Anthropometric Obesity Indices were Stronger than CT-Based Indices in Associations with Carotid Intima-Media Thickness in Japanese Men

Impact of Fat Distribution and Metabolic Diseases on Cerebral Microcirculation: A Multimodal Study on Type 2 Diabetic and Obese Patients

Background: Since metabolic diseases and atherosclerotic vascular events are firmly associated, herein we investigate changes in central microcirculation and atherosclerosis-related body fat distribution in patients with type 2 diabetes mellitus and obesity. Methods: Resting brain perfusion single-photon emission computed tomography (SPECT) imaging with Technetium-99m hexamethylpropylene amine oxime ([99mTc]Tc-HMPAO SPECT) was performed, and the breath-holding index (BHI) and carotid intima-media thickness (cIMT) were measured to characterise central microcirculation. Besides CT-based abdominal fat tissue segmentation, C-peptide level, glycaemic and anthropometric parameters were registered to search for correlations with cerebral blood flow and vasoreactivity. Results: Although no significant difference was found between the resting cerebral perfusion of the two patient cohorts, a greater blood flow increase was experienced in the obese after the breath-holding test than in the diabetics (p < 0.05). A significant positive correlation was encountered between resting and provocation-triggered brain perfusion and C-peptide levels (p < 0.005). BMI and cIMT were negatively correlated (rho = -0.27 and -0.23 for maximum and mean cIMT, respectively), while BMI and BHI showed a positive association (rho = 0.31 and rho = 0.29 for maximum and mean BHI, respectively), which could be explained by BMI-dependent changes in fat tissue distribution. cIMT demonstrated a disproportional relationship with increasing age, and higher cIMT values were observed for the men. Conclusions: Overall, C-peptide levels and circulatory parameters seem to be strong applicants to predict brain microvascular alterations and related cognitive decline in such patient populations.

Association of Anthropometric and CT-Based Obesity Indices with Subclinical Atherosclerosis

AIM

Few studies have compared the strength in the associations of anthropometric and computed tomography (CT)-based obesity indices with coronary artery calcification (CAC), aortic artery calcification (AoAC), and aortic valve calcification (AVC).

METHODS

We assessed cross-sectcional associations of anthropometric and CT-based obesity indices with CAC, AoAC, and AVC. Anthropometric measures included body mass index (BMI), waist circumference, hip ircumference, waist-to-hip circumference ratio, and waist-to-height ratio in 931 men (mean age, 63.7 years) from a population-based cohort. CT images at the L4/5 level were obtained to calculate the areas of abdominal visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), total adipose tissue (TAT), VAT-to-SAT ratio (VSR), and VAT-to-TAT ratio (VTR). CAC, AoAC, and AVC were quantified using the Agatston score based on CT scanning.

RESULTS

CAC, AVC, and AoAC were present in 348 (62.6%), 173 (18.6%), and 769 (82.6%) participants, respectively. In multivariable models adjusting for age, lifestyle factors, and CT types (electron beam CT and multidetector row CT), anthropometric and CT-based obesity indices were positively associated with CAC (p＜0.01). Conversely, VAT-to-SAT ratio and VAT-to-TAT ratio were positively associated with AoAC (p＜0.01). Any obesity indices were not associated with AVC.

CONCLUSIONS

The strength of the associations of obesity indices with subclinical atherosclerosis varied according to the anatomically distinct atherosclerotic lesions, among men.

Relationships between carotid artery intima-media thickness and echogenicity and body composition using a new magnetic resonance imaging voxel-based technique

BACKGROUND

We evaluated how carotid artery intima-media thickness (IMT) and the echogenicity of the intima-media (IM-GSM), measured by ultrasound, were related to body composition, evaluated by both traditional imaging techniques, as well as with a new voxel-based "Imiomics" technique.

METHODS

In 321 subjects all aged 50 years in the POEM study, IMT and IM-GSM were measured together with a DXA scan for determination of fat and lean mass. Also a whole-body MRI scan was performed and the body volume was divided into >1 million voxels in a standardized fashion. IMT and IM-GSM were related to each of these voxels to create a 3D-view of how these measurements were related to size of each part of the body.

RESULTS

IM-GSM was inversely related to almost all traditional measurements of body composition, like fat and lean mass, liver fat, visceral and subcutaneous fat, but this was not seen for IMT. Using Imiomics, IMT was positively related to the intraabdominal fat volume, as well of the leg skeletal muscle in women. In males, IMT was mainly positively related to the leg skeletal muscle volume. IM-GSM was inversely related to the volume of the SAT in the upper part of the body, leg skeletal muscle, the liver and intraabdominal fat in both men and women.

CONCLUSION

The voxel-based Imiomics technique provided a detailed view of how the echogenicity of the carotid artery wall was related to body composition, being inversely related to the volume of the major fat depots, as well as leg skeletal muscle.

The association of waist-to-height ratio and other anthropometric measurements with subclinical atherosclerosis: Results from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

BACKGROUND AND AIMS

To compare the performance of waist-to-height ratio (WHtR), waist-to-hip ratio (WHR), waist circumference (WC) and Body-mass index (BMI) with subclinical atherosclerosis.

METHODS AND RESULTS

The association of quintiles of anthropometric variables (1st as reference) - Odds ratio (OR); 95% Confidence Interval (95% CI) - with Coronary Artery Calcium (CAC: 0 vs. >0; <100 vs. ≥100), Carotid Intima-Media Thickness (CIMT: <75th vs. ≥P75%) and as continuous variables in linear regression models in 4216 participants of ELSA-Brasil baseline. WHtR was associated with CAC >0 (OR, 1.84; 95% CI, 1.16-2.93) and ≥100 after multivariate adjustment including BMI. WHR was associated with CAC >0 OR, 1.81 (95% CI, 1.25-2.82) and ≥100. BMI was not associated with CAC after further adjustment for WHtR, but was associated with CAC >0 after adjustment for WHR (OR, 1.42; 95% CI, 1.02-1.94) or WC (1.63; 95% CI, 1.03-2.59). WHtR was not associated with CIMT after further adjustment for BMI. WHR was associated with CIMT ≥P75% (OR, 1.44; 95% CI, 1.02-2.02) and in linear models (p < 0.0001). WC was associated with CIMT in linear models (p < 0.0001). BMI was associated to CIMT ≥P75% (OR, 2.25; 95% CI, 1.53-2.54); and in linear models (P < 0.0001) after further adjustment for WHtR. After adjustment for WHR and WC the association of BMI with CIMT ≥P75% was respectively (OR 2.31; 95% CI, 1.70-3.13; and OR 2.39; 95% CI, 1.55-3.70); and in both linear models (p < 0.0001).

CONCLUSIONS

WHtR was a good biomarker for subclinical atherosclerosis measured by CAC while BMI was a good biomarker for CIMT. WHR presented the best performance being associated with both biomarkers of subclinical atherosclerosis.