Trend in serum total cholesterol level in 110,000 young adults in The Netherlands, 1974 to 1986

Trends in total and high density lipoprotein cholesterol and their determinants in The Netherlands between 1993 and 1997

BACKGROUND

The aim of this study is to describe trends in plasma total and high density lipoprotein (HDL) cholesterol in The Netherlands between 1993 and 1997 and to examine whether these trends in cholesterol could be explained by changes in body mass index, smoking, alcohol intake, use of cholesterol lowering medication, intake of saturated fat, trans fatty acids and dietary cholesterol.

METHODS

Each year a random sample of men and women aged 20-59 years living in three towns in The Netherlands was invited to participate in the study. In total more than 21 000 people were examined.

RESULTS

Between 1993 and 1997 plasma total cholesterol decreased significantly by 0.19 mmol/l in men and by 0.27 mmol/l in women. During this period HDL cholesterol remained stable in both men and women. Small decreases were observed in the intake of saturated fat, trans fatty acids and dietary cholesterol in both men and women. The use of cholesterol lowering medication and for women oral contraceptives and prescribed oestrogens increased significantly. After adjustment for these determinants in multivariate analyses the trend in total cholesterol remained highly significant.

CONCLUSIONS

Between 1993 and 1997 the mean total cholesterol level decreased significantly while the mean HDL cholesterol remained stable in both men and women in The Netherlands. The observed trend in total cholesterol could only for a small part be explained by changes in the determinants studied.

Blood pressure and cardiovascular morbidity and mortality in a Dutch population: the Nijmegen cohort study

BACKGROUND

The objective was to determine the influence of systolic blood pressure and diastolic blood pressure on the development of coronary heart disease over an 18-year period in a Dutch general practice population.

METHODS

The Nijmegen Cohort Study is a prospective cohort study with an 18-year follow-up. In 1977 systolic blood pressure, diastolic blood pressure, and other cardiovascular risk factors were measured in 7,092 Caucasians, men and women. The screening took place in six general practices, participating in a university registration network. Cardiovascular disease and all mortality was registrated during the 1977-1995 period. A Cox proportional hazard model was performed separately for men and women with the first onset of a coronary heart disease as the outcome variable. Age, smoking, serum cholesterol, blood pressure, and socioeconomic class were included as independent variables.

RESULTS

During the 18-year follow-up period, 205 men and 63 women suffered a nonfatal myocardial infarction. During this time, 205 deaths were identified, of which 54 were cardiovascular. Of all deaths, 139 were noncardiovascular, of which 10% were due to accident or suicide, while in 12 participants the cause of death was uncertain. The analysis indicated that both the systolic and the diastolic blood pressure were independently associated with the likelihood for developing coronary heart disease, as were the other risk factors. For coronary heart disease, the significant risk ratios for the systolic blood pressure were 1.6 for men and 2.1 for women. For the diastolic blood pressure a risk ratio was found of 1.4 for men and 2.0 for women.

CONCLUSION

A significant relation between blood pressure and coronary heart disease was demonstrated. As mean blood pressures, cholesterol levels, smoking habits, and socioeconomic class in this cohort did not differ from other figures in The Netherlands, extrapolation of the results to the Dutch population is possible.

Changes in serum total cholesterol levels over 18 years in a cohort of men and women: The Nijmegen Cohort Study

BACKGROUND

This study aimed to investigate to what extent cholesterol levels change in individuals in different age groups over an 18-year period. Factors that contribute to the changes, with respect to prevention of cardiovascular disease, were taken into account.

METHODS

In 1977 serum cholesterol, systolic and diastolic blood pressures, body mass index, and smoking habits were measured in a cohort of 7,092 patients (men and women from 20 to 50 years of age) from six general practices in The Netherlands. In 1995, a sample of 2,600 of these same patients were invited to take part in a similar screening program; 2,335 patients, consisting of 1,171 men and 1,164 women, agreed to participate. Patients were derived from both high-risk and low- to normal-risk category in 1977. The differences in cholesterol between 1977 and 1995 were calculated and cholesterol levels were tracked over the study period by determining Pearson correlation coefficients. A multiple linear regression analysis was performed to investigate the determinants influencing the changes in cholesterol level.

RESULTS

The mean cholesterol levels rose during the study period in all age groups. The highest mean increase in men was 1.23 mmol/L, or 20%, in the youngest age group (20-24 years), and in women the maximum mean increase was 1.12 mmol/L, or 17%, in the age group 40-44 years. Correlation coefficients between the 1977 and 1995 readings varied from 0.63 in the youngest age group to 0.41 in the oldest. Body weight change during the study period, more than initial body weight, was found to have influenced the rise in serum cholesterol. At basic screening, 19.2% of the men and 12.4% of the women had cholesterol levels of 6. 5 mmol/L or higher, as against 35.8 and 36.8%, respectively, in 1995.

CONCLUSIONS

Over an 18-year period cholesterol level increased in most subjects, at a younger age in men than in women. The highest increase in women took place during the menopausal period. Weight gain, more than baseline weight, had a positive influence on the increase in cholesterol.

Total cholesterol concentration and mortality at a relatively young age: do men and women differ?

OBJECTIVE

To investigate the relation between total cholesterol concentration and mortality from coronary heart disease, cardiovascular diseases, non-cardiovascular causes, and all causes.

DESIGN

Population based cohort study.

SUBJECTS

23,000 men and 26,000 women aged 30-54 years examined between 1974 and 1980.

MAIN OUTCOME MEASURES

Mortality for the above mentioned end points for fifths of cholesterol distribution, and relative risks estimated by using Cox's proportional hazard (survival) analysis. Adjustment was made for age, smoking, systolic blood pressure, and body mass index.

RESULTS

Mortality from coronary heart disease in men was five times higher than that in women. A strong positive association between total cholesterol concentration and mortality from coronary heart disease and cardiovascular diseases was observed in both men and women. The relative risk for the highest compared with the lowest fifth of the cholesterol distribution was for mortality from coronary heart disease (3.0 (95% confidence interval 1.8 to 5.1) in men and 3.8 (1.1 to 13.1) in women) and for mortality from cardiovascular disease (2.8 (1.8 to 4.2) in men and 2.9 (1.4 to 6.0) in women). No increase of non-cardiovascular mortality at low cholesterol concentration was observed. All cause mortality was significantly higher in the highest compared with the lowest fifth of the cholesterol distribution: relative risk 1.6 (1.3 to 2.0) in men and 1.5 (1.1 to 1.9) in women.

CONCLUSION

Total cholesterol concentration is a strong predictor of mortality from coronary heart disease, cardiovascular diseases, and all causes in women as well as in men. Low cholesterol concentrations are not associated with increased mortality from non-cardiovascular causes.