Sex-specific normal values and determinants of infrarenal abdominal aortic diameter among non-aneurysmal elderly population

The Rotterdam Study. Design update and major findings between 2020 and 2024

The Rotterdam Study is a population-based cohort study, started in 1990 in the district of Ommoord in the city of Rotterdam, the Netherlands, with the aim to describe the prevalence and incidence, unravel the etiology, and identify targets for prediction, prevention or intervention of multifactorial diseases in mid-life and elderly. The study currently includes 17,931 participants (overall response rate 65%), aged 40 years and over, who are examined in-person every 3 to 5 years in a dedicated research facility, and who are followed-up continuously through automated linkage with health care providers, both regionally and nationally. Research within the Rotterdam Study is carried out along two axes. First, research lines are oriented around diseases and clinical conditions, which are reflective of medical specializations. Second, cross-cutting research lines transverse these clinical demarcations allowing for inter- and multidisciplinary research. These research lines generally reflect subdomains within epidemiology. This paper describes recent methodological updates and main findings from each of these research lines. Also, future perspective for coming years highlighted.

A Ratio Between Infrarenal and Suprarenal Aortic Diameters Corrects for Absolute Aortic Diameter Variations due to Patients' Sex and Body Size

OBJECTIVES

Aortic diameters may differ significantly between patients with different gender and body size. The aim of this study was to relate absolute aortic diameters to age, sex, height, and weight of the patients and to correct for these factors by calculating the ratio between the infrarenal and the suprarenal aortic diameters.

METHODS

A total of 458 patients who underwent elective endovascular aneurysm repair (EVAR) between 2004 and 2018 were included. The aortic anatomy in this group of elective EVAR patients was compared with a control group of 75 patients without an abdominal aortic aneurysm (AAA). The aortic diameter was measured at 4 suprarenal points and 4 infrarenal points. Ratios were calculated by dividing the mean infrarenal neck diameter by 4 suprarenal measurements.

RESULTS

Patients in the aneurysm group had significantly larger suprarenal and infrarenal aortic diameters. The ratios between the mean infrarenal neck diameter and all 4 suprarenal measurements were larger in the AAA group than in the control group. In both groups, there was a significant correlation between the mean infrarenal neck diameter and sex, height, weight, and body surface area (BSA). However, in both groups, all 4 ratios between the mean infrarenal neck diameter and suprarenal aortic diameters were not correlated with age, sex, height, weight, or BSA, except for the ratio between the mean infrarenal neck diameter and the aortic diameter measurement proximal to the upper renal artery, which was correlated to weight and BSA in the control group.

CONCLUSION

The mean infrarenal neck diameter is correlated with sex, height, weight, and BSA. However, when the suprarenal aortic diameter was used as an internal control for the mean infrarenal neck diameter, we were able to correct for these variations in aortic diameters due to sex and body size. The clinical relevance of this ratio in patients treated by EVAR has yet to be assessed in future research.

CLINICAL IMPACT

In the assessment for EVAR suitability the absolute diameter of the aneurysm neck is taken into account. We believe that using absolute diameters is not the appropriate way to assess this suitability, but that patient characteristics such as age, gender and body size, should be factored into this assessment. In this paper, we show that suprarenal and infrarenal aortic diameters are both significantly increased in patients with an aneurysm compared with patients without an aneurysm. Besides, we found that mean infrarenal aortic diameter is correlated with sex, height, weight, and body surface area. Finally, we propose a new ratio system, using suprarenal diameters as an internal control, to correct for aortic diameter variations due to sex and body size.

The neglected association between central obesity markers and abdominal aortic aneurysm presence: A systematic review and meta-analysis

Purpose

To review the association between central obesity and abdominal aortic aneurysm (AAA).

Materials and methods

The PubMed, Web of Sciences, Embase, The China national knowledge infrastructure (CNKI), and Cochrane Library were searched up to April 30, 2022. Researches includes investigation of the relationship between central obesity markers and AAA. Included studies must use recognized measures of central obesity, i.e., waist circumference (WC) and waist-to-hip ratio (WHR), or use imaging techniques to calculate abdominal fat distribution, such as computed tomography (CT) imaging.

Results

Eleven clinical researches were identified of which eight discussed the association between physical examination and AAA, and three studies mainly focused on abdominal fat volume (AFV). Seven researches concluded that there was a positive correlation between markers of central obesity and AAA. Three studies found no significant link between markers of central obesity and AAA. One of the remaining studies reported different results for each sex. Three studies pooled in a meta-analysis identified correlation between central obesity and AAA presence (RR = 1.29; 95% confidence interval, 1.14-1.46).

Conclusion

Central obesity plays a role in the risk of AAA. Standardized central obesity markers may be predictors of AAA. However, there was no association between abdominal fat volume and AAA. Additional relevant evidence and specific mechanisms warrant further study.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?IDCRD42022332519, identifier CRD42022332519.

Reference values of normal abdominal aortic areas in Chinese population measured by contrast-enhanced computed tomography

Objective

To generate reference values of the normal areas of the abdominal aorta at various levels among Chinese people and to explore the factors that may promote the expansion of the abdominal aorta.

Methods

The areas of normal abdominal aortas were gauged at various levels based on inner-to-inner measurements in 1,066 Chinese adult patients (>18 years) without the abdominal aortic disease. The areas of subphrenic abdominal, suprarenal abdominal, infrarenal abdominal, and distal abdominal aortas were measured. The demographic and clinical characteristics were collected into a specifically designed electronic database. Multivariable linear regression was used to analyze the potential risk factors promoting the expansion of the abdominal aorta.

Results

In males, the median areas of the subphrenic abdominal aorta, suprarenal abdominal aorta, infrarenal abdominal aorta, and distal abdominal aorta were 412.1, 308.0, 242.2, and 202.2 mm2, respectively. In females, the median areas of the subphrenic abdominal aorta, suprarenal abdominal aorta, infrarenal abdominal aorta, and distal abdominal aorta were 327.7, 243.4, 185.4, and 159.6 mm2, respectively. The areas of the abdominal aorta at different levels were larger in males than in females and increased with age. Multiple linear stepwise regression analysis showed that the subphrenic abdominal aortic area was significantly related to age (β = 0.544, p < 0.001), sex (β = 0.359, p < 0.001), and hypertension (β = 0.107, p < 0.001). Suprarenal abdominal aortic area was related to age (β = 0.398, p < 0.001), sex (β = 0.383, p < 0.001), history of smoking (β = 0.074, p = 0.005), and hypertension (β = 0.111, p < 0.001). The infrarenal abdominal aortic area was correlated with age (β = 0.420, p < 0.001), sex (β = 0.407, p < 0.001), and history of smoking (β = 0.055, p = 0.036). The distal abdominal aortic area was correlated with age (β = 0.463, p < 0.001), sex (β = 0.253, p < 0.001), and hypertension (β = 0.073, p = 0.013).

Conclusion

The abdominal aortic areas at different levels were larger in males than in females. Aging, hypertension, and smoking prompt the expansion of abdominal aorta.

Aortic Area as an Indicator of Subclinical Cardiovascular Disease

Aim:

Outward arterial remodeling occurs early in cardiovascular disease (CVD) and, as such, measuring arterial dimension may be an early indicator of subclinical disease.

Objective:

The objective of our study was to measure area at three aortic locations: The ascending thoracic (ASC), the descending thoracic (DSC), and the abdominal (ABD), and to test for association with traditional CVD risk factors and subclinical CVD throughout the body.

Methods:

We measured ASC, DSC, and ABD using computed tomography (CT) in 408 African ancestry men aged 50-89 years. We assessed prevalent CVD risk factors via participant interview and clinical exam, and subclinical CVD, including carotid atherosclerosis through B-mode carotid ultrasound, vascular calcification via chest and abdominal CT, and arterial stiffness via pulse-wave velocity (PWV).

Results:

As expected, all aortic areas were in correlation with each other (r=0.39-0.63, all p<0.0001) and associated with greater age, greater body size, and hypertension (p≤0.01 for all). After adjustment for traditional CVD risk factors, ASC was positively associated with carotid atherosclerosis (p<0.01). A greater area at each location was associated with greater PWV (p<0.03 for all), with the DSC region showing the most significant association.

Conclusion:

This is the first study to test the association of aortic area measured at multiple points with subclinical CVD. We found that combined CT assessment of ascending and descending aortic area may indicate a high risk of prevalent subclinical CVD elsewhere in the body independent of age, body size, and blood pressure.