CRP and metabolic syndrome: Based on prior knowledge and current literature, MetS was primarily analyzed as an exposure (Lin et al. 2022; Mottillo et al. 2010; Zhu et al. 2023) for most comorbidities and complex traits, while it was considered an outcome in analyses involving BMI, BMR, CRP, and vitamin D (Xu et al. 2020; Ridker et al. 2008; Timpson et al. 2005).