Beyond BMI: Is Abdominal Fat Echogenicity the New Key to Morbid Obesity?
"Research suggests ultrasound imaging of abdominal fat can offer more insight into metabolic risk than traditional measures like BMI and waist circumference, especially for postmenopausal women."
Obesity, characterized by excessive fat accumulation, is a major global health concern. While the amount of fat is clearly important, research is increasingly showing that the characteristics of that fat – its quality – may be just as crucial in determining metabolic health. Different fat depots in the body can have varying effects on metabolic risk, leading scientists to investigate how structural and morphological differences within adipose tissue contribute to health problems.
Traditionally, fat quantity has been the primary focus. However, recent studies indicate that assessing fat quality could provide additional insights. Computed tomography (CT) scans have been used to assess fat quality, but concerns about radiation exposure limit their use for widespread screening. This is where ultrasonography comes in. It’s a safe, accessible, and reproducible method for tissue characterization, making it a promising alternative for evaluating fat tissue.
A new study published in the Journal of Clinical Endocrinology and Metabolism explores whether the echogenicity (the ability to bounce back an echo) of abdominal fat tissue, measured by ultrasound, can serve as a qualitative marker of adiposity and a predictor of cardiovascular risk, particularly in postmenopausal women. The study aims to determine if this method offers additional information beyond standard measures like BMI and waist circumference.
Fat Quality vs. Quantity: What the Study Revealed
Researchers at the Vascular Laboratory, Department of Clinical Therapeutics, Alexandra Hospital, Medical School, National and Kapodistrian University of Athens, Greece, conducted a study involving 244 postmenopausal women. The study focused on the echogenicity of subcutaneous adipose tissue (SAT) and preperitoneal adipose tissue (pPAT) – two types of abdominal fat – and its relationship to subclinical atherosclerosis (early signs of arterial disease). A control group of 20 healthy premenopausal women was also included for comparison.
- Participants: 244 postmenopausal women without diabetes and 20 healthy premenopausal women.
- Assessment of Atherosclerosis: Subclinical atherosclerosis was assessed using intima-media thickness (IMT) and the presence of plaques in the femoral and carotid arteries, measured by high-resolution ultrasonography.
- Fat Echogenicity Measurement: Ultrasound images of SAT and pPAT were acquired, and their echogenicity was evaluated using grayscale mean (GSMn) with specialized software. Higher GSMn values indicate greater echogenicity.
- Key Finding: SAT GSMn, but not pPAT, was higher in postmenopausal women compared to premenopausal women. This indicates a change in the quality of subcutaneous fat after menopause.
- Association with Adiposity: SAT GSMn was independently associated with metabolic markers of adiposity, including body mass index (BMI) and waist circumference (WC). This suggests that the echogenicity of subcutaneous fat is related to overall body fat and abdominal fat distribution.
- Link to Atherosclerosis: SAT GSMn was associated with carotid IMT and the presence/number of atheromatous plaques. Higher SAT GSMn was linked to a greater risk of subclinical atherosclerosis.
- Incremental Value: SAT GSMn provided additional predictive value for detecting subclinical atherosclerosis beyond traditional risk factors, insulin resistance, BMI, and WC. This highlights its potential as a novel marker.
- Progression of Atherosclerosis: Increased baseline SAT GSMn was associated with an increased rate of progression in carotid IMT, suggesting that fat quality may influence the development of arterial disease over time.
Emerging Evidence on Abdominal Fat
The supplied research describes abdominal adipose tissue increases in postmenopausal women seen on both CT and MRI, persisting after adjustment for age. A separate study suggests adipose-tissue echogenicity may relate to metabolic and hormonal differences in fat, which could help explain hypoechoic fat in locations such as the breast and pericardium. A pilot longitudinal study in Greece also found that abdominal subcutaneous adipose tissue predicted an increased prevalence of plaque. These findings address different measures and outcomes; the supplied material does not establish abdominal fat echogenicity as a new diagnostic key to morbid obesity.
Comparing Obesity Measures
One study sets out to compare obesity classification by body mass index (BMI) with classification by body fat percentage, reflecting debate over how obesity is identified and classified. A 2005 study notes that obesity is a strong risk factor for type 2 diabetes and that relatively few studies had compared the predictive power of overall obesity with central obesity; it also describes waist-circumference and waist-to-hip-ratio cutoffs as controversial. The supplied hospital articles characterize belly fat as carrying greater health risks than overall obesity, but their snippets provide no comparative data or specific measures. Together, these sources raise the distinction between overall and abdominal adiposity without establishing a single best measure.
The Future of Obesity Screening: Is Ultrasound the Answer?
The study concludes that SAT echogenicity may serve as a qualitative marker of adiposity, providing additional clinical value over BMI and WC in postmenopausal women. This opens the door for further investigation into the utility of ultrasonography-derived fat echogenicity as a screening method for morbid obesity and cardiovascular risk.
Improving Measurement and Projections
A study using burden data from the NCD-RisC database examines global overweight and obesity trends from 1990 to 2022 and projects future trends and associated health inequalities. A 2024 review says the most reliable diagnosis of visceral obesity—focusing on ectopic visceral fat rather than subcutaneous fat—requires advanced methods such as MRI, CT, DXA, or bioimpedance analysis. Another review describes obesity, in the Obesity Medicine Association’s characterization, as chronic, progressive, relapsing, treatable, and multifactorial, involving adipose-tissue dysfunction and adverse health consequences. The supplied material points to continued work on population projections and assessment methods, but does not report a specific future projection figure.
Lived Experience and Obesity Care
A 2025 narrative review examines empirical evidence from countries around the world on the real-life experiences of people living with obesity. Its accompanying account describes psychosocial influences on obesity’s development, lived experience, treatment, and healthcare, and notes early familial pressure and dieting among its key findings. The review also highlights evidence that healthcare professionals can exhibit weight bias and that inequity in care decisions is a concern, arguing for obesity education and training for professionals. The Obesity Medicine Association defines obesity as a chronic, relapsing, multifactorial neurobehavioral disease with metabolic, biomechanical, and psychosocial consequences.
While the study focused on postmenopausal women, the findings suggest that fat quality, as assessed by ultrasound, could be a valuable tool for risk assessment in other populations as well. Further research is needed to determine the broader applicability of this technique.
Given the accessibility, safety, and reproducibility of ultrasound, assessing abdominal fat echogenicity may become a valuable addition to current screening practices, helping to identify individuals at risk for obesity-related complications and cardiovascular disease earlier and more effectively.