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Do all placebos fit the definition of a “placebo”? The variation in glycemic response of different placebos in healthy individuals
Author(s) -
Ezatagha Adish,
Dascalu Anamaria,
Sievenpiper John L.,
Jovanovski Elena,
Panahi Shirin,
Jenkins Alexandra,
Vuksan Vladimir
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a580
Subject(s) - placebo , glycemic , medicine , lactulose , crossover study , lactose , analysis of variance , gastroenterology , insulin , food science , alternative medicine , pathology , chemistry
BACKGROUND Placebo is defined as an inert substance not possessing any biological effect. But this definition may not apply to all placebos. We previously noticed that a cornstarch‐placebo decreased the glycemic response to a 75g‐oral glucose tolerance test (75g‐OGTT) compared with a water‐control. Our objective was to investigate the effect of five common placebos on glycemia. METHODS Using a double‐blind, randomized, multiple‐crossover design, 10 healthy subjects (gender:6M:4F, age:33.1±4y, BMI:27.1±1.7kg/m2) received 7 treatments: 9g glucose‐placebo, lactose‐placebo, lactulose‐placebo, wheat‐bran‐placebo, and cornstarch‐placebo and two water controls. Each treatment was given 40‐min before a 75g‐OGTT with blood drawn at −40, 0, 15, 30, 45, 60, 90, and 120‐min. RESULTS Two‐way ANOVA showed a significant effect of treatment(p<0.001) and time (p<0.001) on incremental glycemia, with no interaction. Glucose‐placebo significantly reduced AUC by 41±15.4% (p<0.001) and peak glycemia (p<0.005) compared with the mean of the two water‐controls. It also reduced AUC (p<0.001) and peak glycemia (p<0.005) significantly compared with the cornstarch, lactulose and wheat‐bran placebos. CONCLUSIONS Glucose may not fit the definition of a true placebo. The implication is that the use of glucose as a placebo may lead to underestimation of efficacy in glycemic testing protocols. Travel grant: Inovobiologic, Calgary, AB.