Diabetes mellitus type 1 is diagnosed on the basis of the clinical picture and laboratory parameters.
Optional medical device diagnostics – depending on the results of the history, physical examination, and laboratory diagnostics – to identify secondary diseases of diabetes mellitus.
- Cardiovascular diagnostics
- Repeated blood pressure measurement on both arms with cuff adjusted to arm circumference.
- 24-hour blood pressure measurement [not infrequently there is masked hypertension/high blood pressure].
- Ankle-brachial index (ABI; examination method that can describe the risk of cardiovascular disease) – in case of non-palpable or weakly palpable foot pulses (caveat: mediasclerosis).
- Transcranial Doppler sonography (ultrasound examination through the intact skull for orienting control of cerebral (“concerning the brain“) blood flow; brain ultrasound).
- Doppler sonography of the carotids (carotid arteries) – evidence of stenosis, plaques, or intima-media thickening (IMT) of the carotids indicate a 6-, 4-, and 2-fold increased risk of myocardial infarction (heart attack), respectively
- Exercise ECG (electrocardiogram during exercise, that is, under physical activity/exercise ergometry) – if myocardial ischemia (insufficient supply of the heart muscle (myocardium) with arterial blood) and normal resting ECG is suspected.
- Cardio-computed tomography (cardio-CT) – early detection of coronary vascular calcification.
- Cardiac catheter examination
- Renal sonography (ultrasound examination of the kidneys) – if renal dysfunction is suspected.
- Electrocardiogram (ECG; recording of the electrical activity of the heart muscle) – to check the electrical activity of the heart to clarify heart problems due to diabetes mellitus.
- Ophthalmologic examination (see “Further therapy” below).
- Visual acuity determination (determination of visual acuity); examination of the anterior segments of the eye.
- Funduscopy (reflection of the fundus of the eye, i.e., examination of the retina) with dilated pupil (see “Further notes” below)
Further notes
- Participants in the Diabetes Control and Complications Trial (DCCT) and its follow-up study, Epidemiology of Diabetes Interventions and Complications (EDIC), had type 1 diabetic patients examined by fundoscopy, and Markov analysis was used to calculate how long it took for 5% of patients to reach the next stage of retinopathy:
- Patients without retinopathy/retinal disease (stage 1): 4 years (on average).
- Patients with mild nonproliferative diabetic retinopathy (stage 2): 3 years.
- Patients with moderate nonproliferative diabetic retinopathy (stage 3): 6 months.
- Patients with severe nonproliferative diabetic retinopathy (stage 4: 3 months
Taking into account the HbA1c values:
- Baseline HbA1c < 6 percent: 1 percent of patients progressed to deterioration from stage 1 to stage 5 within five years
- Baseline HbA1c 10 percent: 4.3 percent of patients progressed from stage 1 to stage 5 within three years
This result indicates that over the course of 20 years, eight ophthalmologic examinations would be sufficient to detect progression of retinopathy in a timely manner.
