Glucose intolerance and risk of cardiovascular disease in Iranian men and women: results of the 7.6-year follow-up of the Tehran Lipid and Glucose Study (TLGS)

The relationship between glucose intolerance status and risk of hospitalization during two decades of follow-up: Tehran lipid and glucose study

OBJECTIVE

To assess the relationship between glucose intolerance statuses at baseline defined as normal glucose tolerance (NGT), pre-diabetes, newly diagnosed (NDM) and known diabetes mellitus (KDM) and all-cause hospitalization among Iranian men and women during 20 years of follow-up.

RESEARCH DESIGN AND METHODS

This study included 8,014 individuals (3,836 men) ≥30 years from the cohort of Tehran Lipid and Glucose Study. Incidence rate ratios (IRRs) and (95% confidence interval (95% CI) for three groups of pre-diabetes, NDM and KDM was estimated using the Negative Binomial regression model, considering NGT group as reference group. Regression models were adjusted for age, body mass index, hypertension, chronic kidney disease, and cardiovascular disease (CVD).

RESULTS

Among men, compared with NGT group, those with pre-diabetes, NDM and KDM had higher incidence rate for hospitalization, with IRRs (95% CI) of 1.08 (0.96-1.20), 1.38 (1.20-1.57) and 1.96 (1.66-2.26), respectively, after adjusting for confounders. The corresponding values were 1.07 (0.96-1.17), 1.40 (1.21-1.59) and 2.07 (1.72-2.42) for women. Men with diabetes, generally had a higher rate of hospitalization for CVD rather than their female counterparts (IRRs: 1.46; 1.17-1.74). In patients with diabetes, the most common causes of hospitalization were macrovascular complications (i.e. coronary heart disease and stroke). Moreover, among the individuals with diabetes, those with poor glycaemic control (fasting plasma glucose (FPG) >10 mmol/l) had 39% higher rate of hospitalization than those with fair glycaemic control (FPG <10 mmol/l) (1.39; 1.12-1.65), adjusted for confounders.

CONCLUSION

Pre-diabetes, NDM, and KDM were associated with increased hospitalization rates during long-term follow-up. Interventions such as lifestyle modification or pharmacological therapies aiming to slow down the pre-diabetes and fair control of diabetes might potentially decrease the rate of hospitalization.Key messagesNDM and KDM status both increased rate of all-cause hospitalization.CVD and T2DM complication were the most common cause of hospitalization among patients with diabetes.Hospitalization due to recurrent CHD was significantly higher in men with diabetes than their female counterparts.

The prevalence of retinopathy among type 2 diabetic patients in Iran: A systematic review and meta-analysis

Diabetic retinopathy is one of the most major causes of blindness and disability in diabetic patients and imposes very high cost on Health Care System. Studies conducted in the country showed different and inconsistent prevalence of the disease. The study aims to determine the overall prevalence of retinopathy in patients with type 2 diabetes in Iran through a systematic review and meta-analysis. The present study was conducted via meta-analysis method during March, 2000 to October, 2018. The articles related to the subject under study were obtained from Magiran, SID, Medline (PubMed), Science Direct, Scopus and Google Scholar databases. I2 index was used to examine the heterogeneity of articles studied; and the data was analyzed by Comprehensive Meta-Analysis Software. Through the study of 34 articles and 17,079 individuals with age range of 5-83, the overall prevalence of retinopathy for type 2 diabetic patients in Iran and on the basis of meta-analysis, was obtained that was 37.8% (32.84-43%, 95% confidence interval); the highest prevalence of retinopathy for type 2 diabetic patients was in Tehran province with 78% (68.8-85.1%, 95% confidence interval) in 2006 and the lowest prevalence of retinopathy for type 2 diabetic patients was in Isfahan province with 9% (7.1-11.4, 95% confidence interval) in 2006; furthermore, the prevalence of retinopathy for type 2 diabetic patients in Iran increases with increased sample size that it was statistically significant (P < 0.05). Regarding the high prevalence of retinopathy for type 2 diabetic patients in the country, it is essential that health policy makers take effective measures to reduce the disease incidence in diabetic patients.

Gender differences in mortality among ST elevation myocardial infarction patients in Malaysia from 2006 to 2013

BACKGROUND

Coronary artery disease (CAD) is one of the leading causes of death in Malaysia. However, the prevalence of CAD in males is higher than in females and mortality rates are also different between the two genders. This suggest that risk factors associated with mortality between males and females are different, so we compared the clinical characteristics and outcome between male and female STEMI patients.

OBJECTIVES

To identify the risk factors associated with mortality for each gender and compare differences, if any, among ST-elevation myocardial infarction (STEMI) patients.

DESIGN

Retrospective analysis.

SETTINGS

Hospitals across Malaysia.

PATIENTS AND METHODS

We analyzed data on all STEMI patients in the National Cardiovascular Database-Acute coronary syndrome (NCVD-ACS) registry for the years 2006 to 2013 (8 years). We collected demographic and risk factor data (diabetes mellitus, hypertension, smoking status, dyslipidaemia and family history of CAD). Significant variables from the univariate analysis were further analysed by a multivariate logistic analysis to identify risk factors and compare by gender.

MAIN OUTCOME MEASURES

Differential risk factors for each gender.

RESULTS

For the 19484 patients included in the analysis, the mortality rate over the 8 years was significantly higher in females (15.4%) than males (7.5%) (P < .001). The univariate analysis showed that the majority of male patients < 65 years while females were >=65 years. The most prevalent risk factors for male patients were smoking (79.3%), followed by hypertension (54.9%) and diabetes mellitus (40.4%), while the most prevalent risk factors for female patients were hypertension (76.8%), followed by diabetes mellitus (60%) and dyslipidaemia (38.1%). The final model for male STEMI patients had seven significant variables: Killip class, age group, hypertension, renal disease, percutaneous coronary intervention and family history of CVD. For female STEMI patients, the significant variables were renal disease, smoking status, Killip class and age group.

CONCLUSION

Gender differences existed in the baseline characteristics, associated risk factors, clinical presentation and outcomes among STEMI patients. For STEMI females, the rate of mortality was twice that of males. Once they reach menopausal age, when there is less protection from the estrogen hormone and there are other risk factors, menopausal females are at increased risk for STEMI.

LIMITATION

Retrospective registry data with inter-hospital variation.

The predictive value of metabolic syndrome for cardiovascular and all-cause mortality: Tehran Lipid and Glucose Study

INTRODUCTION

The association of total and cardiovascular disease (CVD) mortality with metabolic syndrome (Mets) is controversial. We estimated the predictive value of MetS and its components for total and CVD mortality.

MATERIALS AND METHODS

A total of 7932 subjects aged ≥ 30 years; participants of the Tehran Lipid and Glucose Study were enrolled and followed for 9.0 ± 2.3 years. MetS was defined according to three different definitions: World Health Organization (WHO), International Diabetes Federation (IDF) and Joint Interim Statement (JIS).

RESULTS

WHO-MetS remained a significant predictor of total and CVD mortality in men (HR 1.66, 95%CI 1.23-2.24, p < 0.001; 1.93 HR 1.93, 95%CI 1.26-2.94, p = 0.002) and women (HR 2.01, 95%CI 1.39-2.88, p < 0.001; HR 2.71, 95%CI 1.44-5.09, p = 0.002), respectively. IDF-MetS was associated with increased risk of total mortality only in women (HR 1.51, 95%CI 1.07-2.12, p = 0.01), but after controlling for diabetes, IDF and WHO-MetS lost their associations. The incidence of CVD mortality was highest in WHO group (13.4) compared with IDF (8.5), JIS (8.14) and control (5.5) groups. The incidence of total mortality for WHO (27.1) was highest compared with IDF (17.7), JIS (16.5) and control (12.9) groups. In men, hypertension, impaired fasting glucose (IFG) and abdominal obesity and in women, IFG (WHO criteria) and high triglycerides levels increased the risk of CVD mortality. In men, hypertension and IFG directly and high triglycerides inversely were associated with total mortality. In women, IFG and obesity increased the risk of all-cause mortality.

CONCLUSION

Diagnosis of MetS seems no more informative than its individual components in predicting mortality. Copyright © 2016 John Wiley & Sons, Ltd.

The incidence of coronary heart disease and the population attributable fraction of its risk factors in Tehran: a 10-year population-based cohort study

BACKGROUND

Data on incidence of coronary heart disease (CHD) is scarce in the Middle East and little is known about the contribution of known risk factors in this area.

METHODS

The incidence of CHD and the effect of modifiable risk factors were explored in 2889 men and 3803 women aged 30-74 years in the population based cohort of the Tehran Lipid and Glucose Study, during 1999-2010. Average population attributable fraction (aPAF) was calculated for any risk factor using direct method based on regression model.

RESULTS

The crude incidence rate in men was about twice that in women (11.9 vs. 6.5 per 1000 person-years). The aPAF of hypertension, diabetes, high total cholesterol and low-HDL cholesterol was 9.4%, 6.7%, 7.3% and 6.1% in men and 17%, 16.6%, 12% and 4.6% in women respectively. This index was 7.0% for smoking in men. High risk age contributed to 42% and 22% of risk in men and women respectively.

CONCLUSIONS

The incidence in this population of Iran was comparable to those in the US in the seventies. Well known modifiable risk factors explained about 40% and 50% of CHD burden in men and women respectively. Aging, as a reflection of unmeasured or unknown risk factors, bears the most burden of CHD, especially in men; indicating more age-related health care is required.

Sex specific incidence rates of type 2 diabetes and its risk factors over 9 years of follow-up: Tehran Lipid and Glucose Study

Objective

To investigate the population-based incidence of type 2 diabetes and its potential risk factors in a sex-split cohort of Iranian population.

Materials and Methods

A total of 8400 non-diabetic participants, aged ≥20 years (3620 men and 4780 women) entered the study. Crude and age standardized incidence rates per 1000 person-years were calculated for whole population and each sex separately. Cox proportional hazard models were used to evaluate hazard ratios (HR) and 95% confidence intervals for all potential risk factors in both uni-variable and multivariable models.

Results

During a median follow-up of 9.5 years, 736 new cases of diabetes were identified, including 433 women and 303 men. The annual crude and age-standardized incidence rates (95% CI) of diabetes in the total population were 10.6 (9.92–11.4) and 9.94 (7.39–13.6) per 1000 person-years of follow-up and the corresponding sex specific rates were 10.2 (9.13–11.4) and 9.36 (5.84–14.92) in men and 11.0 (9.99–12.0) and 10.1 (7.24–13.9) in women, respectively. In the multivariable model, the risk for incident diabetes was significantly associated with fasting and 2 hour post challenge plasma glucose as well as family history of diabetes in both men and women. However, among women, only the contribution of wrist circumference to incident diabetes achieved statistical significance [HR: 1.16 (1.03–1.31)] with waist/height ratio being marginally significant [HR: 1.02 (0.99–1.04)]; while among men, only body mass index was a significant predictor [HR: 1.12 (1.02–1.22)]. Additionally, low education level conferred a higher risk for incident diabetes only among men [HR: 1.80 (1.23–2.36); P for interaction with sex = 0.003].

Conclusion

Overall, sex did not significantly modify the impact of risk factors associated with diabetes among Iranian adults; however, among modifiable risk factors, the independent role of lower education and general adiposity in men and central adiposity in women might require different preventive strategies.

Isolated post-challenge hyperglycaemia and risk of cardiovascular events: Tehran Lipid and Glucose Study

OBJECTIVE

To evaluate the risk of cardiovascular events in diabetes defined by isolated post-challenge hyperglycaemia (IPH).

METHODS

We followed 3794 subjects aged ≥40 years without known history of diabetes or cardiovascular disease (CVD) at baseline for CVD events. Participants were categorized as subjects without diabetes [fasting plasma glucose (FPG) < 126 mg/dL and 2-h post-challenge plasma glucose (2-hPG) < 200 mg/dL], IPH (FPG < 126 mg/dL and 2-h PG ≥ 200 mg/dL) and fasting hyperglycaemia (fasting blood glucose (FBS) ≥ 126 mg/dL). Hazard ratios (HRs) were calculated with the use of Cox proportional-hazards regression models to evaluate the risk of CVD events.

RESULTS

At baseline, of 486 subjects with newly diagnosed diabetes, 190 (39%) had IPH. Over the next 8 years, age and sex-adjusted HR for incident CVD was 1.77 (95% confidence interval (CI): 1.19-2.64; p = 0.005) in subjects with IPH compared with subjects without diabetes. After further adjustment for potential confounders, the HR for CVD was not significant [1.32 (95% CI: 0.88-1.99; p = 0.2)].

CONCLUSIONS

IPH in middle-aged adults adds nothing for identifying CVD risks when other risk factors are taken into account. Associated metabolic risk factors seem to be more important than hyperglycaemia per se.

Clinical usefulness of the Framingham cardiovascular risk profile beyond its statistical performance: the Tehran Lipid and Glucose Study

The utility of a risk function in clinical practice is an important concept that has received insufficient attention. The authors evaluated the clinical usefulness of the Framingham risk function (FRF) for cardiovascular disease in a Middle Eastern population (2,640 men and 3,584 women aged 30-74 years) free of cardiovascular disease at baseline in 1999. They calculated the net benefit fraction for treatment of subjects with an estimated 10-year risk of ≥10% and also ≥20%, where the net benefit fraction is a weighted sum of true-positive and false-positive rates divided by incidence, as estimated by Kaplan-Meier analysis. The authors drew a decision curve by plotting the net benefit fraction against a wide range of risk thresholds for treatment. The cumulative incidence of cardiovascular disease was 7.6% and 12.3% in women and men, respectively. The FRF had a C index of 0.832 in women and 0.785 in men with a reasonable calibration. On the basis of the net benefit fraction, about 50% of the incidence in men and women could be appropriately treated by using the 10% threshold; however, the FRF was not useful at the 20% threshold, especially in women. In both genders, usefulness of the FRF was as good as the function derived directly from Tehrani data with the same variables; however, it could be useful in low thresholds for treatment.

Cardiovascular risk and all-cause mortality attributable to diabetes: Tehran lipid and glucose study

AIM

To quantify the burden of cardiovascular diseases (CVD), and all-cause mortality attributable to diabetes.

SUBJECTS AND METHODS

Data on an 8.6-yr follow-up of 6331 participants (2741 men), free of CVD at baseline, were analyzed to determine the burden of CVD and all-cause mortality attributable to self-reported and screen-detected diabetes mellitus (SRDM and SDDM, respectively). Risks of events of interest were separately assessed for women and men using Cox-proportional-hazard model.

RESULTS

The mean age at baseline was 47 yr with 997 (15.7%) of participants having diabetes (men 14.8%, women 16.5%). SRDM and SDDM prevailed in 9.7% (men 9.2, women 10.2%) and 6.0% of participants (men 5.7, women 6.3%), respectively. During follow up (52,404 person-yr), we observed 447 incident cases of CVD [387 had coronary heart disease (CHD)] and 209 deaths. Among men, participants with SDDM had increased relative hazard for all-cause mortality translated to a population attributable risk fraction (PAF) of 10.1%. Among women, SDDM was associated with CVD and CHD but not with all-cause mortality; so that 9.3% and 8.8% of CVD and CHD events were respectively attributable to the SDDM. If SRDM had been eliminated from the population, the incidences of CVD, CHD, and death would have decreased by 10.5, 9.5, and 17.3% in men; and 22.0, 24.2, and 17.8% in women, respectively.

CONCLUSION

SDDM and SRDM have high PAF for all-cause mortality and CVD. Besides diabetes treatment and prevention, screening to detect undiagnosed diabetes should warrant high priority among the public health strategies to lower the incidence of CVD and mortality.

New and known type 2 diabetes as coronary heart disease equivalent: results from 7.6 year follow up in a Middle East population

Background

To investigate whether the known diabetes mellitus (KDM) or newly diagnosed diabetes mellitus (NDM) could be regarded as a coronary heart disease (CHD) risk equivalent among a relatively young Middle East population with high prevalence of diabetes mellitus (DM).

Methods

A population based cohort study of 2267 men and 2931 women, aged ≥ 30 years. Prior CHD was defined as self-reported or ECG positive CHD at baseline, KDM as subjects using any kind of glucose-lowering medications and NDM according to fasting plasma glucose and 2-h postchallenge glycemia.

Participants were categorized to six groups according to the presence of known or newly diagnosed DM and CHD at baseline (DM-/CHD-, DM-/CHD+, NDM+/CHD-, NDM+/CHD+, KDM+/CHD-, KDM+/CHD+) and Cox regression analysis were used to estimate the hazard ratio (HR) of CHD events for these DM/CHD groups, given DM-/CHD-as the reference.

Results

During 7.6-year follow up, 358 CHD events occurred. After controlling traditional risk factors, HRs of CHD events for DM-/CHD+ group were 2.1 (95% CI: 1.4-3.1) and 5.2 (3.2-8.3) in men and women respectively. Corresponding HRs for NDM+/CHD-were 1.7 (1.1-2.7) and 3.1 (1.8-5.6) and for KDM+/CHD-were 1.7 (0.9-3.3) and 6.2 (3.6-10.6) in men and women respectively. The HRs for NDM+/CHD+ and KDM+/CHD+ groups (i.e. participants with history of both diabetes and CHD) were 6.4 (3.2-12.9) and 8.0 (4.3-14.8) in women and 3.2 (1.9-5.6) and 4.2 (2.2-7.8) in men, respectively.

The hazard of CHD events did not differ between KDM+/CHD-and DM-/CHD+ in both genders using paired homogeneity test, however the HR for NDM+/CHD-was marginally lower than the HR for DM-/CHD+ in women (p = 0.085).

Conclusions

KDM patients in both genders and NDM especially in men exhibited a CHD risk comparable to nondiabetics with a prior CHD, furthermore diabetic subjects with prior CHD had the worst prognosis, by far more harmful in women than men; reinforcing the urgent need for intensive care and prophylactic treatment for cardiovascular diseases.

Lipid measures for prediction of incident cardiovascular disease in diabetic and non-diabetic adults: results of the 8.6 years follow-up of a population based cohort study

BACKGROUND

Diabetes is a strong risk factor for cardiovascular disease (CVD).The relative role of various lipid measures in determining CVD risk in diabetic patients is still a subject of debate. We aimed to compare performance of different lipid measures as predictors of CVD using discrimination and fitting characteristics in individuals with and without diabetes mellitus from a Middle East Caucasian population.

METHODS

The study population consisted of 1021 diabetic (men = 413, women = 608) and 5310 non-diabetic (men = 2317, women = 2993) subjects, aged > or = 30 years, free of CVD at baseline. The adjusted hazard ratios (HRs) for CVD were calculated for a 1 standard deviation (SD) change in total cholesterol (TC), log-transformed triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), non-HDL-C, TC/HDL-C and log-transformed TG/HDL-C using Cox proportional regression analysis. Incident CVD was ascertained over a median of 8.6 years of follow-up.

RESULTS

A total of 189 (men = 91, women = 98) and 263(men = 169, women = 94) CVD events occurred, in diabetic and non-diabetic population, respectively. The risk factor adjusted HRs to predict CVD, except for HDL-C, TG and TG/HDL-C, were significant for all lipid measures in diabetic males and were 1.39, 1.45, 1.36 and 1.16 for TC, LDL-C, non- HDL-C and TC/HDL-C respectively. In diabetic women, using multivariate analysis, only TC/HDL-C had significant risk [adjusted HR1.31(1.10-1.57)].Among non-diabetic men, all lipid measures, except for TG, were independent predictors for CVD however; a 1 SD increase in HDL-C significantly decreased the risk of CVD [adjusted HR 0.83(0.70-0.97)].In non-diabetic women, TC, LDL-C, non-HDL-C and TG were independent predictors.There was no difference in the discriminatory power of different lipid measures to predict incident CVD in the risk factor adjusted models, in either sex of diabetic and non-diabetic population.

CONCLUSION

Our data according to important test performance characteristics provided evidence based support for WHO recommendation that along with other CVD risk factors serum TC vs. LDL-C, non-HDL-C and TC/HDL-C is a reasonable lipid measure to predict incident CVD among diabetic men. Importantly, HDL-C did not have a protective effect for incident CVD among diabetic population; given that the HDL-C had a protective effect only among non- diabetic men.

Impact of metabolic syndrome, diabetes and prediabetes on cardiovascular events: Tehran lipid and glucose study

AIMS

To compare the cardiovascular disease (CVD) risk associated with the metabolic syndrome (MetS) and dysglycemia, independent of each other during a median follow-up of 6.7 years.

METHODS

Study population included 4018 Iranian subjects >or=40 years, free of CVD or coronary heart disease (CHD) at baseline. Incidence rates and hazard ratio (HR) were estimated by the presence or absence of MetS and dysglycemia. Considering the glycemic status, the ability of MetS in prediction of CVD after adjustment for age, sex and CVD risk factors was assessed.

RESULTS

The prevalence of MetS, impaired fasting glucose or impaired glucose tolerance (IFG/IGT) and diabetes were 51.4%, 27.3%, and 18.7%, respectively. The addition of MetS to diabetes did not change the CVD risk compared to diabetic subjects without MetS (reference group) after adjustment for age and sex [HR: 1.62 (95% CI 0.93-2.81)] and CVD risk factors [HR: 1.49 (95% CI 0.86-2.60)]. However, addition of MetS to IFG/IGT increased the risk of CVD by 2.5 times compared to those with IFG/IGT without MetS (the risk factor adjusted HR: 2.45 (95% CI 1.32-4.55)).

CONCLUSIONS

In Iranian population, MetS did not add to diabetes to predict incident CVD however, IFG/IGT was a significant predictor only in the presence of MetS.