Patterns of abdominal fat distribution: the Framingham Heart Study

Area of Science:

• Cardiology
• Endocrinology
• Public Health

Background:

• Abdominal obesity, particularly visceral obesity, is a growing concern with significant health implications.
• Prevalence of abdominal obesity often surpasses general obesity, necessitating detailed characterization of fat distribution.

Purpose of the Study:

• To determine the prevalence of abdominal subcutaneous and visceral obesity in a community sample.
• To characterize distinct patterns of adipose tissue distribution and their association with metabolic risk factors.

Main Methods:

• Utilized multidetector computed tomography (CT) to assess subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) volumes in 3,348 Framingham Heart Study participants.
• Defined high SAT and VAT based on sex-specific 90th percentile cut points from a healthy referent group.
• Examined metabolic risk factors, including metabolic syndrome, hypertension, dyslipidemia, in relation to SAT and VAT levels.

Main Results:

• Prevalence of high SAT was approximately 30-31% in women and men, while high VAT prevalence was 42-44%.
• A significant portion (27.8%) of the sample showed discordant fat distribution: 19.9% had low SAT with high VAT, and 7.9% had high SAT with low VAT.
• Individuals with low SAT and high VAT exhibited higher prevalence of metabolic syndrome, hypertension, elevated triglycerides, and low HDL cholesterol compared to those with high SAT and low VAT, even with lower BMI and waist circumference.

Conclusions:

• Over 40% of the community sample exhibited visceral obesity, and nearly one-third had abdominal subcutaneous obesity.
• Clinical measurements like Body Mass Index (BMI) and waist circumference may inadequately classify individuals regarding visceral adipose tissue (VAT) and associated metabolic risk.
• Understanding specific fat distribution patterns is crucial for accurate metabolic risk assessment.