Effect of Alcohol Consumption on Balance as Measured by Posturography

Abstract

Objectives:

Evaluate the effect of increasing blood alcohol concentration (BAC) on the vestibular system as measured by abnormal body sway on posturography. Determine if there is a consistent level of BAC during which sway becomes adversely affected, as suggested by legal state limits of BAC for driving.

Methods:

Prospective study of 30 healthy adults randomized to alcohol versus no alcohol who consumed one beverage hourly followed by BAC measurement by BACtrack Select S80 Breathalyzer and posturography on both firm/soft surfaces with eyes open/closed. Primary outcome was dose-response rate of BAC on mean body sway. Nonlinear growth models were used to control for covariates.

Results:

The experimental (alcohol) group had 20 adults, and the control (no alcohol) group had 10 adults. BAC levels measured by breathalyzer ranged from 0 to 0.12. Overall analysis showed no statistically significant difference between male and female performance (P > 0.05). Increased alcohol consumption was associated with increased abnormal body sway (P < 0.05); however, the exact level of BAC inducing abnormal sway was variable from individual to individual. An ANOVA model demonstrated a trend toward a learning curve with repeat posturography for the control group.

Conclusions:

This study demonstrated increasing vestibular dysfunction from increasing alcohol ingestion as measured with abnormal body sway by posturography. While all participants eventually showed increased sway with increased BAC, the point at which abnormal sway became evident was highly variable between individuals. Therefore, using strict state legal BAC limits do not always correlate with balance impairment.