Abdominal Fat Tissue Echogenicity: A Marker of Morbid Obesity

Abstract

Purpose: Menopause-related changes may affect regional but also morphological characteristics of adipose tissue. We sought to assess the clinical value of echogenicity of subcutaneous adipose tissue (SAT) and preperitoneal adipose tissue (pPAT) in postmenopausal women without cardiovascular disease.

Methods: In 244 consecutively recruited postmenopausal women, subclinical atherosclerosis was assessed in the femoral and carotid arteries by intima-media thickness (IMT) and atheromatous plaques using high-resolution ultrasonography. In 41 women with a second visit (median follow-up 41.5 months), carotid atherosclerosis was re-evaluated. Images of SAT and pPAT were ultrasonographically acquired, and their echogenicity was evaluated by grayscale mean (GSMn) using a dedicated software. A control group of 20 healthy premenopausal women was used for comparisons in fat echogenicity.

Results: SAT GSMn but not pPAT was higher in postmenopausal as compared with healthy premenopausal women and was independently associated with metabolic markers of adiposity including body mass index (BMI) and waist circumference (WC). SAT GSMn was associated with carotid IMT and the presence and number of atheromatous plaques [adjusted OR 2.44 and 2.32 per 1-SD increase in GSMn (95% CIs 1.55 to 3.93 and 1.55 to 3.45), respectively]. SAT GSMn conferred incremental value over traditional risk factors, insulin resistance, BMI, and WC for the detection of subclinical atherosclerosis. Increased baseline SAT GSMn was associated with increased rate of progression in carotid IMT.

Conclusions: SAT echogenicity may serve as a qualitative marker of adiposity, conferring incremental clinical value over BMI and WC in postmenopausal women. Further investigation is warranted to assess the utility of ultrasonography-derived fat echogenicity as a screening method for morbid obesity.