Increased levels of intracellular calcium are thought to diminish maximal cellular response to insulin and induce insulin resistance. Also, both hypertension and diabetes are thought to be conditions of altered intracellular ionic state. The aim of the present study is to investigate the possible effect of oral calcium supplementation on intracellular ions, insulin sensitivity, 24-h blood pressure and sodium/hydrogen exchanger activity in patients with type 2 diabetes and essential hypertension.

Inclusion Criteria:

• Patients with hypertension, diabetes and the metabolic syndrome (according to the definition of the National Cholesterol Education Program, Adult Panel III (NCEP, ATP III).
• Signed the concent form

Exclusion Criteria:

• Secondary Hypertension
• Stage II or III hypertension
• History of renal disease
• Sleep apnea
• Acute or chronic inflammation
• History of coronary artery disease
• Heart failure stage III or IV according to the New York Heart Association
• Active liver disease
• History of malignancy
• Parathyroidism
• History of kidney stones
• Calcium supplement ingestion
• Drugs that alter insulin resistance
• Treatment with insulin
• Alcohol abuse or other conditions with poor prognosis
• Treatment with non-inflammatory steroid agents, corticosteroids, or any other treatment that affects blood pressure