The effects of diet- and RYGB-induced weight loss on insulin sensitivity in obese patients with and without type 2 diabetes.
OBJECTIVE
The impact of diet-induced weight loss and weight loss due to RYGB in patients with (T2DM, N = 16) and without (OB, N = 27) type 2 diabetes was studied.


METHODS
At inclusion (A), after diet-induced weight loss (B), 4 months post-surgery (C) and 18 months post-surgery (D) body composition, hepatic glucose production (HGP), insulin-mediated glucose uptake (GIR), respiratory exchange ratio, hepatic insulin sensitivity and clearance were determined. GLUT4, intramuscular triglycerides (IMTG) and glycogen content were measured in skeletal muscle.


RESULTS
Weight loss was 35-40 kg, and approximately one-third of the total improvement in GIR in T2DM was observed after the diet-induced weight loss of only ~6 kg (B). Insulin clearance, visceral fat and fasting plasma insulin also improved significantly after the diet (P < 0.05). Throughout the study, HGP, GLUT4 and glycogen content did not change significantly, but IMTG decreased significantly consistent with significant increases in GIR. Metabolic flexibility and hepatic insulin sensitivity improved after RYGB.


CONCLUSIONS
Metabolic improvements of RYGB are present already after the diet-induced weight loss prior to surgery. GLUT4 content in skeletal muscle cannot and IMTG content can only partly explain increases in GIR after RYGB.
Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark. hansen.merethe@gmail.com.
Merethe
M
Hansen
Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.|Department of Surgery, Koege University Hospital, Lykkebaekvej 1, 4600, Koege, Denmark.
Michael Taulo
MT
Lund
Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
Anne Line Kjærholm
AL
Jørgensen
Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
Marie Kroman
MK
Palsøe
Clinical Metabolism, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.
Gerrit
G
van Hall
Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
Jørn Wulff
JW
Helge
Xlab, Center for Healthy Aging, Department of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
Flemming
F
Dela
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D004038:Diet, Reducing / Q000009:adverse effects*; D005260:Female; D015390:Gastric Bypass / Q000009:adverse effects*; D006003:Glycogen / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D009765:Obesity / Q000150:complications* / Q000178:diet therapy / Q000601:surgery; D014280:Triglycerides / Q000097:blood; D015431:Weight Loss
D001786:Blood Glucose; D007328:Insulin; D014280:Triglycerides; D006003:Glycogen
Bariatric surgery; GLUT4; Glycogen; IMTG; Insulin sensitivity; RYGB; Type 2 diabetes mellitus