Sarcopenia, a loss of lean body mass that occurs with aging, is also associated with which change?

• A. Loss of bone mineral density
• B. Increased bone density
• C. Increased total body fat
• D. Decreased bone density

Answer: (D)

The main idea is how muscle and bone health are connected. When aging causes sarcopenia, there’s less lean muscle and weaker muscle contractions, which means bones receive fewer mechanical signals to stimulate growth and maintenance. Bone responds to these loads by remodeling; with reduced stimulation, bone resorption can outpace formation, leading to a decrease in bone mineral density. That drop in density is what we mean by decreased bone density. While some aging people also gain fat, the change most directly linked to loss of muscle mass is weaker bone density, increasing fracture risk.