Scientific Reports
Resting blood irisin levels were lower in older adults
Each additional year of age was associated with 4.57 picograms per milliliter less resting plasma irisin, after accounting for body composition and physical activity.Each additional year of age was associated with 4.57 picograms per milliliter less resting plasma irisin, after accounting for body composition and physical activity.

Cross-sectional studyMechanisms
Who was studiedMiddle-aged and older adults
What changedResting blood irisin levels were lower at older ages
The catchIndividual changes in resting irisin with aging were not measured