Abdominal circumference measurement by ultrasound does not enhance estimating the association of visceral fat with cardiovascular risk

Comparative Study of Ultrasonographic and Anthropometric Measurements of Regional Adiposity in Metabolic Syndrome

INTRODUCTION

Metabolic syndrome is complex disorder unifying dyslipidemia, insulin resistance and hyper insulinemia. Rising global epidemic of obesity has tremendous impact on metabolic syndrome. Ultrasound is becoming widely utilized modality for measuring the visceral adiposity.

AIM

To determine the usefulness of ultrasonographic measurements in the estimation of regional adiposity and to compare them with anthropometric measurements and to correlate ultrasonographic measurements of regional adiposity and metabolic syndrome.

MATERIALS AND METHODS

A cross-sectional study was conducted to compare anthropometry and ultrasonography in assessing the regional adiposity in metabolic syndrome. A total of 105 consecutive participants were included in the study after scrutinizing them for various definable factors of metabolic syndrome. Body Mass Index (BMI) of all participants was calculated and their available serological investigations were gathered. Primarily participants were subjected for anthropometric measurements like waist circumference and hip circumference, further waist/hip ratio was calculated. Following which all participants underwent sonological examination and sonographic indices like intraabdominal fat thickness, preperitoneal fat thickness, minimum and maximum subcutaneous fat thicknesses were measured. Abdominal wall fat index was calculated as ratio of maximum preperitoneal fat thickness to minimum subcutaneous fat thickness. Statistical analysis was performed using SPSS (Statistical Package Social Science, version-10.0.5) software. A p-value was calculated and values <0.05 were considered as statistically significant.

RESULTS

Significant correlation was established between the BMI and waist and hip circumferences. Mild positive correlation was obtained between BMI and sonographic indices like IAF, SCF and PPF with Pearson correlation (r) values of 0.324, 0.585 and 0.211 respectively. Anthropometric measurements showed higher r-values (WC- 0.624 and HC- 0.825) than sonographic indices; indicating anthropometry is better in assessing the regional adiposity than the sonography.

CONCLUSION

Sonography can be considered as one of the reliable imaging modality for assessing the regional adiposity but not as better as waist or hip circumferences.

Relationship between visceral obesity and plasma fibrinogen in obese children

BACKGROUND

The prevalence of obesity in children and adolescents has increased significantly worldwide with an alarming rise of its co-morbidities. The excess of visceral adipose tissue is associated with hypertension, prothrombotic and pro-inflammatory states. Our aim was to find a possible association between visceral obesity and plasma fibrinogen, as one of the cardiovascular risk factors, in obese children.

METHODS

Forty-three obese children and 40 non-obese controls were studied regarding their history, complete physical examination, anthropometric assessment, body composition analysis, ultrasonographic measurement of visceral adipose tissue and subcutaneous fat as well as laboratory measurement of plasma fibrinogen.

RESULTS

Our study revealed significant higher levels of fibrinogen in obese children than controls (14.5+5.1 and 2.9+0.52 mg/mL, respectively) with p-value <0.01. Moreover, the obese group had statistically significant difference in visceral fat (5.96+0.77 cm) and subcutaneous fat (2.66+0.70 cm) than controls (2.45+0.65 and 0.70+0.18 mg/mL, respectively) with p-value <0.01. In addition, fibrinogen had significant positive correlation with body mass index (r=0.327), waist/hip ratio (r=0.394), fat percentage (r=0.301), visceral adipose tissue (r=0.323) and subcutaneous fat (r=0.301).

CONCLUSIONS

There was highly significant increase in the fibrinogen level, visceral and subcutaneous abdominal fat in the obese group with insignificant sex differences. Fibrinogen had a significant positive correlation with the different adiposity markers, blood pressure, visceral and subcutaneous fat. Visceral adipose tissue is a stronger predictor for cardiovascular risk compared to subcutaneous fat.

Visceral adipose tissue is a better predictor of subclinical carotid atherosclerosis compared with waist circumference

We investigated whether visceral adipose tissue (VAT) measured by ultrasonography is better than waist circumference (WC) in predicting the presence of subclinical carotid atherosclerosis. We recruited 100 individuals without a history of cardiovascular disease or diabetes mellitus. VAT volume was measured by ultrasonography and common carotid artery intima-media thickness (CCA-IMT) by B-mode ultrasonography. Both VAT and WC were positively associated with body mass index, triglycerides, uric acid, systolic/diastolic blood pressure and high sensitivity C-reactive protein and inversely correlated with high-density lipoprotein cholesterol. However, only VAT was associated with CCA-IMT (r = 0.309, p = 0.002). Multivariate logistic regression analysis revealed that VAT, but not WC, was an independent predictor of carotid plaques after adjustment for cardiovascular risk factors (odds ratio [OR] = 1.017, 95% confidence interval [CI] = 1.003-1.031, p = 0.017), and this association persisted after additional adjustment for WC (OR = 1.024, 95% CI = 1.003-1.031, p = 0.027). Our data suggest that VAT volume measured by ultrasonography may be a better predictor of subclinical carotid atherosclerosis than waist circumference in healthy individuals.