Metabolically healthy obese adults had higher CRP levels than metabolically healthy non-obese (SMD 0.63; 95% CI 0.49-0.76) and unhealthy non-obese, but lower than unhealthy obese subjects.
Meta-Analysis (n=435,007)
Does the metabolically healthy obese (MHO) phenotype have different levels of inflammatory markers (CRP, IL-6, TNF-α) compared to other obesity phenotypes in adults?
Metabolically healthy obesity is associated with higher systemic inflammation than metabolically healthy non-obese states, but lower inflammation than metabolically unhealthy obesity, suggesting MHO is an intermediate inflammatory state.
Effect estimate: SMD 0.63 (95% CI 0.49-0.76)
AIMS: The aim of this study was to systematically review and analyze differences in the levels of C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) comparing metabolically healthy but obese (MHO) with metabolically healthy non-obese (MHNO), metabolically unhealthy non-obese (MUNO), and metabolically unhealthy obese (MUO) subjects. DATA SYNTHESIS: We searched PubMed, Embase, Web of Science, and Scopus for studies that matched the relevant search terms. Differences in inflammatory marker levels between MHO and the other three phenotypes were pooled as standardized mean differences (SMD) or differences of medians (DM) using a random-effects model. We included 91 studies reporting data on 435,007 individuals. The CRP levels were higher in MHO than in MHNO subjects (SMD = 0.63, 95% CI: 0.49, 0.76; DM = 0.83 mg/L, 95% CI: 0.56, 1.11). The CRP levels were higher in MHO than in MUNO subjects (SMD = 0.16, 95% CI: 0.05, 0.28; DM = 0.39 mg/L, 95% CI: 0.09, 0.69). The CRP levels were lower in MHO than in MUO individuals (SMD = -0.43, 95% CI: -0.54, -0.31; DM = -0.82 mg/L, 95% CI: -1.16, -0.48). The IL-6 levels in MHO were higher than in MHNO while lower than in MUO subjects. The TNF-α levels in MHO were higher than in MHNO individuals. CONCLUSIONS: This review provides evidence that CRP levels in MHO are higher than in MHNO and MUNO subjects but lower than in MUO individuals. Additionally, IL-6 levels in MHO are higher than in MHNO but lower than in MUO subjects, and TNF-α levels in MHO are higher than in MHNO individuals. SYSTEMATIC REVIEW REGISTRATION: PROSPERO number: CRD42021234948.
Su et al. (Sat,) conducted a meta-analysis in Obesity phenotypes (n=435,007). Metabolically healthy obese (MHO) phenotype vs. MHNO, MUNO, and MUO phenotypes was evaluated on Differences in C-reactive protein (CRP) levels between MHO and MHNO subjects (SMD 0.63, 95% CI 0.49-0.76). Metabolically healthy obese adults had higher CRP levels than metabolically healthy non-obese (SMD 0.63; 95% CI 0.49-0.76) and unhealthy non-obese, but lower than unhealthy obese subjects.