title: Associations of visceral and liver fat with the metabolic syndrome across the spectrum of obesity: the AGES-Reykjavik study.
abstract: Visceral adipose tissue (VAT) is a key pathogenic fat depot in the metabolic syndrome (MetS), but liver fat (LF) may also play an important role. We evaluated associations of VAT and LF with MetS in normal weight, overweight, and obese men and women (BMI <25, 25-29.9, and ≥30 kg/m2, respectively). This analysis included 2,495 participants from the Age, Gene/Environment Susceptibility (AGES)-Reykjavik study with computed tomography measurements for VAT and LF. MetS was defined by ≥3 of the following: larger abdominal circumference, hypertension, elevated triglyceride (TG), low high-density lipoprotein (HDL), impaired fasting glucose (IFG), and microalbuminuria. We estimated the odds of MetS per 1-s.d. increase in VAT and LF, adjusting for key covariates. VAT was associated with an increased odds of MetS in normal weight, overweight, and obese women (odds ratios (OR) = 2.78, 1.63, and 1.43, respectively; all P < 0.01) that diminished in magnitude with increasing BMI (VAT × BMI class interaction P < 0.001). In men, VAT was related to MetS only among the overweight (OR = 1.69, P < 0.01). LF was associated with MetS in the overweight and obese groups in women (OR = 1.38 and 1.45; both P < 0.001) and in men (OR = 1.38, P = 0.01; and OR = 1.27, P = 0.10), but not in the normal weight groups. These BMI-specific relationships persisted when both fat depots were included in the model. VAT and LF were associated with MetS independently of each other, and these relationships were modified by BMI class such that, VAT was the more important depot at lower levels of obesity and LF at higher levels. Importantly, fatty liver may be a novel metabolic risk factor in overweight and obese individuals.
authors.affiliation: Laboratory of Epidemiology, Demography, and Biometry, Intramural Research Program, National Institute on Aging, Bethesda, Maryland, USA. KimLJ@mail.nih.gov
authors.forename: Lauren J
authors.initials: LJ
authors.lastname: Kim
authors.forename: Michael A
authors.initials: MA
authors.lastname: Nalls
authors.forename: Gudny
authors.initials: G
authors.lastname: Eiriksdottir
authors.forename: Sigurdur
authors.initials: S
authors.lastname: Sigurdsson
authors.forename: Lenore J
authors.initials: LJ
authors.lastname: Launer
authors.forename: Annemarie
authors.initials: A
authors.lastname: Koster
authors.forename: Paulo H M
authors.initials: PH
authors.lastname: Chaves
authors.forename: Birna
authors.initials: B
authors.lastname: Jonsdottir
authors.forename: Melissa
authors.initials: M
authors.lastname: Garcia
authors.forename: Vilmundur
authors.initials: V
authors.lastname: Gudnason
authors.forename: Tamara B
authors.initials: TB
authors.lastname: Harris
mesh_terms: D050154:Adiposity; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005234:Fatty Liver / Q000000981:diagnostic imaging* / Q000209:etiology; D005260:Female; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D050152:Intra-Abdominal Fat / Q000000981:diagnostic imaging*; D008099:Liver / Q000000981:diagnostic imaging; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology* / Q000209:etiology; D009765:Obesity / Q000503:physiopathology*; D056128:Obesity, Abdominal / Q000503:physiopathology; D050177:Overweight / Q000503:physiopathology; D012307:Risk Factors; D012720:Severity of Illness Index; D012727:Sex Characteristics; D014057:Tomography, X-Ray Computed