Sex-specific effects of naturally occurring variants in the dopamine receptor D2 locus on insulin secretion and type 2 diabetes susceptibility

AIMS

Modulation of dopamine receptor D2 (DRD2) activity affects insulin secretion in both rodents and isolated pancreatic β-cells. We hypothesized that single nucleotide polymorphisms in the DRD2/ANKK1 locus may affect susceptibility to type 2 diabetes in humans.

METHODS

Four potentially functional variants in the coding region of the DRD2/ANKK1 locus (rs1079597, rs6275, rs6277, rs1800497) were genotyped and analysed for type 2 diabetes susceptibility in up to 25 000 people (8148 with type 2 diabetes and 17687 control subjects) from two large independent Dutch cohorts and one Danish cohort. In addition, 340 Dutch subjects underwent a 2-h hyperglycaemic clamp to investigate insulin secretion. Since sexual dimorphic associations related to DRD2 polymorphisms have been previously reported, we also performed a gender-stratified analysis.

RESULTS

rs1800497 at the DRD2/ANKK1 locus was associated with a significantly increased risk for type 2 diabetes in women (odds ratio 1.14 (1.06-1.23); P = 4.1*10⁴) but not in men (odds ratio 1.00 (95% CI 0.93-1.07); P = 0.92) or the combined group. Although rs1800497 was not associated with insulin secretion, we did find another single nucleotide polymorphism in this locus, rs6275, to be associated with increased first-phase glucose-stimulated insulin secretion in women (P = 5.5*10⁴) but again not in men (P = 0.34).

CONCLUSION

The present data identify DRD2/ANKK1 as a potential sex-specific type 2 diabetes susceptibility gene.

Effects of long-term averaging of quantitative blood pressure traits on the detection of genetic associations

Blood pressure (BP) is a heritable, quantitative trait with intraindividual variability and susceptibility to measurement error. Genetic studies of BP generally use single-visit measurements and thus cannot remove variability occurring over months or years. We leveraged the idea that averaging BP measured across time would improve phenotypic accuracy and thereby increase statistical power to detect genetic associations. We studied systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), and pulse pressure (PP) averaged over multiple years in 46,629 individuals of European ancestry. We identified 39 trait-variant associations across 19 independent loci (p < 5 × 10(-8)); five associations (in four loci) uniquely identified by our LTA analyses included those of SBP and MAP at 2p23 (rs1275988, near KCNK3), DBP at 2q11.2 (rs7599598, in FER1L5), and PP at 6p21 (rs10948071, near CRIP3) and 7p13 (rs2949837, near IGFBP3). Replication analyses conducted in cohorts with single-visit BP data showed positive replication of associations and a nominal association (p < 0.05). We estimated a 20% gain in statistical power with long-term average (LTA) as compared to single-visit BP association studies. Using LTA analysis, we identified genetic loci influencing BP. LTA might be one way of increasing the power of genetic associations for continuous traits in extant samples for other phenotypes that are measured serially over time.

Arterial Stiffness Is Associated With Carotid Intraplaque Hemorrhage in the General Population

Objective—

The relation between arterial stiffness and atherosclerosis, and specifically the influence of arterial stiffness on plaque composition, is largely unknown. In a population-based study, we investigated the association between arterial stiffness and the presence and composition of carotid atherosclerotic plaques.

Approach and Results—

Arterial stiffness was measured in 6527 participants (67.0±8.6 years) using aortic pulse wave velocity (PWV). Presence of carotid atherosclerotic plaques was assessed with ultrasound. Subsequently, 1059 subjects with carotid plaques (>2.5 mm) underwent MRI to assess plaque composition (presence of intraplaque hemorrhage, lipid, and calcification). Generalized estimation equation analyses adjusted for age, sex, mean arterial pressure, heart rate, carotid wall thickening, pulse pressure, and traditional cardiovascular risk factors were used to study the association between PWV and the presence and composition of carotid atherosclerotic plaques. In multivariable analysis, higher PWV was independently related to higher prevalence of carotid atherosclerotic plaque on ultrasound (odds ratio for highest quartile of PWV compared with lowest quartile, 1.24 [95% confidence interval, 1.02–1.51]). Furthermore, higher PWV was associated with intraplaque hemorrhage (age- and sex-adjusted odds ratio per SD increase in PWV, 1.20 [1.04–1.38] and calcification, 1.18 [1.03–1.35]), but not with lipid. After adjustment for cardiovascular risk factors, PWV remained significantly associated with intraplaque hemorrhage (1.20 [1.01–1.43]). Additional adjustment for pulse pressure did not materially affect the effect estimate (1.19 [1.00–1.42]).

Conclusions—

Higher PWV is associated with presence and composition of carotid atherosclerotic plaques, in particular with intraplaque hemorrhage. These findings provide further clues for understanding the development of vulnerable atherosclerotic plaque.

Drug-gene interactions and the search for missing heritability: a cross-sectional pharmacogenomics study of the QT interval

Variability in response to drug use is common and heritable, suggesting that genome-wide pharmacogenomics studies may help explain the 'missing heritability' of complex traits. Here, we describe four independent analyses in 33 781 participants of European ancestry from 10 cohorts that were designed to identify genetic variants modifying the effects of drugs on QT interval duration (QT). Each analysis cross-sectionally examined four therapeutic classes: thiazide diuretics (prevalence of use=13.0%), tri/tetracyclic antidepressants (2.6%), sulfonylurea hypoglycemic agents (2.9%) and QT-prolonging drugs as classified by the University of Arizona Center for Education and Research on Therapeutics (4.4%). Drug-gene interactions were estimated using covariable-adjusted linear regression and results were combined with fixed-effects meta-analysis. Although drug-single-nucleotide polymorphism (SNP) interactions were biologically plausible and variables were well-measured, findings from the four cross-sectional meta-analyses were null (Pinteraction>5.0 × 10(-8)). Simulations suggested that additional efforts, including longitudinal modeling to increase statistical power, are likely needed to identify potentially important pharmacogenomic effects.

Comparison of prognosis in unrecognized versus recognized myocardial infarction in men versus women >55 years of age (from the Rotterdam Study)

Unrecognized myocardial infarction (MI) is frequent in the general population. Its prognosis is reported to be at least as unpropitious as that of recognized MI, particularly in men. However, contemporary data with long follow-up are lacking. The aims of this study were to investigate the long-term prognosis of unrecognized MI with respect to all-cause and cause-specific mortality and to investigate possible differences in prognosis by gender. In the population-based Rotterdam Study (2,672 men and 3,862 women), the presence of unrecognized MI and recognized MI was determined at baseline (1990 to 1993). The cohort was followed for nearly 2 decades for all-cause and cause-specific mortality. During 82,268 patient-years of follow-up (median 15.6 years) 3,412 patients died (1,300 from cardiovascular causes). Men and women with recognized and unrecognized MIs had increased total mortality rates compared with those without MIs. Hazard ratios (HRs) for men and women were 1.57 (95% confidence interval [CI] 1.36 to 1.81) and 1.89 (95% CI 1.56 to 2.30) for recognized MI and 1.72 (95% CI 1.43 to 2.07) and 1.36 (95% CI 1.14 to 1.61) for unrecognized MI. Unrecognized MI was associated with increased risks for cardiovascular mortality (men: HR 2.19, 95% CI 1.66 to 2.91; women: HR 1.36, 95% CI 1.03 to 1.81) and noncardiovascular mortality (men: HR 1.47, 95% CI 1.14 to 1.89; women: HR 1.39, 95% CI 1.10 to 1.75). In conclusion, the long-term prognosis of patients with unrecognized MIs is worse compared with those without MIs and applies not only to cardiovascular mortality but also to noncardiovascular mortality. In men, the prognosis is as unfavorable as that of patients with recognized MIs.

Development and validation of an ankle brachial index risk model for the prediction of cardiovascular events

BACKGROUND

The ankle brachial index (ABI) is related to risk of cardiovascular events independent of the Framingham risk score (FRS). The aim of this study was to develop and evaluate a risk model for cardiovascular events incorporating the ABI and FRS.

DESIGN

An analysis of participant data from 18 cohorts in which 24,375 men and 20,377 women free of coronary heart disease had ABI measured and were followed up for events.

METHODS

Subjects were divided into a development and internal validation dataset and an external validation dataset. Two models, comprising FRS and FRS + ABI, were fitted for the primary outcome of major coronary events.

RESULTS

In predicting events in the external validation dataset, C-index for the FRS was 0.672 (95% CI 0.599 to 0.737) in men and 0.578 (95% CI 0.492 to 0.661) in women. The FRS + ABI led to a small increase in C-index in men to 0.685 (95% CI 0.612 to 0.749) and large increase in women to 0.690 (95% CI 0.605 to 0.764) with net reclassification improvement (NRI) of 4.3% (95% CI 0.0 to 7.6%, p = 0.050) and 9.6% (95% CI 6.1 to 16.4%, p < 0.001), respectively. Restricting the FRS + ABI model to those with FRS intermediate 10-year risk of 10 to 19% resulted in higher NRI of 15.9% (95% CI 6.1 to 20.6%, p < 0.001) in men and 23.3% (95% CI 13.8 to 62.5%, p = 0.002) in women. However, incorporating ABI in an improved newly fitted risk factor model had a nonsignificant effect: NRI 2.0% (95% CI 2.3 to 4.2%, p = 0.567) in men and 1.1% (95% CI 1.9 to 4.0%, p = 0.483) in women.

CONCLUSIONS

An ABI risk model may improve prediction especially in individuals at intermediate risk and when performance of the base risk factor model is modest.

Common carotid intima-media thickness does not add to Framingham risk score in individuals with diabetes mellitus: the USE-IMT initiative

AIMS/HYPOTHESIS

The aim of this work was to investigate whether measurement of the mean common carotid intima-media thickness (CIMT) improves cardiovascular risk prediction in individuals with diabetes.

METHODS

We performed a subanalysis among 4,220 individuals with diabetes in a large ongoing individual participant data meta-analysis involving 56,194 subjects from 17 population-based cohorts worldwide. We first refitted the risk factors of the Framingham heart risk score on the individuals without previous cardiovascular disease (baseline model) and then expanded this model with the mean common CIMT (CIMT model). The absolute 10 year risk for developing a myocardial infarction or stroke was estimated from both models. In individuals with diabetes we compared discrimination and calibration of the two models. Reclassification of individuals with diabetes was based on allocation to another cardiovascular risk category when mean common CIMT was added.

RESULTS

During a median follow-up of 8.7 years, 684 first-time cardiovascular events occurred among the population with diabetes. The C statistic was 0.67 for the Framingham model and 0.68 for the CIMT model. The absolute 10 year risk for developing a myocardial infarction or stroke was 16% in both models. There was no net reclassification improvement with the addition of mean common CIMT (1.7%; 95% CI -1.8, 3.8). There were no differences in the results between men and women.

CONCLUSIONS/INTERPRETATION

There is no improvement in risk prediction in individuals with diabetes when measurement of the mean common CIMT is added to the Framingham risk score. Therefore, this measurement is not recommended for improving individual cardiovascular risk stratification in individuals with diabetes.

Genome-wide meta-analysis identifies 11 new loci for anthropometric traits and provides insights into genetic architecture

Approaches exploiting trait distribution extremes may be used to identify loci associated with common traits, but it is unknown whether these loci are generalizable to the broader population. In a genome-wide search for loci associated with the upper versus the lower 5th percentiles of body mass index, height and waist-to-hip ratio, as well as clinical classes of obesity, including up to 263,407 individuals of European ancestry, we identified 4 new loci (IGFBP4, H6PD, RSRC1 and PPP2R2A) influencing height detected in the distribution tails and 7 new loci (HNF4G, RPTOR, GNAT2, MRPS33P4, ADCY9, HS6ST3 and ZZZ3) for clinical classes of obesity. Further, we find a large overlap in genetic structure and the distribution of variants between traits based on extremes and the general population and little etiological heterogeneity between obesity subgroups.

Genetic Loci for Coronary Calcification and Serum Lipids Relate to Aortic and Carotid Calcification

Background—

Atherosclerosis in different vessel beds shares lifestyle and environmental risk factors. It is unclear whether this holds for genetic risk factors. Hence, for the current study genetic loci for coronary artery calcification and serum lipid levels, one of the strongest risk factors for atherosclerosis, were used to assess their relation with atherosclerosis in different vessel beds.

Methods and Results—

From 1987 persons of the population-based Rotterdam Study, 3 single-nucleotide polymorphisms (SNPs) for coronary artery calcification and 132 SNPs for total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol or triglycerides were used. To quantify atherosclerotic calcification as a marker of atherosclerosis, all participants underwent nonenhanced computed tomography of the aortic arch and carotid arteries. Associations between genetic risk scores of the joint effect of the SNPs and of all calcification were investigated. The joint effect of coronary artery calcification–SNPs was associated with larger calcification volumes in all vessel beds (difference in calcification volume per SD increase in genetic risk score: 0.15 [95% confidence interval, 0.11–0.20] in aorta, 0.14 [95% confidence interval, 0.10–0.18] in extracranial carotids, and 0.11 [95% confidence interval, 0.07–0.16] in intracranial carotids). The joint effect of total cholesterol SNPs, low-density lipoprotein SNPs, and of all lipid SNPs together was associated with larger calcification volumes in both the aortic arch and the carotid arteries but attenuated after adjusting for the lipid fraction and lipid-lowering medication.

Conclusions—

The genetic basis for aortic arch and carotid artery calcification overlaps with the most important loci of coronary artery calcification. Furthermore, serum lipids share a genetic predisposition with both calcification in the aortic arch and the carotid arteries, providing novel insights into the cause of atherosclerosis.

Arterial Stiffness and Cerebral Small Vessel Disease

Background and Purpose—

Aging and vascular risk factors contribute to arterial stiffening. Increased arterial stiffness exposes the small vessels in the brain to abnormal flow pulsations and, as such, may contribute to the pathogenesis of cerebral small vessel disease. In a population-based study, we investigated the association between arterial stiffness, as measured by aortic pulse wave velocity (aPWV), and small vessel disease.

Methods—

Overall, 1460 participants (mean age, 58.2 years) underwent aPWV measurement and brain MRI scanning. We calculated aPWV by measuring time differences and distances between pulse waves in the carotid and femoral arteries. Using automated MRI analysis, we obtained white matter lesion volumes. Infarcts and microbleeds were rated visually. We used linear and logistic regression models to associate aPWV with small vessel disease, adjusting for age, sex, mean arterial pressure, and heart rate and additionally for cardiovascular risk factors. Subsequently, we explored associations in strata of hypertension.

Results—

In the study group, higher aPWV was associated with larger white matter lesion volume (difference in volume per SD increase in aPWV 0.07; 95% CI, 0.02–0.12) but not with lacunar infarcts or microbleeds. In persons with uncontrolled hypertension, higher aPWV was significantly associated with larger white matter lesion volume (difference in volume per SD increase in aPWV 0.09; 95% CI, 0.00–0.18), deep or infratentorial microbleeds (OR, 2.13; 95% CI, 1.16–3.91), and to a lesser extent also with lacunar infarcts (OR, 1.63; 95% CI, 0.98–2.70). No such associations were present in persons with controlled hypertension or without hypertension.

Conclusions—

In our study, increased arterial stiffness is associated with a larger volume of white matter lesions.

A genome-wide approach accounting for body mass index identifies genetic variants influencing fasting glycemic traits and insulin resistance

Recent genome-wide association studies have described many loci implicated in type 2 diabetes (T2D) pathophysiology and β-cell dysfunction but have contributed little to the understanding of the genetic basis of insulin resistance. We hypothesized that genes implicated in insulin resistance pathways might be uncovered by accounting for differences in body mass index (BMI) and potential interactions between BMI and genetic variants. We applied a joint meta-analysis approach to test associations with fasting insulin and glucose on a genome-wide scale. We present six previously unknown loci associated with fasting insulin at P < 5 × 10(-8) in combined discovery and follow-up analyses of 52 studies comprising up to 96,496 non-diabetic individuals. Risk variants were associated with higher triglyceride and lower high-density lipoprotein (HDL) cholesterol levels, suggesting a role for these loci in insulin resistance pathways. The discovery of these loci will aid further characterization of the role of insulin resistance in T2D pathophysiology.

Coronary Artery Calcification in Hemophilia A

Objective—

Ischemic heart disease mortality is lower in hemophilia patients than in the general male population. As coagulation plays a role in the inflammatory pathways involved in atherogenesis, we investigated whether the clotting factor deficiency protects hemophilia patients from developing atherosclerosis.

Methods and Results—

Coronary artery calcification, measured with multidetector-row computed tomography, was compared between 42 men, ≥59 years, with severe or moderate hemophilia A, and 613 nonhemophilic men from the Rotterdam Study, a prospective population-based study. None of the study subjects were HIV infected or had a history of cardiovascular disease. Coronary artery calcification was quantified by calculating the Agatston score and calcification mass. Data were analyzed using linear regression. Mean difference (β) of the natural log–transformed Agatston score between men with and without hemophilia was 0.141 (95% CI −0.602 to 0.885, P =0.709). Results did not change after adjustment for age, body mass index, hypercholesterolemia, hypertension, and use of antidiabetic medication (β=0.525, 95% CI −0.202 to 1.252, P =0.157). Comparable results were found for calcification mass.

Conclusion—

The extent of coronary artery atherosclerosis is comparable between elderly men with and without hemophilia. Results from this study underline the importance of screening and treating atherosclerosis risk factors in hemophilia patients.

Eight genetic loci associated with variation in lipoprotein-associated phospholipase A2 mass and activity and coronary heart disease: meta-analysis of genome-wide association studies from five community-based studies

AIMS

Lipoprotein-associated phospholipase A2 (Lp-PLA2) generates proinflammatory and proatherogenic compounds in the arterial vascular wall and is a potential therapeutic target in coronary heart disease (CHD). We searched for genetic loci related to Lp-PLA2 mass or activity by a genome-wide association study as part of the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium.

METHODS AND RESULTS

In meta-analyses of findings from five population-based studies, comprising 13 664 subjects, variants at two loci (PLA2G7, CETP) were associated with Lp-PLA2 mass. The strongest signal was at rs1805017 in PLA2G7 [P = 2.4 × 10(-23), log Lp-PLA2 difference per allele (beta): 0.043]. Variants at six loci were associated with Lp-PLA2 activity (PLA2G7, APOC1, CELSR2, LDL, ZNF259, SCARB1), among which the strongest signals were at rs4420638, near the APOE-APOC1-APOC4-APOC2 cluster [P = 4.9 × 10(-30); log Lp-PLA2 difference per allele (beta): -0.054]. There were no significant gene-environment interactions between these eight polymorphisms associated with Lp-PLA2 mass or activity and age, sex, body mass index, or smoking status. Four of the polymorphisms (in APOC1, CELSR2, SCARB1, ZNF259), but not PLA2G7, were significantly associated with CHD in a second study.

CONCLUSION

Levels of Lp-PLA2 mass and activity were associated with PLA2G7, the gene coding for this protein. Lipoprotein-associated phospholipase A2 activity was also strongly associated with genetic variants related to low-density lipoprotein cholesterol levels.

Total zinc intake may modify the glucose-raising effect of a zinc transporter (SLC30A8) variant: a 14-cohort meta-analysis

OBJECTIVE

Many genetic variants have been associated with glucose homeostasis and type 2 diabetes in genome-wide association studies. Zinc is an essential micronutrient that is important for β-cell function and glucose homeostasis. We tested the hypothesis that zinc intake could influence the glucose-raising effect of specific variants.

RESEARCH DESIGN AND METHODS

We conducted a 14-cohort meta-analysis to assess the interaction of 20 genetic variants known to be related to glycemic traits and zinc metabolism with dietary zinc intake (food sources) and a 5-cohort meta-analysis to assess the interaction with total zinc intake (food sources and supplements) on fasting glucose levels among individuals of European ancestry without diabetes.

RESULTS

We observed a significant association of total zinc intake with lower fasting glucose levels (β-coefficient ± SE per 1 mg/day of zinc intake: -0.0012 ± 0.0003 mmol/L, summary P value = 0.0003), while the association of dietary zinc intake was not significant. We identified a nominally significant interaction between total zinc intake and the SLC30A8 rs11558471 variant on fasting glucose levels (β-coefficient ± SE per A allele for 1 mg/day of greater total zinc intake: -0.0017 ± 0.0006 mmol/L, summary interaction P value = 0.005); this result suggests a stronger inverse association between total zinc intake and fasting glucose in individuals carrying the glucose-raising A allele compared with individuals who do not carry it. None of the other interaction tests were statistically significant.

CONCLUSIONS

Our results suggest that higher total zinc intake may attenuate the glucose-raising effect of the rs11558471 SLC30A8 (zinc transporter) variant. Our findings also support evidence for the association of higher total zinc intake with lower fasting glucose levels.

Biological, clinical and population relevance of 95 loci for blood lipids

Plasma concentrations of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides are among the most important risk factors for coronary artery disease (CAD) and are targets for therapeutic intervention. We screened the genome for common variants associated with plasma lipids in >100,000 individuals of European ancestry. Here we report 95 significantly associated loci (P < 5 x 10(-8)), with 59 showing genome-wide significant association with lipid traits for the first time. The newly reported associations include single nucleotide polymorphisms (SNPs) near known lipid regulators (for example, CYP7A1, NPC1L1 and SCARB1) as well as in scores of loci not previously implicated in lipoprotein metabolism. The 95 loci contribute not only to normal variation in lipid traits but also to extreme lipid phenotypes and have an impact on lipid traits in three non-European populations (East Asians, South Asians and African Americans). Our results identify several novel loci associated with plasma lipids that are also associated with CAD. Finally, we validated three of the novel genes-GALNT2, PPP1R3B and TTC39B-with experiments in mouse models. Taken together, our findings provide the foundation to develop a broader biological understanding of lipoprotein metabolism and to identify new therapeutic opportunities for the prevention of CAD.

A prospective analysis of elevated fasting glucose levels and cognitive function in older people: results from PROSPER and the Rotterdam Study

OBJECTIVE

To investigate the relationship between fasting glucose levels, insulin resistance, and cognitive impairment in old age. Diabetes is associated with cognitive impairment in older people. However, the link between elevated fasting glucose levels and insulin resistance in nondiabetic individuals, and the risk of cognitive impairment is unclear.

RESEARCH DESIGN AND METHODS

We analyzed data from, in total, 8,447 participants in two independent prospective studies: the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER), 5,019 participants, aged 69-84 years, and the Rotterdam Study, 3,428 participants, aged 61-97 years. Fasting glucose levels were assessed at baseline in both studies; fasting insulin levels were assessed in the Rotterdam Study only. Cognitive function was assessed in both studies at baseline and during follow-up.

RESULTS

Subjects with diabetes had impaired cognitive function at baseline. In contrast, in people without a history of diabetes, there was no clear association between baseline fasting glucose levels and executive function and memory, nor was there a consistent relationship between elevated baseline fasting glucose levels and the rate of cognitive decline in either cohort. Insulin resistance (homeostasis model assessment index) was also unrelated to cognitive function and decline.

CONCLUSIONS

Elevated fasting glucose levels and insulin resistance are not associated with worse cognitive function in older people without a history of diabetes. These data suggest either that there is a threshold for effects of dysglycemia on cognitive function or that factors other than hyperglycemia contribute to cognitive impairment in individuals with frank diabetes.

A high menaquinone intake reduces the incidence of coronary heart disease

BACKGROUND AND AIM

Vitamin K dependent proteins have been demonstrated to inhibit vascular calcification. Data on the effect of vitamin K intake on coronary heart disease (CHD) risk, however, are scarce. To examine the relationship between dietary vitamins K(1) and K(2) intake, and its subtypes, and the incidence of CHD.

METHODS AND RESULTS

We used data from the Prospect-EPIC cohort consisting of 16,057 women, enrolled between 1993 and 1997 and aged 49-70 years, who were free of cardiovascular diseases at baseline. Intake of vitamin K and other nutrients was estimated with a food frequency questionnaire. Multivariate Cox proportional hazards models were used to analyse the data. After a mean+/-SD follow-up of 8.1+/-1.6 years, we identified 480 incident cases of CHD. Mean vitamin K(1) intake was 211.7+/-100.3 microg/d and vitamin K(2) intake was 29.1+/-12.8 microg/d. After adjustment for traditional risk factors and dietary factors, we observed an inverse association between vitamin K(2) and risk of CHD with a Hazard Ratio (HR) of 0.91 [95% CI 0.85-1.00] per 10 microg/d vitamin K(2) intake. This association was mainly due to vitamin K(2) subtypes MK-7, MK-8 and MK-9. Vitamin K(1) intake was not significantly related to CHD.

CONCLUSIONS

A high intake of menoquinones, especially MK-7, MK-8 and MK-9, could protect against CHD. However, more research is necessary to define optimal intake levels of vitamin K intake for the prevention of CHD.

Cigarette smoking and risk of atrial fibrillation: the Rotterdam Study

BACKGROUND

Cigarette smoking is an important risk factor for cardiovascular disease, but it is unknown whether it also contributes to the risk of atrial fibrillation.

METHODS AND RESULTS

The study is part of the Rotterdam Study, a population-based cohort study among subjects aged > or =55 years. The association between cigarette smoking and the risk of atrial fibrillation was examined in 5,668 subjects without atrial fibrillation at baseline. During a median follow-up of 7.2 years, 371 cases of atrial fibrillation were identified. Relative risks (RR) were calculated with 95% CIs using the Cox proportional hazards model, adjusted for age, gender, body mass index, hypertension, systolic blood pressure, serum cholesterol level, diabetes mellitus, left ventricular hypertrophy on the electrocardiogram, prevalent and incident myocardial infarction, prevalent heart failure, and the use of pulmonary medication. After multivariate adjustment, current smokers and former smokers had increased risks of atrial fibrillation as compared to never smokers (RR 1.51, 95% CI 1.07-2.12; and RR 1.49, 95% CI 1.14-1.97, respectively). No differences were found between men and women.

CONCLUSIONS

The results of this prospective, population-based study show that current and former smoking of cigarettes are associated with increased risk of atrial fibrillation.

Ankle brachial index combined with Framingham Risk Score to predict cardiovascular events and mortality: a meta-analysis

CONTEXT

Prediction models to identify healthy individuals at high risk of cardiovascular disease have limited accuracy. A low ankle brachial index (ABI) is an indicator of atherosclerosis and has the potential to improve prediction.

OBJECTIVE

To determine if the ABI provides information on the risk of cardiovascular events and mortality independently of the Framingham risk score (FRS) and can improve risk prediction.

DATA SOURCES

Relevant studies were identified. A search of MEDLINE (1950 to February 2008) and EMBASE (1980 to February 2008) was conducted using common text words for the term ankle brachial index combined with text words and Medical Subject Headings to capture prospective cohort designs. Review of reference lists and conference proceedings, and correspondence with experts was conducted to identify additional published and unpublished studies.

STUDY SELECTION

Studies were included if participants were derived from a general population, ABI was measured at baseline, and individuals were followed up to detect total and cardiovascular mortality.

DATA EXTRACTION

Prespecified data on individuals in each selected study were extracted into a combined data set and an individual participant data meta-analysis was conducted on individuals who had no previous history of coronary heart disease.

RESULTS

Sixteen population cohort studies fulfilling the inclusion criteria were included. During 480,325 person-years of follow-up of 24,955 men and 23,339 women, the risk of death by ABI had a reverse J-shaped distribution with a normal (low risk) ABI of 1.11 to 1.40. The 10-year cardiovascular mortality in men with a low ABI (< or = 0.90) was 18.7% (95% confidence interval [CI], 13.3%-24.1%) and with normal ABI (1.11-1.40) was 4.4% (95% CI, 3.2%-5.7%) (hazard ratio [HR], 4.2; 95% CI, 3.3-5.4). Corresponding mortalities in women were 12.6% (95% CI, 6.2%-19.0%) and 4.1% (95% CI, 2.2%-6.1%) (HR, 3.5; 95% CI, 2.4-5.1). The HRs remained elevated after adjusting for FRS (2.9 [95% CI, 2.3-3.7] for men vs 3.0 [95% CI, 2.0-4.4] for women). A low ABI (< or = 0.90) was associated with approximately twice the 10-year total mortality, cardiovascular mortality, and major coronary event rate compared with the overall rate in each FRS category. Inclusion of the ABI in cardiovascular risk stratification using the FRS would result in reclassification of the risk category and modification of treatment recommendations in approximately 19% of men and 36% of women.

CONCLUSION

Measurement of the ABI may improve the accuracy of cardiovascular risk prediction beyond the FRS.

Coffee Consumption and Coronary Calcification

Background— The role of coffee in the cardiovascular system is not yet clear. We examined the relation of coffee intake with coronary calcification in a population-based cohort.

Methods and Results— The study involved 1570 older men and women without coronary heart disease who participated in the Rotterdam Study. Coffee intake was assessed with a semiquantitative food frequency questionnaire. Coronary calcification was detected with electron beam computed tomography. Severe calcification was defined as an Agatson calcium score >400. Sex-specific odds ratios (ORs) with 95% confidence intervals (95% CI) were obtained by logistic regression with adjustment for age, smoking, body mass index, education, and intake of energy and alcohol. In multivariable analysis, coronary calcification in women was significantly reduced for moderate (>3 to 4 cups) and high (>4 cups) coffee intake, compared with a daily intake of 3 cups or less (OR of 0.41 [95% CI: 0.25 to 0.65] and 0.54 [0.33 to 0.87], respectively). The association persisted after additional adjustment for tea and other dietary confounders, and was not modified by smoking. A nonsignificant inverse relationship was also found in men who smoked, whereas in nonsmoking men a direct association was observed.

Conclusion— The present study suggests a beneficial effect of coffee drinking against coronary calcification, particularly in women. More research is needed to confirm these findings and to clarify possible effect modification by gender and smoking.

Polymorphisms of the renin-angiotensin system are associated with blood pressure, atherosclerosis and cerebral white matter pathology

BACKGROUND

The renin-angiotensin system is involved in the development of hypertension, atherosclerosis and cardiovascular disease. We studied the association between the M235T polymorphism of the angiotensinogen gene (AGT) and the C573T polymorphism of the angiotensin II type 1 receptor (AT1R) and blood pressure, carotid atherosclerosis and cerebrovascular disease.

METHODS

We genotyped over 6000 subjects from the Rotterdam Study and more than 1000 subjects from the Rotterdam Scan Study. We used logistic regression and univariate analyses, adjusting for age and sex with, for AGT, the MM and, for AT1R, the TT genotype as reference.

RESULTS

We found that AGT-235T increased systolic (p for trend = 0.03) and diastolic blood pressure (p for trend = 0.04). The prevalence of carotid plaques was increased 1.25-fold (95% CI 1.02-1.52) in AGT-TT carriers. There was a significant increase in mean volume deep subcortical white matter lesions (WML) for AGT-TT carriers (1.78 ml vs 1.09 ml in the reference group; p = 0.008). A significant interaction was found between AGT and AT1R, further increasing the effect on periventricular and subtotal WML (p for interaction = 0.02). We found a non-significant increased risk of silent brain infarction for AGT-TT carriers and AT1R-CC carriers, but no effect on stroke.

CONCLUSION

We found an association between AGT and blood pressure, atherosclerosis and WML. Also, we found synergistic effects between AGT and AT1R on the development of WML. These findings raise the question of whether the renin-angiotensin system may be a therapeutic target for the prevention of cerebral white matter pathology.

A comparison of body mass index, waist-hip ratio and waist circumference as predictors of all-cause mortality among the elderly: the Rotterdam study

OBJECTIVE

To compare body mass index (BMI), waist-hip ratio (WHR) and waist circumference as predictors of all-cause mortality among the elderly.

DESIGN

Population-based cohort study; mean follow-up was 5.4 y.

SETTING

The Rotterdam Study.

PARTICIPANTS

A total of 6296 men and women; baseline age 55-102 y.

MEASUREMENTS

Sex-specific all-cause mortality was compared between quintiles of BMI, WHR and waist circumference and between predefined categories of BMI and waist circumference, stratified for smoking category.

RESULTS

High quintiles of waist circumference, but not high quintiles of BMI and WHR were related to increased mortality among never smoking men, without reaching statistical significance. Only the highest category of BMI (BMI>30 kg/m2) among never smoking men was related to increased mortality, compared to normal BMI (hazard ratio 2.6 (95% confidence interval: 1.3-5.3)). Waist circumference between 94 and 102 cm and waist circumference 102 cm and larger were related to increased mortality, compared to normal waist circumference (hazard ratios 1.7 (95% confidence interval 1.1-2.8) and 1.6 (95% confidence interval 1.0-2.8), respectively). The proportion of mortality attributable to large waist circumference among never smoking men was three-fold the proportion attributable to high BMI. Among never smoking women and ex- and current smokers, categories of large body fatness did not predict increased mortality.

CONCLUSION

Among never smoking elderly men waist circumference may have more potential for detecting overweight than the BMI.

Parity and carotid artery atherosclerosis in elderly women: The Rotterdam Study

BACKGROUND AND PURPOSE

It has been postulated that physiological changes in the cardiovascular system, lipids, and glucose metabolism during pregnancy may increase subsequent risk of cardiovascular disease. Examination of the association between parity and risk factors for atherosclerosis may contribute information regarding possible mechanisms.

METHODS

The relationship of parity with cardiovascular risk factors and the presence of carotid atherosclerosis was examined in the Rotterdam Study, a population-based study comprising 4878 women aged 55 years and older. Carotid atherosclerosis was assessed by ultrasonographic detection of plaques in the common carotid artery and bifurcation. Logistic regression models were used to compute odds ratios and 95% confidence intervals, adjusted for confounding factors.

RESULTS

Parity was inversely associated with high-density lipoprotein cholesterol, and alcohol intake. Parity was positively associated with body mass index, total/HDL cholesterol ratio, insulin resistance, age at menopause, and socioeconomic status. Relative to nulliparous women, parous women had 36% (9% to 71%) greater risk of carotid atherosclerosis, rising to 64% in women with >/=4 children (19% to 127%). Adjustment for known cardiovascular risk factors, including insulin resistance and current lipid levels, did not diminish the magnitude of this association.

CONCLUSIONS

Data demonstrated that there is a positive association between parity and risk of carotid artery plaques in elderly women and, further, that high parity is associated with lower HDL cholesterol levels and higher glucose/insulin ratios long after childbearing has ceased.

The effect of hormone replacement therapy on serum homocysteine levels in perimenopausal women: a randomized controlled trial

Serum homocysteine levels may be lowered by hormone replacement therapy, but randomized controlled trial data are scarce. We performed a single center randomized placebo-controlled trial to assess the 6 months effect of hormone replacement therapy compared with placebo on fasting serum homocysteine levels in 121 perimenopausal women free of cardiovascular disease, and recruited from the general population. The trial was double-blind with respect to a sequential combined regimen of oral 17 beta-estradiol and desogestrel (17 beta E(2)-D) and the placebo group and open with respect to a combination of conjugated equine estrogens and norgestrel (CEE-N). At baseline and after 6 months, fasting serum homocysteine levels were measured. Differences in 6 months serum homocysteine levels from baseline between treatment and placebo groups were calculated, and expressed as a percentage of the 6 months placebo level. After 6 months, the difference in serum homocysteine levels between women receiving 17 beta E(2)-D and placebo was -6.3% (95% CI, -12.4%; 0.0%, P=0.06). The difference between women receiving CEE-N and placebo was -10.1% (95% CI, -16.7%; -2.9%, P<0.01). The difference between the combined group of both types of hormone replacement therapy users and placebo was -7.8% (95% CI, -13.2%; -2.0%, P=0.01). No significant difference was observed between the two active regimens. Our results indicate that hormone replacement therapy decreases homocysteine levels in perimenopausal women.

Effect of hormone replacement therapy on lipids in perimenopausal and early postmenopausal women

OBJECTIVE

To determine the effects of oral sequential hormone replacement therapy (HRT) on lipid-profile in perimenopausal and early postmenopausal women.

METHODS

We performed a single-center, randomized, placebo-controlled trial. The trial was double blind with respect to 17beta-estradiol/desogestrel (17beta-E-D) and placebo and open with respect to conjugated estrogens/norgestrel (CEE-N). A total of 125 healthy perimenopausal and early postmenopausal women, aged 43-58 years, were recruited from the general population in Zoetermeer, the Netherlands. The intervention consisted of 6 months treatment with 1.5 mg 17beta-estradiol/0.15 mg desogestrel (n=53), 0.625 mg conjugated estrogens/0.15 mg norgestrel (n=36) or placebo (n=36). At baseline, cycle 1, 3 and 6, overnight fasting blood samples were obtained in which lipids were determined. We used linear regression analysis to calculate differences in mean change from baseline in lipids in the active treatment groups compared to placebo.

RESULTS

In both treatment groups significant (P<0.05) falls in low-density-lipoprotein (LDL)-cholesterol (17beta-E-D: -7.8% and CEE-N: -8.4%) and lipoprotein(a) (17beta-E-D: -11.7% and CEE-N: -28.3%) were found compared to placebo. Apolipoprotein A1 (17beta-E-D: 6.8% and CEE-N: 7.3%) and HDL-cholesterol (17beta-E-D: 6.4% and CEE-N: 8.0%) significantly increased compared to placebo. No significant changes were found in the other lipids. Mean changes from baseline in total cholesterol, LDL-cholesterol and apolipoprotein B were significantly more pronounced in postmenopausal women compared to perimenopausal women, adjustment for age-differences did not change the results.

CONCLUSION

Treatment of perimenopausal and early postmenopausal women with 17beta-E-D or CEE-N changes their lipid-profile in a potentially anti-atherogenic direction. Changes appear to be more pronounced in postmenopausal women compared to perimenopausal women.

Markers of inflammation and cellular adhesion molecules in relation to insulin resistance in nondiabetic elderly: the Rotterdam study

Insulin resistance, which is highly prevalent in the elderly, is suggested to be accompanied by an increased acute phase response. Until now, it is unclear whether cellular adhesion molecules are involved in the clustering of insulin resistance. In the present study, we examined the relationship of insulin resistance (measured by postload insulin) with levels of markers of inflammation and cellular adhesion molecules in a random sample of 574 nondiabetic elderly men and women participating in the Rotterdam Study. Associations were assessed by regression analysis, with ln-insulin as the dependent variable [regression coefficient (95% confidence interval)]. In our population, insulin was strongly and significantly (P < 0.001) associated with the markers of inflammation C-reactive protein [1.52 (0.96-2.08)], alpha-1-antichymotrypsin [1.25 (0.82-1.69)], and IL-6 [2.60 (1.69-3.52)], adjusted for age and gender. Associations weakened, to some extent, after additional adjustment for measures of obesity, smoking, and cardiovascular disease. Insulin was associated with the soluble intercellular adhesion molecule 1 [2.22 (1.29-3.16; P < 0.001)], whereas no association with the soluble vascular cell adhesion molecule 1 was found. The strength of the associations of insulin with C-reactive protein, alpha-1-antichymotrypsin, IL-6, and soluble intercellular adhesion molecule 1, as assessed by standardized regression coefficients, was comparable with the strength of the associations of insulin with high-density lipoprotein cholesterol, body mass index, and waist-to-hip ratio. The results of this population-based study indicate that low-grade inflammation and the cellular adhesion molecule soluble intercellular adhesion molecule 1 are an integral part of insulin resistance in nondiabetic elderly. These factors may contribute to the well-known relationship between insulin resistance and cardiovascular disease risk and might potentially become therapeutic targets in insulin resistant subjects.

Apolipoprotein E and carotid artery atherosclerosis: the Rotterdam study

BACKGROUND AND PURPOSE

Carotid artery atherosclerosis is a strong predictor for future stroke. It is yet unclear whether the apolipoprotein E polymorphism (APOE) is related to atherosclerosis in the carotid arteries. The aim of the present study was to investigate the role of APOE in carotid artery atherosclerosis.

METHODS

A population-based cross-sectional study was performed on 5401 subjects. Atherosclerosis was noninvasively assessed by the common carotid artery intima-media wall thickness and the presence of plaques in the carotid arteries. The relationship of the 6 APOE genotypes with these 2 indicators was studied with linear and logistic regression analysis, respectively, with adjustments for age and sex.

RESULTS

Carriers of the E2E3 genotype had a thinner intima-media wall thickness (mean difference, -0.02 mm; 95% CI, -0.03 to -0.01 mm) and fewer plaques (odds ratio for >3 plaques at 6 sites, 0.6; 95% CI, 0.4 to 0.8) than the most common group, E3E3. The E4E4 group had slightly more atherosclerosis, but this was not statistically significant. Adjusting for the level of the apolipoprotein E protein (apoE) in serum or total or HDL cholesterol did not essentially change these findings.

CONCLUSIONS

Our results suggest that APOE*4 is not an important risk factor for carotid artery atherosclerosis. The inverse relationship of E2E3 with carotid artery atherosclerosis seems to be independent of serum apoE and total and HDL cholesterol levels. However, the low frequency, together with the small effects, implies that any protective effect of E2E3 on carotid artery atherosclerosis is limited.

Is open-angle glaucoma associated with early menopause? The Rotterdam Study

The authors examined the association between age at menopause and open-angle glaucoma among women aged > or = 55 years in the population-based Rotterdam Study (1990--1993). Information on age and type of menopause was obtained by interview. Subjects (n = 3,078) were stratified into three categories according to age at menopause: <45 years, 45--49 years, and > or = 50 years, with the last group serving as the reference group. Diagnosis of open-angle glaucoma was based on the presence of a glaucomatous visual field defect and glaucomatous optic neuropathy. Open-angle glaucoma was diagnosed in 78 women with a natural menopause and 15 women with an artificial menopause. In the category of natural menopause, women who went through menopause before reaching the age of 45 years had a higher risk of open-angle glaucoma than the reference group (odds ratio = 2.6; 95% confidence interval: 1.5, 4.8), after adjustment for age and use of hormone replacement therapy. Among women who went through menopause between the ages of 45 and 49 years, the odds ratio was 1.1 (95% confidence interval: 0.7, 2.0). These findings suggest that early menopause is associated with a higher risk of open-angle glaucoma.

Dietary antioxidants and peripheral arterial disease : the Rotterdam Study

This study examined cross-sectionally the association of dietary beta-carotene, vitamin C, and vitamin E with peripheral arterial disease in Rotterdam, the Netherlands (1990--1993). The 4,367 subjects from the Rotterdam Study were aged 55--94 years and had no previous cardiovascular disease at baseline. Diet was assessed with a food frequency questionnaire. Peripheral arterial disease was defined as an ankle-arm systolic blood pressure index (AAI) of < or = 0.9 and was present in 204 men and 370 women. In multivariate-adjusted logistic regression analyses, vitamin C intake was significantly inversely associated with peripheral arterial disease in women (highest vs. lowest quartile: relative risk = 0.64, 95% confidence interval (CI): 0.48, 0.89; p(trend) = 0.006), and a 100-mg increase in intake was associated with a 0.013 AAI increase (95% CI: 0.001, 0.025). In men, vitamin E intake was inversely associated with peripheral arterial disease (relative risk = 0.67, 95% CI: 0.44, 1.03; p(trend) = 0.067); a 10-mg increase in intake was associated with a 0.015 AAI increase (95% CI: 0.001, 0.031). Whether these differences in antioxidant intake and the risk of a low AAI and of peripheral arterial disease between sexes are attributable to a different food pattern for men compared with women remains to be elucidated.

Is carotid intima-media thickness useful in cardiovascular disease risk assessment? The Rotterdam Study

BACKGROUND AND PURPOSE

We determined the contribution of common carotid intima-media thickness (IMT) in the prediction of future coronary heart disease and cerebrovascular disease when added to established risk factors.

METHODS

We used data from a nested case-control study comprising 374 subjects with either an incident stroke or a myocardial infarction and 1496 controls. All subjects were aged 55 years and older and participated in the Rotterdam Study. Mean follow-up was 4.2 years (range, 0.1 to 6.5 years). We evaluated which correlates of coronary heart disease and cerebrovascular disease contribute to the prediction of either a new incident myocardial infarction or a stroke. Logistic regression modeling and the area under the receiver operating characteristic curve (ROC area) were used to quantify the predictive value of the established risk factors and the added value of IMT.

RESULTS

The ROC area of a model with age and sex only was 0.65 (95% CI, 0.62 to 0.69). Independent risk factors were previous myocardial infarction and stroke, diabetes mellitus, smoking, systolic blood pressure, diastolic blood pressure, and total and HDL cholesterol levels. These risk factors increased the ROC area from 0.65 to 0.72 (95% CI, 0.69 to 0.75). This model correctly predicted 17% of all subjects with coronary heart disease and cerebrovascular disease. When common carotid IMT was added to the previous model, the ROC area increased to 0.75 (95% CI, 0.72 to 0.78). When only the IMT measurement was used, the ROC area was 0.71 (95% CI, 0.68 to 0.74), and 14% of all subjects were correctly predicted. There was no difference in ROC area when different measurement sites were used.

CONCLUSIONS

Adding IMT to a risk function for coronary heart disease and cerebrovascular disease does not result in a substantial increase in the predictive value when used as a screening tool.

Reproductive period and risk of dementia in postmenopausal women

CONTEXT

Exogenous estrogen use may lower risk of dementia in postmenopausal women. A relationship between long-term exposure to endogenous estrogens and incident dementia has been hypothesized but not studied.

OBJECTIVE

To determine whether a longer reproductive period, as an indicator of longer exposure to endogenous estrogens, is associated with lower risk of dementia and Alzheimer disease (AD) in women who have natural menopause.

DESIGN AND SETTING

The Rotterdam Study, a population-based prospective cohort study conducted in the Netherlands.

PARTICIPANTS

A total of 3601 women aged 55 years or older who did not have dementia at baseline (1990-1993) and had information on age at menarche, age at menopause, and type of menopause. Participants were reexamined in 1993-1994 and 1997-1999 and were continuously monitored for development of dementia.

MAIN OUTCOME MEASURES

Incidence of dementia, based on Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition criteria, and AD, based on National Institute of Neurological Disorders and Stroke/Alzheimer's Disease and Related Disorders Association criteria, compared by quartiles of reproductive period among women with natural menopause.

RESULTS

During 21 046 person-years of follow-up (median follow-up, 6.3 years), 199 women developed dementia, including 159 who developed AD. After adjusting for age, dementia was not clearly associated with length of reproductive period. However, after adjusting for multiple covariates, women with natural menopause and more reproductive years had an increased risk of dementia (adjusted rate ratio [RR] for women with >39 reproductive years [highest quartile] compared with <34 reproductive years [lowest quartile], 1.78; 95% confidence interval [CI], 1.12-2.84). The adjusted RR per year of increase was 1.04 (95% CI, 1.01-1.08). For risk of AD, the adjusted RRs were 1.51 (95% CI, 0.91-2.50) and 1.03 (95% CI, 1.00-1.07), respectively. Risk of dementia associated with a longer reproductive period was most pronounced in APOE epsilon4 carriers (adjusted RR for >39 reproductive years compared with <34 reproductive years, 4.20 [95% CI, 1.97-8.92] for dementia and 3.42 [95% CI, 1.51-7.75] for AD), whereas in noncarriers, no clear association with dementia or AD was observed.

CONCLUSION

Our findings do not support the hypothesis that a longer reproductive period reduces risk of dementia in women who have natural menopause.

A polymorphism in the gene for IGF-I: functional properties and risk for type 2 diabetes and myocardial infarction

Evidence is accumulating that low levels of IGF-I play a role in the pathogenesis of type 2 diabetes and cardiovascular diseases. We examined the role of a genetic polymorphism in the promoter region of the IGF-I gene in relation to circulating IGF-I levels and growth measured as body height, and we studied the relationship of this polymorphism with type 2 diabetes and myocardial infarction. The relation between the IGF-I polymorphism and body height was assessed in a population-based sample of 900 subjects from the Rotterdam Study. Within each genotype stratum, 50 subjects were randomly selected for a study of the relation of this polymorphism with serum IGF-I levels. To assess the risk for type 2 diabetes, we studied 220 patients and 596 normoglycemic control subjects. For myocardial infarction, 477 patients with evidence of myocardial infarction on electrocardiogram and 808 control subjects were studied. A 192-bp allele was present in 88% of the population, suggesting that this is the wild-type allele from which all other alleles originated. Body height was, on average, 2.7 cm lower (95% CI for difference -4.6 to -0.8 cm, P = 0.004), and serum IGF-I concentrations were 18% lower (95% CI for difference -6.0 to -1.3 mmol/l, P = 0.003) in subjects who did not carry the 192-bp allele. In noncarriers of the 192-bp allele, an increased relative risk for type 2 diabetes (1.7 [95% CI 1.1-2.7]) and for myocardial infarction (1.7 [95% CI 1.1-2.5]) was found. In patients with type 2 diabetes, the relative risk for myocardial infarction in subjects without the 192-bp allele was 3.4 (95% CI 1.1-11.3). Our study suggests that a genetically determined exposure to relatively low IGF-I levels is associated with an increased risk for type 2 diabetes and myocardial infarction.

Association between arterial stiffness and atherosclerosis: the Rotterdam Study

BACKGROUND AND PURPOSE

Studies of the association between arterial stiffness and atherosclerosis are contradictory. We studied stiffness of the aorta and the common carotid artery in relation to several indicators of atherosclerosis.

METHODS

This study was conducted within the Rotterdam Study in >3000 elderly subjects aged 60 to 101 years. Aortic stiffness was assessed by measuring carotid-femoral pulse wave velocity, and common carotid artery stiffness was assessed by measuring common carotid distensibility. Atherosclerosis was assessed by common carotid intima-media thickness, plaques in the carotid artery and in the aorta, and the presence of peripheral arterial disease. Data were analyzed by ANCOVA with adjustment for age, sex, mean arterial pressure, and heart rate.

RESULTS

Both aortic and common carotid artery stiffness were found to have a strong positive association with common carotid intima-media thickness, severity of plaques in the carotid artery, and severity of plaques in the aorta (P: for trend <0.01 for all associations). Subjects with peripheral arterial disease had significantly increased aortic stiffness (P:=0.001) and borderline significantly increased common carotid artery stiffness (P:=0.08) compared with subjects without peripheral arterial disease. Results were similar after additional adjustment for cardiovascular risk factors and after exclusion of subjects with prevalent cardiovascular disease.

CONCLUSIONS

This population-based study shows that arterial stiffness is strongly associated with atherosclerosis at various sites in the vascular tree.