Research on the comprehensive therapy for impaired glucose tolerance (IGT) by traditional Chinese medicine

INTERVENTION: 1. Traditional Chinese medicine Tian‐qi Jiang‐tang Capsule™, 5 capsules three times a day, combined with lifestyle interventions 2. Placebo combined with lifestyle interventions Lifestyle interventions: Diabetes experts will give a talk on physical exercise and diet to a group of participants at baseline, lasting about 45 minutes. In addition, the researchers (usually doctors) will give advice to the participants individually at baseline and every 3 months. We will examine the results of the lifestyle interventions every 3 month by questionnaires, and will adjust the individual advice according to the results of the questionnaires. Total duration of interventions: 3 years CONDITION: Type 2 diabetes/ cardiovascular diseases ; Nutritional, Metabolic, Endocrine ; Non‐insulin‐dependent diabetes mellitus PRIMARY OUTCOME: Blood glucose (FPG and 2hPG of OGTT) at baseline, and every 3 months during intervention (3 years) and follow‐up (6 months). SECONDARY OUTCOME: Risk of cardiovascular disease, assessed by the following: ; 1. Blood lipid, assessed at baseline, 6, 12, 18, 24, 30 and 36 months; 2. Blood pressure, measured at baseline and then every 3 months during the intervention (3 years) and follow‐up (6 months) ; 3. BMI, measured every 3 months during the intervention (3 years) and follow‐up (6 months); 4. Electrocardiogram (ECG), carried out every 6 months during the intervention (3 years); ; The following will be assessed in a sub‐group of approximately 500 participants: ; 1. HbA1c, assessed every 6 months during the intervention (3 years); 2. Urinary albumin excretion rate (UAER), assessed at baseline, at 3, 6, 12 and 36 months ; 3. High‐sensitivity C‐reactive protein (hs‐CRP) baseline, 12 and 36 months; 4. Adiponection, baseline, 12 and 36 months ; 5. OGTT: ; 5.1. At baseline (0 hour), assessed at baseline and every 3 month during the intervention (3 years) and follow‐up (6 months) ; 5.2. 0.5 hours, assessed at baseline, 6, 12, 24 and 36 months; 5.3. 1 hour, assessed at baseline, 12 and 36 months; 5.4. 2 hours, assessed at baseline and then every 3 months during the intervention (3 years) and follow‐up (6 months) ; 6. Insulin level: ; 6.1. Baseline insulin level, measured at baseline (0 month) and every three months until 12 months, and then 24 and 36 months; 6.2. Insulin level at 0.5 hours, measured at baseline (0 month) and every three months until 12 months, and then 24 and 36 months ; 6.3. Insulin level at 1 hour, measured at baseline (0 month), 12 and 36 months; 6.4. Insulin level at 2 hours, measured at baseline, every three months until 12 months, and then 24 and 36 months; ; Note: We will choose the participants who will likely to be compliant for the sub‐group study. INCLUSION CRITERIA: 1. Both males and females 2. 25 =< age <=70 3. Intravenous plasma glucose: Fasting plasma glucose (FPG) <7.0 mmol/L and 2‐hour plasma glucose (2hPG) of oral glucose tolerance test (OGTT) <11.1 mmol/L, >=7.8 mmol/L 4. Deficiency of both qi and yin syndromes accompanied by heat 5. Taking no medicine for treatment of IGT 6. 18.5 kg/m2 < body mass index (BMI) <30 kg/m2 7. Voluntariness, and signed letter of consent 8. Those who do not take part in any other trails within 3 months