This is a randomized controlled trial with 12 month sleep education as intervention, followed by a 12 month observational period, to study whether sleep education would improve glycemic control and cardiometabolic profile of sleep deprived type 2 diabetic patients and evaluate the neurohormonal changes associated with sleep education.

Patients will be identified from the Diabetes Mellitus and Endocrine Centre of Prince of Wales Hospital and Yao Chung Kit Diabetes Assessment Centre, The Chinese University of Hong Kong. All participants will have diabetes complications screening and comphrensive evaluations for glycemic control and cardiometabolic risk factors.Eligible subjects will be randomized to 2 groups (usual or conventional care versus intervention with sleep education program) for 12 months.

Inclusion Criteria:

1. Aged 18-65 years
2. Type 2 diabetes mellitus
3. Chinese ethnicity
4. Able and willing to give informed written consent
5. Sleep deprived, defined as subjective sleeping time <6 hours per day

Exclusion Criteria:

1. Type 1 diabetes mellitus
2. Known history of psychiatric disorders (e.g. depression, anxiety, dementia)
3. Sleep disorders secondary to another medical condition (e.g. obstructive sleep apnoea (OSA), circadian rhythm sleep disorder)
4. Concomitant chronic medical condition that was likely to be the cause of sleep problem (e.g. benign prostatic hypertrophy, chronic pain)
5. Concurrent use of hypnotic drugs, psychotic medications and any drugs that are known to affect sleep.
6. Any condition, as judged by the investigators, as ineligible to participate in this study