Table 2.
Telomere-length differences in relation to lifetime history of work-schedule characteristics
| N (%) | Age-adjusted* beta (Δ bp) | 95% CI | Covariate-adjusted† beta (Δ bp) | 95% CI | |
|---|---|---|---|---|---|
| N=608 | |||||
| Hours | |||||
| Full-time | |||||
| None/<1 year | 30 (5) | −389 | −848 to 71 | −528 | −991 to −66 |
| 1–5 years | 57 (9) | Referent | Referent | ||
| 6–10 years | 85 (14) | −168 | −518 to 182 | −155 | −510 to 200 |
| 11–20 years | 196 (32) | −202 | −508 to 106 | −274 | −587 to 37 |
| 20+ years | 240 (39) | −472 | −786 to−158 | −525 | −847 to−204 |
| p-trend‡ | 0.0017 | 0.0003 | |||
| Overtime | |||||
| None/<1 year | 284 (47) | Referent | Referent | ||
| 1–5 years | 95 (16) | −151 | −396 to 94 | −147 | −396 to 102 |
| 6–10 years | 82 (13) | 75 | −183 to 333 | 144 | −118 to 405 |
| 11–20 years | 86 (14) | 156 | −98 to 411 | 164 | −100 to 427 |
| >20 years | 61 (10) | 147 | −150 to 444 | 178 | −126 to 483 |
| p-trend | 0.13 | 0.08 | |||
| Part-time | |||||
| None/<1 year | 410 (67) | Referent | Referent | ||
| 1–5 years | 123 (20) | 4 | −207 to 215 | −4 | −220 to 212 |
| 6–10 years | 37 (6) | 317 | −38 to 627 | 332 | −27 to 690 |
| >10 years | 38 (6) | 401 | 55 to 749 | 356 | 1 to 711 |
| p-trend | 0.013 | 0.024 | |||
| Other characteristics | |||||
| Irregular hours | |||||
| None/<1 year | 420 (69) | Referent | Referent | ||
| 1–5 years | 69 (11) | 98 | −172 to 368 | 122 | −151 to 396 |
| 6–10 years | 38 (6) | 20 | −330 to 370 | 81 | −276 to 437 |
| 11–20 years | 47 (8) | 93 | −224 to 409 | 116 | −206 to 438 |
| >20 years | 34 (6) | 243 | −128 to 614 | 275 | −99 to 649 |
| p-trend | 0.20 | 0.11 | |||
| Rotating shifts | |||||
| None/<1 year | 514 (85) | Referent | Referent | ||
| 1–5 years | 55 (9) | 1 | −291 to 294 | −27 | −320 to 267 |
| 6–10 years | 15 (2) | 14 | −526 to 555 | 40 | −201 to 585 |
| >10 years | 24 (4) | −233 | −663 to 197 | −209 | −642 to 223 |
| p-trend | 0.40 | 0.44 | |||
| Nights (22:00–02:00) | |||||
| None/<1 year | 456 (75) | Referent | Referent | ||
| 1–5 years | 102 (17) | 84 | −141 to 310 | 112 | −116 to 341 |
| 6–10 years | 27 (4) | 30 | −380 to 440 | −58 | −489 to 373 |
| >10 years | 23 (4) | −120 | −563 to 322 | −10 | −448 to 440 |
| p-trend | 0.98 | 0.83 | |||
| Multiple jobs | |||||
| None/<1 year | 484 (80) | Referent | Referent | ||
| 1–5 years | 77 (13) | −81 | −334 to 171 | −25 | −281 to 230 |
| 6–10 years | 30 (5) | −8 | −394 to 378 | 42 | −358 to 442 |
| >10 years | 17 (3) | −513 | −1024 to −3 | −542 | −1054 to −31 |
| p-trend | 0.12 | 0.18 | |||
Difference in base pairs (Δ bp) relative telomere length, adjusted for age and total years worked. Not mutually adjusted for other variables listed in table. Bold indicates when 95% CI excludes the null.
Adjusted for age, sampling variables (race, current smoking status, perceived stress), health behaviours and status (BMI, sleep, physical activity, health status, and cardiovascular disease or diabetes), demographic factors (marital status, education, number of children and having a child in the household) and total number of years worked; N=3 missing covariate data.
Trend test across categories of increasing years for each schedule characteristic; for full-time limited to those working at least 1 year full-time.