Autonomic neuropathy is a common complication of type 2 diabetes mellitus. Symptoms from cardiovascular autonomic neuropathy include, dizziness, orthostatic hypotension and insufficient heart rate and blood pressure (BP) regulation during physical exertion. The degree of cardiovascular autonomic neuropathy is most commonly measured as cardiac autonomic neuropathy based on at least two abnormal cardiac reflex tests, which primarily measures parasympathetic indices of the autonomic nervous system (ANS).

Few measures are available for quantifying the sympathetic/adrenergic branch of the ANS.

Circadian changes in BP is a documented measure of BP variability, regulated centrally by a multitude of centers. A growing number of studies indicate that a diminished BP variability is associated with increased cardiovascular risk and injury. The ANS plays a pivotal role in the execution of these circadian BP changes, mainly through sympathetic adrenergic nerve fibers

Few studies have investigated the applicability of 24-hour indices as predictor for autonomic adrenergic dysfunction. No previous studies have investigated the association between clinical markers of adrenergic function, and 24-hour blood pressure indices in type 2 diabetes.

Inclusion Criteria:

• Type 2 diabetes
• Normal 12-lead ECG

Exclusion Criteria:

• Significant cardiovascular, muscular, lung, kidney or psychiatric disease
• Pregnancy
• Malignant disease, HIV, alcoholism or drug abuse
• Parkinson disease
• Ischemic heart disease
• Vital medicine that can affect the autonomic nervous system

Type 2 diabetics previously screened for diabetic polyneuropathy will be invited