To exam the metabolomic profiling of CSF and plasma in diabetes and establish the human CSF Metabolome Database of Type 2 DM.

Human cerebral spinal fluid (CSF) is known to be a rich source of small molecule biomarkers for central neurological and neurodegenerative diseases. However, the metaboloic bases of CSF in diabetes patient have not been studied. In this plan, the investigators will use analytical platforms, including nuclear magnetic resonance (NMR), liquid chromatography-mass spectrometry (LC-MS), to perform quantitative metabolomics on human CSF and blood samples and further establish the human CSF Metabolome Database of DM. This work will can supply important CSF metabolic profit information and help to facilitate a wide range of metabolomic studies on central nervous system diseases and their associations disease.

Inclusion Criteria:

Diabetes group

1. .20-75 years of age
2. .Type 2 diabetes patient by clinical diagnosis
3. .American Association of Anesthesiologists (ASA)≦III

Control group (non-diabetic group):

1. .20-75 years of age
2. .No history of DM and other systemic illness
3. .American Association of Anesthesiologists (ASA)≦ II

Exclusion Criteria:

1. patient refuses to sign informed consent

2. patients with coagulopathy, systemic infective disease and severe liver and renal function impairment.

3. patients with spine or brain tumor and severe CNS disease.

4. the presence of severe and/or uncontrolled and/or unstable medical disease within 12 months prior to study other than DM which could compromise participation in the study (e.g. acute pancreatitis, stroke, liver cirrhosis, congestive heart failure, and systemic immune disorder etc.

5. Concurrent participation or planning to participate in another interventional clinical trial (Concurrent participation in an observational trial allowed)

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Patients with received spinal anesthesia and had written informed consent