 March 2018. Multivariable Cox proportional hazard models, adjusted for age, sex, body mass index, educational level, current smoking, glucose-lowering drug use, family history of CVD, hypertension, hypercholesterolemia, chronic kidney disease, and fasting plasma glucose (FPG) were applied to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of weight change categories for incident CVD/CHD, considering stable weight as reference. RESULTS: After the weight change measurement, during a median follow-up of 14.4 years, 258 CVD and 214 CHD occurred. Over 5% weight gain was associated with reduced risks of CVD and CHD development by the HRs of 0.70 [95% CI 0.48-1.01; P-value: 0.058] and 0.61 [0.40-0.93], respectively, in multivariable analysis. After further adjustment for FPG change, the HRs of weight gain > 5% were attenuated to 0.75 [0.51-1.10; P-value: 0.138] and 0.66 [043-1.01; P-value: 0.053] for incident CVD and CHD, respectively. The effect of weight loss > 5% was in opposite direction among those older versus younger than 60 years; with suggestive increased risk (not statistically significant) of incident CHD/CVD for the older group. Moreover, weight gain > 5% significantly reduced the risk of CHD only among those older than 60 years (P-value for interaction < 0.2). Furthermore, weight gain > 5% had an association with lower risk of CVD and CHD among sulfonylurea users (0.56 [0.32-0.98] for CVD and 0.54 [0.29-0.99] for CHD). CONCLUSIONS: Our results with a long-term follow-up showed that weight gain > 5% was associated with better CVD/CHD outcomes among Iranian participants with T2DM, especially older ones. Moreover, we did not find an unfavorable impact on incident CVD/CHD for sulfonylurea-induced weight gain.

Sex-Specific Incidence Rates and Risk Factors for Hypertension During 13 Years of Follow-up: The Tehran Lipid and Glucose Study.

Background: Hypertension, with a prevalence of 25.6% is a serious public health concern in Iran. Objective: To investigate the population-based incidence of hypertension and its potential risk factors in Tehranian adults during a median follow-up of 13.1 years. Methods: A total of 6,533 non-hypertensive participants (women = 3,639), aged ≥20 years participated in the study. Crude and age-standardized incidence rates per 1000 person-years were calculated for each sex, separately. Multivariable Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI) for all potential risk factors. Results: The crude and age-standardized incidence rates (95% CI) of hypertension per 1000 person-years were 29.7 (27.8-31.6) and 34.9 (32.5-37.4) among men and 25.8 (24.3-27.3) and 38.7 (35.5-42.0) among women, respectively. The incidence rate of hypertension in younger age groups was higher among men. However, after the 4th decade, the incidence rate was higher among women. Significant interactions of sex with age groups, body mass index categories, marital status, hypertriglyceridemia and glycemic categories were found in multivariable analyses (all p-values < 0.05). In the multivariable model, the risk in both sexes was found to be significantly associated with older age, obesity, and normal or high normal blood pressure (BP). Moreover, factors such as being overweight [HR: 1.20 (1.00-1.44)], former smoking [2.15 (1.52-3.04)], hypertriglyceridemia [1.23 (1.06-1.43)] and pre-diabetes status [1.19 (1.02-1.39)] were significant predictors of incident hypertension among women. Central obesity was found to be a significant predictor among men [1.26 (1.03-1.54)]. The optimism-corrected Harrell's C index (95% CI) in the categorical adjusted model was 0.75 (0.74-0.79) among men and 0.75 (0.74-0.76) among women. Conclusion: In the Tehranian population, nearly 2.7% of total participants (3% of men and 2.6% of women) develop hypertension each year. Obesity and high BP levels are the main modifiable risk factors in both sexes. Hypertriglyceridemia, prediabetes and former smoking are risk factors for hypertension among women.

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.