Comparison of body composition in middle-aged and elderly males using computed tomography

Area of Science:

• Gerontology
• Human Physiology
• Body Composition Analysis

Background:

• Aging is associated with significant physiological changes.
• Understanding age-related body composition shifts is crucial for health.
• Previous research indicates potential alterations in lean mass and fat distribution with advancing age.

Purpose of the Study:

• To investigate age-related differences in body composition between middle-aged and older men.
• To quantify changes in lean tissue mass, fat mass, and fat distribution.
• To determine if fat redistribution occurs with aging, specifically a centripetal and internal shift.

Main Methods:

• Computed tomography (CT) scans were utilized to assess body composition in two male age groups.
• Measurements included total body weight, lean tissue mass, and adipose tissue distribution (subcutaneous vs. visceral).
• Whole body potassium counting was employed to estimate total fat mass.

Main Results:

• Older men (mean age 69.4 years) weighed significantly less (8.2 kg) than middle-aged men (mean age 46.3 years).
• The weight difference was primarily due to a reduction in lean tissue across multiple body areas (legs, arms, abdomen, chest).
• While total abdominal adipose tissue area was similar, older men showed less subcutaneous fat and more intra-abdominal (visceral) fat, indicating a centripetal and internal fat redistribution.

Conclusions:

• Aging in men is characterized by a decrease in lean tissue mass and a significant redistribution of fat towards the abdominal cavity.
• These findings suggest a 'centripetalization' and 'internalization' of fat with age, independent of overall body weight.
• The underlying causes for these observed age-related body composition changes remain unknown and warrant further investigation.