Background: Despite a close association of adiponectin with metabolic syndrome (MetS), its usefulness as an additional MetS factor has not been well investigated.
Methods: We studied 2327 apparently healthy Japanese male office workers aged 35 to 66 years old and investigated cross-sectionally whether categorization by serum adiponectin distinguished participants' levels of high-sensitivity C-reactive protein (CRP) beyond the conventional MetS.
Results: In a linear regression analysis, adiponectin was associated with CRP independently of all MetS factors (beta=-0.192, P<0.001). Furthermore, a graded decrease in CRP level was observed with elevation of adiponectin in every stratum characterized by the presence or absence of each MetS component (trend P<0.05 in all strata except those of decreased high-density lipoprotein cholesterol or hyperglycemia). Similarly, geometric means of CRP levels (mg/l) decreased as adiponectin increased from the lowest to the highest tertile in all strata classified by the number of MetS components, though a P value did not reach statistical significance in those with 3 MetS components (the stratum of 0 MetS component: 0.41 [95% confidence interval, 0.34-0.49], 0.32 [0.28-0.37] and 0.26 [0.23-0.30], trend P<0.001; 1 component: 0.45 [0.39-0.52], 0.38 [0.34-0.43], and 0.32 [0.28-0.36], trend P<0.001; 2 components: 0.58 [0.50-0.67], 0.51 [0.44-0.60], and 0.46 [0.38-0.55], trend P=0.043; 3 components: 0.80 [0.66-0.96], 0.69 [0.55-0.87], and 0.58 [0.39-0.85], trend P=0.139).
Conclusions: Adiponectin evaluation provides additional inflammatory information on conventional MetS, supporting the potential of hypoadiponectinemia as an additional MetS component for identifying high-risk individuals for cardiovascular disease.