heart rate rose more in the higher-dose groups, peaked around week 24, then eased off
During GLP-1associated weight loss, lean-mass changes are typically adaptive and preventable , not degenerative. GLP-1 Body Composition Changes: What Clinical Trials Show About Muscle Loss Clinical trials and body-composition sub-studies of semaglutide and tirzepatide consistently demonstrate: Fat mass accounts for most weight lost during treatment. Lean mass may decrease , particularly without resistance training or adequate protein intake. In many patients, the proportion of lean mass relative to total body weight is preserved or improved , because fat loss exceeds lean loss. Key clinical insight: GLP-1/GIP therapies improve overall body composition by preferentially reducing fat massnot by causing muscle breakdown. Lean mass refers to all the non-fat tissues in the bodyprimarily skeletal muscle , but also organs, bones, connective tissue, and body waterthat support metabolism, movement, and overall physical function
However, during the weight loss process, lean body mass (including muscle) shows heterogeneity of increase, decrease, and remain unchanged in different clinical studies
It can be involved in helping to maintain normal protein structures in the body, marking certain molecules for elimination as waste in the liver, and in important enzymatic reactions necessary to neutralize potentially harmful free radicals throughout the body
