Table 1.
Characteristics of the study population at baseline (n = 501)
| Variables | Patients (n = 181) | Control subjects (n = 320) | P-value |
|---|---|---|---|
| Age, years | |||
| Mean (SD) | 41.9 (11.1) | 44.6 (12.5) | 0.02a |
| Sex, n (%) | |||
| Male | 22 (12) | 197 (62) | <0.0001b |
| Female | 159 (88) | 123 (38) | |
| Telomere length | |||
| Mean (SD) | 0.77 (0.12) | 0.81 (0.14) | 0.006a |
| BMI, n (%)c | |||
| Underweight | 2 (1.1) | ||
| Normal weight | 70 (39) | N/A | N/A |
| Overweight | 56 (31) | ||
| Obese | 44 (24) | ||
| Smoking status, n (%)d | |||
| Yes | 27 (15) | N/A | N/A |
| No | 151 (83) | ||
| Alcohol status, n (%)e | |||
| Standard size drinks per week | |||
| < 1 | 100 (55) | ||
| 1–4 | 54 (30) | N/A | N/A |
| > =5 | 22 (12) | ||
| Education, n (%)f | |||
| Low | 15 (8) | ||
| Middle | 72 (40) | N/A | N/A |
| High | 92 (51) | ||
| Antidepressants, n (%)g | |||
| Yes | 63 (35) | N/A | N/A |
| No | 102 (56) | ||
| Tranquilizers, n (%)h | |||
| Yes | 27 (15) | N/A | N/A |
| No | 131 (72) | ||
| Baseline MADRS-S | |||
| Median score (IQR) | 20 (14–25) | N/A | N/A |
| Baseline HAD-D | |||
| Median score (IQR) | 8 (6–11) | N/A | N/A |
| Baseline HAD-A | |||
| Median score (IQR) | 12 (9–15) | N/A | N/A |
| Baseline PHQ-9 | |||
| Median score (IQR) | 13 (9–17) | N/A | N/A |
Abbreviations: SD Standard Deviation, BMI Body Mass Index, IQR Interquartile Range, N/A Not Available
Education: Low = 0–9 years; Middle = 10–12 years; High = More than 12 years
a P-value is given for the comparison of patients and control subjects using independent sample t-test
b P-value is based on Chi-square test
c9 (5%) had missing on BMI
d3 (2%) had missing on smoking status
e5 (3%) had missing on alcohol status
f2 (1%) had missing on education
g16 (9%) had missing on antidepressants
h23 (13%) had missing on tranquilizers