OBJECTIVETo investigate the effect and mechanism of Tangyikang (TYK) for improving pancreatic islet beta cell function in patients with latent autoimmune diabetes mellitus in adults (LADA).

METHODSSeventy-four LADA patients were randomly assigned to two groups. The 37 patients in the treatment group were treated with TYK decoction (one dose consisted of red ginseng 10 g, milkvetch root 30 g, lilyturf root 15 g, wild weed 10 g, coptis root 15 g, cape-jasmine fruit 10 g, giant knotweed rhizome 10 g, safflower 10 g and moutan bark 10 g) combined with insulin therapy, and the 37 in the control group treated with insulin therapy alone, and the course for all was 3 months. Changes of glycosylated hemoglobin, index of pancreatic islet beta-cell function (delta CP(2h)/delta BS(2h)), serum interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) were observed before and after treatment.

RESULTSAll the above-mentioned indexes were improved after treatment in both groups, the post-treatment data showed significant difference between groups in delta CP(2h)/delta BS(2h), (0.258 +/- 0.106 vs 0.168 +/- 0.054, higher in the treatment group, t = 4.626, P < 0.01), but with insignificant difference in glycosylated hemoglobin (t = 0.441, P = 0.660). Besides, the dosage of insulin used in the treatment group was less than that in the control group (t = -4.169, P < 0.01); covariance analysis showed, through excluding impact of different dosages insulin used, IL- 4 level was higher (F = 24.217, P < 0.01) and IFN-gamma level was lower (F = 14.198, P < 0.01) in the treatment group than those in the control group.

CONCLUSIONSTYK could improve the function of islet beta-cell, its possible mechanism is related with the regulation on cell immunity and the correction of T-lymphocyte subsets (Th1/Th2 ratio) imbalance.