pulse-wave-velocity-testing-baltimore-longitudinal-study

Pulse Wave Velocity Testing in the Baltimore Longitudinal Study of Aging

Carotid-femoral pulse wave velocity is considered the gold standard for measurements of central arterial stiffness obtained through noninvasive ...

National Institute of Aging

Genomewide association studies are increasingly being applied to search for novel genes that might underlie cardiovascular diseases. In this article, we briefly review the principles that underlie modern genetic analyses and provide several illustrations from the SardiNIA study of genomewide association studies for cardiovascular risk factor traits.

Using new tools to define the genetic underpinnings of risky traits associated with coronary artery disease: the SardiNIA study.

Pulse wave velocity (PWV), a noninvasive index of central arterial stiffness, is a potent predictor of cardiovascular mortality and morbidity. Heritability and linkage studies have pointed toward a genetic component affecting PWV. We conducted a genome-wide association study to identify single-nucleotide polymorphisms (SNPs) associated with PWV.

COL4A1 is associated with arterial stiffness by genome-wide association scan.

Aging represents a convergence of declining cardioprotective systems and increasing disease processes that is fertile ground for the development of heart failure. Fifty percent of all heart failure diagnoses and 90% of all heart failure deaths occur in individuals older than 70. This article discusses the microscopic and macroscopic changes in cardiovascular structure, function, protective systems, and disease associated with aging. In addition to outlining important clinical considerations and conditions in older persons, the link between normal aging and the elevated risk for development of stage B heart failure is explained and potential therapeutic pathways are highlighted.

Aging-associated cardiovascular changes and their relationship to heart failure.

We examined the relations of central adiposity with left ventricular (LV) diastolic dysfunction in men and women who participated in the Baltimore Longitudinal Study of Aging, a prospective community-based study of older persons. The sample for this cross-sectional analysis included 399 women and 370 men. Central adiposity was estimated using the waist circumference (WC) and global adiposity using the body mass index (BMI). Using data from a comprehensive echocardiographic study that included tissue Doppler imaging, diastolic function was graded according to 3 parameters (E/A ratio, E/Em ratio, and left atrial volume index). In the logistic regression models adjusted for age, gender, cardiovascular risk factors, and hemodynamic parameters, WC and BMI were both independently associated with LV diastolic dysfunction. However, when both WC and BMI were in the same model, only WC remained significantly associated with LV diastolic dysfunction (odds ratio 1.04, 95% confidence interval 1.01 to 1.08, p = 0.02). In the gender-stratified analyses, WC was significantly associated with LV diastolic dysfunction-independently of BMI-in women (odds ratio 1.08, 95% confidence interval 1.04 to 1.14, p <0.001) but not in men (odds ratio 1.00, 95% confidence interval 0.95 to 1.05, p = 0.91). Additional adjustment for LV mass index failed to modify these relations. In conclusion, the adverse effect of central adiposity on LV diastolic function was independent of general adiposity and more pronounced among women. The effect of visceral adiposity on LV diastolic dysfunction would benefit from confirmation in longitudinal studies.

Contribution of central adiposity to left ventricular diastolic function (from the Baltimore Longitudinal Study of Aging).

Although vascular risk factors have been implicated in the development of all-cause dementia and Alzheimer disease (AD), few studies have examined the association between subclinical atherosclerosis and prospective risk of dementia.

Carotid atherosclerosis and prospective risk of dementia.

Carotid-femoral pulse wave velocity (PWV), a marker of arterial stiffness, is an established independent cardiovascular risk factor. Little information is available on the pattern and determinants of the longitudinal change in PWV with aging. Such information is crucial to elucidating mechanisms underlying arterial stiffness and the design of interventions to retard it. Between 1988 and 2013, we collected 2 to 9 serial measures of PWV in 354 men and 423 women of the Baltimore Longitudinal Study of Aging, who were 21 to 94 years of age and free of clinically significant cardiovascular disease. Rates of PWV increase accelerated with advancing age in men more than women, leading to sex differences in PWV after the age of 50 years. In both sexes, not only systolic blood pressure (SBP) ≥140 mm Hg but also SBP of 120 to 139 mm Hg was associated with steeper rates of PWV increase compared with SBP<120 mm Hg. Furthermore, there was a dose-dependent effect of SBP in men with marked acceleration in PWV rate of increase with age at SBP ≥140 mm Hg compared with SBP of 120 to 139 mm Hg. Except for waist circumference in women, no other traditional cardiovascular risk factors predicted longitudinal PWV increase. In conclusion, the steeper longitudinal increase of PWV in men than women led to the sex difference that expanded with advancing age. Age and SBP are the main longitudinal determinants of PWV, and the effect of SBP on PWV trajectories exists even in the prehypertensive range.

Longitudinal trajectories of arterial stiffness and the role of blood pressure: the Baltimore Longitudinal Study of Aging.

Obesity is independently associated with left ventricular (LV) hypertrophy and thus may be an important modifier of the hypertrophic cardiomyopathy (HC) phenotype. We examined if obesity modifies the clinical presentation, LV morphology, outflow hemodynamics, and exercise tolerance in HC. In this cross-sectional study, 88 obese (body mass index [BMI] ≥30 kg/m(2)) and 154 nonobese (BMI <30 kg/m(2)) patients from the Johns Hopkins HC clinic were compared with respect to a variety of clinical and LV echocardiographic measurements. Obese patients (36.4%) were more likely to report exertional dyspnea (p = 0.04) and chest pain (p = 0.002) and had greater prevalence of hypertension (p = 0.008). LV posterior wall thickness (p = 0.01) but not the septal wall (p ≥0.21) was significantly greater in obese patients, resulting in an increased LV mass index (p = 0.003). No significant differences in LV systolic and diastolic functions were observed, but obesity was associated with higher LV stroke volume (p = 0.03), inducible LV outflow tract gradients (p = 0.045), and chance of developing LV outflow tract obstruction during stress (p = 0.035). In multivariate analysis, BMI was associated with increased posterior (but not septal) wall thickness (β = 0.15, p = 0.02) and LV mass index (β = 0.18, p = 0.005), particularly in those with hypertension. Obesity was also associated with reduced exercise time and functional capacity, and BMI independently correlated with reduced exercise tolerance. In conclusion, obesity is associated with larger LV mass, worse symptoms, lower exercise tolerance, and labile obstructive hemodynamics in HC. The association with increased outflow tract gradients has particular importance as contribution of obesity to the pressure gradients may influence clinical decisions in labile obstructive HC.

Comparison of clinical presentation, left ventricular morphology, hemodynamics, and exercise tolerance in obese versus nonobese patients with hypertrophic cardiomyopathy.

A significant inter-arm difference in systolic blood pressure (IADSBP) has recently been associated with worse cardiovascular outcomes. The authors hypothesized that part of this association is mediated by arterial stiffness, and examined the relationship between significant IADSBP and carotid-femoral pulse wave velocity (CF-PWV) in a sample from the Baltimore Longitudinal Study of Aging. Of 1045 participants, 50 (4.8%) had an IADSBP ≥10 mm Hg at baseline, and 629 had completed data from ≥2 visits (for a total of 1704 visits during 8 years). CF-PWV was significantly higher in patients with an IADSBP ≥10 mm Hg (7.3±1.9 vs 8.2±2, P=.002). Compared with others, patients with IADSBP ≥10 mm Hg also had higher body mass index, waist circumference, and triglycerides; higher prevalence of diabetes; and lower high-density lipoprotein (HDL) cholesterol (P<.001 for all). A significant association with IADSBP ≥10 mm Hg was observed for CF-PWV in both cross-sectional (odds ratio [OR], 1.19; 95% confidence interval [CI], 1.06-1.87; P=.01) and longitudinal (OR, 1.15; 95% CI, 1.03-1.29; P=.01) multivariate analyses. Female sex, Caucasian race, high body mass index (plus diabetes and low HDL cholesterol only cross-sectionally) were other independent correlates of IADSBP ≥10 mm Hg. Significant IADSBP is associated with increased arterial stiffness in community-dwelling older adults.

James B. Strait

Clinical Research Branch

National Institute of Aging

Pulse Wave Velocity Testing in the Baltimore Longitudinal Study of Aging