Evidence lacking for Chinese medicine in diabetes

While there is some evidence that Chinese herbal medicines may help treat people with impaired glucose control most of the studies are not well designed and have a high risk of bias, a Cochrane review concludes. Although herbal medicines are widely used in Asian countries to treat IGT there is still not enough hard scientific evidence to confidently recommend their use, researchers said. The review analysed 16 studies that included 15 unique herbal formulations, although only three of the 16 were classified by the review authors as well designed with a low risk of bias. Of these three trials, a double-blind, placebo controlled trial of Dan zhi jiang tang jiao reported a significant improvement in 2 hr-oGTT blood glucose, insulin and triglycerides but no significant difference in fasting blood glucose. The second double-blind trial compared Bofu-Tsusho-San plus lifestyle modification versus placebo plus lifestyle modification in 81 people over six months. People randomised to Bofu-Tsusho- San plus lifestyle modification demonstrated a significantly improved fasting blood glucose but not 2hr-oGTT blood glucose. There was no significant difference in glycosylated HbA1c between those taking Bofu-Tsusho-San and the control group. The third double-blind trial, comparing Qi wei jiangtang yin with placebo, demonstrated a significant improvement in the rate of normalisation of fasting blood glucose, reduction of fasting blood glucose, and 2hr-oGTT in those randomised to the placebo group. “Overall the positive evidence in favour of Chinese herbal medicines for the treatment of impaired glucose tolerance is constrained by the following factors: a lack of trials that tested the same medicine, lack of details on co-interventions, unclear methods of randomisation, poor reporting and other risks of bias,” the review authors concluded. Cochrane Database of Systematic Reviews 2009, Issue 4. Art. No.: CD006690.  ...