Atherosclerosis begins early in life and is the major underlying cause of cardiovascular morbidity and death. Yet, population-based information on age and sex differences in the extent and morphology of atherosclerosis throughout life is scarce. Carotid atherosclerosis can be visualized with B-mode ultrasound and is a marker of atherosclerosis elsewhere in the circulation. We assessed both the prevalence and the morphology of carotid atherosclerosis by B-mode ultrasound in 3016 men and 3404 women, 25 to 84 years old, who participated in a population health survey. The participation rate was 88%. Plaque morphology was graded according to whether a plaque was predominantly soft (echolucent) or hard (echogenic). Atherosclerotic plaques were found in 55.4% of the men and 45.8% of the women. In men, there was a linear increase with age in the prevalence of carotid atherosclerosis, whereas in women, there was a curvilinear age trend, with an inflection in the prevalence rate of women at approximately 50 years of age. The male predominance in atherosclerosis declined after the age of 50 years, the plaque prevalence being similar in elderly men and women. Men had softer plaques than women; this sex difference in plaque morphology increased significantly (P=0.005) with age. The sex difference in the prevalence of atherosclerosis and the female age trend in atherosclerosis show significant changes at the age of approximately 50 years, suggesting an adverse effect of menopause on atherosclerosis. The higher proportion of soft plaques in men compared with women increases with age and may partly account for the prevailing male excess risk of coronary heart disease in the elderly despite a similar prevalence of atherosclerosis in elderly men and women.
BACKGROUND: Ultrasound measurement of carotid artery intima-media thickness (IMT) is regarded as a valid index of atherosclerosis. Age and sex differences in the distribution of, and risk factors for, IMT have not been investigated thoroughly. METHODS: In 1994-1995 a total of 6408 men and women aged 25-84 years living in the municipality of Tromsø, Norway, underwent ultrasound examination of carotid artery IMT and measurements of cardiovascular risk factors. RESULTS: Age, systolic blood pressure, total cholesterol, HDL cholesterol, body mass index, and smoking were independent predictors of IMT in both sexes. Fibrinogen levels and physical activity were associated with IMT in men only, whereas triglyceride levels were associated with IMT independently of HDL cholesterol in women only. A family history of cardiovascular disease (CVD) was an independent predictor of IMT in both sexes, also when controlling for traditional CVD risk factors. The magnitude of the association between most risk factors and IMT did not differ depending on age, but the effects of physical activity and triglycerides were more pronounced at higher age. CONCLUSION: These data suggest that there are significant age and sex differences in the distribution and the determinants of subclinical atherosclerosis.
BACKGROUND. High blood pressure has been associated with elevated atherogenic blood lipid fractions, but epidemiological surveys often give inconsistent results across population subgroups. A better understanding of the relation between blood pressure and blood lipids may provide insight into the mechanism(s) whereby hypertension is associated with increased risk of coronary heart disease. METHODS AND RESULTS. We assessed the cross-sectional relations of serum total cholesterol, high density lipoprotein (HDL) cholesterol, non-HDL cholesterol (total minus HDL cholesterol), and triglyceride levels with blood pressure in a population of 8,081 men 20-54 years old and 7,663 women 20-49 years old. Stratified analyses and multivariable methods were used to control for potential confounding anthropometric and lifestyle variables. Total and non-HDL cholesterol levels increased significantly with increasing systolic or diastolic blood pressure in both sexes. Men 20-29 years old had steeper regression slopes for blood pressure by total cholesterol level than did women of similar age. In men, the association between blood pressure and total cholesterol level decreased with age, whereas in women, it increased with age. Body mass index modified the relation, whereas smoking, physical activity, and alcohol consumption had little influence on the association. Triglyceride levels increased with blood pressure, but this relation was weak in lean subjects. HDL cholesterol level correlated positively with blood pressure in population subgroups having a high alcohol consumption. CONCLUSION. These results support the hypothesis that there are biological interrelations between blood pressure and blood lipids that may influence the mechanisms whereby blood pressure is associated with risk of coronary heart disease.
BACKGROUND. Prospective epidemiological studies indicate that elevated heart rate may carry increased risk for coronary heart disease. Little is known about the relation between heart rate and serum lipid and lipoprotein concentrations in the general population. METHODS AND RESULTS. We assessed anthropometric and life-style determinants of heart rate and examined the association between heart rate and serum lipid and lipoprotein concentrations in a cross-sectional study of 9,719 men and 9,433 women 12-59 years old. Stratified and multivariate analyses were used to detect possible modification of effect and to control for confounding variables. Heart rate was positively associated with male sex and smoking, decreased with body height and physical activity, and showed a U-shaped relation to body mass index. In both sexes, there was a significant progressive increase in age-adjusted levels of total cholesterol, non-high density lipoprotein (HDL) cholesterol, and triglycerides and a decrease in HDL cholesterol with heart rate. Men with heart rate greater than 89 beats per minute had 14.5% higher non-HDL cholesterol and 36.3% higher triglyceride levels than men with heart rate less than 60 beats per minute. The corresponding differences in women were 12.5% and 22.2%. The associations remained significant when anthropometric and life-style factors were controlled for. The slopes relating total and non-HDL cholesterol level to heart rate were steeper with advancing age. CONCLUSIONS. Increases in heart rate correlate with higher levels of atherogenic serum lipid fractions in the general population. Alterations in aortic impedance and/or autonomic influences may underlie these associations.
BACKGROUND: The present epidemiologic study was conducted in Tromso, Northern Norway, in 1994-1995. OBJECTIVE: The objective was to evaluate the relation between calcium intake from dairy products and the intake of vitamin D on systolic and diastolic blood pressure. DESIGN: Subjects who were taking drugs for hypertension or heart disease, those taking calcium tablets, subjects reporting cardiovascular disease, and pregnant women were excluded, leaving 7543 men and 8053 women aged 25-69 y for analysis. Calcium and vitamin D intakes were calculated from a food-frequency questionnaire. RESULTS: After correction for age, body mass index, alcohol and coffee consumption, physical activity, cigarette smoking, and vitamin D intake, there was a significant linear decrease in systolic and diastolic blood pressure with increasing dairy calcium intake in both sexes (P
Comment In: Am J Clin Nutr. 2001 Mar;73(3):659-6011237953
Objectives. In the Norwegian Vitamin Trial and the Western Norway B Vitamin Intervention Trial, patients were randomly assigned to homocysteine-lowering B-vitamins or no such treatment. We investigated their effects on cardiovascular outcomes in the trial populations combined, during the trials and during an extended follow-up, and performed exploratory analyses to determine the usefulness of homocysteine as a predictor of cardiovascular outcomes. Design. Pooling of data from two randomized controlled trials (1998-2005) with extended post-trial observational follow-up until 1 January 2008. Setting. Thirty-six hospitals in Norway. Subjects. 6837 patients with ischaemic heart disease. Interventions. One capsule per day containing folic acid (0.8 mg) plus vitamin B12 (0.4 mg) and vitamin B6 (40 mg), or folic acid plus vitamin B12, or vitamin B6 alone or placebo. Main outcome measures. Major adverse cardiovascular events (MACEs; cardiovascular death, acute myocardial infarction or stroke) during the trials and cardiovascular mortality during the extended follow-up. Results. Folic acid plus vitamin B12 treatment lowered homocysteine levels by 25% but did not influence MACE incidence (hazard ratio, 1.07; 95% CI, 0.95-1.21) during 39 months of follow-up, or cardiovascular mortality (hazard ratio, 1.12; 95% CI, 0.95-1.31) during 78 months of follow-up, when compared to no such treatment. Baseline homocysteine level was not independently associated with study outcomes. However, homocysteine concentration measured after 1-2 months of folic acid plus vitamin B12 treatment was a strong predictor of MACEs. Conclusion. We found no short- or long-term benefit of folic acid plus vitamin B12 on cardiovascular outcomes in patients with ischaemic heart disease. Our data suggest that cardiovascular risk prediction by plasma total homocysteine concentration may be confined to the homocysteine fraction that does not respond to B-vitamins.
The Finnmark Health Survey of 1987-88 showed that there was no significant difference in the prevalence of coronary heart disease between a Sámi population and a Norwegian population. Among men 40-59 years of age, a prevalence of myocardial infarction or angina pectoris or both, of 5.5%, was found both in Norwegians and in the predominantly Sámi population of Inner Finnmark. Among women, a prevalence of 3.1% and 3.3% was found among Norwegians and Sámis, respectively. The difference in results between males and females was less among Sámis than Norwegians, despite Sámi women having a lower risk factor level than Norwegian women. A clinical follow-up study done in 1992-93 showed no significant differences in serum lipid concentrations between the Sámi and the Norwegian population. Sámis had a lower familial occurrence of coronary heart disease than Norwegians. Waist to hip ratio was higher among Sámis than Norwegians.
STUDY OBJECTIVE: The aim was to estimate health and economic consequences of interventions aimed at reducing the daily intake of salt (sodium chloride) by 6 g per person in the Norwegian population. Health promotion (information campaigns), development of new industry food recipes, declaration of salt content in food and taxes on salty food/subsidies of products with less salt, were possible interventions. DESIGN: The study was a simulation model based on present age and sex specific mortality in Norway and estimated impact of blood pressure reductions on the risks of myocardial infarction and stroke as observed in Norwegian follow up studies. A reduction of 2 mm Hg systolic blood pressure (range 1-4) was assumed through the actual interventions. The cost of the interventions in themselves, welfare losses from taxation of salty food/subsidising of food products with little salt, cost of avoided myocardial infarction and stroke treatment, cost of avoided antihypertensive treatment, hospital costs in additional life years and productivity gains from reduced morbidity and mortality were included. RESULTS: The estimated increase in life expectancy was 1.8 months in men and 1.4 in women. The net discounted (5%) cost of the interventions was minus $118 millions (that is, cost saving) in the base case. Sensitivity analyses indicate that the interventions would be cost saving unless the systolic blood pressure reduction were less than 2 mm Hg, productivity gains were disregarded or the welfare losses from price interventions were high. CONCLUSION: Population interventions to reduce the intake of salt are likely to improve the population's health and save costs to society.
The level of serum calcium appears to be associated with blood pressure and metabolic risk factors for cardiovascular disease. Determinants of serum calcium may therefore be of interest. In a health survey in Tromsø in 1994-1995, 27,159 subjects were examined. The survey included measurements of serum calcium and questionnaires on diet and lifestyle factors. In males mean serum calcium declined from 2.41 mmol/l for those in their 20s to 2.34 mmol/l for those in their 80s. In females mean serum calcium was stable at a level of 2.35 mmol/l before the menopause, and thereafter reached a plateau of 2.39 mmol/l. In both sexes serum calcium showed a positive association with body mass index (BMI) and coffee consumption that persisted after correcting for other variables in a multiple regression model (p
The Samis are an ethnic minority living in the Northern region of Norway, Sweden, Finland and Russia. Traditionally the Samis made their living from reindeer herding with some fishing and agriculture. Earlier studies have shown that their diet consisted of large amounts of reindeer meat, some fish and wild berries with low intakes of other fruits, vegetables and dairy products. Due to the introduction of technical improvements like snowmobiles and terrain vehicles which makes moving with the herd less necessary, their lifestyle has changed. There is little documentation how this has affected their dietary habits. In this study, the dietary pattern and nutrient intake of a group of Samis (n = 75) living in traditional reindeer herding areas of North Norway were investigated and compared with that of a group of Norwegians (n = 65). Dietary information was obtained through an interview by a nutritionist using the dietary history method. The findings indicate that nutrient content of the Sami diet is adequate except for folic acid. Calcium and iron intake was slightly below recommended levels for Sami females. There seems to be some difference between the diet of the Samis and Norwegians. The Samis consume more meat, fat, table sugar and coffee and less fruits and vegetables. The dietary pattern of the Samis seems, however, to be changing toward a more typically Norwegian diet.