The Atherosclerosis Risk in Young Adults (ARYA) study: rationale and design

Cardiometabolic Profiles in Women with a History of Hypertensive and Normotensive Fetal Growth Restriction

Background: The majority of evidence on associations between pregnancy complications and future maternal disease focuses on hypertensive (Ht) complications. We hypothesize that impaired cardiometabolic health after pregnancies complicated by severe fetal growth restriction (FGR) is independent of the co-occurrence of hypertension. Materials and Methods: In a prospective cohort of women with a pregnancy complicated by early FGR (delivery <34 weeks gestation), with or without concomitant hypertension, cardiometabolic risk factors were assessed after delivery. A population-based reference cohort was used for comparison, and analyses were adjusted for age, current body mass index (BMI), smoking habits, and hormonal contraceptive use. Results: Median time from delivery to assessment was 4 months in both the Ht (N = 115) and normotensive (Nt) (N = 42) FGR groups. Compared with the reference group (N = 380), in both FGR groups lipid profile and glucose homeostasis at assessment were unfavorable. Women with Ht-FGR had the least favorable cardiometabolic profile, with higher prevalence ratios (PRs) for diastolic blood pressure >85 mmHg (PR 4.0, 95% confidence interval [CI] 2.1-6.7), fasting glucose levels >5.6 mmol/L (PR 2.9, 95% CI 1.4-5.6), and total cholesterol levels >6.21 mmol/L (PR 4.5, 95% CI 1.9-8.8), compared with the reference group. Women with Nt-FGR more often had a BMI >30 kg/m² (PR 2.5, 95% CI 1.2-4.7) and high-density lipoprotein-cholesterol levels <1.29 mmol/L (PR 2.4, 95% CI 1.4-3.5), compared with the reference group. Conclusions: Women with a history of FGR showed unfavorable short-term cardiometabolic profiles in comparison with a reference group, independent of the co-occurrence of hypertension. Therefore, women with a history of FGR may benefit from cardiovascular risk factor assessment and subsequent risk reduction strategies.

Carotid Intima-media Thickness Measurements: Relations with Atherosclerosis, Risk of Cardiovascular Disease and Application in Randomized Controlled Trials

Advances in the field of carotid ultrasound have been incremental, resulting in a steady decrease in measurement variability. Improvements in edge detection algorithms point toward increasing automation of CIMT measurements. The major advantage of CIMT is that it is completely noninvasive and can be repeated as often as required. It provides a continuous measure since all subjects have a measurable carotid wall. It is also relatively inexpensive to perform, and the technology is widely available. A graded relation between raising LDL cholesterol and increased CIMT is apparent. Increased CIMT has been shown consistently to relate the atherosclerotic abnormalities elsewhere in the arterial system. Moreover, increased CIMT predicts future vascular events in both populations from Caucasian ancestry and those from Asian ancestry. Furthermore, lipid‑lowering therapy has been shown to affect CIMT progression within 12–18 months in properly designed trials with results congruent with clinical events trials. In conclusion, when one wants to evaluate the effect of a pharmaceutical intervention that is to be expected to beneficially affect atherosclerosis progression and to reduce CV event risk, the use of CIMT measurements over time is a valid, suitable, and evidence‑based choice.

Determinants of premature atherosclerosis in children with end-stage renal disease

Cardiovascular disease is a major cause of morbidity and mortality in young adults with end-stage renal disease (ESRD), but its basis is still not well understood. We therefore evaluated the determinants of atherosclerosis in children with ESRD. A total of 37 children with ESRD (with 31 who had undergone transplantation) were examined and compared to a control group comprising 22 healthy children. The common carotid intima-media thickness (CIMT) was measured by ultrasound as a marker of preclinical atherosclerosis. The association of CIMT with anthropometrical data, blood pressure, plasma lipid levels, and other biochemical parameters potentially related to cardiovascular disease was evaluated. Children with ESRD had significantly higher CIMT, blood pressure, and levels of lipoprotein (a), urea, creatinine, ferritin, homocysteine, and serum uric acid as well as significantly lower values of apolipoprotein A. The atherogenic index of plasma (log(triglycerides/HDL cholesterol)) was also higher in patients with ESRD; however, this difference reached only borderline significance. In addition, a negative correlation was found between CIMT and serum albumin and bilirubin in the ESRD group, and this correlation was independent of age and body mass index. In the control group, a significant positive correlation was observed between CIMT and ferritin levels. Factors other than traditional cardiovascular properties, such as the anti-oxidative capacity of circulating blood, may be of importance during the early stages of atherosclerosis in children with end-stage renal disease.

Polycystic ovary syndrome and early-onset preeclampsia: reproductive manifestations of increased cardiovascular risk

OBJECTIVE

Primary prevention of cardiovascular disease (CVD) in women is a major healthcare issue. Detection of premenopausal women with increased risk of CVD could enhance prevention strategies and reduce first event-related morbidity and mortality. In this study, we argue that an unfavorable metabolic constitution in women may present itself early in life as a reproductive complication, such as polycystic ovary syndrome (PCOS) and preeclampsia. We evaluated the cardiovascular risk of women with a history of early-onset preeclampsia and women with PCOS and assessed their need for implementation of early risk factor-reduction strategies.

METHODS

We performed a standardized evaluation of 240 women with a history of early-onset preeclampsia and 456 women diagnosed with PCOS for established major CVD risk factors. Metabolic syndrome characteristics were analyzed per body mass index category.

RESULTS

Mean age was 30.6 and 29.0 years for women with preeclampsia and PCOS, respectively. High percentages of metabolic syndrome were found in both groups (preeclampsia group, 14.6%; and PCOS group, 18.4%), with an incidence of greater than 50% in both groups of women if body mass index was greater than 30 kg/m. Overall, more than 90% of the women qualified for either lifestyle or medical intervention according to the American Heart Association guideline for CVD prevention in women.

CONCLUSIONS

Women with PCOS and early-onset preeclampsia already show an unfavorable cardiovascular risk profile with high need for lifestyle or medical intervention at a young age. We therefore recommend an active role of the gynecologist in routine screening and follow-up of women with reproductive conditions linked to future cardiovascular risk.

Long-term exposure to air pollution and vascular damage in young adults

BACKGROUND

Long-term exposure to ambient air pollution has recently been linked to atherosclerosis and cardiovascular events. There are, however, very limited data in healthy young people. We examined the association between air pollutants and indicators of vascular damage in a cohort of young adults.

METHODS

We used data from the Atherosclerosis Risk in Young Adults study. We estimated exposure to nitrogen dioxide (NO2), particulate matter less than 2.5 microm in aerodynamic diameter (PM2.5), black smoke, sulfur dioxide (SO2), and various traffic indicators for participants' 2000 home addresses. Exposure for the year 2000 was estimated by land-use regression models incorporating regional background annual air pollution levels, land-use variables, population densities, and traffic intensities on nearby roads. Outcomes were common carotid artery intima-media thickness (n = 745), aortic pulse wave velocity (n = 524), and augmentation index (n = 729).

RESULTS

Exposure contrasts were substantial for NO2, SO2, and black smoke (5th-95th percentiles = 19.7 to 44.9, 2.5 to 5.2, and 8.6 to 19.4 microg/m3, respectively) and smaller for PM2.5 (16.5 to 19.9 microg/m3). The variability of carotid artery intima-media thickness was less than for pulse wave velocity and especially augmentation index (5-95th percentiles = 0.42 to 0.58 mm, 4.9 to 7.4 m/s and -12.3% to 27.3%, respectively). No associations were found between any of the pollutants or traffic indicators and carotid artery intima-media thickness, although PM2.5 effect estimates were in line with previous studies. We observed a 4.1% (95% confidence interval = 0.1% to 8.0%) increase in pulse wave velocity and a 37.6% (2.2% to 72.9%) increase in augmentation index associated with a 25 microg/m3 increase in NO2, and a 5.3% (0.1% to 10.4%) increase in pulse wave velocity with a 5 microg/m3 increase in SO2. PM2.5 and black smoke were not associated with either of these 2 outcomes.

CONCLUSIONS

Air pollution may accelerate arterial-wall stiffening in young adults. Small outcome variability and lack of residential mobility data may have limited the power to detect an effect on intima-media thickness.

Pulse pressure amplification and risk of cardiovascular disease

BACKGROUND

Whether pulse pressure amplification (PPA) relates to established markers of cardiovascular risk is unknown. The purpose of this study was to investigate the relationship between PPA and cardiovascular risk factors and cardiovascular risk in a population-based sample of 40- to 80-year old men.

METHODS

A cross-sectional, single-center study was performed in 400 men aged 40-80 years. PPA was calculated as a ratio (brachial pulse pressure/central pulse pressure). Detailed information on vascular risk factors was obtained. Aortic pulse wave velocity (PWV) and common carotid intima-media thickness (CIMT), as markers of vascular risk, were measured. We calculated the absolute 10-year risk of coronary heart disease using the Framingham risk score. Regression analysis was used to evaluate the relations under study.

RESULTS

In models adjusted for age, mean arterial pressure (MAP), heart rate, and height, significant inverse relations with PPA were found for waist-to-hip ratio, triglycerides, smoking, pack-years, and hypertension. Furthermore, an increased PPA was significantly inversely related to aortic PWV, common CIMT, and history of symptomatic vascular disease. Finally, the Framingham risk score decreased with increasing PPA.

CONCLUSION

Our study shows that a higher PPA reflects a lower vascular risk in men between 40 and 80 years of age, as shown by a better cardiovascular risk profile, a reduced PWV, common CIMT, and a lower Framingham risk of coronary heart disease.

Birth size and coronary heart disease risk score in young adulthood. The Atherosclerosis Risk in Young Adults (ARYA) study

Data of the Atherosclerosis Risk in Young Adults (ARYA) study were used to investigate the association between birth size and the absolute risk for coronary heart disease in healthy young adults. The cohort study comprises 750 (46.9% men) subjects born between 1970 and 1973. Birth characteristics were obtained from school health records. At young adulthood, blood pressure, anthropometry and fasting lipid levels were measured. Questionnaires were taken about smoking and diabetes. The young adult 10-year risk for coronary heart disease was calculated using the Framingham risk score. The overall 10-year risk for coronary heart disease was 1.6% (standard deviation (SD) 1.9), 3.0% (SD 1.9) in men and 0.3% (SD 0.2) in women. Using linear regression it was shown that a SD lower birth weight (=0.54 kg) was associated with 0.1% greater risk in the overall population (95% confidence interval (CI): -0.19, -0.004). Similarly, a lower ponderal index at birth was associated with an 0.11% higher risk (95% CI: -0.21, -0.002). These relations were stronger in men. Lower birth length was related with an increased risk in women (-0.02% risk/SD birth length; 95% CI: -0.04, 0.0001). These results suggest that small birth size is associated with an increased risk score for coronary artery disease in young adulthood.

Spurious systolic hypertension in young adults; prevalence of high brachial systolic blood pressure and low central pressure and its determinants

OBJECTIVE

To investigate the prevalence and determinants of spurious systolic hypertension (SSH) in a population-based sample of young adults and estimate their 20-year risk of coronary heart disease.

POPULATION AND METHODS

Seven hundred and fifty young adults (352 men and 398 women), aged 26-31 years, from the Atherosclerosis Risk in Young Adults study were studied. Blood pressure levels were measured twice and central (aortic) pressures were derived by applanation tonometry on the radial artery using a generalized transfer function. SSH was defined as brachial systolic blood pressure (SBP) > or = 140 mmHg, brachial diastolic blood pressure (DBP) < 90 mmHg, and central SBP < 124 mmHg for men and < 120 mmHg for women. The Framingham risk score was calculated. Analysis of variance models were used to compare SSH individuals with normotensive and hypertensive males for cardiovascular risk factors.

RESULTS

SSH was diagnosed in 57 men (16.1%; 95% confidence interval, 12.3-20.0) versus only three women (8%; 95% confidence interval, 0-1.6). The female population was excluded from further analysis. Compared with normotensive males, SSH individuals were heavier (88.7 versus 81.8 kg, P < 0.05) had a higher body mass index (25.8 versus 24.2 kg/m, P < 0.01) and significantly higher brachial and central SBP, DBP, pulse pressure, and mean arterial pressure. They had significantly higher pulse pressure amplification. Twenty-year Framingham risk scores based on DBP did not differ significantly between SSH subjects and normotensive individuals (2.72 versus 2.10%, respectively).

CONCLUSION

SSH is predominantly found among young adult men. Apart from weight and body mass index, no other cardiovascular risk factors differed significantly between subjects with SSH and normotension or hypertension. When calculating the 20-year risk of coronary heart disease based on brachial DBP, SSH individuals were at intermediate risk between normotensive and hypertensive participants, but differences were not statistically significant.

Noninvasive Arterial Measurements of Vascular Damage in Healthy Young Adults: Relation to Coronary Heart Disease Risk

PURPOSE

There is an increasing interest in noninvasive measurements of early structural or functional changes in large arteries such as pulse wave velocity (PWV), carotid intima-media thickness (CIMT), and augmentation index (AIx). These measurements may be applied in etiologic or prognostic research. The role of the AIx as a marker of cardiovascular risk has not fully been established. Our aim was to study whether AIx is related to coronary heart disease (CHD) risk and to compare the strength of the relations of AIx, PWV, and CIMT with cardiovascular risk in healthy young adults.

METHODS

Our study included 224 men and 273 women (mean age 28 years, range 27-30 years) from the Atherosclerosis Risk in Young Adults (ARYA) study. Cardiovascular risk profile was determined and CHD risk was estimated using the Framingham risk score. AIx, PWV and CIMT were measured using standard methods. Data were analyzed in strata of gender using linear regression models.

RESULTS

In men, PWV and CIMT were most strongly related to CHD risk. The increase in CHD risk per standard deviation increase in measurement was 0.24%/m/s, 95% CI (0.01;0.33) and 0.32%/mm, 95% CI (0.08;0.55), whereas the AIx was not significantly related to CHD risk (0.09 %/% 95% CI [-0.15;0.33]). In women, AIx, PWV, and CIMT were weakly but significantly related to CHD risk; there was no clear difference between the measurements.

CONCLUSION

In young men, PWV and CIMT are better measures of CHD risk than AIx. In women, AIx, PWV and CIMT estimate CHD risk equally well.

Lower birth weight predicts metabolic syndrome in young adults: the Atherosclerosis Risk in Young Adults (ARYA)-study

OBJECTIVE

To study the relationship between intrauterine growth and the metabolic syndrome, particularly fasting serum lipids in young adulthood.

METHODS

Seven hundred and forty-four young adults aged 26-31 years participated in the ARYA birth cohort. Birth characteristics were available from charts kept by the Municipal Health Service, Utrecht, The Netherlands. Adult medical history and lifestyle information were assessed by questionnaires. Adult anthropometry, blood pressure, fasting plasma glucose, total cholesterol, HDL-cholesterol, triglycerides were measured, and LDL-cholesterol was calculated.

RESULTS

Subjects in the lower tertiles of birth weight (1250-3209 and 3210-3649 g) had higher risks for metabolic syndrome than those in the highest birth weight tertile (3650-5500 g): odds ratio, 1.8; 95% confidence interval (CI) 1.0-3.5 and 1.4; 0.7-2.7, respectively; p for trend = 0.064, adjusted for gender, cardiovascular disease family history and current education. Birth weight was inversely related to systolic blood pressure (linear regression coefficient, -1.9 mmHg/kg birth weight; 95% CI -3.4 to -0.3) and to (log) triglycerides in mmol/L (-0.03/kg birth weight; 95% CI -0.06 to -0.01), adjusted for gender, current body mass index and current education. Birth weight showed inverse relations to diastolic blood pressure, serum glucose, total and LDL cholesterol and positive relations to waist circumference and HDL cholesterol levels, although not statistically significant. Birth length and ponderal index were not related to the metabolic syndrome or lipid profiles.

CONCLUSION

Lower birth weight indicates a higher risk for metabolic syndrome in young adults, particularly through higher serum triglycerides and higher systolic blood pressure.

Alcohol intake and aortic stiffness in young men and women

BACKGROUND

Moderate alcohol consumption has been shown to protect against cardiovascular disease. Aortic stiffness can be regarded as a marker of cardiovascular disease risk. Previously we have shown an inverse to J-shaped association between alcohol intake and aortic stiffness in middle-aged and elderly men and postmenopausal women.

OBJECTIVE

In the present study we examined whether a relation between alcohol intake and aortic stiffness is already present at a younger age.

DESIGN

Cross-sectional data of a cohort study in men and women aged 28 years were analysed stratified by gender (240 men and 283 women).

MEASUREMENTS

Alcohol intake was derived from a questionnaire and aortic stiffness was assessed by pulse-wave velocity measurement.

RESULTS

In women an alcoholic beverage intake of >/=1 glass/day is associated with a 0.36 m/s (95% confidence interval, -0.58 to -0.14) lower pulse-wave velocity compared with non-drinkers. In men alcohol intake is also inversely related to pulse-wave velocity, but this was not significant. These findings were independent of age, blood pressure and heart rate.

CONCLUSIONS

These findings suggest that moderate intake of alcohol may affect vascular stiffness at an early age, notably in women. These findings may be viewed as compatible with a vascular protective effect of alcohol that expresses well before the occurrence of symptomatic cardiovascular disease.

Intrauterine growth retardation in full-term newborn infants with birth weights greater than 2,500 g

Intrauterine growth retardation (IUGR) is an overlooked problem in full-term infants with birth weights greater than 2,500 g. Birth weight less than the 10th percentile underestimates the presence of IUGR. The purpose of this study was to determine the prevalence of IUGR in full-term infants and to identify sociodemographic and maternal characteristics associated with IUGR. The Ohio Department of Health Vital Statistics database was used to obtain data related to sociodemographic and maternal characteristics. The fetal growth ratio (FGR) was used to determine the presence of IUGR. The sample consisted of 1,569 infants with normal ratios and 1,364 infants classified as IUGR. Infants with IUGR were more often male and African American or Asian American. Maternal characteristics associated with IUGR included history of smoking during pregnancy, lower pre-pregnancy weight, lower weight gain during pregnancy, and inadequate prenatal care. IUGR is present in a significant number of full-term infants with birth weights greater than 2,500 g. The long-term effects of IUGR in these infants remain to be determined.

Determinants of augmentation index in young men: the ARYA study

BACKGROUND

There is an increasing interest in the augmentation index (AIx), the proportion of the central pulse pressure resulting from peripheral arterial wave reflection, which has been related to cardiovascular disease risk and mortality. Most of the data on the AIx have been collected in patients with established cardiovascular disease. In contrast, data in the young are scarce. However, as AIx might be used to evaluate cardiovascular disease risk already at an early age, we aimed to study determinants of AIx in a population of healthy young men.

MATERIALS AND METHODS

Three hundred and thirty males (mean age of 28 years) of the Atherosclerosis Risk in Young Adults study (ARYA-study) were studied in this cross sectional, population-based study. Anthropometrics and risk factors for cardiovascular disease were determined and AIx was estimated by radial applanation tonometry. The data were analysed using linear regression models.

RESULTS

Augmentation index was associated with age, height (inverse), heart rate (inverse) and mean arterial pressure (positive). After adjustment for these determinants, smoking (beta = 0.31%/pack years, 95% CI [0.06; 0.55]) and LDL-cholesterol (beta = 1.28%/(mmol L(-1)), 95% CI [0.04; 2.51]) were statistically significant related to AIx.

CONCLUSIONS

This study among young adult males shows that smoking and LDL-cholesterol are positively related to AIx. These findings support the view that AIx may be used as a marker for early vascular damage and cardiovascular disease risk.