Dorzagliatin and 1st Phase Insulin and Beta-cell Glucose Sensitivity in IGT and NGT

Inclusion Criteria: 1. Individuals aged ≥ 18 years but \< 65years 2. Male or female 3. Body mass index of over 18 kg/m2 and \< 30 kg/m2 Additional inclusion criteria for IGT group * Fasting plasma glucose \<7.0 mmol/L and HbA1c \< 6.5% * 2 hour plasma glucose ≥7.8 and \<11.1 mmol/L on 75g oral glucose tolerance test (OGTT) * Never been treated with glucose lowering drugs (including traditional Chinese medicine for glycemic control) Additional inclusion criteria for NGT group * Fasting plasma glucose \<5.6 mmol/L and HbA1c \< 5.7% * 2 hour plasma glucose \<7.8 mmol/L on 75g oral glucose tolerance test (OGTT) * Never been treated with glucose lowering drugs (including traditional Chinese medicine for glycemic control Exclusion Criteria: 1. Subjects who do not agree to participate in this study. 2. Country of birth is unknown. 3. Body weight less than 45kg. 4. Acute phase of cerebrovascular and cardiovascular diseases (within 6 months of recruitment). 5. Subjects with severe renal dysfunction as defined by eGFR \<30 ml/min/1.73m2 or patients receiving renal dialysis (such as haemodialysis or continuous ambulatory peritoneal dialysis). 6. Severe hepatic dysfunction as defined by AST and/or ALT \> 3 times upper limit of normal. 7. Severe cardiovascular disease, history of stroke, heart failure (NYHA III or IV) or history of myocardial infarction within last 12 months. 8. History of drug abuse or excessive alcohol intake based on investigator judgment. 9. History of diabetes mellitus. 10. Dehydration, diarrhoea or vomiting at the time of recruitment. 11. Subjects with severe infection, in perioperative period or with serious injury at the time of recruitment. 12. Subjects with anaemia (Haemoglobin \<11.0mg/dL or haematocrit \<0.35 ) at screening, known iron deficiency, haemoglobinopathies or anaemia due to chronic disease. 13. Pregnant or lactating or intending to become pregnant within 30 days after last dose of study drug. 14. Participation in a clinical trial with investigational product within 30 days before enrolment. 15. Donation or loss of blood (excluding the volume of blood that will be drawn during screening procedures) as follows: ≥300 mL of blood within 30 days prior to study drug administration. 16. Subjects judged unsuitable for the study based on investigator judgment. 17. Use of strong or moderate CYP3A4 inhibitors or inducers and cannot be discontinued. 18. Unwilling or unable to follow protocol requirements