Associations of cigarette smoking and burden of thoracic aortic calcification in asymptomatic individuals: A dose-response relationship

Thoracic Aortic Calcium Density and Area in Long-Term Atherosclerotic Cardiovascular Disease Risk Among Men Versus Women

BACKGROUND

The development of thoracic aortic calcium (TAC) temporally precedes coronary artery calcium more often in women versus men. Whether TAC density and area confer sex-specific differences in atherosclerotic cardiovascular disease (ASCVD) risk is unknown.

METHODS

We studied 5317 primary prevention patients who underwent coronary artery calcium scoring on noncontrast cardiac gated computed tomography with TAC >0. The Agatston TAC score (Agatston units), density (Hounsfield units), and area (mm2) were compared between men and women. Cox proportional hazards regression calculated adjusted hazard ratios for TAC density-area groups with ASCVD mortality, adjusting for traditional risk factors, coronary artery calcium, and TAC. Multinomial logistic regression calculated adjusted odds ratios for the association between traditional risk factors and TAC density-area groups.

RESULTS

The mean age was 60.7 years, 38% were women, and 163 ASCVD deaths occurred over a median of 11.7-year follow-up. Women had higher median TAC scores (97 versus 84 Agatston units; P=0.004), density (223 versus 210 Hounsfield units; P<0.001), and area (37 versus 32 mm2; P=0.006) compared with men. There was a stepwise higher incidence of ASCVD deaths across increasing TAC density-area groups in men though women with low TAC density relative to TAC area (3.6 per 1000 person-years) had survival probability commensurate with the high-density-high-area group (4.8 per 1000 person-years). Compared with low TAC density-area, low TAC density/high TAC area conferred a 3.75-fold higher risk of ASCVD mortality in women (adjusted hazard ratio, 3.75 [95% CI, 1.13-12.44]) but not in men (adjusted hazard ratio, 1.16 [95% CI, 0.48-2.84]). Risk factors most strongly associated with low TAC density/high TAC area differed in women (diabetes: adjusted odds ratio, 2.61 [95% CI, 1.34-5.07]) versus men (hypertension: adjusted odds ratio, 1.45 [95% CI, 1.11-1.90]).

CONCLUSIONS

TAC density-area phenotypes do not consistently associate with ASCVD mortality though low TAC density relative to area may be a marker of increased ASCVD risk in women.

Exposure to perchlorate, nitrate, and thiocyanate and the prevalence of abdominal aortic calcification

Perchlorate, nitrate, and thiocyanate are reported to affect human health. However, it is unclear about the associations between exposure to these chemicals and abdominal aortic calcification (AAC). A total of 959 individuals were included in a large representative survey. Urinary levels of perchlorate, nitrate, and thiocyanate were measured by ion chromatography coupled with electrospray tandem mass spectrometry. AAC was diagnosed based on dual-energy X-ray absorptiometry (DXA). There were 276 (28.8%) cases of AAC among the participants. The level of urinary nitrate was significantly lower in AAC patients compared with non-AAC patients (36.4 mg/L [20.6, 59.5] vs. 42.4 [23.8, 68.3]; P = 0.013). In multivariable-adjusted logistic regression models, urinary nitrate was associated with the prevalence of AAC. Compared with the lowest quartile, the odds ratios (95% confidence intervals) across increasing quartiles were 1.06 (0.69-1.61; P = 0.799), 0.64 (0.41-1.00; P = 0.049) and 0.74 (0.47-1.15; P = 0.180). Restricted cubic splines suggested that urinary nitrate ranging between 43.7 and 115.4 mg/L was associated with a lower risk of AAC. Moderate exposure to nitrate was associated with a lower risk of AAC.

Vascular Calcification Is Associated with Fetuin-A and Cortical Bone Porosity in Stone Formers

Background: Nephrolithiasis has been associated with bone loss and vascular calcification (VC), reflecting abnormal extraosseous calcium deposition. Fetuin-A (Fet-A) acts as a potent inhibitor of ectopic mineralization. The aim of the present study was to evaluate the prevalence of VC in stone formers (SF) and non-stone formers (NSF) and to investigate potential determinants of VC among SF, including circulating levels of Fet-A and bone microarchitecture parameters. Methods: Abdominal aortic calcification (AAC) was assessed using available computed tomography in SF and in age-, sex-, and BMI-matched NSF (potential living kidney donors). Serum Fet-A was measured in stored blood samples from SF. Bone microarchitecture parameters were obtained as a post hoc analysis of a cross-sectional cohort from young SF evaluated by high-resolution peripheral quantitative computed tomography (HR-pQCT). Results: A total of 62 SF (38.0 [28.0−45.3] years old) and 80 NSF (40.0 [37.0−45.8] years old) were included. There was no significant difference in AAC scores between SF and NSF. However, when dividing SF according to mean AAC score, below <5.8% (n = 33) or above ≥5.8% (n = 29), SF with higher AAC presented significantly higher BMI and tibial cortical porosity (Ct.Po) and significantly lower serum HDL, klotho, Fet-A, and eGFR. Urinary calcium did not differ between groups, but fractional excretion of phosphate was higher in the former. Upon multivariate regression, BMI, serum Fet-A, and tibial Ct.Po remained independently associated with AAC. Conclusions: This study suggests an association between reduced circulating Fet-A levels and increased bone Ct.Po with VC in SF.

Favorable Cardiovascular Health Is Associated With Lower Prevalence, Incidence, Extent, and Progression of Extracoronary Calcification: MESA

BACKGROUND

Ideal cardiovascular health (CVH) is associated with a lower incidence of cardiovascular disease. Extracoronary calcification (ECC)-measured at the aortic valve, mitral annulus, ascending thoracic aorta, and descending thoracic aorta-is an indicator of systemic atherosclerosis. This study examined whether favorable CVH was associated with a lower risk of ECC.

METHODS

We analyzed data from MESA (Multi-Ethnic Study of Atherosclerosis) participants aged 45 to 84 years without cardiovascular disease at baseline. ECC was measured by noncontrast cardiac computed tomography scan at baseline and after an average of 2.4 years. Prevalent ECC was defined as an Agatston score >0 at the baseline scan. Incident ECC was defined as Agatston score >0 at the follow-up scan among participants with Agatston score of 0 at the baseline scan. Each CVH metric (smoking, physical activity, body mass index, diet, blood pressure, total cholesterol, and blood glucose) was scored 0 to 2 points, with 2 indicating ideal; 1, intermediate; and 0, poor. The aggregated CVH score was 0 to 14 points (0-8, inadequate; 9-10, average; 11-14, optimal). We used Poisson and linear mixed-effects regression models to examine the association between CVH and ECC adjusted for sociodemographic factors.

RESULTS

Of 6504 participants, 53% were women with a mean age (SD) of 62 (10) years. Optimal and average CVH scores were associated with lower ECC prevalence, incidence, and extent. For example, optimal CVH scores were associated with 57%, 56%, 70%, and 54% lower risk of incident aortic valve calcification, mitral annulus calcification, ascending thoracic aorta calcification, and descending thoracic aorta calcification, respectively. In addition, optimal and average CVH scores were associated with lower ECC progression at 2 years, although these associations were only significant for mitral annulus calcification and descending thoracic aorta calcification.

CONCLUSIONS

In this multiethnic cohort, favorable CVH was associated with a lower risk of extracoronary atherosclerosis. These findings emphasize the importance of primordial prevention as an intervention to reduce the burden of cardiovascular disease.

Calcification prevalence in different vascular zones and its association with demographics, risk factors, and morphometry

Vascular calcification is associated with a higher incidence of cardiovascular events, but its prevalence in different vascular zones and the influence of demographics, risk factors, and morphometry remain insufficiently understood. Computerized tomography angiography scans from 211 subjects 5-93 yr old (mean age 47 ± 24 yr, 127 M/84 F) were used to build 3D vascular reconstructions and measure arterial diameters, tortuosity, and calcification volumes in six vascular zones spanning from the ascending thoracic aorta to the pelvic arteries. A machine learning random forest algorithm was used to determine the associations between calcification in each zone with demographics, risk factors, and vascular morphometry. Calcification appeared during the fourth decade of life and was present in all subjects after 65 yr. The abdominal aorta and the iliofemoral segment were the first to develop calcification, whereas the ascending thoracic aorta was the last. Demographics and risk factors explained 33-59% of the variation in calcification. Age, creatinine level, body mass index, coronary artery disease, and hypertension were the strongest contributors, whereas the effects of sex, race, tobacco use, diabetes, dyslipidemia, and alcohol and substance use disorders on calcification were small. Vascular morphometry did not directly and independently affect calcium burden. Vascular zones develop calcification asynchronously, with distal segments calcifying first. Understanding the influence of demographics and risk factors on calcium prevalence can help better understand the disease pathophysiology and may help with the early identification of patients that are at higher risk of cardiovascular events.NEW & NOTEWORTHY We investigated the prevalence of vascular calcification in different zones of the aorta and pelvic arteries using computerized tomography angiography reconstructions and have applied machine learning to determine how calcification is affected by demographics, risk factors, and morphometry. The presented data can help identify patients at higher risk of developing vascular calcification that may lead to cardiovascular events.

Prevalence and risk factors for the development of abdominal aortic calcification among the US population: NHANES study

Introduction

Abdominal aortic calcification (AAC) is an important marker of subclinical cardiovascular disease and its prognosis. Advanced age, hypertension, smoking, dyslipidemia, diabetes mellitus, and higher truncal fat are known markers of AAC in studies conducted around the world. However, literature for these risk factors and their co-occurrence is limited in the US.

Material and methods

We used data from dual energy X-ray absorptiometry (Hologic, v4.0) to detect the occurrence of AAC in a sample population (n = 3140) of the NHANES survey using a computer-assisted interviewing system to assess the risk factors for AAC.

Results

We found the national prevalence of AAC in the US to be 28.8%. After adjusting for confounders, persons with hypertension: OR = 1.66 (95% CI: 1.30–2.13) and smokers: OR = 1.63 (95% CI: 1.24–2.14) were more likely to have AAC compared to their respective counterparts. Increasing age was positively associated with AAC: OR = 1.06 (95% CI: 1.04–1.08). There was a statistically significant negative association between body mass index (BMI) and AAC, more so in smokers than in non-smokers: OR = 0.97 (95% CI: 0.94–0.97). We did not observe any statistically significant association between diabetes and AAC.

Conclusions

Advanced age, smoking, and hypertension was associated with increased occurrence of AAC. Paradoxically, increasing BMI was inversely associated with AAC and there was no statistically significant association between total body and trunk fat percentages and AAC. To the best of our knowledge, this is the first study to establish the nationwide prevalence and associated factors in the US.