title: Establishing computed tomography-defined visceral fat area thresholds for use in obesity-related cancer research.
abstract: Excess visceral adiposity is associated with increased gastrointestinal cancer risk. Evidence suggests that the systemic inflammation and dysmetabolism observed in visceral obesity underpins this association. Along with magnetic resonance imaging, computed tomography is a gold standard for abdominal fat quantification and is routinely available for gastrointestinal cancer research. However, no gender-specific cutoff values are currently available for classifying visceral obesity in white populations. Using the metabolic syndrome (MetSyn) as an indicator of obesity-associated dysmetabolism, this study aimed to establish pathologically relevant, gender-specific cut-off values for use in obesity-associated cancer research. Total, visceral and subcutaneous fat areas were calculated between the L3 and L4 invertebral space from computed tomography scans in a cohort of 170 males and 66 females undergoing gastrointestinal resection. Receiver operating characteristics analysis was used to determine cut-off values for total, visceral and subcutaneous fat areas associated with MetSyn. Linear regression was used to correlate these values with waist circumference. Visceral fat area (VFA) strongly correlated with the presence of MetSyn (P < .0001). The cut-off value for VFA associated with the presence of MetSyn was 163.8 cm(2) in males (83.6% sensitivity, 62.5% specificity) and 80.1 cm(2) for females (96% sensitivity, 73.2% specificity). The waist circumference corresponding to these VFA values was 96.1 cm in males and 83.2 cm in females. This study is the first to generate gender-specific and pathologically relevant cut-off values for VFA in patients with gastrointestinal cancer. In the field of obesity-associated research, this new anthropometric measure is of paramount importance for determining the accurate pathological obesity status of cancer patients.
authors.affiliation: Department of Surgery, Institute of Molecular Medicine, Trinity Centre for Health Sciences, St. James's Hospital, Dublin 8, Ireland.
authors.forename: Suzanne L
authors.initials: SL
authors.lastname: Doyle
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Bennett
authors.forename: Claire L
authors.initials: CL
authors.lastname: Donohoe
authors.forename: Ann Marie
authors.initials: AM
authors.lastname: Mongan
authors.forename: Julia M
authors.initials: JM
authors.lastname: Howard
authors.forename: Fiona E
authors.initials: FE
authors.lastname: Lithander
authors.forename: Graham P
authors.initials: GP
authors.lastname: Pidgeon
authors.forename: John V
authors.initials: JV
authors.lastname: Reynolds
authors.forename: Joanne
authors.initials: J
authors.lastname: Lysaght
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000209:etiology*; D006801:Humans; D050152:Intra-Abdominal Fat / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D024821:Metabolic Syndrome / Q000000981:diagnostic imaging* / Q000473:pathology; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000473:pathology; D012372:ROC Curve; D012016:Reference Values; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012737:Sex Factors; D014057:Tomography, X-Ray Computed; D055105:Waist Circumference