Tilt table testing in obesity

An imbalance between the sympathetic and parasympathetic nervous systems has been indicated in obesity. The aim of the present study was to evaluate the results of tilt table testing (TT) in obese patients.

59 patients with simple obesity (F/M: 50/9; BMI: 36.9+/-3.9 kg/m(2)), and 19 healthy subjects of the control group (F/M: 16/3; BMI: 24.7+/-4.3 kg/m(2)) were examined. Additionally, TT was carried out in 11 patients from the obese group after a 3-month weight reduction treatment. We evaluated HR (heart rate), SBP (systolic blood pressure), DBP (diastolic blood pressure): values at rest, post-inclination values (HRt-1, SBPt-1, DBPt-1), differences between the maximum and minimum values as obtained on TT (HRt-range, SBPt-range, DBPt-range), and % differences of HR (%HRt-increase, %HRt-decrease, %HRt-range).

A positive TT response was observed in 10 obese patients, and in none of the controls. Higher differences of HR values were observed in the obese (P<0.05) in comparison to control group. Patients with a positive TT response presented a significant increase in HRt-1, HRt-range, and %HRt-range when compared to negative TT and controls (P<0.02). A 3-month weight reduction treatment resulted in a decrease in HR at rest, and decrease in SBP and DBP-both rest values and values after table-inclination.

A positive TT response is observed more often in patients with simple obesity. HR reaction to tilting varies between the patients and controls. A 3-month weight reduction treatment influences the cardiovascular response to tilting. Our results seem to support the hypothesis of autonomic imbalance in obesity.