Postural blood pressure changes and associated factors in long-term Type 1 diabetes: Wisconsin Epidemiologic Study of Diabetic Retinopathy.

PURPOSE: To describe the frequency of orthostatic hypotension and hypertension and associations with risk factors in a cohort of persons with long-term Type 1 diabetes (n=440) participating in the Wisconsin Epidemiologic Study of Diabetic Retinopathy.

METHODS

Evaluations included detailed medical history, electrocardiography (ECG), and laboratory tests. Blood pressure (BP) was measured in supine and standing positions. Standing decrease in systolic (SBP) or diastolic (DBP) BP of at least 20 or 10 mmHg, respectively, was defined as orthostatic hypotension; increase of SBP from <140 to >or=140 mmHg or DBP from <90 to >or=90 mmHg was defined as orthostatic hypertension.

RESULTS

Prevalence of orthostatic hypotension and orthostatic hypertension was 16.1% and 15.2%, respectively. Some ECG measurements of cardiac autonomic dysfunction were significantly associated with orthostatic hypotension. Association between SBP and orthostatic hypotension and orthostatic hypertension were significant [odds ratio, 1.02 (95% confidence interval, or CI, 1.01-1.05) and 1.02 (95% CI, 1.01-1.04), per 1 mmHg, respectively] after adjusting for confounders. Interaction between SBP and age was observed. SBP was significantly associated with orthostatic hypotension and orthostatic hypertension in people <or=40 years old [1.35 (1.02-1.78) and 1.12 (1.05-1.18), respectively].

CONCLUSIONS

Results showed that measurements derived from the ECG can help describe an individual at increased risk of having postural BP changes. Moreover, SBP was associated with postural BP changes among individuals who were <40 years of age with long-term Type 1 diabetes.