Herbal capsule may lower risk of developing type 2 diabetes in prediabetes patients

Patients with impaired glucose tolerance who were treated with Chinese herbs for a year were significantly less likely to develop diabetes than matched patients who didn't take the herbs, a study found.

In a double-blind, multicenter trial, researchers randomized 420 Chinese patients with impaired glucose tolerance (IGT) to receive placebo pills or Tianqui capsules for 12 months. The capsules contain 10 Chinese herbal medicines and are used in China to treat type 2 diabetes. Patients underwent glucose tolerance tests every 3 months to see if normal glucose tolerance was restored or if diabetes had developed. Patients in both groups received a month of lifestyle education, including nutrition counseling, and were asked to maintain their usual patterns of exercise. Results were published in the February Journal of Clinical Endocrinology & Metabolism.

Three hundred eighty-nine patients completed the trial. Eighteen percent of the patients in the Tianqui group (n=36) and 29% in the placebo group (n=56) developed diabetes (P=0.01). Tianqui reduced the risk of diabetes by 32% compared to placebo, according to Cox proportional hazards model analysis. Also, patients in the Tianqui group were more likely to have normal glucose tolerance after 12 months (63% vs. 47%; P=0.001). Patients didn't differ significantly by group in terms of body weight or body mass index changes after a year, and neither group experienced serious adverse events. Fifteen patients in the Tianqui group had mild adverse reactions versus 11 in the placebo group; these included flatulence, nausea, constipation and diarrhea.

The risk reduction associated with Tianqui is less than what has been found with rosiglitazone (62%) and pioglitazone (72%), but similar to that of acarbose (25%) and metformin (31%), the researchers noted. The capsule was safe and well tolerated, they added, suggesting Tianqui has potential for preventing type 2 diabetes, especially in areas where herbal medicines are widely used and culturally accepted.