Total and HDL-cholesterol in The Netherlands: 1987-1992. Levels and changes over time in relation to age, gender and educational level

Socioeconomic status and education level are associated with dyslipidemia in adults not taking lipid-lowering medication: a population-based study

BACKGROUND

Socio-economic disparities account for changes in the lipid profile in developing countries. We aimed to investigate the association between blood lipids and socio-economic and educational strata in adults not taking lipid-lowering medications.

METHODS

A cross-sectional, population-based study enrolled 1614 individuals not taking lipid-lowering medications. Sociodemographic characteristics, monthly income, education level and the number of consumer goods available at home were obtained and individuals were classified into five socio-economic categories. Blood lipids were obtained in fasting participants.

RESULTS

In men, the higher the socio-economic or educational stratum, the higher the total cholesterol, low-density lipoprotein cholesterol (LDL-c) and triglyceride (TG) levels and the lower the high-density lipoprotein cholesterol (HDL-c), after controlling for age, body mass index, hypertension, smoking habit and physical activity. In women, the higher socio-economic strata were associated with elevated total cholesterol and HDL-c, while lower total cholesterol, LDL-c and TG levels were found in those with higher education levels. Also, individuals in the upper socio-economic strata had higher levels of total cholesterol and LDL-c, showing more than two times higher odds of having multiple alterations in blood lipids (men: OR 2.99 [95% CI 1.23 to 5.07]; women: OR 2.31 [95% CI 1.09 to 5.83]).

CONCLUSIONS

Dyslipidemia is highly prevalent in developing countries. Individuals in the highest socio-economic category are the ones at higher risk for dyslipidemia. This phenomenon calls for strategies to stimulate healthy diet habits and a physically active lifestyle to minimize health problems.

The relationship of physical activity to high-density lipoprotein cholesterol level in a sample of community-dwelling older adults from Amazonas, Brazil

OBJECTIVES

(1) To study the relation of physical activity (PA) to high-density lipoprotein cholesterol (HDL-C) and (2) to investigate if the strength of these associations holds after adjustments for sex, age, and other key correlates.

METHODS

This study included 550 older adults from Amazonas. HDL-C was derived from fasting blood samples. PA at sport and leisure, smoking, alcohol consumption, and socioeconomic status (SES) were interviewed. Waist circumference (WACI) was assessed.

RESULTS

HDL-C was positively related to PA sport, PA leisure, and SES (0.22≤r≤0.34; p≤0.001) and negatively related to smoking and WACI (r≤-0.10; p<0.05). Controlling for sex and age did not affect these relationships. Hierarchical multiple regression analyses showed that the relation of HDL-C to PA sport and leisure remained significant when controlling for all other investigated correlates (0.14≤β≤0.24; p≤0.001).

DISCUSSION

In order to prevent low HDL-C in older adults, promoting PA seems to be an important additional component besides common recommendations concerning weight reduction.

The prevalence of dyslipoproteinemia in Thai patients with systemic lupus erythematosus

Fasting blood samples taken from 93 pairs of outpatient systemic lupus erythematosus (SLE) women and matched controls were assessed for total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL)- and low-density lipoprotein (LDL)-cholesterol. The demographic data, clinical manifestations, Mexican-SLE Disease Activity Index (MEX-SLEDAI), Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) damage index and medication prescribed in the SLE patients were reviewed. A significant elevation of TG levels was observed in the SLE patients compared to controls (mean ±SD 113.3 ±59.5 versus 77.7 ±45.7 mg/dL, P < 0.001). The HDL-c level was also significantly lower in SLE patients than controls (mean ±SD 49.7 ±12.7 versus 65.0 ±14.8 mg/dL, P < 0.001). The percentage of samples with low HDL-c (<35 mg/dL) was higher in the SLE group (9.7%) than controls (0%; P = 0.002). The LDL-c and TC levels were comparable in both groups. The use of antimalarial drugs was negatively associated with TC (OR 0.22, 95%CI 0.08-0.61) and LDL-c levels (OR 0.27, 95%CI 0.09-0.80). The increased prevalence of dyslipoproteinemia in SLE patients in this report has confirmed the results of previous studies and emphasized the importance of controlling this modifiable cardiovascular risk factor by the combination of lifestyle modification and medical treatments.

Prevalence and associated factors of dyslipidemia in the adult Chinese population

To determine the prevalence, associated factors, awareness and control of dyslipidemia in Chinese living in Greater Beijing, we measured the serum cholesterol concentration in 3251 Chinese adults (age: 45 to 89 years) as participants of the population-based Beijing Eye Study 2006. Additional information on treatment of dyslipidemia was obtained using a standard questionnaire. The mean concentrations of total, HDL cholesterol, LDL cholesterol and triglycerides were 4.92±1.01 mmol/L, 1.61±0.36 mmol/L, 2.88±0.85 mmol/L, and 1.76±1.29 mmol/L, respectively. Prevalence of dyslipidemia was 56.1±0.9%%. Presence of dyslipidemia was significantly associated with increasing age (odds ratio (OR):1.02; 95% confidence interval (CI): 1.01, 1.03), female gender (OR:1.51; 95%CI: 1.25, 1.83), urban region (OR:1.82; 95%CI: 1.30, 2.55), body mass index (OR:1.13; 95%CI: 1.10, 1.15), income (OR:1.11; 95%CI:1.02, 1.21), blood glucose concentration (OR:1.10; 95%CI:1.05, 1.16), diastolic blood pressure (OR:1.02; 95%CI: 1.01, 1.03), and smoking (OR:1.23; 1.01, 1.51). Among those who had dyslipidemia, the proportion of subjects who were aware, treated and controlled was 50.9%, 23.8%, and 39.91%, respectively. The awareness rate was associated with urban region (P = 0.001; OR: 6.50), body mass index (P = 0.001; OR:1.06), and income (P = 0.02; OR:1.14). The data suggest that dyslipidemia may be present in about 56% of the population aged 45+ years in Greater Beijing. Factors likely associated with dyslipidemia were higher age, female gender, urban region, higher body mass index, higher income, higher blood concentration of glucose, higher diastolic blood pressure, and smoking. In the examined study population, treatment rate was 24% with about 60% of the treated subjects still having uncontrolled dyslipidemia.

Hypoalphalipoproteinemia in populations of Native American ancestry: an opportunity to assess the interaction of genes and the environment

PURPOSE OF THIS REVIEW

Our aim is to review the environmental and genetic factors associated with hypoalphalipoproteinemia in populations of Native American ancestry. We examine the strength of the association and outline the population-specific genetic factors that lead to a higher susceptibilty for this condition.

RECENT FINDINGS

Low HDL is the most common lipid abnormality in populations of Native American ancestry. Population-based surveys carried out in Latin America and in Mexican Americans shows that 40-60% of adults have hypoalphalipoproteinemia. The contribution of this trait to the metabolic syndrome is greater in individuals with Native American ancestry than in other ethnic groups. Several environmental factors have contributed to this phenomenon (i.e. high dietary content of carbohydrates and fat due to cultural factors and a growing incidence of obesity). In addition, results from recent genetic studies show that certain hypoalphalipoproteinemia susceptibility alleles are ethnic specific for Native Americans. The variant R230C of the ATP-binding cassette transporter subfamily A member 1 gene (ABC-A1) is common among mestizos (10.9% in Mexican mestizos) and its presence has a significant negative effect on HDL cholesterol levels (-4.2%). An additional noteworthy finding is that the R230C variant appears to be specific for the Amerindian populations. Its allele frequency is 0.28 in Mayans, 0.214 in Purepechas, 0.203 in Yaquis and 0.179 among Teenek. In contrast, the C230 allele has not been found in African, European, Chinese or South Asian populations.

SUMMARY

The assessment of the genetic and environmental determinants of hypoalphalipoproteinemia in populations of Native American origin provides an opportunity to assess the population-specific interactions between genes and the environment

Analysis of multiple SNPs in genetic association studies: comparison of three multi-locus methods to prioritize and select SNPs

Nonparametric approaches have been developed that are able to analyze large numbers of single nucleotide polymorphisms (SNPs) in modest sample sizes. These approaches have different selection features and may not provide similar results when applied to the same dataset. Therefore, we compared the results of three approaches (set association, random forests and multifactor dimensionality reduction [MDR]) to select from a total of 93 candidate SNPs a subset of SNPs that are important in determining high-density lipoprotein (HDL)-cholesterol levels. The study population consisted of a random sample from a Dutch monitoring project for cardiovascular disease risk factors and was dichotomized into cases (low HDL-cholesterol, n = 533) and non-cases (high HDL-cholesterol, n = 545) based on gender-specific median values for HDL cholesterol. Clearly, all three approaches prioritized three SNPs as important (CETP Taq1B, CETP-629 C/A and LPL Ser447X). Two SNPs with weaker main effects were additionally prioritized by random forests (APOC3 3175 G/C and CCR2 Val62Ile), whereas MTHFR 677 C/T was selected in combination with CETP Taq1B as best model by MDR. Obtained p-values for the selected models were significant for the set association approach (p =.0019), random forests (p<.01) and MDR (p<.02). In conclusion, the application of a combination of multi-locus methods is a useful approach in genetic association studies to select a well-defined set of important SNPs for further statistical and epidemiological interpretation, providing increased confidence and more information compared with the application of only one method.

Exposure and effectiveness of phytosterol/-stanol-enriched margarines

BACKGROUND

Studies on effectiveness of phytosterol/-stanol-enriched margarines in the community have received low priority. For postlaunch monitoring purposes including risk-benefit analyses, it is needed to investigate both exposure and effectiveness of these margarines.

OBJECTIVE

To study the use and effectiveness of phytosterol/-stanol-enriched margarine.

DESIGN, SETTING AND SUBJECTS

The study population consisted of 2379 subjects that participated in a community intervention study ('Hartslag Limburg') aged 28-76 years. In 1998 and 2003, blood samples for total and high-density lipoprotein (HDL) cholesterol were obtained. A general questionnaire and food frequency questionnaire (FFQ) were administered. From 1999 onwards, phytosterol/-stanol-enriched margarines were introduced on the Dutch market. On the basis of 2003 data, subjects were classified in users of (a) phytosterol/-stanol-enriched margarine, (b) cholesterol-lowering drugs, (c) the combination (both enriched margarine and drugs) and (d) neither enriched margarines nor cholesterol-lowering drugs.

RESULTS

Mean (+/-s.d.) daily intake of phytosterol-enriched margarine (n=99) and phytostanol-enriched margarine (n=16) was 14+/-9 g. From 1998 to 2003, total serum cholesterol concentration changed significantly different among the four groups: in the combination users -2.04+/-1.50 mmol/l (-29%), in cholesterol-lowering drug users -1.09+/-1.17 mmol/l (-17%), in the enriched margarine users -0.24+/-0.75 mmol/l (-4%) and in non-users +0.10+/-0.72 mmol/l (+2%)(P<0.05).

CONCLUSION

Recommended doses are not consumed, but phytosterol/-stanol-enriched margarines can modestly reduce serum total cholesterol in the community. These margarines cannot equal the effect of cholesterol-lowering drugs, but may act additively. Further investigation of the health effects that may occur during simultaneous cholesterol lowering drugs and phytosterol-or -stanol-enriched margarines usage is important, as well as community education about the cholesterol lowering foods and drugs.

SPONSORSHIP

Netherlands Organization for Health Research and Development (ZonMW) (data collection of Hartslag Limburg and further data- analyses).

Analysis of the relationship between total cholesterol, age, body mass index among males and females in the WHO MONICA Project

OBJECTIVE

To explore the relationship between hypercholesterolaemia, age and BMI among females and males.

DESIGN

Population-based cross-sectional survey.

SUBJECTS

The data came from the initial surveys of the WHO MONICA Project. In all, 27 populations with 48 283 subjects (24 017 males and 24 266 females) aged 25-64 y were used for the analysis.

MEASUREMENTS

Total cholesterol, weight, height, BMI, prevalence of hypercholesterolaemia (PHC) defined as cholesterol >/=6.5 mmol/l, and the prevalence of obesity (POB) defined as BMI >/=30 kg/m(2).

RESULTS

PHC increased with age, with PHC in males being significantly higher than in females at age range 25-49 y and significantly lower than in females at age range 50-64 y. Age-related increase in hypercholesterolaemia was steeper in females than in males. There was a statistically significant positive association between hypercholesterolaemia and BMI. Multiple logistic regression analysis revealed a negative statistically significant (P<0.001) effect modification involving age and BMI on the risk of having hypercholesterolaemia both in females and males. The relation between PHC and BMI became weaker in higher age groups, with no statistically significant association in females aged 50-64 y.

CONCLUSION

Public health measures should be directed at the prevention of obesity in young adults since the strongest effect of obesity on the risk of hypercholesterolaemia has been found in subjects aged 25-39 y.

Effects of Greek Orthodox Christian Church fasting on serum lipids and obesity

BACKGROUND

No study to date has focused on the impact of Greek Orthodox Christian fasting on serum lipoproteins and obesity yet.

METHODS

120 Greek adults were followed longitudinally for one year. Sixty fasted regularly in all fasting periods (fasters) and 60 did not fast at all (controls). The three major fasting periods under study were: Christmas (40 days), Lent (48 days) and Assumption (August, 15 days). A total of 6 measurements were made during one year including pre- and end-fasting blood collection, serum lipoprotein analyses and anthropometric measurements.

RESULTS

Statistically significant end-fasting total and LDL cholesterol differences were found in fasters. Fasters compared to controls presented 12.5% lower end-total cholesterol (p < 0.001), 15.9% lower end-LDL cholesterol (p < 0.001) and 1.5% lower end-BMI (p < 0.001). The end- LDL/HDL ratio was lower in fasters (6.5%, p < 0.05) while the change in end- HDL cholesterol in fasters (4.6% decline) was not significant. Similar results were found when the pre- and end-fasting values of fasters were compared. No change was found in control subjects.

CONCLUSIONS

Adherence to Greek Orthodox fasting periods contributes to a reduction in the blood lipid profile including a non-significant reduction in HDL cholesterol and possible impact on obesity.

Patterns of food consumption and risk factors for cardiovascular disease in the general Dutch population

BACKGROUND

Few studies have examined food consumption patterns in relation to biological risk factors for cardiovascular disease.

OBJECTIVE

The objective of the study was to describe food consumption patterns in the general Dutch population and their association with cardiovascular risk factors.

DESIGN

We performed a cross-sectional study of 19 750 randomly selected men and women aged 20-65 y from 3 Dutch municipalities. Food consumption patterns were identified with the use of factor analysis of data from a validated food-frequency questionnaire.

RESULTS

Three food consumption patterns were identified: the "cosmopolitan" pattern (greater intakes of fried vegetables, salad, rice, chicken, fish, and wine), the "traditional" pattern (greater intakes of red meat and potatoes and lesser intakes of low-fat dairy and fruit), and the "refined-foods" pattern (greater intakes of French fries, high-sugar beverages, and white bread and lesser intakes of whole-grain bread and boiled vegetables). Higher scores for the traditional pattern were associated with older age, and higher scores for the refined-foods pattern were associated with younger age, but both were associated with lower educational level, cigarette smoking, less physical activity, and higher body mass index. Independent of other lifestyle factors and body mass index, the cosmopolitan-pattern score was significantly associated with lower blood pressure and higher HDL-cholesterol concentrations, and the traditional-pattern score was associated with higher blood pressure and higher concentrations of HDL cholesterol, total cholesterol, and glucose. The refined-foods-pattern score was associated with higher total cholesterol concentrations and lower intakes of micronutrients.

CONCLUSION

In this Dutch population, food consumption patterns were independently associated with blood pressure and plasma glucose and cholesterol concentrations.

Coronary heart disease mortality, plasma homocysteine, and B-vitamins: a prospective study

The results of prospective studies on the relations between the plasma concentration of total homocysteine (tHcy) and B-vitamins, on the one hand, and coronary heart disease (CHD) mortality, on the other hand, are inconclusive and scarce considering the relation with B-vitamins. We prospectively determined these relations in a case-cohort study. The full-cohort existed in approximately 36,000 Dutch adults aged 20-59 years at baseline. The statistical analyses were done with a random sample from the cohort (n=630) complemented with all subjects who died of CHD (n=102) during a mean follow-up of 10.3 years. All subjects reported the absence of cardiovascular diseases (CVDs) at baseline. The plasma concentrations of tHcy, folate, PLP, and vitamin B12 were determined in samples obtained at baseline. Men with a tHcy concentration in the highest tertile (T3) compared with men in the lowest tertile (T1) had a relative risk (RR) of 1.14 for CHD (95% confidence interval (CI): 0.50, 2.61) after adjusting for age, study center, hypertension, HDL and total cholesterol, smoking, and creatinine. For women, this RR was 2.04 (95% CI: 0.48, 8.62). For each 5 micromol/l increase in tHcy, the RR of CHD was 1.03 (95% CI: 0.83-1.29) for men and women combined. In women only, high folate levels were associated with a statistically significant protection of fatal CHD (T3 versus T1; RR: 0.22, 95% CI: 0.06, 0.87). Plasma PLP (B6) and vitamin B12 concentrations were not associated with CHD risk. We conclude that elevated tHcy concentrations do not seem to be a risk factor for CHD mortality in these relatively young healthy Dutch subjects free of baseline CVD. Higher folate concentrations may be protective of CHD, but this needs confirmation.

Trends in serum cholesterol and lifestyle indicators in Members of the Finnish Parliament

OBJECTIVE

To examine the extent that public health promotion activity is reflected in life styles of national decision makers, by analysing trends in coronary heart disease risk factors in Members of the Finnish Parliament (MPs).

METHODS

The MPs were studied at the beginning of two subsequent 4-year parliamentary periods between 1991 and 1999. The studies included analyses of serum total cholesterol and high-density lipoprotein (HDL) cholesterol, and a questionnaire about alcohol, smoking and physical activity.

RESULTS

Serum total cholesterol was above the national recommendation of 5.0 mmol/l in 85% of the male MPs and 62% of the female MPs. The mean level of serum total cholesterol increased in female MPs during the 4-year follow-up period (P < 0.05), and male MPs showed an increase in mean HDL cholesterol (P < 0.001). The mean body mass index increased in both male (P < 0.01) and female (P < 0.01) MPs during the same period. Alcohol consumption, smoking and physical activity were unchanged during follow-up.

CONCLUSIONS

From the public health perspective, serum cholesterol is too high in most MPs, and the level in males is above the national average. Both males and females put on weight during the parliamentary period, and male MPs also showed an increase in HDL cholesterol, which may be explained by other lifestyle factors.

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.

Review of first 5 years of screening for familial hypercholesterolaemia in the Netherlands

BACKGROUND

Familial hypercholesterolaemia is a common lipid disorder that predisposes for premature cardiovascular disease (CVD). We set up a screening programme in the Netherlands in 1994 to: establish the feasibility of active family screening supported by DNA diagnostics; assess whether or not active identification of these patients with familial hypercholesterolaemia would lead to more cholesterol-lowering treatment; and compare diagnosis by DNA analysis with that by cholesterol measurement.

METHODS

Both DNA analysis and measurement of cholesterol concentrations were used to screen families in which a functional mutation in the LDL-receptor gene had been detected.

FINDINGS

In the first 5 years, 5442 relatives of 237 people with familial hypercholesterolaemia were screened; 2039 individuals were identified as heterozygous by LDL-receptor gene mutation analysis. At the time of examination, 667 of these adults with familial hypercholesterolaemia (39%) received some form of lipid-lowering treatment; 1 year later, this percentage had increased to 93%. In addition, laboratory analysis showed that for carriers as well as non-carriers 18% would have been misdiagnosed by cholesterol measurement alone, with sex-specific and age-specific 90th percentiles of the general Dutch population as diagnostic criteria.

INTERPRETATION

Targeted family screening with DNA analysis proved to be highly effective in identifying patients with hypercholesterolaemia. Most of the identified patients sought treatment and were successfully started on cholesterol-lowering treatment to lower the risk of premature CVD. Our findings could have wider relevance for the screening of other prevalent genetic disorders in the population at large.

Trends in plasma cholesterol levels in the atherosclerosis risk in communities (ARIC) study

BACKGROUND

Data from the Atherosclerosis Risk in Communities (ARIC) cohort study were examined both cross-sectionally and intraindividually to confirm recent findings from population-based studies showing a decline in total cholesterol (TC) levels in the United States.

METHODS

For the cross-sectional analysis, mean plasma TC levels from 15,792 participants aged 45-64 at baseline visit, and who were selected randomly from four U.S. communities, were examined for each year covered by the first cohort visit (1987, 1988, and 1989). Ninety-three percent of the cohort participants returned for the follow-up visit (1990, 1991, and 1992), and were included in the assessment of intraindividual TC trends.

RESULTS

Both mean TC and prevalence of hypercholesterolemia (defined as plasma cholesterol concentration >/=240 mg/dl) consistently declined over the 3 years covered by visit 1 for all age-gender-race groups. For 1987, 1988, and 1989, mean TC values (mg/dl) were, respectively, 220.3, 216.7, and 214.1 (annual average change, -1.4%, P < 0.001). For these same years, hypercholesterolemia prevalence rates were 30. 0, 27.8, and 25.3% (annual average change, -7.8%, P < 0.001). The mean plasma TC also decreased within individuals between the two visits across race, gender, and age decade categories. With the exception of black men, this decline was more marked for older than younger subjects, but no consistent differences were seen between the racial groups. However, in whites, decreases were greater for men than for women. Expected results were seen when these changes were correlated with changes in cardiovascular risk factors between the two visits.

CONCLUSION

The current study results are consistent with those of previous studies, and confirm the notion that preventive programs appear to be effective in reducing mean population TC levels.

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.

Primordial prevention of cardiovascular disease risk in The Netherlands

Developments about cardiovascular disease (CVD) risk factors in The Netherlands since the 1970s are described in relation to health policy. The prevalence of hypercholesterolemia, hypertension, and obesity changed little in the 1970s and 1980s. In recent years, however, the prevalence of hypercholesterolemia tended to decrease and that of obesity to increase. The prevalence of hypertension remained stable but the percentage of treated hypertensives declined since 1987. Between 1958 and 1993 the percentage of male smokers decreased from 90% to about 40%. In women the percentage of smokers decreased from about 40% in 1975 to about 30% in 1993. Between 1987 and 1992 the intake of saturated fat decreased from 16.5 to 14.1% of energy. But during that period the intake of vegetables also decreased from 144 to 128 g/day and that of fruits from 125 to 114 g/day. Recent surveys show that up to age 65, approximately 25% of the Dutch population is physically inactive. This percentage increases sharply after age 65. Health policy for primordial prevention of CVD in The Netherlands is aimed at reduction of smoking prevalence, improvement of dietary habits, and promotion of physical activity.

The prevalence of subclinical hypothyroidism at different total plasma cholesterol levels in middle aged men and women: a need for case-finding?

OBJECTIVE

In order to determine whether screening of thyroid function is justified in patients with hypercholesterolaemia, we determined the prevalence of subclinical hypothyroidism at different levels of total plasma cholesterol in middle-aged men and women.

DESIGN AND METHODS

1200 participants were selected from a population based cross sectional study on risk factors for cardiovascular diseases. The participants were divided into three groups: total plasma cholesterol < 5 mmol/l, total plasma cholesterol 5-8 mmol/l, total plasma cholesterol > 8 mmol/l. Each group was comparable in size and sex distribution. Subclinical hypothyroidism was defined as plasma TSH levels higher than 4 mU/l, in the presence of normal free thyroxine (FT4(4)) concentration.

RESULTS

Plasma samples of a total of 1191 participants were analyzed. The overall prevalence of subclinical hypothyroidism was 1.9% in men and 7.6% in women of middle age. In women the prevalence of subclinical hypothyroidism increased from 4.0 percent in the lowest, to 10.3 percent in the highest cholesterol stratum (P = 0.02). In men, the mean prevalence was 1.8 percent and roughly similar in the various strata. After age correction, an increase of 1 mU/l TSH in women was associated with an increase of 0.09 mmol/l total plasma cholesterol (95% confidence interval (CI) 0.02-0.16 mmol/l). A similar trend was found in men (0.16 mmol/l, 95% CI -0.02-0.34 mmol/l).

CONCLUSIONS

In the population, the prevalence of subclinical hypothyroidism is up to 10 percent in middle aged women with high levels of total plasma cholesterol and may justify case-finding. In these women approximately 0.5 mmol/l of total plasma cholesterol can be attributed to the subclinical thyroid dysfunction. In men a similar correlation between thyroid dysfunction and total plasma cholesterol is seen, but the prevalence of thyroid dysfunction is considerably lower.

Serum lipids and cardiovascular reactivity to stress

Several studies have reported an association between serum lipid levels and cardiovascular reactivity to laboratory stressors. Their findings, however, are equivocal. The inconsistencies may be due to shortcomings such as the small number of subjects, the inclusion of patient groups, no control for medication, and no control for age effects. Two studies are presented investigating the relationship in large groups of adolescent and middle-aged males and females. Cholesterol, triglycerides and HDL were measured. Subjects were exposed to mental stressors, and in one study also to a cold pressor test. In addition to heart rate and blood pressure, in one study impedance cardiography was used to measure pre-ejection period, stroke volume and total peripheral resistance. Canonical correlation analysis suggested an association between triglycerides and decreased cardiac reactivity to mental stressors in middle-aged females. Trends in the same direction were found in both middle-aged males and females with respect to reactivity to the cold pressor. These associations, however, were not confirmed when the extreme deciles of the triglyceride distributions were compared with respect to stress reactivity. The fact that associations were completely absent in youngsters but sometimes showed up in older persons suggested an age dependency of the association. In post hoc analyses, indeed, some evidence was found for stronger cardiac responsivity being associated with cholesterol specifically in relatively older males. In females, in contrast to this, the association between triglycerides and cardiac responsivity was stronger in the younger group. More detailed measurement techniques, of specifically vascular processes, may be needed to explore further the effects of sex and age on the association between lipids and stress reactivity.

Survival after the age of 80 in the United States, Sweden, France, England, and Japan

BACKGROUND

In many developed countries, life expectancy at birth is higher than in the United States. Newly available data permit, for the first time, reliable cross-national comparisons of mortality among persons 80 years of age or older. Such comparisons are important, because in many developed countries more than half of women and a third of men now die after the age of 80.

METHODS

We used extinct-cohort methods to assess mortality in Japan, Sweden, France, and England (including Wales) and among U.S. whites for cohorts born from 1880 to 1894, and used cross-sectional data for the year 1987. Extinct-cohort methods rely on continuously collected data from death certificates and do not use the less reliable data from censuses.

RESULTS

In the United States, life expectancy at the age of 80 and survival from the ages of 80 to 100 significantly exceeded life expectancy in Sweden, France, England, and Japan (P < 0.01). This finding was confirmed with accurate cross-sectional data for 1987. The average life expectancy in the United States is 9.1 years for 80-year-old white women and 7.0 years for 80-year-old white men.

CONCLUSIONS

For people 80 years old or older, life expectancy is greater in the United States than it is in Sweden, France, England, and Japan. This finding suggests that elderly Americans are receiving better health care than the elderly citizens of other developed countries.