Tohoku J. Exp. Med., 2005, 206(4)

Cognitive Decline in Patients with Long-Term Domiciliary Oxygen Therapy

TAKASHI OHRUI,^* KAZUNORI TANAKA,^3* KAZUE CHIBA,³ TOSHIFUMI MATSUI, SATORU EBIHARA, MEI HE, ICHIRO TSUJI,¹ HIROYUKI ARAI² and HIDETADA SASAKI

Department of Geriatric and Respiratory Medicine, ¹Division of Epidemiology, Department of Public Health, ²Department of Geriatric and Complementary Medicine, Tohoku University Graduate School of Medicine, Sendai, and ³Teijin Home Healthcare East Japan Limited, Saitama, Japan

Cognitive and psycho-physiological condition in patients with long-term domiciliary oxygen therapy (DOT) remains uncertain. A cross sectional analysis was performed to investigate the age-related changes in cognitive and psycho-physiologic functions in patients with chronic respiratory failure receiving long-term DOT. Two expert practitioners visited the patient's home and examined them for analysis of cognitive function, emotional status, physical activity and degree of dyspneic sensation. One hundred and thirty-five patients completed the study. Control data from a cohort of 718 community dwellers were also included in this study. Male patients had significantly higher rates of chronic obstructive pulmonary disease (71% vs 47%, p = 0.001), lower values of forced expiratory volume in one second (FEV1.0) % (49.7 ± 10.3 [standard deviation, S.D.] vs 66.0 ± 7.5% predicted, p = 0.002) and higher Borg score, an indicator of dyspneic sensation, during daily exercise (3.2 ± 0.8 [S.D.] vs 1.4 ± 0.6, p = 0.01) compared with female patients. Linear regression analysis based on mean Mini-Mental State Examination scores, an indicator of cognitive function, showed that age-related cognitive decline was more pronounced in female patients than in female controls (−0.524/year, R² = 0.426 vs −0.120/year, R² = 0.027, p < 0.0001), while there was no significant difference between male patients and male controls (−0.156/year, R² = 0.054, vs −0.077/year, R² = 0.016, p = 0.231). These results demonstrate that age-related cognitive decline is more exaggerated in female patients receiving long-term DOT which should be taken into consideration in caring for patients with chronic respiratory failure.

keywords —— chronic respiratory failure; domiciliary oxygen therapy; long-term survivor; cognitive function; Borg scale

© 2005 Tohoku University Medical Press

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^*The first two authors contributed equally to this work.

Correspondence: Takashi Ohrui, M.D., Department of Geriatric and Respiratory Medicine, Tohoku University Graduate School of Medicine, 1-1 Seiryomachi, Aoba-ku, Sendai 980-8574, Japan.