TABLE 1.
Characteristics of the included studies
| Author, published year, country | Study design | Gender; sample size; age | Occupation | Sample size | Definition of shift work | MetS criteria | MetS cases (%) | p value | OR/RR | Adjusted confounders | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Day | Non‐day | Day | Night | Adjusted/crude | ||||||||
| Arias et al., 37 2021; Ecuador | CS |
M & F 300 18–60 years |
Volunteers worked in healthcare centers |
150 (M:6; F:90) |
150 (M:46; F:104) |
8 h or more at night, from 7:00 p.m. to 6:00 a.m. and ≥6 month | NCEP‐ATP III | 6 (4.0%) | 84 (56.0%) | <0.001 | 22.13 (8.68–66.07) c | Age, gender, physical activity and energy consumption. |
| Copertaro et al., 38 2008; Italy | CS |
M & F 147 (M:74, F:73) 35–65 years |
hospital staff (mostly nurses) |
77 (M:31; F:46) |
70 (M:43; F:27) |
10:00 p.m.–6:00 a.m. night shift and ≥1.5 nights/month | IDF | 16 (20.8%) | 26 (37.1%) | <0.05 | 2.25 (1.08–4.69) b | None |
|
Farha and Alefishat, 39 2018; Jordan |
CS |
M & F 140 (M:60; F:80) 20–59 years |
Hospital employees |
58 (M:13; F:45) |
82 (M:47; F:35) |
4:00 p.m. to 7:00 a.m. ≥4 night shifts/month for ≥3 years | AHA/NHLBI 2005 | 6 (10.3%) | 13 (15.9%) | 0.48 | 1.63 (0.58–4.58) b | None |
| Holanda et al., 40 2018; Brazil | CS |
F 42 26–40 years |
Nursing professionals | 12 | 30 | ≥3 h between 10:00 p.m. to 5:00 a.m. for ≥6 months. | IDF | 4 (33.3%) | 12 (40.0%) | 0.24 | 1.33 (0.33–5.43) b | None |
| Jung et al., 41 2020; Korea | CS |
F 403 20–45 years |
Nurses | 162 | 241 | 11:00 p.m. to 7:00 a.m. | NCEP‐ATP III | 40 (24.7%) | 47 (19.5.0%) | NR | 0.74 (0.46–1.19) b | None |
| Kirk et al., 42 2015; Canada | CS |
F 466 45.8 ± 9.4 years |
Hospital employees | 300 | 166 | NR | JIS | 60 (20.0%) | 38 (22.9%) | NR | 1.30 (0.78–2.12) c | Age, personal, and leisure time physical activity |
| Korsiak et al., 43 2018; Canada | CS |
F 294 |
Hospital employees. (mostly nurses—68%) | 152 | 142 | NR | JIS | 18 (11.8%) | 29 (20.4%) | 0.04 | 2.72 (1.38–5.36) c | Age |
| Kumar et al., 44 2021; India | CS |
M & F 160 (M:80; F:80) 25–50 years |
Hospital staff |
80 (M:46; F:34) |
80 (M:46; F:34) |
NR | IDF | 33 (41.3%) | 20 (25.0%) | 0.03 | 0.55 (0.24–1.29) c | Age, gender, diet, physical activity, sleep, stress, alcohol consumption |
| Lajoie, et al., 45 2015; Canada | CS |
F 271 |
Hospital employees | 150 | 121 | NR | JIS | 20 (13.3) | 27 (22.3) | 0.05 | 2.29 (1.12–4.70) c | Age, household income, menopausal status |
| Niazi et al., 46 2018; Iran | CS |
M & F 410 (M:124; F:286) 33.43 ± 8.51 years |
Nurse, emergency workers, office workers, and others | 56 | 352 | NR | NCEP‐ATP III | NR | NR | NR | 3.97 (1.67–9.45) | None |
| Pietroiusti et al., 47 2010; Italy | Cohort |
M & F 738 |
Nurses |
336 (M: 92; F:244) |
402 (M:124; F:278) |
Between 9:00 p.m. and 7:00 a.m. and 4 nights/month for ≥1 year | Updated NCEP‐ATP III | 6 (1.8%) | 36 (9.0%) | NR | 5.10 (2.15–12.11) a , c | Age, gender, smoking, alcohol intake, familiar history, physical activity |
| Ritonja et al., 48 2018; Canada | CS | M & F | Hospital employees | 160 | 166 | NR | JIS | 19 (11.9%) | 35 (21.0%) | <0.01 | 1.98 (1.08–3.64) b | |
Abbreviations: AHA/NHLBI, American Heart Association/National Heart, Lung and Blood Institute; CS, cross‐sectional; F, female; h, hours; IDF, International Diabetes Federation; JIS, joint interim statement; M, male; NCEP ATP III, National Cholesterol Education Program, Adult Treatment Panel III; NR, not reported; OR, odd ratio; RR, relative risk.
Relative risk.
Calculated odd ratios with MetS cases in day and night shift worker.
Adjusted odd ratios.