6-Min walk-test data in severe obstructive-sleep-apnea-hypopnea-syndrome (OSAHS) under continuous-positive-airway-pressure (CPAP) treatment

Helmi Ben Saad1e， Ikram Ben Hassen1， Ines Ghannouchi， Imed Latiri， Sonia Rouatbi， Pierre Escourrou， Halima Ben Salem， Mohamed Benzarti2， Ahmed Abdelghani2

1These authors contributed equally to this work.

2These authors contributed equally to this work.

Aims

To assess their functional capacity, identify their 6-min walking-distance (6MWD) influencing factors and compare their data with those of two control-groups.

Methods

Sixty (42 males) clinically consecutive stable patients with severe OSAHS under CPAP were included. Clinical, Epworth questionnaire, anthropometric, polysomnographic, plethysmographic and 6-min walk-test (6MWT) data were collected. Univariate and multivariate analyses were used to identify the 6MWD influencing factors. Data of a subgroup of severe OSAHS aged ≥40 Yrs (n = 49) were compared with those of non-obese (n = 174) and obese (n = 55) groups.

Results

The means ± SD of age and apnea-hypopnea-index were, respectively, 49 ± 10 Yr and 62 ± 18/h. The profile of OSAHS patients carrying the 6MWT, was as follows: at the end of the 6MWT, 31% and 25% had, respectively, a high dyspnea (>5/10, visual analogue scale) and a low heart-rate (<60% of-maximal-predicted), 13% had an abnormal 6MWD (<lower-limit-of-normal), 13% had an oxy-hemoglobin saturation (oxy-sat) fall> 5 points and 3% stopped the walk. The factors that significantly influenced the 6MWD, explaining 80% of its variability, are included in the following equation: 6MWD (m) = 29.66 × first-second-forced-expiratory-volume (L) − 4.19 × Body-mass-index (kg/m2) − 51.89 × arterial-hypertension (0. No; 1. Yes) + 263.53 × Height (m) + 2.63 × average oxy-sat during sleep (%) − 51.06 × Diuretic-use (0. No; 1. Yes) − 20.68 × Dyspnea (NYHA) (0. No; 1. Yes) − 38.09 × Anemia (0. No; 1. Yes) + 5.79 × Resting oxy-sat (%) − 586.25. Compared with non-obese and obese groups, the subgroup of OSAHS has a significantly lower 6MWD [100 ± 9%, 100 ± 8% and 83 ± 12%, respectively).

Conclusion

Severe OSAHS may play a role in reducing the functional capacity.

respiratory medicine

May 2015Volume 109, Issue 5, Pages 642–655

DOI: http://dx.doi.org/10.1016/j.rmed.2015.03.001 |