Correlation of sleep quality, anxiety, depression and sympathetic skin response in chronic insomnia

Objective To investigate the correlation between chronic insomniacs′ sleep quality and age, gender, education level, anxiety, depression and sympathetic skin response (SSR) in chronic insomniacs. Methods General information of 197 outpatients with chronic insomnia was recorded, including age, gender and education, etc. They were tested by Pittsburgh′s Sleep Quality Index (PSQI), Hamilton′s Anxiety Scale (14 item version) (HAMA14), Hamilton′s Depression Scale (24 item version) (HAMD24) and Sympathetic Skin Response (SSR). Distribution properties of different age, gender and education groups were studied. Chronic insomniacs were divided into mild insomnia group (7≤PSQI<14) and moderate-severe insomnia group (PSQI≥14). Dependency relation analysis and stepwise linear regression analysis were conducted among indices of PSQI scores, HAMA14 scores and total score, HAMD24 scores and total score, SSR positive incidence. Results Among 197 chronic insomniacs (male, 50 cases, 25.4%; female, 147 cases, 74.6%), insomniacs aged over 40 accounted for 77.2%. Female patients were older than male patients with statistical significance, of whom those aged 40-60 years accounted for the highest proportion of 37.1%. Female patients with less education (junior high school and below) accounted for the highest proportion of 50.3% (73/197), whose education level was generally lower than male patients. Among 197 chronic insomniacs, 104 cases (52.8%, 99/197) had mild insomnia and 93 cases (47.2%) had moderate-severe insomnia. Total score of HAMA14 of patients with moderate-severe insomnia was significantly higher than that of patients with mild insomnia (16.47±5.40 vs 12.51±4.53; t=5.552, P<0.01). There was statistically significanct difference in subitem HAMA14 scores of anxiety somatization factor (4.31±2.26 vs 5.90±3.10, t=5.600, P<0.01) and spiritualized anxiety factor (10.5±72.97 vs 8.20±3.00, t=4.157, P<0.01) between mild and moderate-severe groups with insomnia. Total score of HAMD24 of patients with moderate-severe insomnia was significantly higher than that of patients with mild insomnia (18.04±5.91 vs 13.41±5.05; t=3.931, P<0.01). There was statistically significanct difference in scores of most HAMD24 subitems including anxiety/somatization (3.56±1.51 vs 2.94±1.28; t=3.110, P=0.002), cognitive dysfunction (2.91±1.68 vs 2.17±1.57; t=3.191, P=0.002), retardation (2.331±1.31 vs 1.72±1.22; t=3.939, P=0.01), dyssomnia (4.51±1.54 vs 3.01±1.80; t=6.228, P<0.01) and hopelessness factor (2.29±1.46 vs 1.66±1.07, t=3.459, P=0.001; except body weight and diurnal variation factor) between groups with different degrees of insomnia. SSR abnormal incidences of moderate-severe insomniacs were significantly higher than that of mild insomniacs. The proportion of poorly differentiated waveform and not elicited waveform in SSR abnormal groups had statistically significant difference. The Pearson correlation analysis showed that PSQI scores in chronic insomnia patients and HAMA14, HAMD24 score as well as abnormal rate of SSR were positively correlated (r=0.439, 0.465, 0.249, all P<0.01). Conclusions Chronic insomnia was commonly seen in middle-aged women with education level of junor high school and below. The degree of sleep quality and anxiety, depression as well as the abnormal rate of SSR was positively correlated in patients with chronic insomnia. Key words: Sleep initiation and maintenance disorders; Anxiety; Depression; Autonomic nerve dysfunction; Sympathetic skin responses