Dag S. Thelle

The Tromsø Heart Study

We examined the relation between coffee consumption and levels of serum total cholesterol, high-density-lipoprotein (HDL) cholesterol, and triglycerides in a population of 7213 women and 7368 men between the ages of 20 and 54 years. Coffee consumption was positively associated with levels of total cholesterol and triglycerides in both sexes and was inversely associated with levels of HDL cholesterol in women. The coffee-cholesterol relation remained strong and statistically significant (P less than 0.0001 in a covariance analysis) after adjustment for age, logarithm of body-mass index, physical activity in leisure time, cigarette smoking, and alcohol consumption. After adjustment for all covariates, the total cholesterol level was 5.56 +/- 0.05 mmol per liter (mean +/- S.E.) in men drinking less than one cup of coffee a day, as compared with 6.23 +/- 0.03 mmol per liter in those consuming more than nine cups a day. The corresponding figures for women were 5.32 +/- 0.05 and 5.92 +/- 0.04 mmol per liter. None of the other variables considered could explain this relation. We conclude that coffee consumption is a major contributor to the variation in levels of total cholesterol.

Mortality in relation to smoking history: 13 years' follow-up of 68,000 Norwegian men and women 35–49 years

A total of 44,290 men and 24,535 women aged 35-49 have been followed with respect to different causes of death during 13.3 years on average. A detailed history of smoking, together with other important risk factors, were recorded in a standardized way. Compared with the classical American and British studies, the excess mortality for the smokers was largely the same for the majority of causes. The exceptions were cerebrovascular mortality and suicides and accidents, which were more strongly related to smoking in this study. Furthermore, men who smoked only pipe, had nearly the same coronary heart disease mortality as men who smoked only cigarettes. The same applies to lung cancer mortality. Among men who had quit cigarette smoking, the coronary heart disease mortality decreased with time since quitting to almost the level of the never cigarette smokers after 5 years or more.

The Tromso heart study: coffee consumption and serum lipid concentrations in men with hypercholesterolaemia: an randomised intervention study.

In a 10 week trial to assess the effects of coffee consumption and coffee brewing methods on serum cholesterol concentrations 33 men with hypercholesterolaemia were randomly assigned to: continue with their usual coffee intake; stop drinking coffee altogether; or stop drinking coffee for five weeks, thereafter drinking either boiled or filter coffee. Cholesterol concentrations fell significantly in all subjects abstaining for the first five weeks compared with subjects not giving up and continued to fall in those abstaining for 10 weeks. Cholesterol concentrations rose again in subjects returning to boiled coffee but remained the same in those returning to filter coffee. Abstention from heavy coffee drinking is an efficient way of reducing serum cholesterol concentrations in men with hypercholesterolaemia. The extent to which the brewing method affects this relation requires further study.

The Tromsø Heart Study: responders and non-responders to a health questionnaire, do they differ?

In 1979–80, 21329 subjects, 20–54 years old, were invited to a screening for coronary heart disease risk factors in Tromsø. 16621 (77%) attended the screening, the response rate was higher in women than in men, lower in single than married and lowest in young (20–29 years) men. At the screening, the men and women were given a second questionnaire which they were asked to fill in and return by mail. 14667 (88.2%) of the subjects did so. Based on information obtained at the screening, the differences between these 14667 subjects and the 1954 men and women who failed to return the questionnaire are presented. 10.9% of the women did not return the questionnaire, the corresponding figure for men was 12.6%. The differences in age, body mass index (kg/m2), blood lipids and blood pressure were minor or non-existent. The subjects who returned the questionnaire tended to be married, non-smokers and report respiratory symptoms less often than non-responders.

Tromsø Heart Study: vitamin D metabolism and myocardial infarction.

The high mortality rates from myocardial infarction in northern Norway lead to the establishment of the Tromso Heart Study (THS) in 1974.1 An investigation by Linden,2 suggested that a high intake of vitamin D might be a precipitating cause of myocardial infarction in this area of Norway. We therefore studied data from the THS to determine whether vitamin D was a risk factor for myocardial infarction.

The Tromsø heart study: The relationship between food habits and the body mass index☆

Associations between food habits and body mass index (BMI) (kg/m2) were explored in a cross-sectional study with 7410 men and 7257 women. High BMI was most strongly associated with low bread consumption and use of low-fat milk. Weaker positive associations were seen for coffee, fish and ground meat consumption, and with use of table fat with a low P/S-ratio. Negative associations were seen for use of fruits and vegetables and amount of table fat at each slice of bread. Inconsistent relationships were noted for use of alcohol. The results suggest that individuals to some extent have changed their food habits in order to keep the BMI within limits they consider to be normal, and underline the need for adjustment for BMI when e.g. relationships between the diet and blood lipids are studied.

Coronary Heart Disease Mortality Trends and Related Factors in Norway

The coronary heart disease (CHD) mortality rates for men aged 35-44 years decreased by 25% from 1966-70 to 1976-80. In older age groups only a modest decline was observed. The decrease in CHD mortality is probably due to a decrease in incidence. The reason for the decline is not known, but some changes in health-related behaviour have occurred in Norway, probably already starting in the 1960s. There was an increase in meat, sugar and total fat consumption and a decrease in the intake of cereals both before and after the Second World War. These trends seem to have slowed down and in a recent survey 44% of the population reported changes towards a low fat diet. The percentage of non-smokers is increasing, particularly since 1975-76. Physical activity in leisure time has increased since the mid-70s but there are social gradients with the most active subjects being recruited from the higher social strata. The improved medical care of CHD patients is not thought to have had a major impact upon the decline in the mortality rates. The most probable explanation for the changes is an increase of non-smokers and a turn towards a less coronary prone diet.

The Tromsø Heart Study: A Multiple Regression Analysis of the Relationship between Coronary Risk Factors and Some Physical and Social Variables

Univariate analysis of the cross-sectional data of the Tromsø Heart Study revealed group differences in the levels of blood pressure and serum lipids. In order to isolate the contribution from each of the physical and social variables which characterized these groups, a multiple variate analysis was carried out with serum triglycerides, serum cholesterol, systolic and diastolic blood pressure as dependent variables. Besides age, height and weight, seasonal variation contributed substantially to the explanation of the variance of the dependent variables. The influence of the social variables was somewhat reduced compared to the univariate analysis, though most of them did remain significant also in the multivariate analysis. The explained percentage of the total variance ranged from 13% for systolic blood pressure to 26% for serum cholesterol.

Patterns of dietary change: the Scandinavian experience

Sunday afternoon 10 August 1628, the naval vessel Wmu embarked on its first trip. The ship had been constructed in Stockholm according to the King’s wishes, and the recommendations of one of the most renowned ship builders at that time. It was heavily decorated, with sculptures both in the bow and the stem. It was armed with sixty-four bronze cannon, at that time a heavy armament, and the ship was meant to impress, frighten and to fight the enemy. It was a beautiful afternoon when the ship was pulled off the shore. Four sails were set and were quickly filled. A sudden increase in the wind made the ship tilt. The water flooded the cannon gates and she sank in only a few minutes, with standing sails, flag and all men aboard, actually also a number of women and children. It was a catastrophe; a thoroughly-designed naval vessel, among the largest ever built, went down on its first trip. Today the vessel is a remarkable source of knowledge about seamen’s life in the 17th century. On 17 November 1975 the Norwegian government put forward a Parliamentary Bill on Norwegian nutrition policy and food supply (Royal Norwegian Ministry of Agriculture 1976). The following four goals deserve to be mentioned.