Cushing's syndrome: a model for sarcopenic obesity

Area of Science:

• Endocrinology
• Geriatrics
• Metabolic Research

Background:

• Sarcopenic obesity, characterized by low muscle mass and high fat mass, is a growing concern, particularly in aging populations.
• Obesity and metabolic dysfunction are recognized risk factors for sarcopenia, contributing to sarcopenic obesity.
• Cushing's syndrome, a condition associated with obesity and muscle atrophy, presents a potential model for studying sarcopenic obesity.

Purpose of the Study:

• To investigate body composition, physical performance, and biochemical markers in Cushing's syndrome patients compared to matched obese controls.
• To test the hypothesis that Cushing's syndrome can serve as a clinical model for sarcopenic obesity.

Main Methods:

• Propensity score matching was used to select 47 obese controls based on body mass index and gender.
• Body composition (fat mass, muscle mass) was assessed using bioelectrical impedance analysis.
• Muscle function was evaluated through the chair rising test and hand grip strength, with peripheral blood markers of glucose metabolism, lipid metabolism, and hsCRP measured.

Main Results:

• Muscle mass did not significantly differ between Cushing's syndrome patients and obese controls.
• Cushing's syndrome patients demonstrated significantly longer chair rising times (9.5s vs. 7.3s) and lower hand grip strength (32.1kg vs. 36.8kg).
• Patients with impaired fasting glucose in the Cushing's syndrome group showed the most pronounced limitations in muscle function.

Conclusions:

• Cushing's syndrome patients exhibit diminished muscle function, not attributable to reduced muscle mass, suggesting impaired muscle quality possibly due to fat infiltration.
• The correlation between impaired glucose metabolism and severe muscle function deterioration in Cushing's syndrome supports the role of metabolic factors.
• Given its distinct clinical profile and potential curability, Cushing's syndrome is proposed as a valuable model for sarcopenic obesity research, overcoming limitations of comorbidities and polypharmacy in elderly populations.