title: Cholesterol absorption decreases after Roux-en-Y gastric bypass but not after gastric banding.
abstract: The differences in cholesterol metabolism after the 2 most common forms of obesity surgery, Roux-en-Y gastric bypass (RYGB) and gastric banding (GB), have not been well characterized. In this study, effects of RYGB and GB on cholesterol absorption and synthesis were investigated. To this aim, 1-year follow-up of cholesterol metabolism in 2 nonrandomized cohorts undergoing either RYGB (n = 29; age, 45.2 +/- 7.7 years; body mass index [BMI], 46.0 +/- 6.1 kg/m(2)) or GB (n = 26; age, 45.9 +/- 8.6 years; BMI, 50.1 +/- 7.7 kg/m(2)) was performed in a university hospital center specializing in the treatment of morbid obesity. Serum markers of cholesterol synthesis (cholestenol, desmosterol, and lathosterol) and cholesterol absorption (campesterol, sitosterol, avenasterol, and cholestanol) were measured preoperatively and at follow-up and expressed as ratios to cholesterol. As expected based on observed weight loss (25% after RYGB and 17% after GB, P < .001 between groups), both operations decreased serum levels of cholesterol synthesis markers by 12% to 28% (all Ps < .001). A decrease in cholesterol absorption markers was only observed after RYGB (-26% for sitosterol) and not after GB (+16%, P = 2 x 10(-6) for difference between the groups). The difference in sitosterol ratio between the groups remained significant after adjustment for age, BMI, fasting insulin levels, and nutritional status (P = 2 x 10(-4)), indicating a specific effect related to RYGB. We conclude that decrease in cholesterol absorption is a novel beneficial effect of RYGB. Together with an improved control of blood glucose, this may contribute to a better cardiovascular risk profile after RYGB.
authors.affiliation: Department of Medicine, University of Kuopio and Kuopio University Hospital, 70210 Kuopio, Finland. jussi.pihlajamaki@uef.fi
authors.forename: Jussi
authors.initials: J
authors.lastname: Pihlajamäki
authors.forename: Sari
authors.initials: S
authors.lastname: Grönlund
authors.forename: Marko
authors.initials: M
authors.lastname: Simonen
authors.forename: Pirjo
authors.initials: P
authors.lastname: Käkelä
authors.forename: Leena
authors.initials: L
authors.lastname: Moilanen
authors.forename: Matti
authors.initials: M
authors.lastname: Pääkkönen
authors.forename: Elina
authors.initials: E
authors.lastname: Pirinen
authors.forename: Marjukka
authors.initials: M
authors.lastname: Kolehmainen
authors.forename: Vesa
authors.initials: V
authors.lastname: Kärjä
authors.forename: Sakari
authors.initials: S
authors.lastname: Kainulainen
authors.forename: Matti
authors.initials: M
authors.lastname: Uusitupa
authors.forename: Esko
authors.initials: E
authors.lastname: Alhava
authors.forename: Tatu A
authors.initials: TA
authors.lastname: Miettinen
authors.forename: Helena
authors.initials: H
authors.lastname: Gylling
mesh_terms: D000328:Adult; D000713:Anastomosis, Roux-en-Y; D050110:Bariatric Surgery; D001786:Blood Glucose / Q000378:metabolism; D001827:Body Height / Q000502:physiology; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D002784:Cholesterol / Q000096:biosynthesis / Q000378:metabolism; D002791:Cholesterol, Dietary / Q000493:pharmacokinetics*; D008078:Cholesterol, LDL / Q000097:blood; D005260:Female; D015390:Gastric Bypass; D006801:Humans; D007408:Intestinal Absorption / Q000502:physiology*; D008099:Liver / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism / Q000601:surgery; D010840:Phytosterols / Q000097:blood; D013261:Sterols / Q000097:blood
chemical_list: D001786:Blood Glucose; D002791:Cholesterol, Dietary; D008078:Cholesterol, LDL; D010840:Phytosterols; D013261:Sterols; D002784:Cholesterol