Validity of the 6 min walk test in outpatients with bipolar disorder

Abstract

Cardiorespiratory fitness is a major modifiable risk factor for cardiovascular diseases. People with bipolar disorder have a reduced cardiorespiratory fitness and its assessment within a multidisciplinary treatment therefore is necessary. We investigated the validity of the 6min walk test in people with bipolar disorder. A secondary aim was to assess clinical and demographic characteristics that might interfere with cardiorespiratory fitness performance. 19 (5♂) outpatients (47.1±8.3 years) underwent a 6min walk test and a maximal cardiopulmonary exercise test on a cycle ergometer and completed the Positive-and-Negative-Affect-Schedule (PANAS) and Beck Depression Inventory (BDI). The distance achieved on the 6min walk test correlated moderately with peak oxygen uptake obtained during the maximal cardiopulmonary exercise test. The variance in age, weight and the PANAS negative score explained 70% of the variance in the distance achieved on the 6min walk test. The 6min walk test can be used as a measure-of-proxy to gauge cardiorespiratory fitness in people with bipolar disorder when maximal cardiopulmonary exercise test equipment is not available. Negative mood should be considered when evaluating the cardiorespiratory fitness of this vulnerable population.