The tilt test: effect of diabetes mellitus and antihypertensive medication on normal values

The Tilt Test is a commonly used clinical tool for the assessment of volume depletion. Most of the data pertaining to the normal limits of the Tilt Test were determined by studying normal, healthy volunteers. Patients presenting with possible volume depletion, however, may have medical conditions (e.g., diabetes) or be taking medication (e.g., antihypertensives) that may affect the cardiovascular response to the Tilt Test. One hundred thirty-three euvolemic, asymptomatic outpatients (34 diabetics, 20 patients on beta blockers, 31 patients on diuretics, 28 patients on diuretics plus beta blockers, and 20 patients on clonidine hydrochloride) underwent Tilt testing. The readings obtained from each subgroup were compared to 33 sex- and age-matched controls who had no medical problems and were on no medications. No significant differences among the groups could be determined. We conclude that in otherwise euvolemic, asymptomatic patients, neither diabetes mellitus nor the specific antihypertensives studied interfere with the normal response to the Tilt Test.