Relationship of glucose tolerance to prevalence of ECG abnormalities and to 5-year mortality from cardiovascular disease: findings of the Chicago Heart Association Detection Project in Industry

The association between insulin sensitivity indices, ECG findings and mortality: a 40-year cohort study

Background

Type 2 Diabetes is a major risk factor for cardiovascular (CV) mortality. Insulin resistance can be evaluated non-invasively by insulin sensitivity indices (ISI) such as the Mcauley index (MCAi), which is a function of the fasting insulin and triglycerides. Currently, the association between ISIs and ECG findings and all-cause and CV mortality is still not established in a large scale and heterogeneous population.

Method

In a prospective study of the Israel cohort on Glucose Intolerance, Obesity and Hypertension (GOH) second phase (1979–1982) 1830 men and women were followed until December-2016 for CV-mortality and December-2019 for all-cause mortality. ECGs were recorded and OGTTs performed during baseline. ISIs were categorized into quartiles and evaluated against ECG findings and all-cause and CV-mortality.

Results

Mean age at baseline was 52.0 ± 8.1 years, and 75 (15.2%) and 47 (25.3%) participants in the upper quartiles (Q_2-4) and the lower quartile (Q₁) of the MCAi, presented with Ischemic changes on ECG respectively (p = 0.02). Multivariable analysis showed higher odds for ECG ischemic changes, for individuals in Q₁-MCAi (adjusted-OR = 1.7, 95% CI 1.02–2.8), compared with Q_2-4-MCAi, which attenuated when excluding individuals with diabetes (adjusted-OR = 1.6, 95% CI 0.9–2.7, p = 0.09).

Median follow up for all-cause and for cardiovascular mortality was 31 years and 37 years, respectively. Cox proportional-hazards regression showed an increased risk for all-cause mortality for individuals in Q₁-MCAi (HR = 1.2, 95% CI 1.02–1.3) as well as an increased risk for CV-mortality (HR = 1.4, 95%CI 1.1–1.8) compared with Q_2-4-MCAi. Individuals in Q₄-Ln Homeostatic model assessment- Insulin Resistance (HOMA-IR) and Q₁- Quantitative Insulin Sensitivity Check Index (QUICKI) also presented with increased risk for all-cause-mortality (HR = 1.2, 95%CI 1.04–1.4; and HR = 1.2, 95% CI 1.04–1.4, respectively). Other ISIs did not show significant associations with CV-mortality.

Conclusion

Higher insulin-resistance, according to the MCAi, associated with ECG-changes, and with greater risk for all-cause and CV-mortality over a 40-year follow-up. The MCAi may be considered as an early predictive and prognostic biomarker for CV-morbidity and mortality in adults.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01284-9.

Asymptomatic myocardial ischaemia in HIV-infected adults

BACKGROUND

Asymptomatic ischaemic heart disease (IHD) in HIV-infected patients has not been studied.

METHODS

Resting, 12-lead electrocardiograms (ECG) were evaluated for asymptomatic IHD (Q-wave and/or ST segment depression) at baseline from HIV-infected participants with no known IHD enrolling in the SMART study. The ECG recordings were standardized and centrally analysed. Factors associated with asymptomatic IHD were identified by logistic regression, sequentially adjusted for demographics, clinical history, metabolic risk factors and type and duration of antiretroviral therapy (ART).

RESULTS

Of 4831 participants with an evaluable, baseline ECG and no prior IHD, mean age was 44 years (SD, 9.3); 28.4% were female; 6.6% had diabetes; 16.5% were receiving antihypertensive therapy; and 95.4% were ART experienced. ECG evidence of IHD was detected in 526 (10.9%) [Q-wave in 283 (5.9%), ST segment depression in 264 (5.5%)]; 16.7% in those 60 years or older. Variables independently associated with these abnormalities were older age [age > or= 60 versus < 40 years: odds ratio (OR), 2.2; 95% confidence interval (CI), 1.5-3.2; P < 0.001], current antihypertensive therapy (OR, 1.5; 95% CI, 1.1-1.9; P = 0.003) and recruitment in Europe (OR, 1.4; 95% CI, 1.1-1.7; P = 0.004) or Asia (OR, 1.6; 95% CI, 1.0-2.6; P = 0.05), both compared with North America. Diabetes was borderline significant (OR, 1.4; 95% CI, 1.0-2.0; P = 0.06).

CONCLUSIONS

ECG evidence of asymptomatic IHD was common in this large cohort of HIV-infected adults and more common than a history of symptomatic IHD. Traditional factors were the predominant determinants of risk. No clear association between ART type or duration and asymptomatic IHD was noted.

Silent myocardial infarction in women with impaired glucose tolerance: the Northern Sweden MONICA study

Background

Patients with impaired glucose tolerance (IGT) have an increased risk of cardiovascular disease (CVD) that is independent of traditional risk factors. Hence, slightly elevated glucose levels, even in the non-diabetic range, might be associated with increased macrovascular disease.

Methods

Within the Northern Sweden MONICA project a population survey was performed in 1986. Electrocardiograms (ECG's) were recorded for half of the survey (n = 790) and oral glucose test was carried out in 78 % of those. The association between subjects with ECG's indicating previously unknown myocardial infarction (ukMI), IGT and conventional risk factors were analyzed by logistic regression for men and women separately, adjusting for age, smoking, hypercholesterolemia and hypertension.

Results

Impaired glucose tolerance was significantly more common among women with ukMI, but not in men, compared to the group with normal ECG. In men, no variable was significantly associated with ukMI although the odds ratio (OR) for hypercholesterolemia was of borderline significance, 3.2 (95% confidence interval (CI) 0.9 to 11). The OR of having ukMI was 4.1 (CI 1.1 to 15) in women with IGT compared to women with normal glucose tolerance after multiple adjustment. The OR for hypertension was of borderline significance; 3.3 (CI 0.97 to 11).

Conclusion

We found that IGT was associated with ECG findings indicating silent myocardial infarction in women in a middle-aged general population in northern Sweden. The results persisted even after adjusting for known risk factors.

Impact of minor electrocardiographic ST-segment and/or T-wave abnormalities on cardiovascular mortality during long-term follow-up

Minor ST-T abnormalities are common on the resting electrocardiogram of otherwise healthy persons, but the long-term importance of these findings has not been extensively evaluated, especially in women. In a prospective study, 7,985 women and 9,630 men (aged 40 to 64 years at baseline) without other electrocardiographic abnormalities and free of previous coronary heart disease (CHD) were studied using Cox regression for 22-years of follow-up. Primary outcomes were death from CHD and total cardiovascular disease (CVD); total mortality was a secondary outcome. Minnesota Code was employed to assess the presence or absence of electrocardiographic abnormalities. Analyses compared persons with minor Minnesota Code ST-segment (codes 4-3 or 4-4) or T-wave findings (codes 5-3 or 5-4) to those with normal electrocardiographic findings. In combined analyses of men and women adjusted for age, isolated minor T-wave abnormality, minor ST-segment depression, or a combination of minor ST-segment and T-wave abnormalities were each associated with increased mortality risks. For CHD mortality, hazard ratios (HRs) ranged from 1.60 to 2.10; for CVD mortality, HRs ranged from 1.50 to 1.95; and for total mortality, HRs ranged from 1.31 to 1.50 (p <0.05 for all HRs). In separate analyses by gender adjusted for age, increased risks were observed for combined ST-T-wave abnormalities in both genders for CHD and CVD mortality (HR 1.72 to 1.75 for men, p <0.05; HR 2.07 to 2.51 for women, p <0.001). These data indicate that nonspecific (minor) ST-segment depression and/or T-wave abnormalities have a long-term prognostic impact for CHD and CVD death in middle-aged women and men and can be considered markers of heightened CHD and CVD risk.

Prevalences of ECG findings in large population based samples of men and women

OBJECTIVE

To obtain accurate estimates of the prevalence of ECG abnormalities in the general population and to describe them in relation to age, sex, and some lifestyle related factors.

DESIGN

The results were obtained from the records of 47 358 men and women participating in four large Belgian epidemiological studies during the past 30 years. All tracings were read and coded by two trained cardiologists on the basis of Minnesota code criteria.

RESULTS

Prevalences of coronary heart disease and abnormal ECG findings rose exponentially with age in both sexes, with the exception of atrioventricular block and the Wolff-Parkinson-White (WPW) syndrome. Major ECG findings were observed in 6.0% of all men and 4.3% of women, resulting in a significant adjusted sex ratio of 1.66 (95% confidence interval 1.46 to 1.88). The prevalence of minor ECG changes was slightly higher among men (10.4% v 9.5% in women). The occurrence of ischaemia-like findings on the ECG was comparable between men and women (9.0% v 9.8%). Independent of age, smoking, obesity, diabetes, employment status, positive history of angina or infarction, and region, there were significantly higher prevalences of Q/QS patterns, left ventricular hypertrophy, left axis deviation, arrhythmias, and atrial fibrillation or flutter in men than in women. Right bundle branch block and WPW syndrome both occurred 3.5 times more often in men, while the prevalence of left bundle branch block was comparable between the sexes.

CONCLUSIONS

The large sample size allowed a precise description of the most important ECG abnormalities. These are not rare in the adult population and most are strongly age related. Sex differences occur with some, but not all, abnormalities. The less common ECG abnormalities were more often observed among men.

One-hour postload plasma glucose and risks of fatal coronary heart disease and stroke among nondiabetic men and women: the Chicago Heart Association Detection Project in Industry (CHA) Study

Associations of baseline one-hour postload plasma glucose with 22-year coronary heart disease, stroke, cardiovascular diseases, and all cause mortality were assessed in five age-specific cohorts of nondiabetic men and women from the Chicago Heart Association Detection Project in Industry: 10,269 men ages 18-39 years; 7993 men ages 40-59 years; 1240 men ages 60-74 years; 6319 women ages 40-59 years; and 932 women ages 60-74 years. Plasma glucose was determined one hour after a 50-gram oral glucose load. Cox regression analyses were used to control for age and other covariates. Generally, higher glucose was significantly associated with mortality from coronary heart disease, stroke, cardiovascular diseases, and all cause mortality in men and women. This large longitudinal study provides evidence that one-hour postload plasma glucose in the absence of clinical diabetes at baseline apparently is an independent risk factor for fatal coronary heart disease and stroke in middle-aged and older nondiabetic men and women, and also for cardiovascular diseases and for all cause mortality.

Prevalences and correlates of ECG abnormalities in the adult Belgian population

Data from 5,817 men and 5,215 women (age range, 25-74 years) who participated in the Belgian Interuniversity Research on Nutrition and Health were used to determine prevalences and associated variables of different abnormalities on the resting electrocardiogram. Electrocardiographic abnormalities were coded according to the Minnesota classification system. About one third of the subjects showed one or more abnormalities on their electrocardiogram. Major abnormalities occurred in 7.3% of the men and in 4.6% of the women. The prevalence of minor abnormalities was twice as high. Minnesota codes 4 (ST abnormalities) and 5 (T wave changes) were found to be the most prevalent in both sexes (9.6 and 10.5% respectively in women and 8.4 and 9.1% respectively in men), while code 2 (QRS axis deviation, 7.9%) and code 7 (ventricular conduction defect, 8.7%) were quite common in men. Most prevalences were rather log-linearly related with age, except codes 6 (atrioventricular conduction defect) and 9 (miscellaneous items). In the asymptomatic subjects, blood pressure showed the strongest positive correlation with minor ST-T abnormalities in both men and women independent of other factors. Other correlates identified by multivariate analyses were serum potassium, serum phosphor, and serum uric acid levels, as well as the intake of diuretics. However, any major, minor, and ST-T abnormalities were, according to sex, differently related to those correlates.

A comparison of the relationships of the glucose tolerance test and the glycated haemoglobin assay with diabetic vascular disease in the community. The Islington Diabetes Survey

We have compared the relationships of fasting and 2 h blood-glucose during a 75 g oral glucose tolerance test, and those of an affinity chromatography assay of glycated haemoglobin, with the presence of vascular complications of diabetes mellitus in 223 subjects without known diabetes aged over 40 years selected from a community screening study population. The subjects included 15 (6.9%) with newly diagnosed diabetes and 52 (24.1%) with impaired glucose tolerance. Employing receiver operating characteristic analysis, the tests were similar in their relationship with three cases of retinopathy, 19 of microalbuminuria and six of peripheral neuropathy. The prevalence of coronary heart disease, defined as angina, myocardial infarction, or electrocardiographic changes of ischaemia, increased linearly across all four quartiles of both 2 h blood glucose and glycated haemoglobin concentration, but using logistic regression analysis, 2 h blood glucose was a better predictor of coronary heart disease than glycated haemoglobin. Receiver operating characteristic analysis also showed that 2 h blood glucose generally performed better than any of four assays of glycated haemoglobin in classifying those subjects with coronary heart disease.

Misclassification of diabetic subjects may account for the increased vascular risk of impaired glucose tolerance: the Islington Diabetes Survey

We have studied the associations of macrovascular disease and hypertension with impaired glucose tolerance in a recall sample of 223 subjects selected from a population aged greater than or equal to 40 years who had been screened for diabetes using two separate glucose tolerance tests. Blood pressure was higher in subjects with diabetes, but not in those with impaired glucose tolerance, than in normals. Coronary heart disease, based on ECG criteria and history, was more frequent both in subjects with impaired glucose tolerance (odds ratio 1.94, 95% CI 1.02-3.69) and those with diabetes (odds ratio 3.88, 95% CI 1.33-11.97) than in normals, but the excess in the impaired glucose tolerance group was reduced, and was no longer significant, when adjusted for other variables (odds ratio 1.29, 95% CI 0.62-2.66). Peripheral vascular disease was more frequent in subjects with diabetes, but not in those with impaired glucose tolerance. When the subjects with impaired glucose tolerance on a single test were reclassified according to the results of a separate glucose tolerance test, the prevalence of coronary heart disease increased significantly with increasing degrees of glucose intolerance. Subjects with impaired glucose tolerance on both tests had an adjusted odds ratio of coronary heart disease of 0.90 (95% CI 0.42-1.94) compared with normal subjects. The excess of macrovascular disease in subjects with impaired glucose tolerance may result, at least in part, from the admixture of 'false negative diabetics' in that class.

The oral glucose tolerance test in men under 55 years of age with intermittent claudication

Blood glucose at sixty, ninety, and one hundred twenty minutes after a standardized oral glucose load was compared in healthy middle-aged men and patients with intermittent claudication. No difference was found when the authors compared blood glucose at zero and sixty minutes. At both ninety and one hundred twenty minutes, however, they found a relative hypoglycemia in patients with peripheral arteriosclerotic disease in an early stage.

Diabetes and atherosclerosis: an epidemiologic view

Diabetes is associated with changes in plasma lipids and lipoproteins into atherogenic direction. In IDDM these changes are small or absent if good metabolic control can be maintained. Diabetic nephropathy is, however, associated with the appearance of dyslipoproteinemia. In NIDDM plasma total and VLDL triglyceride levels are elevated, and HDL-cholesterol level is decreased, and this pattern of dyslipoproteinemia does not always respond to improved control of hyperglycemia. Abnormalities of lipoprotein metabolism, not reflected in conventional plasma lipid and lipoprotein level measurements, and glucosylation of lipoproteins and resulting alterations in lipoprotein catabolism may be of importance in the enhanced atherogenesis in diabetes. Both IDDM and NIDDM are associated with an increased frequency of hypertension, but the underlying mechanisms appear to be different. In IDDM hypertension is usually associated with the development of diabetic nephropathy and thus with a long duration of the disease. In NIDDM hypertension is often present already at the time of diagnosis, and also in IGT, the precursor stage of NIDDM, the prevalence of hypertension is already increased. Obesity explains only in part the high prevalence of hypertension in patients with NIDDM. Diabetes is known to be associated with multiple abnormalities in hemostatic factors and, although these abnormalities may contribute importantly to the increased risk of ASVD in diabetic patients, information about their real role is scanty and conflicting. The impact of general major risk factors for ASVD, elevated plasma cholesterol, elevated blood pressure, and smoking, on the risk of ASVD appears to be similar in diabetics and nondiabetics. Only a relatively small proportion of the excessive occurrence of ASVD in diabetics can, however, be explained by the effects of diabetes on the levels of general risk factors for ASVD. This proportion mediated through the effects of diabetes on risk factors is larger in female diabetics than in male diabetics. The major proportion of the excess of ASVD in diabetics remains, however, unexplained and must be due to effects of diabetes itself through mechanisms that are incompletely understood.

Sex differential in the relationship of electrocardiographic ST-T abnormalities to risk of coronary death: 11.5 year follow-up findings of the Chicago Heart Association Detection Project in Industry

The independent contributions of ST segment depression and/or T wave abnormality (ST-T abnormalities) on the baseline resting electrocardiogram to risk of 11.5 year coronary heart disease (CHD) mortality were explored among 9203 white men and 7818 white women who were 40 to 64 years old and without definite CHD at entry in the Chicago Heart Association Detection Project in Industry. At baseline, prevalence rates of ST-T abnormalities were age related for both sexes, and at every age the rate was higher in women than men (age-adjusted prevalence rates 12.3% and 8.1%, respectively). Univariate analysis showed that ST-T abnormalities were associated with significantly increased risk of death from CHD for both men and women. However, men with ST-T abnormalities had much greater age-adjusted and multiple risk factor-adjusted absolute excess risk and relative risk than women with such electrocardiographic abnormalities. When baseline age, diastolic pressure, serum cholesterol, cigarettes/day, history of diabetes, and baseline use of antihypertensive medication were included in the multivariate analysis, ST-T abnormalities remained significantly related to death from CHD in men but not women. The interaction term between sex and ST-T abnormalities was at a borderline level of statistical significance by Cox regression analysis. In conclusion, ST-T abnormalities indicate an increased risk of subsequent death from CHD independent of major coronary risk factors for middle-aged U.S. men, but this is not clearly so for women.

The role of relative weight in the positive association between age and serum cholesterol in men and women

With advancing age from youth on, there is an increase in mean serum cholesterol level of populations in "western" industrialized countries. Since serum cholesterol is one of the established major risk factors for premature coronary heart disease, it is important to explore the degree to which this age trend is physiologic or due to modern life styles. This study used cross-sectional data for 19,730 white men and 13,872 white women from the Chicago Heart Association Detection Project in Industry to investigate one aspect of this question: does weight explain the association between age and serum cholesterol, in particular whether older age is associated with higher serum cholesterol in the absence of overweight. The relationships among age, relative weight, and serum cholesterol were examined through assessment of mean serum cholesterol levels in 25 subgroups stratified by age (18-24, 25-34, 35-44, 45-54, 55-64) and by relative weight (less than 100, 100-109, 110-119, 120-134, greater than or equal to 135). Age and serum cholesterol were positively associated with each other. In women, it was a simple, linear relationship. In men, the degree of this positive association was less in people over age 35-44 than people in younger ages. These age-cholesterol patterns were present in men and women at desirable weight. However, in men aged 18-54, the positive association between age and prevalence of marked hypercholesterolemia (serum cholesterol greater than or equal to 250) was lower in people at desirable relative weight in comparison to those at higher relative weight.(ABSTRACT TRUNCATED AT 250 WORDS)

A method for combining results from several prospective epidemiologic studies

An approach to the problem of a single study lacking adequate power to examine an important question is to combine the data from several studies to allow a more powerful test of the hypothesis in question. The present paper describes a method used by the International Collaborative Group to pool data on 54,492 men aged 40-69 from 10 population studies in 7 countries to examine the association between cholesterol level and risk of death from cancer. Furthermore, there was a suggestion that the inverse association observed in some studies might be the result of an effect of undetected cancer on cholesterol level, rather than an increase in cancer risk resulting from low cholesterol levels. This paper describes the process for selection of the method used to evaluate this possibility over other potential approaches and the results obtained in the analysis of the International Collaborative Group data that support this hypothesis. This report also indicates how one might expect some of the analyses described to compare with analyses based on a discrete version of the Cox proportional hazards model.

Prevalence of diabetes/hyperglycemia and associated cardiovascular risk factors in blacks and whites: Chicago Heart Association Detection Project in Industry

Prevalence rates of diabetes, asymptomatic hyperglycemia, and cardiovascular risk factors were examined in an employed population of 28,895 whites and 2607 blacks, ages 25 to 64 years. Diabetes had been previously diagnosed in this population among approximately 3% of the males of both races and 2% of the females. Plasma glucose 1 hour after a 50 gm oral load was highest among white males (141 mg/dl), similar and at intermediary levels among black males (134 mg/dl) and white females (135 mg/dl), and lowest among black females (126 mg/dl). A divergent pattern of obesity was observed, however, with black females being by far the most overweight. Preliminary mortality data for males suggest that both blacks and whites with diabetes have sizably higher death rates than those without diabetes; a black-white differential is not apparent.

Coronary-heart-disease risk and impaired glucose tolerance. The Whitehall study

In the Whitehall Study of 18,403 male civil servants aged 40--64 years, 7 1/2 year coronary-heart-disease (CHD) mortality has been examined in relation to blood-sugar concentration 2 h after a 50 g oral glucose load. CHD mortality was approximately doubled for subjects with inpaired glucose tolerance (IGT), defined as a blood-sugar above the 95th centile (greater than or equal to 96 mg/dl). There was no trend of CHD mortality with blood-sugar below the 95th centile. Within the IGT group, age, systolic blood-pressure, and ECG abnormality (Whitehall criteria) were significantly predictive of subsequent CHD mortality. These findings are relevant to discussions on the criteria for diabetes which include the definition of an IGT category with increased risk of large-vessel disease, but without the high risk of small-vessel disease as occurs in diabetes mellitus.