Muscle Dysfunction and Bone Loss in a Woman With Cystic Fibrosis and Obesity Treated With Glucagon‐Like Peptide 1 Agonist: A Case Report

When people lose weight using GLP-1 agonists, about half of the weight lost comes from muscle and bone tissue.

A woman with cystic fibrosis and obesity experienced a reduction in bone mineral density at the hip to osteoporotic levels and at the spine to osteopenic levels over 2.5 years, during which she lost weight and took semaglutide, even though her vitamin D levels were normal and no other causes were found.

In a 42-year-old woman with cystic fibrosis, obesity, and type 2 diabetes, taking 1 mg of semaglutide weekly for 12 months resulted in a 14.8% loss of total body weight and measurable decreases in muscle mass, muscle strength, and bone mineral density at the spine and hip, even with structured exercise and nutrition support.

A woman with cystic fibrosis and obesity gained 15.0 kilograms and experienced increased blood sugar levels after starting elexacaftor/tezacaftor/ivacaftor, which led to her beginning semaglutide treatment.

In people with cystic fibrosis who lose weight using semaglutide, muscle mass and strength continue to decrease over 12 months even when they follow standard exercise and nutrition programs.

In women with cystic fibrosis, obesity, and diabetes, taking semaglutide for 12 months lowered blood sugar to target levels and reduced body weight by 14.8%, while muscle and bone health worsened.