Exploration of cytokines relating to masked obesity in Japanese women.

BACKGROUND: Masked obesity (MO) has been associated with chronic inflammation; however, its immunological profile has not been extensively studied. OBJECTIVE: This exploratory study aimed to investigate immunological profile in MO by examining serum cytokine levels and clinical characteristics in individuals with reduced muscle mass and increased fat. METHODS: Body composition was assessed in 432 female employees of The University of Osaka (aged 30-59 years) using InBody270 during health examinations. Participants with skeletal muscle mass index (SMI) ≥ 5.7 kg/m² and percent body fat (PBF) < 30% were classified as the healthy (H) group, while those with SMI < 5.7 kg/m² and PBF ≥ 30% were classified as the MO group. Serum cytokine concentrations were measured in randomly selected participants, 34 from the H group and 24 from the MO group. RESULTS: Compared to the H group, the MO group had significantly higher triglyceride (p < 0.0001), low-density lipoprotein cholesterol (p = 0.0047), and insulin (p = 0.0008) levels, and significantly lower grip strength (p < 0.0001). Interleukin-17 C levels (unadj. p = 0.017, q = 0.33), colony-stimulating factor-1 (unadj. p = 0.051, q = 0.33) and lymphotoxin-alpha (unadj. p = 0.053, q = 0.33) levels tended to be lower, and interleukin-6 (unadj. p = 0.049, q = 0.33), C-C motif chemokine ligand (CCL) 8 (unadj. p = 0.064, q = 0.33) and CCL2 (unadj. p = 0.066, q = 0.33) levels tended to be higher in the MO group than in the H group. CONCLUSION: This exploratory study demonstrates that MO might be associated with circulating levels of some cytokines, suggesting that these cytokines could be potential biomarkers for MO.