Osteosarcopenic adiposity (OSA) syndrome, the coexistence of osteoporosis, sarcopenia, and adiposity (either excess or redistributed/infiltrated), has been studied globally in different populations and regions (mostly in East Asia, less in Europe and North America), resulting in varied prevalence. We aimed to determine the prevalence of OSA in a large population of apparently healthy Caucasian adults (18–90 years) and to compare it with the prevalence reported in other studies and other ethnicities. This study included 9719 participants (6412 women and 3307 men), stratified into four age-group categories, and recruited from the general medical practices in Italy. OSA was defined based on body composition measurements using bioelectrical impedance BIA-ACC®, which enables assessment of total bone mass, muscle/lean, and adipose tissues. The overall prevalence of OSA was 21.9% in women and 14.0% in men, and it significantly increased in every subsequent age group for both women and men (p < 0.001). The OSA prevalence was not significantly different between men and women below 40 years; however, it was considerably higher in women over 40 years. Participants with OSA had a significantly lower BMI compared to those without OSA, indicating OSA is a separate disorder not necessarily related to physiological fluctuations of BMI. The prevalence in Asian populations was lower than in our sample, indicating ethnic specificity. The relatively high prevalence of OSA detected in this study’s population across the age groups suggests the necessity for its appropriate and timely identification to prevent possible clinical outcomes, including fracture, dismobility, frailty, or chronic diseases.
