Muscle hypotrophy, body mass index and mortality risk

Edited by Doctor Francesco Casillo

Men lose about 20% of their muscle mass between the ages of 40 and 60.
Usually, in individuals with muscularly hypotrophic arms this characteristic is accompanied by an increased circumference of the waist. British researchers found that such a combination predisposes to a high risk of mortality.

The researchers studied the mortality rate of 4107 men in an age group between 60 and 79 years. This monitoring study lasted 6 years. The circumference of the arm and waist were the 2 best predictors of the rate of Mortality: Small arms increased the risk of death by 36%.
The risk was raised to 55% if the reduced circumference of the arms was accompanied by a "high circumference at the waist. Underweight men with a body mass index of less than 18.5, and especially those with a large waist, reported the most high mortality rate.
Paradoxically and surprisingly, men with a body mass index within the recommended range to be optimal (20 to 25) were more prone to die during the time course of the study than overweight subjects with a higher body mass index, including between 25 and 30.
The maintenance of muscle mass and the decrease of visceral fat are therefore the key factors for longevity.

Bibliography:

American Journal Clinical Nutrition, 86: 1339 - 1346, 2007