Study hypothesis: Waking up in response to an alarm clock may evoke a stress reaction that leads to rising glucose concentrations.

The purpose of this study was to prove this hypothesis with continuous glucose monitoring over three nights.

Night (a) with an alarm clock set at 2 h intervals for glucose self monitoring,

Night (b) with a nurse performing blood glucose determinations, and

Night (c) with the patients left undisturbed.

To provide nocturnal glucose control in patients with type 1 diabetes is a therapeutic challenge. Nocturnal glucose profiles are an important tool to secure adequate glycemic control during the night. Often, patients are asked to perform self-monitoring with the help of an alarm clock. Such a recommendation depends on the accuracy of glucose concentrations determined this way. We hypothesized that alarm clocks may trigger a stressful arousal that might be accompanied by rises in glucose concentrations, consecutively leading to nocturnal glucose profiles that are not representative for undisturbed conditions.

We want to prove this hypothesis with 30 patients over three nights.

Night (a) with an alarm clock set at 2 h intervals (midnight, 2 a.m., 4a.m. and 6:45 a.m) for glucose self monitoring,

Night (b) with a nurse performing blood glucose determinations at the 2 h intervals (midnight, 2 a.m., 4a.m. and 6:45 a.m), and

Night (c) with the patients left undisturbed.

All the patients are going to use a continuous glucose monitor and half of the patients (uneven numbers) are going to have an indwelling venous cannula during night (a) and (b.

During night (a) and (b) 5-7 minutes after the scheduled times for glucose measurements the doctoral candidate is going to take the pulse, another capillary blood sample for a laboratory glucose determination (EBIOS, Eppendorf, Hamburg, Germany). Also the doctoral candidate is going to take a venous blood sample in half of the patients (uneven numbers), blood from the indwelling venous cannula for the determination of epinephrine, norepinephrine, cortisol, glucagon, growth hormone, and prolactin (determined by specific immunoassays at Biocientia laboratories, Jena, Germany).

Inclusion Criteria:

• Type 1 Diabetic patients (diagnosed longer than 2 years)
• HBA1c 5,0 - 9,5 %
• Age 18-75 years
• Hospitalized patients
• Male or female, if female exclusion of pregnancy or secure contraception
• Body-Mass-Index 19-40 kg/m²
• Patient is elucidated
• Patients agreement

Exclusion Criteria:

• Type 2-Diabetic patients or other forms of diabetes beside type 1 diabetes, diagnosed after the guidelines of the Deutsche Diabetes Gesellschaft
• HbA1c < 5,0 % or > 9,5 %
• A severe hypoglycemia with unconsciousness within the last 2 month
• Body-Mass-Index < 19 or > 40 kg/m²
• No patient agreement
• Pregnancy (positive pregnancy test) or unsecured contraception.
• Agina pectoris or acute myocardial infarct, as continuous problem
• Inadequate treated arterial hypertension > 160 mmHg systolic and/or < 95 mmHg diastolic
• Active tumor disease
• Anemia hemoglobin < 11,5 g/dl
• Treatment with steroids, sedative or anesthetics
• Infection/fewer > 37.5 °C
• Renal- malfunction (serum- creatinine > 1.5 mg/dl)
• Liver- malfunction (GPT and AP > double of upper- limit)
• Alcohol or drug abuse
• Sleep disorder
• Participation in clinical studies within the last 3 month
• Other significant health dysfunctions, which would affect the outcome of this study
• Incapable to conform the requirements of the protocol