title: The association between obesity and fluid intelligence impairment is mediated by chronic low-grade inflammation.
abstract: Published evidence suggests that obesity impairs cognition. Development of chronic low-grade inflammation (CLGI) represents the earliest consequence of obesity. The present study investigated the association between obesity and fluid intelligence impairment and assessed the potential mediating role of CLGI and psychological (depression/anxiety symptoms), lifestyle (exercise) and physiological (metabolic dysfunction indices) factors in this association. Clinically healthy participants (n 188), grouped as per BMI, underwent cognitive (General Ability Measure for Adults), psychological (Beck Depression Inventory-II and State-Trait Anxiety Inventory) and activity (Godin leisure-time physical activity) measurements. Biochemical parameters included the following: (a) indices of CLGI (high-sensitivity C-reactive protein, erythrocyte sedimentation rate and fibrinogen); (b) insulin resistance (Homeostasis Model Assessment of Insulin Resistance index); (c) adiposity (plasma adiponectin). An inverse association between elevated BMI and fluid intelligence was observed, with obese participants displaying significantly poorer performance compared with age-matched normal-weight peers. Structural equation modelling results were consistent with a negative impact of obesity on cognition that was mediated by CLGI. The results of the present study support the hypothesis that reduced general cognitive ability is associated with obesity, an adverse effect mainly mediated by obesity-associated activation of innate immunity.
authors.affiliation: Laboratory of Clinical Chemistry - Biochemistry, Department of Laboratory Medicine, School of Medicine, University of Crete,HeraklionGR-71003,Crete,Greece.
authors.forename: Eirini C
authors.initials: EC
authors.lastname: Spyridaki
authors.affiliation: Department of Psychiatry,School of Medicine, University of Crete,Heraklion,Crete,Greece.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Simos
authors.affiliation: Laboratory of Clinical Chemistry - Biochemistry, Department of Laboratory Medicine, School of Medicine, University of Crete,HeraklionGR-71003,Crete,Greece.
authors.forename: Pavlina D
authors.initials: PD
authors.lastname: Avgoustinaki
authors.affiliation: Laboratory of Clinical Chemistry - Biochemistry, Department of Laboratory Medicine, School of Medicine, University of Crete,HeraklionGR-71003,Crete,Greece.
authors.forename: Eirini
authors.initials: E
authors.lastname: Dermitzaki
authors.affiliation: Laboratory of Clinical Chemistry - Biochemistry, Department of Laboratory Medicine, School of Medicine, University of Crete,HeraklionGR-71003,Crete,Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Venihaki
authors.affiliation: School of Applied Psychology and Counselor Education, University of Northern Colorado,Greeley,CO,USA.
authors.forename: Achilles N
authors.initials: AN
authors.lastname: Bardos
authors.affiliation: Laboratory of Clinical Chemistry - Biochemistry, Department of Laboratory Medicine, School of Medicine, University of Crete,HeraklionGR-71003,Crete,Greece.
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Margioris
mesh_terms: D052242:Adiponectin / Q000097:blood; D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D003071:Cognition; D003072:Cognition Disorders / Q000209:etiology*; D015444:Exercise; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D007113:Immunity, Innate; D007249:Inflammation / Q000097:blood / Q000209:etiology; D007333:Insulin Resistance; D007360:Intelligence; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000150:complications* / Q000523:psychology; D055815:Young Adult
chemical_list: D052242:Adiponectin; D015415:Biomarkers; D005340:Fibrinogen; D002097:C-Reactive Protein