Sex Differences in Longitudinal Determinants of Carotid Intima Medial Thickening With Aging in a Community-Dwelling Population: The Baltimore Longitudinal Study on Aging

Longitudinal decline in peak V̇o2 with aging in a healthy population is associated with a reduction in peripheral oxygen utilization but not in cardiac output

Aging is associated with a significant decline in aerobic capacity assessed by maximal exercise oxygen consumption (V̇o2max). The relative contributions of the specific V̇o2 components driving this decline, namely cardiac output (CO) and arteriovenous oxygen difference (A - V)O2, remain unclear. We examined this issue by analyzing data from 99 community-dwelling participants (baseline age: 21-96 yr old; average follow-up: 12.6 yr old) from the Baltimore Longitudinal Study of Aging, free of clinical cardiovascular disease. V̇o2peak, a surrogate of V̇o2max, was used to assess aerobic capacity during upright cycle ergometry. Peak exercise left ventricular volumes, heart rate, and CO were estimated using repeated gated cardiac blood pool scans. The Fick equation was used to calculate (A - V)O2diff,peak from COpeak and V̇o2peak. In unadjusted models, V̇o2peak, (A - V)O2diff,peak, and COpeak declined longitudinally over time at steady rates with advancing age. In multiple linear regression models adjusting for baseline values and peak workload, however, steeper declines in V̇o2peak and (A - V)O2diff,peak were observed with advanced entry age but not in COpeak. The association between the declines in V̇o2peak and (A - V)O2diff,peak was stronger among those ≥50 yr old compared with their younger counterparts, but the difference between the two age groups did not reach statistical significance. These findings suggest that age-associated impairment of peripheral oxygen utilization during maximal exercise poses a stronger limitation on peak V̇o2 than that of CO. Future studies examining interventions targeting the structure and function of peripheral muscles and their vasculature to mitigate age-associated declines in (A - V)O2diff are warranted.NEW & NOTEWORTHY The age-associated decline in aerobic exercise performance over an average of 13 yr in community-dwelling healthy individuals is more closely associated with decreased peripheral oxygen utilization rather than decreased cardiac output. This association was more evident in older than younger individuals. These findings suggest that future studies with larger samples examine whether these associations vary across the age range and whether the decline in cardiac output plays a greater role earlier in life. In addition, studies focused on determinants of peripheral oxygen uptake by exercising muscle may guide the selection of preventive strategies designed to maintain physical fitness with advancing age.

Psychological stress and the longitudinal progression of subclinical atherosclerosis

OBJECTIVE

In a midlife sample of adults, the present study tested the extent to which changes in psychological stress relate to the progression of subclinical cardiovascular disease over multiple years and explored the potential moderating role of cardiometabolic risk.

METHOD

Participants were screened to exclude those with clinical cardiovascular, respiratory, metabolic, and other chronic illnesses, as well as those taking psychotropic, cardiovascular, lipid, and glucose control medications. At baseline (N = 331) and then again at follow-up an average of 3 years later (N = 260), participants completed the 10-item Perceived Stress Scale, underwent assessments of their cardiometabolic risk, and underwent ultrasonography to measure carotid artery intima-media thickness (IMT), which is a surrogate indicator of subclinical atherosclerosis.

RESULTS

Regression models showed that the change in psychological stress from baseline to follow-up was positively associated with the corresponding change in IMT, with covariate control for age at baseline, sex at birth, and variability in length of follow-up across participants. Cardiometabolic risk factors did not statistically moderate this longitudinal association. In exploratory analyses, cardiometabolic risk factors also did not statistically mediate this association.

CONCLUSION

These longitudinal findings suggest that increases in psychological stress in midlife relate to corresponding increases in subclinical atherosclerosis. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Angiogenin Levels and Carotid Intima-Media Thickness in Patients with Type 1 Diabetes and Metabolic Syndrome

It is well documented that in patients with type 1 diabetes (DM1), decreased levels of angiogenin are associated with the development of overt nephropathy. However, little is known about angiogenin levels and subclinical macrovascular organ damage in patients with DM1 and concomitant metabolic syndrome (MS). Therefore, we analyzed the relationship between angiogenin levels and carotid intima-media thickness (cIMT) in DM1 patients with and without MS. We found that angiogenin concentration was significantly lower in DM1 patients compared to controls, while the cIMT measurements were comparable. Exclusion of patients with MS, patients with hypertension, undergoing treatment, or cigarette smokers did not change these findings. Of note, when comparing the subgroups of DM1 patients with and without MS, there was no significant difference between angiogenin levels. However, we did note a significant difference in these levels after the exclusion of smokers. The comparison of cIMT in these subgroups showed a significant difference between the study subgroups. This difference was no longer observed when the age of the patients was taken into account. In summary, it can be concluded that metabolic syndrome in patients with type 1 diabetes does not appear to impact angiogenin levels or cIMT.

Aging and Vascular Disease: A Multidisciplinary Overview

Vascular aging, i.e., the deterioration of the structure and function of the arteries over the life course, predicts cardiovascular events and mortality. Vascular degeneration can be recognized before becoming clinically symptomatic; therefore, its assessment allows the early identification of individuals at risk. This opens the possibility of minimizing disease progression. To review these issues, a search was completed using PubMed, MEDLINE, and Google Scholar from 2000 to date. As a network of clinicians and scientists involved in vascular medicine, we here describe the structural and functional age-dependent alterations of the arteries, the clinical tools for an early diagnosis of vascular aging, and the cellular and molecular events implicated. It emerges that more studies are necessary to identify the best strategy to quantify vascular aging, and to design proper physical activity programs, nutritional and pharmacological strategies, as well as social interventions to prevent, delay, and eventually revert the disease.

Aging of the Arterial System

Aging of the vascular system is associated with deep changes of the structural proprieties of the arterial wall. Arterial hypertension, diabetes mellitus, and chronic kidney disease are the major determinants for the loss of elasticity and reduced compliance of vascular wall. Arterial stiffness is a key parameter for assessing the elasticity of the arterial wall and can be easily evaluated with non-invasive methods, such as pulse wave velocity. Early assessment of vessel stiffness is critical because its alteration can precede clinical manifestation of cardiovascular disease. Although there is no specific pharmacological target for arterial stiffness, the treatment of its risk factors helps to improve the elasticity of the arterial wall.

Longitudinal trajectory of vascular age indices and cardiovascular risk factors: a repeated-measures analysis

This study aimed to identify the modifiable cardiovascular risk factors associated with longitudinal changes, which are nine functional and structural biological vascular aging indicators (BVAIs), to propose an effective method to prevent biological vascular aging. We conducted a longitudinal study of 697 adults (a maximum of 3636 BVAI measurements) who were, at baseline, aged between 26 and 85 years and whose BVAIs were measured at least twice between 2007 and 2018. The nine BVAIs were measured using vascular testing and an ultrasound device. Covariates were assessed using validated questionnaires and devices. During the mean follow-up period of 6.7 years, the average number of BVAI measurements ranged from 4.3 to 5.3. The longitudinal analysis showed a moderate positive correlation between the common carotid intima-media thickness (IMT) and chronological age in both men (r = 0.53) and women (r = 0.54). In the multivariate analysis, BVAIs were associated with factors such as age, sex, residential area, smoking status, blood clinical chemistry test levels, number of comorbidities, physical fitness, body mass, physical activity, and dietary intake. The IMT is the most useful BVAI. Our findings suggest that modifiable cardiovascular risk factors are associated with longitudinal changes in BVAI as represented by IMT.

Dilated hypertrophic phenotype of the carotid artery is associated with accelerated age-associated central arterial stiffening

Hypertrophic carotid geometric phenotypes (h-CGP) are predictors of incident cardiovascular disease (CVD). While arterial aging is hypothesized as a contributor to this associated risk, the association of CGPs with chronological age is not clear. In this manuscript we examine whether hypertrophic CGPs represent accelerated biological, rather than chronological, aging by examining their association with carotid-femoral pulse wave velocity (PWV), the hallmark of arterial aging. We analyzed data from 5516 participants of the SardiNIA study with a wide range of age at baseline (20-101 years), and a median follow-up time of 13 years (mean 11.5 years; maximum 17.9 years). Baseline CGPs were defined based on the common carotid lumen diameter, wall thickness, and their ratio. Subject-specific rates of change of PWV, blood pressure parameters, body mass index, glucose, and lipids were estimated using linear mixed effects models. Compared to those with typical(t-) CGP, those with dilated hypertrophy (dh-) CGP had a greater longitudinal increase in PWV; this increase was significantly greater among older individuals and men. The greater PWV longitudinal increase in dh-CGP remained significant after adjusting for baseline values and rates of change of covariates. Dilated hypertrophic CGP is independently associated with accelerated increase in age-associated arterial stiffening over time, with a strong association in men than in women. Future studies are needed to examine if this association mediates the increased risk for CVD observed in individuals with hypertrophic cardiac remodelling and the role of retarding it to reduce this risk. HIGHLIGHTS: • Individuals with dilated hypertrophic geometric phenotypes of the common carotid artery (increased age- and sex-specific wall thickness and lumen diameter) have greater future central arterial stiffening, independently of other determinants of arterial stiffening. • The dilated hypertrophic phenotype group has a greater age-specific arterial dilation, wall thickening, and stiffness (the arterial aging triad). This suggests that this phenotype is a form of accelerated aging that might explain the worse clinic outcomes observed in this group. • Understanding the natural history of the carotid geometric phenotype across the lifespan and the determinants of the deleterious progression towards the dilated hypertrophic phenotype are needed to develop interventions that reduce the adverse clinical outcomes associated with it.

Sex differences in pressure and flow waveform physiology across the life course

Cardiovascular disease (CVD) has long been deemed a disease of old men. However, in 2019 CVD accounted for 35% of all deaths in women and, therefore, remains the leading cause of death in both men and women. There is increasing evidence to show that risk factors, pathophysiology and health outcomes related to CVD differ in women compared with men, yet CVD in women remains understudied, underdiagnosed and undertreated. Differences exist between the sexes in relation to the structure of the heart and vasculature, which translate into differences in blood pressure and flow waveform physiology. These physiological differences between women and men may represent an important explanatory factor contributing to the sex disparity in CVD presentation and outcomes but remain understudied. In this review we aim to describe sex differences in arterial pressure and flow waveform physiology and explore how they may contribute to differences in CVD in women compared to men. Given that unfavourable alterations in the cardiovascular structure and function can start as early as in utero, we report sex differences in waveform physiology across the entire life course.

Implementation of exercise countermeasures during spaceflight and microgravity analogue studies: Developing countermeasure protocols for bedrest in older adults (BROA)

Significant progress has been made in the development of countermeasures to attenuate the negative consequences of prolonged exposure to microgravity on astronauts’ bodies. Deconditioning of several organ systems during flight includes losses to cardiorespiratory fitness, muscle mass, bone density and strength. Similar deconditioning also occurs during prolonged bedrest; any protracted time immobile or inactive, especially for unwell older adults (e.g., confined to hospital beds), can lead to similar detrimental health consequences. Due to limitations in physiological research in space, the six-degree head-down tilt bedrest protocol was developed as ground-based analogue to spaceflight. A variety of exercise countermeasures have been tested as interventions to limit detrimental changes and physiological deconditioning of the musculoskeletal and cardiovascular systems. The Canadian Institutes of Health Research and the Canadian Space Agency recently provided funding for research focused on Understanding the Health Impact of Inactivity to study the efficacy of exercise countermeasures in a 14-day randomized clinical trial of six-degree head-down tilt bedrest study in older adults aged 55–65 years old (BROA). Here we will describe the development of a multi-modality countermeasure protocol for the BROA campaign that includes upper- and lower-body resistance exercise and head-down tilt cycle ergometry (high-intensity interval and continuous aerobic exercise training). We provide reasoning for the choice of these modalities following review of the latest available information on exercise as a countermeasure for inactivity and spaceflight-related deconditioning. In summary, this paper sets out to review up-to-date exercise countermeasure research from spaceflight and head-down bedrest studies, whilst providing support for the proposed research countermeasure protocols developed for the bedrest study in older adults.

Longitudinal uncoupling of the heart and arteries with aging in a community-dwelling population

Although mechanical energy transfer between the heart and arterial system, referred to as arterial-ventricular (AV) coupling, is an important determinant of cardiovascular performance, how AV coupling changes over time within and among individuals as they age has not been fully explored. We studied 129 participants (baseline age 21-96) of the Baltimore Longitudinal Study of Aging, free of clinical CVD. Participants underwent repeated multigated cardiac blood pool scans to estimate left ventricular (LV) volumes (SV, EDV, and ESV). Total systemic vascular resistance (TSVR), total arterial compliance (TAC), effective arterial elastance (Ea), and end-systolic LV elastance (Elv) were calculated using LV volumes and brachial BP measurements; calculated Ea/Elv was the measure of AV coupling. Linear mixed-effects models were used to estimate person-specific rates of change (Change) for each variable. The rate at which Ea increased over time was faster than the rate at which Elv increased, resulting in AV uncoupling (increased Ea/Elv) over time that was significantly greater in women than in men. Loss of arterial compliance was the main determinant of (Ea/Elv)_Change, which was negatively associated with changes in SV and EDV but positively with changes in ESV. Progressive AV uncoupling occurred with aging and was more pronounced in women than men. While Ea change did not differ by sex, Elv increased at a slower rate in women than in men. AV uncoupling was inversely associated with EDV and SV rates of change and a directly associated with an increase in ESV rate of change. Additional studies are needed to explore the functional consequences of AV uncoupling in healthy individuals with respect to the emergence of age-associated clinical cardiovascular diseases, such as heart failure with preserved ejection fraction.

Sex Differences in Longitudinal Determinants of Carotid Intima Medial Thickening With Aging in a Community-Dwelling Population: The Baltimore Longitudinal Study on Aging

Background Common carotid intima medial thickness (IMT) increases with aging. However, the longitudinal association between IMT and other age-associated hemodynamic alterations in men and in women are not fully explored. Methods and Results We analyzed repeated measures of IMT, blood pressure, and carotid-femoral pulse wave velocity over a 20-year period in 1067 men and women of the Baltimore Longitudinal Study on Aging; participants were ages 20 to 92 years at entry and free of overt cardiovascular disease. Linear mixed-effects models were used to calculate the individual rates of change (_Change) of IMT, pulse pressure, mean arterial pressure, and pulse wave velocity, among other covariates. Multivariate regression analysis was used to examine the association of IMT_Change with baseline and rates of change of hemodynamic parameters and cardiovascular risk factors. IMT increased at accelerating rates from 0.02 mm/decade at age 50 years to 0.05 mm/decade at age 80 years greater rates in men than in women. IMT_Change was positively associated with baseline low-density lipoprotein, low-density lipoprotein_Change, and baseline systolic blood pressure and systolic blood pressure_Change, but inversely with baseline diastolic blood pressure and diastolic blood pressure_Change. When blood pressure was expressed as pulse pressure and MAP, IMT_Change was positively associated with baseline pulse pressure and pulse pressure_Change and inversely with baseline mean arterial pressure and mean arterial pressure_Change. In sex-specific analysis, these associations were observed in women, but not in men. Conclusions In summary, our analyses showed that IMT increases at accelerating rates with aging. Age-associated changes in IMT were modulated by concurrent changes of low-density lipoprotein in both sexes, and of pulsatile and mean blood pressure in women but not men.