CRP and metabolic syndrome: There were generally no heterogeneities across age, sex, and BMI subgroups for the association between hs-CRP changes and MetS components (P for interaction ≥ 0.09), except for sex (P for interaction = 0.04) and BMI (P for interaction < 0.001) subgroups for elevated WC, age subgroups (P for interaction = 0.01) for elevated TG, and age subgroups (P for interaction = 0.02; Additional file 1: Table S6) for elevated BP.