Bariatric surgery in obesity: changes of glucose and lipid metabolism correlate with changes of fat mass.
OBJECTIVE
Bariatric surgery induces significant weight loss and improves glucose metabolism in obese patients (BMI>35 kg/m(2)). Our aim was to compare restrictive (LAGB, laparoscopic gastric banding) and malabsorptive approaches (BIBP, biliary-intestinal bypass) on the loss of fat-free mass (FFM), fat mass (FM), and on changes of glucose and lipid metabolism.


RESULTS
Body composition (bio-impedance analysis, BIA), blood glucose (BG), insulin, triglycerides, total- and HDL-cholesterol, liver enzymes (AST and ALT) were measured at baseline and 1 year after surgery in patients undergoing LAGB, BIBP, and in diet-treated control patients. In the main study, with patients matched for initial BMI (43-55 kg/m(2), LAGB=24, BIBP=12, controls=6), decreases of BMI, FM, BG and cholesterol were greater in patients with BIBP than with LAGB (p<0.01), while decreases of FFM, insulin, HOMA-IR and triglycerides were similar. No effects on BMI, FM, FFM, BG, insulin, HOMA-IR or cholesterol were observed in the control patients. Decreases of BG, insulin, HOMA-IR, cholesterol and triglycerides correlated with FM but not with FFM decrease. Similar results were obtained in an additional study in patients with a different initial BMI (LAGB=25, BIBP=6, controls=24) and when considering all subjects together. A decrease of liver enzymes (ALT) was greater with LAGB than with BIBP, and HDL-cholesterol increased with LAGB and decreased with BIBP.


CONCLUSIONS
BMI, FM, BG and cholesterol decrease more with malabsorptive than with restrictive surgery, while FFM, insulin, HOMA-IR and triglycerides decrease in a similar way. FFM loss is of low entity. Changes of glucose and lipid metabolism are proportional to a decrease of fat mass but not of fat-free mass.
Frige'
F
F
Università degli Studi di Milano, Milano, Italy.
Laneri
M
M
Veronelli
A
A
Folli
F
F
Paganelli
M
M
Vedani
P
P
Marchi
M
M
Noe'
D
D
Ventura
P
P
Opocher
E
E
Pontiroli
A E
AE
D000273:Adipose Tissue / Q000473:pathology*; D000328:Adult; D050110:Bariatric Surgery / Q000379:methods*; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism*; D001823:Body Composition; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D015391:Gastroplasty / Q000379:methods; D006801:Humans; D007328:Insulin / Q000097:blood; D007408:Intestinal Absorption; D007581:Jejunoileal Bypass; D010535:Laparoscopy; D050356:Lipid Metabolism; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000473:pathology / Q000601:surgery*; D011184:Postoperative Period; D014280:Triglycerides / Q000097:blood
D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D014280:Triglycerides; D002784:Cholesterol