Association of brain arterial diameters with demographic and anatomical factors in a multi-national pooled analysis of cohort studies

BACKGROUND AND PURPOSE

Brain arterial diameters are markers of cerebrovascular disease. Demographic and anatomical factors may influence arterial diameters. We hypothesize that age, sex, height, total cranial volume (TCV), and persistent fetal posterior cerebral artery (fPCA) correlate with brain arterial diameters across populations.

METHODS

Participants had a time-of-flight MRA from nine international cohorts. Arterial diameters of the cavernous internal carotid arteries (ICA), middle cerebral arteries (MCA), and basilar artery (BA) were measured using LAVA software. Regression models assessed the association between exposures and brain arterial diameters.

RESULTS

We included 6,518 participants (mean age: 70 ± 9 years; 41% men). Unilateral fPCA was present in 13.2% and bilateral in 3.2%. Larger ICA, MCA, and BA diameters correlated with older age (Weighted average [WA] per 10 years: 0.18 mm, 0.11 mm, and 0.12 mm), male sex (WA: 0.24 mm, 0.13 mm, and 0.21 mm), and TCV (WA: for one TCV standard deviation: 0.24 mm, 0.29 mm, and 0.18 mm). Unilateral and bilateral fPCAs showed a positive correlation with ICA diameters (WA: 0.39 mm and 0.73 mm) and negative correlation with BA diameters (WA: -0.88 mm and -1.73 mm). Regression models including age, sex, TCV, and fPCA explained on average 15%, 13%, and 25% of the ICA, MCA, and BA diameter interindividual variation, respectively. Using height instead of TCV as a surrogate of head size decreased the R-squared by 3% on average.

CONCLUSION

Brain arterial diameters correlated with age, sex, TCV, and fPCA. These factors should be considered when defining abnormal diameter cutoffs across populations.

On the association between abdominal aorta and basilar artery diameters: a population-based study in community-dwelling older adults

INTRODUCTION

Information on the relationship between the diameters of the abdominal aorta (AA) and the basilar artery (BA) is limited. Using the Atahualpa Project cohort, we aimed to assess this association in Atahualpa residents aged ≥ 60 years.

MATERIALS AND METHODS

Atahualpa residents aged ≥ 60 years underwent abdominal ultrasound and MRA of intracranial vessels. The independent association between both arterial diameters was estimated in a generalized linear model adjusted for demographics, cardiovascular risk factors, the presence of a fetal-type Circle of Willis, and severity of white matter hyperintensities. Fractional polynomials were fitted to model the relationship between AA and BA diameters.

RESULTS

The mean age of 277 participants was 69.5 ± 7.7 years (61% women). The mean AA diameter was 19.8 ± 3.3 mm, and the mean BA diameter was 3.1 ± 0.7 mm. The mean diameters of both arteries were significantly higher in men than in women. Locally weighted scatterplot smoothing showed a non-linear relationship between both arterial diameters. Fractional polynomial models showed that AA and BA diameters had a significant non-linear association in men (p = 0.005), but not in women (p = 0.315). When sex was excluded from a generalized linear model, the relationship between both arterial diameters became significant (p = 0.017).

CONCLUSION

In this population of community-dwelling older adults, the relationship between AA and BA diameters was confined to men. The finding of a large AA diameter in men should prompt the investigation of the intracranial vasculature because of the possibility of BA ectasia.