Objective: The present study aimed to explore the relationships between the distribution of abdominal fat and muscle and age and gender in a middle-aged and elderly population.
Methods: The levels of abdominal (visceral and subcutaneous) fat, pericardial fat, and psoas major muscle were measured in subjects who had physical examinations at the Health and Medical Department of Peking Union Medical College Hospital from July 2019 to June 2020. The relationship between fat in different areas (ie, different types of fat) and the relationship between different types of fat and the psoas major muscle were investigated in the context of different genders and ages.
Results: The distribution of fat and muscle differed between males and females of the middle-aged and elderly study sample. Volumes of pericardial fat, total abdominal fat, and visceral fat were significantly lower in females than in males, and the area of the psoas major muscle was also significantly lower in females than in males. Levels of subcutaneous fat and total abdominal fat showed no significant correlation with age. The level of muscle showed a significant negative correlation with age.
Conclusion: 1) Within the middle-aged and elderly sample, male subjects had higher levels than females of all types of fat except for abdominal subcutaneous fat, and had higher levels of psoas muscle than females. 2) Pericardial fat increased with age, whereas levels of abdominal fat did not change significantly with age. 3) The area of psoas major muscle appears to be positively correlated with volumes of all types of fat: subjects with more fat tended to have higher levels of psoas major muscle.
Keywords: middle-aged and elderly, abdominal fat, pericardial fat, psoas major muscle, age, gender