Increasing glucose levels and BMI predict future heart failure experience from the Reykjavík Study.

BACKGROUND: Heart failure is common in diabetes and ischaemic heart disease is the most likely link. Still, it has been suggested that the relation extends beyond such disease. METHODS: 7060 subjects with two or more visits in the Reykjavík Study were followed--during 30 years from 1967. All underwent oral glucose tolerance tests. Disease status was defined according to the glycaemic level and presence of heart failure. The incidence and predictive factors for these diseases were determined. FINDINGS: Age and sex standardized incidence of heart failure was 5.3/1000/year, of diabetes 4.6/1000/year and abnormal glucose regulation 12.6/1000/year. Body mass index (BMI) and fasting glucose predicted the development of these conditions (p<0.001). Increasing fasting glucose by 1 mmol/l increased the risk for heart failure by 14% (p=0.04) after adjusting for IHD, BMI and other risk factors for CVD. There was a strong association between diabetes and heart failure, OR 3.0 (2.3-4.0), and abnormal glucose regulation and heart failure, OR 1.8 (1.5-2.3). Diabetes and heart failure were, however, not independent predictors of each other. INTERPRETATION: There was an independent relationship between increases in fasting glucose and development of heart failure. BMI was a strong predictor of heart failure. Although fasting glucose and BMI were significant risk factors for glucose disturbances and heart failure the conditions themselves did not independently predict each other.

Survival and trends of occurrence of left ventricular hypertrophy, gender differences, 1967-92: The Reykjavik Study.

OBJECTIVE: We estimated the prevalence, incidence and risk factors of left ventricular hypertrophy (LVH) in a prospective cohort study of 26 489 participants. MATERIAL AND METHODS: The LVH was defined as Minnesota Code 310 on electrocardiogram (ECG). Everyone with this code at first visit was defined as a prevalence case and those who developed it between subsequent visits were incidence cases. The comparison cohort were all other participants in the Reykjavik Study stages I-V. RESULTS: A total of 297 men and 49 women were found to have LVH of 3.2% and 0.5%, respectively. The incidence was 25 per 1000 per year amongst men and six per 1000 per year amongst women. Prevalence in both genders increased with increasing age. Risk factors at the time of diagnosis were systolic blood pressure [odds ratio (OR) per mmHg 1.02; 95% confidence interval (CI): 1.01-1.03], age (OR per year 1.04; 95% CI: 1.02-1.05), silent myocardial infarction (MI) (OR 3.18; 95% CI: 1.39-7.27) and ST-T changes (OR 3.06; 95% CI: 2.14-4.38) amongst men and systolic blood pressure and age for women with similar odds ratio. Predictive factors for acquiring LVH were systolic blood pressure [incidence ratio (IR) 1.01; 95% CI: 1.01-1.02] and angina with ECG changes (IR 2.33; 95% CI: 1.08-5.02) amongst men and systolic blood pressure amongst women (IR 1.03; 95% CI: 1.01-1.04). The risk for coronary mortality was significantly increased amongst women with hypertrophy [hazard ratio (HR) 3.07; 95% CI: 1.5-6.31] and their total survival was poorer with increasing time from diagnosis of LVH (HR 2.17; 95% CI: 1.36-3.48). CONCLUSIONS: We conclude that the presence of LVH and its appearance is associated with age and increased blood pressure amongst both genders. Women with LVH have poorer survival than other women and they are at threefold risk of dying of ischaemic heart disease.

[Newly acquired right bundle branch block. Association with heart disease and risk factors in the Reykjavik Study.].

PURPOSE: To find risk factors for the appearance of right bundle branch block (RBBB) and to assess the prognosis of people with it. METHODS: Subjects were participants in the Reykjavik Study who had acquired RBBB following an examination in a previous stage in this prospective population study, carried out in five stages in 1967-1991. Cases with two matched controls were recruited for a special examination in 1992. RESULTS: Acquired RBBB was seen in 33 men and 14 women. Multivariate analysis showed, compared to the total population, that men with RBBB more often had cardiomegaly (odds ratio=OR 1.7;confidence limit=CL 1.2-2.5) women more often took antihypertensive drugs (OR 2.5; CL 1.5-4.1) and had lower diastolic blood pressure (OR 0.97; CL 0.95-0.99). Predictive factors in people with acquired RBBB were age (men: relative risk=RR 1.08; CL 1.05-1.11, women: RR 1.09; CL 1.02-1.17) and antihypertensive medication in women (RR 3.5; CL 1.2-10.4). There was no significant difference between cases and controls regarding examination, echocardiography and mortality. CONCLUSION: Factors associated with the appearance of RBBB are mainly age, cardiomegaly and antihypertensive medication.

The epidemiology of right bundle branch block and its association with cardiovascular morbidity--the Reykjavik Study.

This study is based on the Reykjavik Study, a long-term prospective cardiovascular survey, which included a representative population of 9135 men and 9627 women, 33-79 years old, who were invited to participate during the years 1967-91. Right bundle branch block (RBBB) was found in 126 men and 67 women. The prevalence increased with age, from 0% among men and women 30-39 years of age to 4.1% and 1.6% in men and women, respectively, who where 75-79 years old. The incidence increased with age. In men younger than 60 years RBBB had a significant relationship with hypertension (P < 0.05), elevated fasting blood glucose (P = 0.05), and increased heart size (P < 0.05). In men with RBBB regardless of age, an association was found with cardiomegaly (P < 0.05), ischaemic heart disease (P < 0.05), arrhythmias (P < 0.001) and bradycardia (P < 0.01). A higher mortality from heart disease (P < 0.01) was found in men with RBBB compared to the control population. This was not significant when risk factors of heart disease were taken into account by multivariate Cox analysis. There was a relationship (P < 0.05) between hypertension and RBBB in women younger than 60 years. RBBB in women younger than 60 years is often associated with hypertension and in men younger than 60 it is often associated with an underlying cardiovascular disease, hypertension, cardiomegaly and elevated blood glucose.