Kallwitz et al. [14] observed that the severity of OSA was related to increased alanine aminotransferase (ALT) levels and also suggested that the apnea–hypopnea index (AHI) was a major contributing factor to abnormal levels of ALT or aspartate transaminase (AST), but AHI was not an independent risk factor for NASH [15]. Here, GPT is linked to obstructive sleep apnea syndrome.