Konjac-Glucomannan Fibre Blend and American Ginseng in Type 2 Diabetes

The study used a partially blinded, randomized, placebo controlled, crossover design. Due to the nature of the fibres it was not possible to blind the participant with respect to type of fibre. The study was divided into two phases with each phase having a four 4-week run-in period, and a 12-week treatment period, separated by a minimum 4-week wash-out period.

The treatments consisted of an ad libitum Canadian Diabetes Association recommended diet supplemented with capsules which contained either cornstarch (control) or AG (test) and a fiber supplement consisting of either wheat bran (control) or a viscous fiber blend of konjac mannan and xanthan (test). Participants were asked to attend the clinic at weeks -4, 0, 3, 6, and 12 during each phase.

Outcome measures There were three levels of outcome measures including efficacy, safety, and compliance. Statistical analysis The results are presented as mean ± SEM and considered statistically significant at p<0.05. Statistical analysis was performed using the SAS version 8.2 (SAS Institute, Cary, NC). Parametric analyses were conducted following a comparison of the sampling distribution to a normal distribution (Shapiro-Wilk and Kolmogorov-Smirnov tests). GLM was used to perform two-way ANOVA to detect differences of outcome variables in treatments and visits, controlling for treatment sequence and sex. If the effect of treatment was significant then percent differences were calculated between weeks 12 of test and control and analyzed using the GLM repeated measures one-way ANOVA controlling for sex. Parametric analyses were conducted following a comparison of the sampling distribution to a normal distribution (Shapiro-Wilk and Kolmogorov-Smirnov tests). The tests did not reject the null hypothesis at α=0.05. All comparisons were paired, thus each participant served as his/her own control. As this was a cross-over study, only participants who completed the study were included in the analysis.

Inclusion criteria

• Diagnosis of type 2 diabetes of at least 1 year
• age between 40 and 75 years old
• treated with diet and anti hyperglycemic medications
• HbA1c between 6.5% and 8.4%
• Systolic blood pressure <140mmHg
• Diastolic blood pressure <90mmHg
• Clinically euthyroid
• Normal renal and liver function

Exclusion criteria

• treated with insulin
• age less than 40 or older than 75 years old at the start of the trial