Prevalence of hepatitis A antibodies in a normal population and some selected groups of patients in Norway.

The prevalence of hepatitis A virus antibodies was tested by radioimmunoassay in Norway in healthy blood donors, in patients without clinical signs of liver diseases and in two selected groups of patients. The presence of hepatitis A antibodies was highly age-dependent in 625 normal persons. A major reduction occurred from 50 per cent or more in those born before 1938 to 10 per cent or less among those born after 1943. The decline of hepatitis A antibody prevalence was correlated to the history of infectious hepatitis epidemics in the entire country during World War II. The prevalence was not different from controls in a group of patients with various liver disorders. Hepatitis A antibodies were more prevalent in males than in females in blood donors, patients with chronic liver disorders and their controls. Hepatitis A antibodies were frequently present in prison inmates; their presence was associated with the presence of antibodies against hepatitis B virus and with anamnestic data on drug addiction.

Risk factors and raised atherosclerotic lesions in coronary and cerebral arteries. Statistical analysis from the Oslo study.

In 1972-1973, about 16,200 men living in Oslo, aged 40 to 49 years, were examined for cardiovascular disease, and had a number of coronary risk factors measured. This report gives the results of 129 autopsied cases with regard to the association between raised atherosclerotic lesions in coronary and cerebral arteries and various coronary risk factors. For coronary raised lesions, the high density lipoprotein (HDL) cholesterol ratio was the most significant risk factor. Systolic blood pressure and total serum cholesterol were also significantly associated. Physical activity at work and at leisure, nonfasting triglycerides, and cigarette smoking did not show a significant association with coronary artery raised lesions. The association between total serum cholesterol and systolic blood indicates that total serum cholesterol may be more important than systolic pressure in the synergism affecting the development of coronary atherosclerosis. For cerebral artery raised lesions, blood pressure was the most important risk factor, even though serum cholesterol was highly associated with the lesions. The interaction analysis also suggested that blood pressure was more important than serum cholesterol in the synergism.

High density lipoprotein cholesterol, total cholesterol and triglycerides in serum after a single exposure to prolonged heavy exercise.

Serum high density lipoprotein (HDL) cholesterol, total serum cholesterol and triglycerides were determined in twenty men before, immediately after, and 1, 2 and 4 days after a 70 km cross-country ski race. HDL cholesterol increased by 12% of the pre-race level immediately after the race, rose further to 17% above the initial level on the following day, and was still elevated 4 days after the race. LDL + VLDL cholesterol, however, showed a tendency to decrease immediately after the race and was reduced by 17% and 11% of the pre-race level on the following 2 days. Triglycerides were reduced by 30% of the initial level immediately after the race, were still low on the following day, but were restored to normal 2 days after the race. It is concluded that a single exposure to prolonged heavy exercise induces changes in the HDL metabolism, showing that the physical exercise per se plays an important role for the increased HDL level seen in well-trained athletes.

Plasma HDL cholesterol and the in vitro esterification of cholesterol.

In vitro esterification of plasma cholesterol was measured in twelve healthy subjects, six of whom had high plasma concentrations of high density lipoprotein (HDL) cholesterol, whereas the other six had low concentrations. Irrespective of the method used no difference between the groups with the respect to cholesterol esterification could be demonstrated. This may indicate that the beneficial effect of HDL on the development of atherosclerotic disease works thorugh other mechanisms than by facilitating the transport of cholesterol from peripheral tissues to the liver.

High density lipoproteins, insulin secretion and coronary risk factors in latent coronary insufficiency.

Coronary heart disease (CHD) risk factors were studied in presumably healthy men, examined for preclinical CHD. Coronary angiography was performed in most "latent CHD" subjects. High density lipoprotein (HDL) cholesterol and apoproteins did not differ significantly between men with latent CHD (some with angiographic changes) and men without evidence of CHD. HDL cholesterol was positively correlated with physical activity. Insulin secretion was, however, positively associated with physical inactivity, body weight and serum triglycerides. Men with the highest insulin secretion had the lowest glucose tolerance. The study confirms the covariance between HDL cholesterol, insulin secretion, serum triglycerides, body weight and physical activity, but does not support the theory that HDL is a major "negative risk factor" in middle-aged men with preclinical CHD.

High density lipoprotein cholesterol and myocardial infarction or sudden coronary death: a prospective case-control study in middle-aged men of the Oslo study.

The high density lipoprotein (HDL) cholesterol concentrations of frozen specimen obtained in 1972-73 are reported from 93 men aged 40-49 years who later developed coronary heart disease (CHD), and for 186 controls. Mean HDL cholesterol of CHD-patients was 7.9% lower than that of controls matched for smoking habits and serum concentrations of triglycerides and total cholesterol (p 0.05 for 82 men who had myocardial infarction, n.s. difference for 11 with sudden coronary death), and 10.2% lower (p 0.05) than that of controls who were not matched for the parameters mentioned. The present prospective study confirms that HDL cholesterol is inversely associated with the risk of developing CHD in middle-aged men.

Smoking, lung function, physical performance and latent coronary heart disease in presumably healthy middle-aged men.

During a cardiovascular survey comprising 2014 presumably healthy men aged 40-59 years, latent (previously undetected) coronary heart disease (CHD), lung function and physical performance were related to differences in smoking habits. The survey examination classified 1 832 individuals as "normals" (without clinical signs/symptoms of CHD). Among the others, a strong supicion of CHD was found in 115, of whom 105 had diagnostic coronary angiography. No angiography was performed in another 35 individuals with slight, albeit typical angina pectoris. The remaining 42 men were excluded from this presentation for various reasons. The following findings were obtained: 1) in the 69 men with positive coronary angiography, the extent of coronary atheromatosis was positively related to the number of cigarettes smoked. 2) The smoking habits of the 35 individuals with slight angina pectoris but no angiography did not differ from those of the "normals". 3) Physical performance during a near maximal bicycle exercise test and lung function according to spirometry were strongly and negatively related to smoking (in "normals"). 4) Previous smokers and never-smokers among "normals" had almost identical lung function and physical performance.

The effect of smoking on selected coronary heart disease risk factors in middle-aged men.

Associations between smoking and selected factors supposed to promote coronary heart disease (CHD) were studied in 1832 healthy men, 809 of whom were smokers. Triglycerides were 7% higher in smokers; the heaviest smokers had the highest levels. Unfavourable changes were not seen in the other parameters in smokers. There was no trend indicating an influence of smoking on total and HDL cholesterol in the individuals who had abstained from smoking for a few hours just before the examination. Body mass index and weight, blood pressure and resting heart rate were lower in smokers, whereas heart volume, glucose tolerance, thyroid function and ECG findings did not differ significantly in smokers and non-smokers. The present study indicates that smoking promotes the development of CHD independently of the commonly accepted CHD risk factors.

High density lipoproteins (HDL) and physical activity: the influence of physical exercise, age and smoking on HDL-cholesterol and the HDL-/total cholesterol ratio.

220 trained men, examined the day before participation in a cross country ski-race, had significantly higher HDL-cholesterol and HDL-/total cholesterol ratio than untrained men, but did not differ signficantly from untrained women. HDL-cholesterol was significantly higher in skiers above 60 years than in skiers of younger age. Tobacco smokers ahd lower HDL-cholesterol and HDL-/total cholesterol ratio than non-smokers, but the differences were only significant in skiers, not in controls. HDL-cholesterol was positively correlated to total cholesterol in skiers. The HDL-cholesterol level may possibly contribute to the lower morbidity of CHD in men who are physically active during leisure time.

The effect of clofibrate on glucose tolerance, insulin secretion, triglycerides and fibrinogen in patients with coronary heart disease.

The effects of clofibrate treatment have been monitored in a double-blind cross-over study conducted in 16 male patients with coronary heart disease. Most had latent diabetes mellitus with elevated and delayed insulin release after i.v. glucose administration. Blood glucose and insulin levels were measured during repeated i.v. glucose tolerance tests in each patient and serum triglyceride and plasma fibrinogen were estimated at intervals. Clofibrate treatment significantly lowered fasting blood glucose levels (p less than 0.01) and improved the glucose tolerance (p less than 0.01). Fasting plasma insulin levels and those at 30 min after glucose loading were reduced (p less than 0.05). Serum triglycerides (p less than 0.01) and plasma fibrinogen levels (p less than 0.05) were lowered during the treatment period. The change in k-value (glucose utilization) did not correlate to changes in triglyceride or fibrinogen. This study confirms the beneficial effect of clofibrate therapy on abnormal glucose tolerance observed by other workers. It is suggested that clofibrate acts by reducing peripheral insulin resistance.

Intravenous glucose tolerance test in middle-aged men with and without latent coronary heart disease.

During a cardiovascular survey, aimed at detecting cases of latent coronary heart disease (CHD), glucose elimination was studied after i.v. loading in 1970 presumably healthy men aged 40-59 years. The aim was to throw light on the importance of deranged glucose tolerance for the development of CHD. Of the 1970 individuals, 1798 were defined as "normals", 33 had chronic, non-anginal chest pain, 34 had slight albeit typical angina pectoris. The remaining 105 had various symptoms/signs strongly suggestive of CHD, and underwent diagnostic coronary angiography (69 angiopositive, 36 angionegative). Plasma insulin was determined in relation to the test in 249 of the subjects. The following conclusions were reached: 1) Mean k-values were similar in all subgroups (p less than 0.10). 2) Low and borderline k-values were significantly more frequent in angiographed individuals compared with the group of normals (p less than 0.025). However, an almost identical frequency was seen in angiopositive and angionegative cases. 3) K-values did not change with age between 40 and 59 years. 4) K-values were unrelated to the severity of angiographic findings in individuals with proven CHD. 5) Significantly lower k-values were found in individuals with a positive diabetic heredity, and 6) in individuals with a high insulin response. 7) The i.v. glucose loading did not influence an exercise ECG recorded in relation to a near-maximal bicycle exercise test.

The esterification of cholesterol in plasma after acute myocardial infarction.

The rate of plasma cholesterol esterification (LCAT activity) and the concentration of eight proteins in the plasma have been studied in the ten male patients during the course of acute myocardial infarction. Samples were drawn 22 hr, 3 days, 8 days, 2 weeks, and 7 weeks after the onset of the acute myocardial infarction. The changes of the plasma proteins were typical for the acute-phase reaction. LCAT activity decreased initially during the illness. The lowest values were found after 8 days. Concomitantly, a reducation in the plasma concentration of total and free cholesterol and cholesteryl esters was demonstrated. The rate of cholesterol esterification correlated significantly with the concentration of prealbumin, alpha-lipoprotein, and albumin. Seven weeks after onset of the infarction, the LCAT values were equal to those in a reference group. The results suggest that the synthesis of LCAT was decreased during the acute-phase reaction.