Postural hypotension and postural dizziness in patients with non-insulin-dependent diabetes

Background: Postural hypotension with a decline of 20 mm Hg or more in syst olic blood pressure on standing is considered a potentially dangerous hypot ensive response. Postural dizziness is often strongly associated with postu ral hypotension. However, there is conflicting evidence, and previous studi es have been confined to the elderly, not specifically to patients with dia betes. Thus, we evaluated the association between postural hypotension and postural dizziness, and determined the factors most likely related to postu ral hypotension in patients with diabetes. Methods: The subjects were 204 consecutive noninsulin-dependent patients wi th diabetes and 408 age- and sex-matched control subjects. Postural hypoten sion was defined as a decline of 20 mm Hg or more in systolic blood pressur e 1 minute: after standing. Postural dizziness was any feelings of dizzines s, lightheadedness, or faintness that occurred while standing during the ex amination. Results: The prevalence of postural hypotension and postural dizziness in p atients with diabetes was higher than in control subjects. Those patients w ith both diabetes and postural hypotension were-older and had higher supine systolic blood pressures and higher plasma glycosylated hemoglobin and fas ting glucose levels. They had higher prevalence of postural dizziness, hype rtension, and cerebrovascular disease; and lower standing systolic blood pr essures than those without postural hypotension. They also were more often being treated with antihypertensive agents. Only 32.8% of patients with dia betes with postural hypotension Suffered from postural dizziness. Postural dizziness, hypertension, cerebrovascular disease, and plasma glycosylated h emoglobin levels were independently associated with postural hypotension in patients with diabetes. Conclusions: Postural dizziness, glycemic control, hypertension, and cerebr ovascular-disease were important determinants of postural hypotension in pa tients with diabetes. Postural hypotension was associated with postural diz ziness, but it cannot be determined clinically just from the presence of po stural dizziness because the sensitivity for diagnosis of postural hypotens ion is low.