DNA Methylation and Gene Expression in Qataris With Type 2 Diabetes

With the assessment of the healthy vs. diabetic and pre-diabetic Qatari population the investigators intend to measure the changes in DNA methylation and gene expression in blood monocytes and lymphocytes attributed to diabetes, and to evaluate whether theses changes are persistent or can be reversed by improving diabetes control.

The global prevalence of Type 2 Diabetes (T2D) is rapidly rising throughout most regions of the developed and developing world. In Middle East countries, particularly in the Gulf Council countries, the diabetes pandemic along with the rates of obesity have risen due to the adoption of a modern lifestyle. In the Qatari population alone, T2D is highly prevalent as 18% of the Qatari adults are estimated to suffer from this disease. Consanguineous marriages, sedentary lifestyle, obesity and bad dietary habits are cited as the main causes for this high incidence rate. Chronic hyperglycemia caused by long-term uncontrolled diabetes state can lead to devastating complications such as cardiovascular diseases, neuropathy, and retinopathy. Such complications are also highly prevalent in the Qatari population, perhaps due to the relatively low adherence to clinical guidelines but vary among Qatari individuals based on their genetic predisposition and shared family environment.It is already known that inflammation is part of the complex biochemical process of initiating and further developing cardiovascular complications of diabetes. Experimental models have showed that exposure to hyperglycemia induces epigenomic changes in inflammatory pathways, which subsequently regulate gene expression leading to the development of vascular inflammation. The investigators therefore hypothesized that chronic hyperglycemia leads to altered DNA methylation and dysregulation of gene expression in peripheral blood monocytes and lymphocytes in patients with type 2 diabetes.

Eligibility Criteria:
Inclusion Criteria:

1. Must provide informed consent
2. Males or Females aged 30 years or older to minimize the potential confounding of other forms of diabetes mellitus
3. In patients with diabetes, no concomitant diseases except for micro- and macrovascular complications of diabetes (nephropathy, retinopathy, peripheral arterial disease, coronary artery disease, neuropathy) or symptoms of the metabolic syndrome (hypertension, dyslipidemia and obesity)
4. Not taking any chronic medications (except of the diabetes and cardiovascular related drugs).

Exclusion Criteria:

1. Diagnosis of Type-I Diabetes
2. Active situational diabetes (steroids use/pregnancy)
3. Active infection or acute illness of any kind
4. Chronic inflammation (auto-immune diseases) or infection
5. Evidence of malignancy within the past 5 years
6. Chronic hematological disorders known to affect glycated hemoglobin results such as hemoglobinopathies (e.g. sickle cell disease and thalassemia), increases red-cell turnover (e.g. hemolytic anemia and spherocytosis.

   * Evidence of malignancy within the past 5 years
   * Chronic hematological disorders known to affect glycated hemoglobin results such as hemoglobinopathies