TABLE 2.
Nocturnal symptoms, early morning symptoms, sleep disturbances and cognitive functioning in the study population
| COPD | GOLD I | GOLD II | GOLD III | GOLD IV | p-value# | |
| Subjects n | 562 | 194 | 232 | 103 | 33 | |
| Nocturnal symptoms | ||||||
| IUATLD shortness of breath | 100 (17.8) | 10 (5.2)¶,+,§ | 39 (16.8)+,§ | 31 (30.1)§ | 20 (60.6) | <0.001 |
| IUATLD coughing | 203 (36.1) | 39 (20.1)¶,+,§ | 80 (34.5)+,§ | 60 (58.3) | 24 (72.7) | <0.001 |
| Early morning symptoms | ||||||
| Coughing | 232 (41.3) | 35 (18.0)¶,+,§ | 91 (39.2)+,§ | 76 (73.8)§ | 30 (90.9) | <0.001 |
| Expectoration | 264 (47.0) | 37 (19.1)¶,+,§ | 112 (48.3)+,§ | 88 (85.4) | 27 (81.8) | <0.001 |
| Sleep disturbances | ||||||
| EPESE points | 4.2±4.4 | 4.5±4.5 | 4.1±4.4 | 3.7±4.1 | 5.1±4.6 | 0.257 |
| EPESE ≥8 | 175 (31.1) | 64 (33.0) | 70 (30.2) | 29 (28.2) | 12 (36.4) | 0.739 |
| EPESE difficulty falling asleep | 97 (17.3) | 38 (19.6) | 31 (13.4) | 23 (22.3) | 5 (15.2) | 0.160 |
| EPESE nocturnal awakenings | 171 (30.4) | 64 (33.0) | 68 (29.3) | 31 (30.1) | 8 (24.2) | 0.720 |
| EPESE morning tiredness | 38 (6.8) | 29 (14.9) | 38 (16.4) | 19 (18.4) | 8 (24.2) | 0.569 |
| EPESE early awakenings | 94 (16.7) | 14 (7.2) | 213 (5.6) | 9 (8.7) | 2 (6.1) | 0.748 |
| Cognitive functioning | ||||||
| Age and education adjusted MMSE | 28.4±3.7 | 28.9±2.9 | 28.4±4.0 | 27.7±4.6 | 28.6±3.1 | 0.064 |
| MMSE ≤24 | 142 (25.3) | 39 (20.1) | 68 (29.3) | 24 (23.3) | 11 (33.3) | 0.107 |
| MMSE orientation percentage correct | 0.93±0.1 | 0.96±0.09¶ | 0.92±0.16 | 0.92±0.15 | 0.93±0.14 | 0.014 |
| MMSE memory percentage correct | 0.86±0.2 | 0.87±0.17 | 0.86±0.18 | 0.83±0.20 | 0.85±0.18 | 0.228 |
| MMSE attention and calculation percentage correct | 0.76±0.3 | 0.78±0.31 | 0.75±0.34 | 0.72±0.36 | 0.79±0.30 | 0.462 |
| MMSE language percentage correct | 0.91±0.1 | 0.95±0.10¶,+ | 0.91±0.14 | 0.88±0.19 | 0.91±0.12 | 0.001 |
| MMSE design copying failed | 178 (33.3) | 48 (25.3)+ | 76 (34.5) | 41 (43.6) | 13 (43.3) | 0.001 |
Data are presented as n, mean±sd or n (%), unless otherwise stated. COPD: chronic obstructive pulmonary disease; GOLD: Global Initiative for Chronic Obstructive Lung Disease; IUATLD: International Union against Tuberculosis and Lung Disease Bronchial Symptoms questionnaire; EPESE: Established Populations for Epidemiologic Studies of the Elderly questionnaire; MMSE: Mini-Mental State Examination. #: comparisons between patients with COPD GOLD grade I–IV; ¶: p<0.05 versus GOLD II; +: p<0.05 versus GOLD III; §: p<0.05 versus GOLD IV.