Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR, China
This review focuses on the efficacy and safety of Chinese medicine in the treatment of type-2 diabetes. Included were 84 controlled clinical studies of type-2 diabetes treated with Chinese medicine for at least 1 month. Reported outcomes were: symptom relief; improvement in glycemia, insulin resistance and secondary failure, and adverse events. Symptom relief was achieved in most (>80%) of the patients receiving Chinese medicine. Compared with orthodox drugs, Chinese medicine had a 1.2-fold (95% CI 1.2-1.3) increase in symptom relief. The relative risk of achieving a fasting blood glucose of <7.3mmol/l or a postprandial blood glucose of <8.2mmol/l was: 3.0 (95% CI 1.4-6.5) for Chinese medicine plus diet versus diet; 2.0 (95% CI 1.4-3.0) for Chinese medicine versus placebo; 1.8 (95% CI 1.4-2.3) for combined Chinese medicine and orthodox drugs versus Yuquan Wan (a classic Chinese herbal formula for diabetes), 1.5 (95% CI 1.4-1.7) for combined Chinese medicine and orthodox drugs vs. orthodox drugs, and 1.3 (95% CI 1.2-1.5) for Chinese medicine versus orthodox drugs. A fasting blood glucose of <8.2mmol/l plus symptom relief was observed in 71-100% of the patients with secondary failure to oral anti-diabetic drugs. Serious adverse events including hypoglycemic coma and death were caused by adulteration with orthodox drugs, erroneous substitution, self-meditation, overdoses, and improper preparation. Chinese herbal medicine should be used cautiously with doctors' prescription and follow-up. Long-term clinical studies may disclose the effectiveness of Chinese medicine in reducing the mortality and morbidity of diabetic complications.
Copyright © 2006 Nestec Ltd., Vevey/S. Karger AG, Basel
Diabetes mellitus is a group of complex diseases characterized by chronic hyperglycemia due to defects in insulin secretion, insulin action, or both. The long-term damage of chronic hyperglycemia of diabetes occurs in various organs, especially the eyes, kidneys, nerves, heart, and blood vessels. Type-2 diabetes is the most prevalent form of diabetes that often coexists with other metabolic components such as obesity, hypertension and dyslipi-demia. In China, type-2 diabetes is increasing in epidemic dimensions. In 2002 the National Survey on the Status of Nutrition and Health of the Chinese People conducted in adults over the age of 18 years revealed an increased morbidity from overweight (22.8% and 200 million, prevalence and total number), obesity (7.1% and 60 million), hypertension (18.8% and 160 million), impaired fasting glucose (1.9% and 20 million), diabetes (2.6% and 27 million), and dyslipidemia (18.6% and 160 million) . The prevalence of metabolic syndrome is approximately 13% in the Chinese population [1, 2].
In parallel to the epidemic trend of diabetes and metabolic syndrome, the integration of traditional Chinese medicine (TCM) into the management of diabetes and metabolic syndrome has also grown. In hospital clinics, over 70% of adult patients with type-2 diabetes used both TCM and Western medicine [3, 4]. Over a 25-year period between 1981 and 2005, 511 clinical trials of TCM included 33,274 patients with type-2 diabetes. The majority (96%) of the patients had integrated treatment with TCM and Western medicines . This review expounds evidence from clinical and pharmacological studies of TCM in the treatment of diabetes.
The clinical studies included in this review meet the following criteria : (1) controlled trials; (2) adult participants (18 years or older) with type-2 diabetes; (3) documented diagnostic criteria of type-2 diabetes; (4) intervention of TCM including Chinese herbal medicines and Chinese proprietary medicines for a duration of at least 1 month; (5) outcomes of all-cause mortality, cardiocerebrovascular events, quality of life, symptom-relief rate and normalization of blood glucose, and (6) adverse events (death, stroke, hypoglycemia, liver toxicity, kidney damage). Major findings from relevant mechanistic and pharmacological studies were highlighted to provide insight explanations of clinical efficacy. Electronic databases on Wan Fang data (827 Chinese medical journals by July, Week 3, 2005), Cochrane Library (2nd Quarter, 2005), and MEDLINE (1966 to July, Week 2, 2005) were searched using the index terms for type-2 diabetes, clinical trials and Chinese medicine. Relative risk (RR) with 95% confidential interval (CI) was used to express data extracted from the controlled trials of TCM.
TCM is both an art and a science of patient-centered healing with combined attention to body, mind, and spirit. Knowledge of TCM has been enriched for over 4,000 years of observation, investigation and clinical experience. The philosophy of TCM is rooted in Chinese cultures of Taoism (to follow nature's way) and Confucius (to nurture humanity and morality) and the religion of Buddhism (to free from suffering). Traditionally, TCM doctors are usually pharmacists and pharmacologists who themselves identify and collect herbs, prepare formulation and follow up their patients. Most of the published clinical trials of TCM were conducted by TCM doctors.
TCM includes Chinese herbal medicine (CHM), acupuncture and specialized disciplines of surgery, orthopedics, pediatrics, and obstetrics and gyne-cology. Qigong (energy practice), Tuina (massage), Chinese martial arts, and diet per se are not representatives of TCM, although diet therapy is an important modality in disease management. Chinese herbs and herbal products are not necessarily the same term of TCM. In literature, TCM is characterized by individualized treatments based on the differentiation of syndrome (Zheng).
CHM is the major modality in TCM practice. A prescription for CHM usually refers to a compound recipe (Fu Fang) that consists of principal, assistant, adjuvant, and guiding herbs to maximize therapeutic effects and minimize toxic effects. Ingredients in a CHM prescription are individualized and changed on a weekly basis to tailor for the patient's age, gender, symptoms, anthropological characters, geological location and living environment. From a literature review, approximately 1,200 recipes and 150 herbs for diabetes, metabolic syndrome and associated complications have been documented since 1980 [5, 7-9]. Table 1 lists the Chinese herbs and classic recipes commonly used in clinical trials in diabetes and diabetic complications [5, 7, 8]. Although the bioactive components of most medicinal herbs remain unknown, several kinds of chemical compounds have reported properties for lowering blood glucose, increasing insulin secretion, and improving insulin resistance [7, 10]. The compounds extracted from Chinese herbal medicines include flavonoids, xanthones, triterpenoids, alkaloids, glycosides, alkyldisulfides, aminobutyric acid derivatives, guanidine, polysaccharides, peptides, and minerals [7, 10, 11].
TCM is particularly effective in symptom relief. A systemic review of 6 clinical trails by Liu et al.  reported that most of the type-2 diabetic patients receiving CHM experienced an improvement in symptoms of dry mouth, polyphagia, polydipsia, polyuria, fatigue, sweating, constipation, numb limbs, and low back pain (table 2). Improvement rates were higher in patients receiving CHM than those treated with antidiabetic drugs (table 2). After using either CHM alone or integrated CHM and Western medicine for at least 2 months, symptoms also substantially improved in most (>80%) of the patients with diabetic complications. Reported complications include diabetic gastroparesis [12-16], nephropathy [17-25], neuropathy [26-44], retinopathy [45-47], gangrene [48, 49], peripheral vascular disease [50-52], and myocar-dial infarction .
Table 1. Traditional Chinese medicine for diabetes mellitus
Single herbs - Chinese Pin
Chi Xiao Dou
Di Gu Pi
Huai Niu Xi
Jin Ying Zi
Niu Bang Zi
Sang Piao Xiao
Sang Shen Zi
Shan Dou Gen
Shan Zhu Yu
She Chuang Zi
Sheng Di Huang
Sheng Shai Shen
Yin and English name Ovate atractylodes White peony root Pinellia Hyacinth bean Silkworm moth Atractylodes root Bupleurum root Red Peony root Adsukibean Ligusticum root Rhubarb Moutan bark Salvia root Angelica Codonopsis root Lycium root bark Eucommia bark Zedoary Poria
Liquorice root Pueraria root Cibotium root Achyranthes root Phellodendron bark Polygonatum root Coptis root Astragalus root Scutellaria root Silkworm
Cherokee rose fruit Litchee pit Ophiopogon tuber Arctium seed Ginseng
Mulberry root bark
Mantis egg-case powder
Root of straight sophora
Asiatic cornelian cherry fruit
Dried rehmannia root
Table 1. (continued)
Shu Di Huang Tai Zi Shen Tao Ren Tian Dong Tian Hua Fen Wu Wei Zi Xi Yang Shen Xian Ling Pi Xuan Shen Yi Mi Yi Mu Cao Yu Zhu Ze Xie Zhi Mu Zhu Ling
Classic recipes and ingredients
(white tiger decoction)
Buyang Huanwu Tang (decoction invigorating Yang for recuperation)
Liuwei Dihuang Wan (bolus of rehmannia six)
Shen Qi Wan (bolus invigorating the kidney Qi)
Yu Quan Wan (jade spring bolus)
Cooked rehmannia root Pseudostellaria root Peach kernel Arisaema tuber Trichosanthes root Schisandra berry American ginseng Epimedium herb Scrophularia root Coix seed Leonurus
Solomon's seal root Alisma tuber Anemarrhena root Polyporus
- Chinese Pin Yin and English name Shi Gao (gypsum) Zhi Mu (wind-weed rhizome) Gan Cao (prepared licorice root) Geng Mi (polished round-grained nonglutious rice)
1) Huang Qi (astragalus root)
2) Dang Gui (Chinese angelica root)
3) Chi Shao (red peony root)
4) Chuan Xiong (Chuanxiong rhizome)
5) Tao Ren (peach kernel)
6) Hong Hua (safflower)
7) Di Long (earthworm)
Shu Di Huang (prepared rhizome of rehmannia)
Shan Zhu Yu (dogwood fruit)
Shan Yao (dried Chinese yam)
Ze Xie (oriental water plantain)
Fu Ling (poria)
Mu Dan Pi (mountain bark)
Di Huang (dried rehmannia)
Shan Yao (Chinese yam)
Shan Zhu Yu (dogwood fruit)
Ze Xie (oriental water plantain)
Fu Ling (poria)
Mu Dan Pi (mountain bark)
Gui Zhi (cinnamon twig)
Fu Zi (prepared aconite root)
Ge Gen (pueraria root)
Tian Hua Fen (trichosanthes root)
Mai Dong (ophiopogon tuber)
Sheng Di Huang (dried rehmannia root)
Geng Mi (polished round-grained nonglutinous rice)
Gan Cao (prepared licorice root)
Wu Wei Zi (schisandra berry)
Table 2. Improvement rates (%) of diabetic symptoms in 35 clinical trials of Chinese medicine
Was this article helpful?