ICAM1 and obstructive sleep apnea syndrome: These include differences in diagnostic criteria for OSA across studies (e.g., varying AHI cut-offs), lack of standardization in ICAM-1 measurement techniques (e.g., different assay platforms or sample types such as serum vs. plasma), as well as variations in study population age, sex distribution, comorbidities, and lifestyle-related variables such as smoking status, physical activity, and body mass index.