Increased Adipose Tissue Insulin Resistance in Metabolic Syndrome: Relationship to Circulating Adipokines

<jats:sec> <jats:title>Background:</jats:title> <jats:p>Although hepatic insulin resistance has been documented in patients with metabolic syndrome using homeostasis model assessment of insulin resistance (HOMA-IR) as a measure, there is scanty data on adipose insulin resistance (Adipo-IR) and its relationship with the dysregulation of adipokines in metabolic syndrome. Thus, we examined whether Adipo-IR is increased in metabolic syndrome as well as its correlation with circulating adipokines.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods:</jats:title> <jats:p>In 42 individuals including controls and participants with metabolic syndrome, we measured fasting plasma insulin and free fatty acids (FFA). Adipo-IR was calculated as the product of FFA×insulin. We examined the association between Adipo-IR, metabolic syndrome variables, and circulating adipokines, including leptin, adiponectin, chemerin, omentin-1, and retinol-binding protein-4.</jats:p> </jats:sec> <jats:sec> <jats:title>Results:</jats:title> <jats:p> Adipo-IR was higher in metabolic syndrome ( <jats:italic toggle="yes">n</jats:italic> =19; median 68.7 mmol/L·pmol/L; 25 <jats:sup>th</jats:sup> –75 <jats:sup>th</jats:sup> percentile, 50.0–104.7) compared to controls ( <jats:italic toggle="yes">n</jats:italic> =23; 22.9 mmol/L·pmol/L; 6.8–36.1; <jats:italic toggle="yes">P</jats:italic> <0.0001), and this difference was similar following adjustments for waist circumference or body mass index (BMI). Adipo-IR correlated significantly with certain adipokines: Leptin, <jats:italic toggle="yes">r</jats:italic> =0.45, <jats:italic toggle="yes">P</jats:italic> =0.004; adiponectin, <jats:italic toggle="yes">r</jats:italic> =−0.33, <jats:italic toggle="yes">P</jats:italic> <0.05; chemerin <jats:italic toggle="yes">r</jats:italic> =0.55, <jats:italic toggle="yes">P</jats:italic> =0.0008; omentin-1, <jats:italic toggle="yes">r</jats:italic> =−0.46, <jats:italic toggle="yes">P</jats:italic> =0.04, and with all features of metabolic syndrome. </jats:p> </jats:sec> <jats:sec> <jats:title>Conclusions:</jats:title> <jats:p>Adipo-IR is increased in metabolic syndrome following adjustment for adiposity and may be an important biomarker of adipose tissue dysregulation, including adipokine secretion and a potential relevant therapeutic target.</jats:p> </jats:sec>