Education and the metabolic syndrome in women.

OBJECTIVE: The main objective was to examine the association between the metabolic syndrome and socioeconomic position (as indicated by education) among women. RESEARCH DESIGN AND METHODS: The study sample comprised healthy women (aged 30-65 years) in Sweden who were representative of the general population in a metropolitan area. Socioeconomic position was measured by educational level (mandatory [< or = 9 years], high school, or college/university). The metabolic syndrome was defined as the presence of two or more of the following components: 1) fasting plasma glucose level > or = 7.0 mmol/l; 2) arterial blood pressure > or = 160/90 mmHg; 3) fasting plasma triglycerides > or = 1.7 mmol/l and/or HDL cholesterol < 1.0 mmol/l; and 4) central obesity (waist-to-hip ratio > 0.85 and/or BMI > 30 kg/m2). RESULTS: After adjustment for age, the risk ratio for the presence of the metabolic syndrome comparing the lowest (< or = 9 years) with the highest (college/university) education was 2.7 (95% CI 1.1-6.8). This association persisted after controlling for menopausal status, family history of diabetes, and behavioral risk factors. CONCLUSIONS: Low education is associated with increased risk for metabolic syndrome in middle-aged women. These findings show that not only are women with low socioeconomic position at increased risk for individual risk factors that are associated with cardiovascular disease and type 2 diabetes, they are also at increased risk for the metabolic clustering of risk factors.

A common polymorphism in the fatty acid transport protein-1 gene associated with elevated post-prandial lipaemia and alterations in LDL particle size distribution.

The fatty acid transport proteins (FATPs) have been implicated in facilitated cellular uptake of non-esterified fatty acids (NEFAs), thus having the potential to regulate local and systemic NEFA concentrations and metabolism. Hypothesising that genetic variation within the FATP genes may affect lipid metabolism, we investigated a G/A substitution at position 48 in intron 8 of the fatty acid transport-1 (FATP1) gene with respect to associations with fasting and post-prandial plasma lipid and lipoprotein variables in 628 healthy 50-year-old Swedish men and 426 Swedish women, aged 37-65 years. A subset of 105 men with the apoE3/E3 genotype underwent an oral fat tolerance test. Although fasting plasma TG concentrations were not different, male A/A individuals had significantly higher post-prandial TG concentrations and VLDL(1) (S(f) 60-400 apoB100)-to-VLDL(2) (S(f) 20-60 apoB100) ratio compared to male G/A and G/G individuals. A/A individuals apparently failed to suppress plasma NEFA concentrations during the oral fat tolerance test. Furthermore, fasting plasma concentrations of the largest, most buoyant LDL subfraction (LDL-I) were significantly lower in carriers of the A allele in the male cohort. Electromobility shift assays and reporter gene studies indicated that binding of nuclear factors and effect on transcriptional activity differ between the intron 8 alleles. These findings suggest that through regulation of NEFA trafficking, FATP1 might play a role in post-prandial lipid metabolism and development of cardiovascular disease.

Coagulation factor VII in middle-aged women with and without coronary heart disease.

Epidemiological studies of coagulation factor VII as a risk factor for coronary heart disease (CHD), mainly conducted in men, have shown discrepant results. We examined the associations of coagulation factor VII antigen (VIIag) and activated factor VII (VIIa) with manifest CHD in a community-based case-control study of women aged < or =65 years. Mean plasma concentrations of VIIag and VIIa in patients and controls were 443 +/- 10(8) and 418 +/- 89 ng/L (p <0.01) and 5.26 +/- 2.21 and 4.90 +/- 1.65 ng/L (NS), respectively. The odds ratio (OR) for CHD for the highest versus the lowest quartile of VIIag was 1.75 (95% CI, 1.05 to 2.92). The adjusted OR was 0.76 (95% CI, 0.28-1.98) after controlling for other cardiovascular risk factors. The corresponding ORs for VIIa were non-significant. In conclusion, the plasma concentration of VIIa was not significantly increased in a large group of women with precocious CHD, and VIIag levels, although elevated, were not independently associated with manifest disease.

Lipid profile and socioeconomic status in healthy middle aged women in Sweden.

STUDY OBJECTIVE: To examine the relationship between socioeconomic status (SES) and full lipid profile in middle aged healthy women. PARTICIPANTS: These comprised 300 healthy Swedish women between 30 and 65 years who constitute the control group of the Stockholm female coronary risk study, a population based, case-control study of women with coronary heart disease (CHD). The age matched control group, drawn from the census register of greater Stockholm, was representative of healthy Swedish women aged 30-65 years. Five measures of SES were used; educational level, occupation, decision latitude at work, annual income, and size of house or apartment. MAIN RESULTS: Swedish women with low decision latitude at work, low income, low educational level, blue collar jobs, and who were living in small houses or apartments had an unhealthy lipid profile, suggesting an increased risk of CHD. Part of this social gradient in lipids was explained by an unhealthy lifestyle, but the lipid gradients associated with decision latitude at work and annual income were independent of these factors. Decision latitude, educational level, and annual income had the strongest associations with lipid profile. These associations were independent of age, menopausal status, smoking, sedentary lifestyle, alcohol consumption, obesity, excess abdominal fat, and unhealthy dietary habits. Of the lipid variables, low high density lipoprotein cholesterol (HDL) levels were most consistently associated with low SES. CONCLUSIONS: Decision latitude at work was the strongest SES predictor of HDL levels in healthy middle aged Swedish women, after simultaneous adjustment for other SES measures, age, and all lifestyle factors in the multivariable regression model.

The measurement of social support in population surveys.

There is an increasing interest to include measures of social support in population surveys of chronic disease risk. The choice among a variety of measurement instruments, however, is difficult. We reviewed social support instruments, which were potentially applicable in population studies. Their conceptual framework, their reported predictive capacity and their psychometric properties were compiled and systematically compared. The convenience, clarity and applicability of the social support instruments were tested in a group of health care employees. Two distinct groups of instruments were identified, those describing quantitative aspects of social network and social interaction and those describing functions and adequacy of social support. The former instruments were more easily applicable, questions were more easily and quickly understood and answered. Furthermore, these instruments had been found to predict physical illness in prospective studies. Their psychometric properties, however, were unknown. Qualitative instruments, on the other hand, were found to include questions, not universally applicable to a general population. These instruments were mostly carefully tested for psychometric properties, but their illness predictive capacity was found to be less well examined. Thus, instruments which satisfied all the desirable requirements could not be identified.

Development of a social support instrument for use in population surveys.

A wide variety of measures have been used to assess the effects of social support on physical and psychological well-being. Many instruments have incomplete information about reliability and validity. Other instruments appear to be reasonably valid, but involve a large number of questions and are therefore not suitable in population surveys. The main purpose of the study was to examine whether a psychometrically well documented, but time consuming instrument. The Interview Schedule for Social Interaction, could be abbreviated and simplified for the use in population surveys. By means of both item and content analyses the original instrument was shortened and both versions were tested in a study group of 83 middle-aged Swedish men. The distribution of scale scores were similar in the complete and in the abbreviated version and so was reliability, measured as internal consistency and split-half reliability. Validity was examined by comparing the two versions in relation to other measures of social integration, as well as personality and behaviour characteristics. Men with low social support were less socially and physically active, were more depressed and were less trustful than men with high support. Men who scored low on social support were also more often smokers, of lower social class, lower occupational level and lower education and had more complaints of ill health, mainly of cardiovascular nature. The discriminative capacity was as good for the complete as for the abbreviated version. Thus no obvious disadvantages in terms of reliability and validity could be demonstrated for the abbreviated version.

Job stress and the occupational gradient in coronary heart disease risk in women. The Stockholm Female Coronary Risk Study.

Recent studies of men have shown that job stress is important in understanding the occupational gradient in coronary heart disease (CHD), but these relationships have rarely been studied in women. With increasing numbers of women in the workforce it is important to have a more complete understanding of how CHD risk may be mediated by job stress as well as other biological and behavioural risk factors. The objective of this study was to examine the occupational gradient in CHD risk in relation to job stress and other traditional risk factors in currently employed women. We used data from the Stockholm Female Coronary Risk Study, a population based case-control study, comprising 292 women with CHD aged 65 years or younger and 292 age-matched healthy women (controls). An inversely graded association was observed between occupational class and CHD risk. Compared with the highest (executive/professional), women in the lowest occupational class (semi/unskilled) had a four-fold (95% CI 1.75-8.83) increased age-adjusted risk for CHD. Simultaneous adjustment for traditional risk factors and job stress attenuated this risk to 2.45 (95% CI 1.01-6.14). Neither job control nor the Karasek demand-control model of job stress substantially explained the increased CHD risk of women in the lowest occupational classes. It is likely that lower occupational class working women face multiple and sometimes interacting sources of work and non-work stress that are mediated by behavioural and biological factors that increase their CHD risk.

The biological effects of solar activity.

The synchronization of biological circadian and circannual rhythms is broadly viewed as a result of photic solar effects. Evidence for non-photic solar effects on biota is also slowly being recognized. The ultrastructure of cardiomyocytes from rabbits, the time structure of blood pressure and heart rate of neonates, and the heart rate variability of human adults on earth and in space were examined during magnetically disturbed and quiet days, as were morbidity statistics. Alterations in both the about-daily (circadian) and about-weekly (circaseptan) components are observed during disturbed vs. quite days. The about-weekly period of neonatal blood pressure correlates with that of the local geomagnetic disturbance index K. Circaseptans which are seen early in human life and in various other forms of life, including unicells, may provide information about the possible site(s) of life's origins from an integrative as well as adaptive evolutionary perspective.

The effects of the strain of returning to work on the risk of cardiac death after a first myocardial infarction before the age of 45.

Seventy-nine men who had suffered a myocardial infarction before the age of 45 while they were vocationally active in the greater Stockholm area were followed for five years. Forty-nine survived without cardiac complications and 13 died due to ischaemic heart disease during the period of follow-up. These two contrasting groups were compared with regard to psychosocial risk factors at work before the first myocardial infarction (as reported by the patient when he was interviewed during the weeks after the onset of disease). It was hypothesized that returning to stressful work (high demands and limited possibilities of influencing decisions and developing skills) would be associated with an increased risk of death. All the subjects who died had returned to the work that they had performed prior to the first myocardial infarct. Work performed by these patients was described as having significantly higher psychological demands in relation to the possibility of learning new things and higher demands in relation to variety as well as almost significantly higher demands in relation to influence. Multivariate logistic regression with these factors concerning employment, together with biomedical risk factors recorded at the same time, showed that increasing age, increasing degree of coronary atherosclerosis and number of stenosed coronary arteries, as well as high demands in relation to the possibility of learning new things, were independent predictors of death due to coronary arterial disease. The remaining 17 subjects either survived a re-infarction, or had coronary arterial by-pass surgery during the period of follow-up. This heterogeneous group occupied intermediate positions with regard to psychosocial job factors.

Psychosocial work conditions before myocardial infarction in young men.

All male patients in the greater Stockholm area who had survived a myocardial infarction below the age of 45 were examined with regard to medical and psychosocial risk factors 3-6 months after the onset of the infarction. For each patient, a male control subject was randomly selected after matching with regard to age and residence area. In the patient group, coronary angiograms were performed and rated with regard to degree of coronary atherosclerosis. The psychosocial variables were not correlated with degree of coronary atherosclerosis. Excessive work demands combined with boredom at work ("variety" and "intellectual discretion") were significantly more often reported by the patients after adjustment had been made for life style factors. In the multivariate analysis a high LDL/HDL cholesterol ratio, a high cumulative tobacco consumption, high demands in relation to variety at work as well as high demands in relation to influence over work and finally a low alcohol consumption were significant independent predictors of case status. Excessive work demands in themselves did not differentiate cases from controls.

Type A behaviour, education and psychosocial work characteristics in relation to ischemic heart disease--a case control study of young survivors of myocardial infarction.

The interaction of Type A behaviour, psychosocial work environment and education in relation to medical risk factors for IHD was analyzed in a case-control study of male and female post-MI-patients under age 45. In multivariate analysis LDL/HDL-cholesterol ratio and smoking (explaining 27 and 6% of the variance) emerged as the two most important discriminators of patients from control subjects. The third factor, variety of work tasks, explained 5% of the variance. Type A behaviour ranked as factor no. 7, explaining only 2% of the variance and educational level did not reach statistical significance as an independent explanatory factor. When the sample was divided into men and women with high and low education, most of the patient-control difference in Type A and psychosocial work characteristics was found among highly educated men on one hand and women with a low level of education on the other. Thus Type A behaviour seems to be less important and psychosocial work environment more important in adding psychosocial risk to the medically established risk of IHD.

Stressful life events, social support, and mortality in men born in 1933.

OBJECTIVE: To examine relations between stressful life events and mortality in middle aged men. DESIGN: Prospective population study. Data on stressful life events, social network, occupation, and other psychosocial factors derived from self administered questionnaires. Mortality data obtained from official registers. SETTING: City of Gothenburg, Sweden. SUBJECTS: 752 men from a random population sample of 1016 men aged 50. MAIN OUTCOME MEASURE: Mortality from all causes during seven years' follow up. RESULTS: Life events which had occurred in the year before the baseline examination were significantly associated with mortality from all causes during seven years' follow up. Of the men who had experienced three or more events during the past year 10.9% had died compared with 3.3% among those with no life events (odds ratio 3.6; 95% confidence interval 1.5 to 8.5). The association between recent life events and mortality remained true after smoking, self perceived health, occupational class, and indices of social support were controlled for. Many of the deaths were alcohol related, but the number of deaths was too small to allow for analyses of specific causes of death. The association between life events and mortality was evident only in men with low emotional support. CONCLUSION: Stressful life events are associated with high mortality in middle aged men. Men with adequate emotional support seem to be protected.

Meta-analyzed heart rate variability, exposure to geomagnetic storms, and the risk of ischemic heart disease.

The aim was to examine how heart rate variability (HRV) relates to the risk of ischemic heart disease (IHD) and may provide a means to assess effects of exposure to geomagnetic storms. In Stockholm, the 24-hour SD of hourly estimates of heart rate (HR) were obtained by Holter monitoring from 50 men who had had an acute myocardial infarction or had angina pectoris and compared to that of 50 clinically healthy men of similar age. In Tokyo, the HR 121 normotensives and 176 treated hypertensives was monitored. The incidence of IHD was recorded prospectively for 6 years. These results are aligned with those of a retrospective analysis of archived data on all crews of the Soyuz spacecraft for 1990-1994 focused on ECG from cosmonauts (47 male and 2 female) at times corresponding to geomagnetic storms. The results clearly indicate a decrease in HRV in association with IHD (20.5%, p=0.002 in Stockholm, 20.0%, p=0.04 in Tokyo). By comparison, the about 30% decrease (p=0.041) in rms SD of HR in cosmonauts studied during a geomagnetic storm as compared to cosmonauts monitored on quiet days adds supportive evidence to the proposition that exposure to geomagnetic disturbances increases cardiovascular disease risk.