Partial ileal bypass affords protection from onset of type 2 diabetes.
BACKGROUND
Partial ileal bypass (PIB) in the National Institutes of Health-sponsored Program on the Surgical Control of the Hyperlipidemias (POSCH) randomized controlled trial was found to reduce plasma cholesterol, in particular low density lipoprotein cholesterol, with concomitant retardation of atherosclerotic cardiovascular disease and increased life expectancy. Glucagon-like peptide-1, related to amelioration of type 2 diabetes, is increased over 5-fold after PIB. We hypothesized that PIB, in addition to its action on cholesterol metabolism, may also prevent type 2 diabetes.


METHODS
We surveyed by telephone inquiry of former POSCH patients the 30+year posttrial incidence of type 2 diabetes or prediabetes, the presence of which was a trial exclusion criteria. We were able to contact 17.4% (n = 838) of the original POSCH population.


RESULTS
Of 66 control responders, 17 contracted type 2 diabetes (25.8%); of 80 PIB responders, 8 contracted type 2 diabetes (10%). The difference between groups was significant (P = .015 by Fisher exact test) with an odds ratio of .320 for the PIB group and an over 2-fold (2.6) increase in the incidence of type 2 diabetes in the controls. Including borderline type 2 diabetes (prediabetic) patients, these values were 22 of 66 controls (33.3%) and 10 of 80 PIB patients (12.5%), with an odds ratio of .286 and a P<.004, and again an over 2-fold (2.7) increase in the incidence of type 2 diabetes in the control patients.


CONCLUSIONS
PIB appears to afford partial protection from the onset of type 2 diabetes for over 30 years.
Department of Surgery, the Medical School, University of Minnesota, Minneapolis, Minnesota. Electronic address: buchw001@umn.edu.
Henry
H
Buchwald
Department of Surgery, the Medical School, University of Minnesota, Minneapolis, Minnesota.
Danette M
DM
Oien
Department of Surgery, the Medical School, University of Minnesota, Minneapolis, Minnesota.
Decel J
DJ
Schieber
Department of Medicine, the Medical School, University of Minnesota, Minneapolis, Minnesota.
John P
JP
Bantle
School of Public Health, the Medical School, University of Minnesota, Minneapolis, Minnesota.
John E
JE
Connett
D003924:Diabetes Mellitus, Type 2 / Q000517:prevention & control*; D005500:Follow-Up Studies; D015390:Gastric Bypass / Q000379:methods*; D006801:Humans; D006949:Hyperlipidemias / Q000601:surgery; D008297:Male; D011182:Postoperative Care; D011236:Prediabetic State / Q000517:prevention & control; D012189:Retrospective Studies
4 partial ileal bypass; POSCH; Type 2 diabetes