Sarcopenia is a little-known term that affects a significant proportion of the aging population. It refers to a progressive loss of muscle mass, strength and function, generally associated with advancing age. This condition has consequences for mobility, autonomy and overall quality of life. In particular, it increases the risk of falls and fractures.
Causes of sarcopenia
Sarcopenia is not a fatality of aging, but the result of a combination of factors. Physical inactivity, insufficient protein in the diet, and hormonal changes (such as a drop in testosterone in men and estrogen in women) can be the main causes. As the body ages, it also becomes more difficult to repair and maintain muscle mass.
Are you at risk?
The diagnosis of sarcopenia takes into account muscle mass and function. It is not, however, a sudden onset disease, but a progressive one linked to muscle loss. Loss of muscle mass occurs as early as middle age around 40 (∼1%/year) and, in the most severe cases, can reach ∼50% in the 8th or 9th decade of life [1]. Below you’ll find a calculator to estimate your muscle mass [2] and the potential age of onset of low muscle mass (11 kg/m2 for men and 9 kg/m2 for women) [3]
About calculations
The calculator uses formulas developed in a study investigating the relationships between height, age, mass, waist circumference and muscle mass [2]. This study was based on a large database of 12,330 individuals from the National Health and Nutrition Survey (NHANES). Skeletal muscle mass was measured by dual-photon absorptiometry (DXA), and an MRI-derived predictive equation was used to calculate total muscle mass from lean limb mass (arms and legs). For low muscle mass thresholds, these were determined from a base of 1293 patients with muscle mass measurement by bioimpedancemetry (BIA) and comparison to handshake strength.