The lifestyle-related factors associated with visceral fat mass has been unknown. In this study, we showed that skeletal muscle mass especially lower limb muscle mass are negatively associated with VFAI.
We showed that the VFAI is positively associated with age and negatively associated with skeletal muscle mass. VFA is positively associated with number of metabolic risk factors in the elderly , and skeletal muscle mass is inversely associated with age [17, 18]. However, our data showed that skeletal muscle mass was not associated with age, which is supported by the evidence that muscular strength is inversely associated with the incidence of MetS, independently of age . Although the age outliers might have affected the results (Additional file 1), they nevertheless indicate that the decrease in skeletal muscle mass can be prevented by physical activity.
Decreased skeletal muscle mass leads to physical inactivity . Conversely, physical inactivity leads to decreased skeletal muscle mass . Decreased skeletal muscle mass and strength is associated with increased morality [21, 22]. Sarcopenic obesity is also associated with hypertension, independent of abdominal obesity . Increasing skeletal muscle mass and strength via daily exercise may therefore prevent MetS and prolong life span.
In addition, in patients with metabolic syndrome, visceral fat accumulation is accompanied by excess lipid deposition in skeletal muscle, which may contribute to impaired glucose uptake leading to insulin resistance . Improved skeletal muscle functions (including metabolic system) through exercise may contribute to the prevention of MetS .
The American Heart Association recommends daily exercise to prevent the accumulation of abdominal fat . Although some subjects exercised in their spare time, our results showed that the association between total energy expenditure during daily activity and VFAI was stronger than the association between energy expenditure during exercise and VFAI. Because the duration of energy expenditure during exercise is relatively short, it may be insufficient for reducing VFA. Therefore, the length of continuous caloric consumption is important for reducing VFA. Enhanced energy expenditure combined with daily exercise is essential for reducing the volume of visceral fat.
Lower limb muscle mass is a determinant of VFAI. Lower limb muscle including the quadriceps forms the largest muscle mass in the body and may therefore contribute to decreased VFA to a greater extent than upper limb or truncal muscle. Lower limb muscle mass and performance in gait are also important because they are associated with reduced mobility, a poor quality of life, CVD, and death [26–28]. Increased physical activity and daily lower body exercise (e.g., brisk walking, cycling, and stair climbing) may be the most useful way to reduce visceral fat and improve mortality. Increased daily activity in young- and middle-aged men may prevent MetS and CVD by decreasing the volume of visceral fat.
In conclusion, skeletal muscle mass especially lower limb muscle mass negatively contributed to VFA in healthy men. Maintaining lower limb muscular fitness through daily exercise may therefore be a useful strategy for controlling visceral obesity and MetS.
Informed consent was obtained from the participants for the publication of this report and any accompanying images.