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Table 2 Baseline characteristics of shift workers according to night shifts work status

From: Association of shift work with incident dementia: a community-based cohort study

Characteristics

Shift workers

Shift but non-night shift workers

Night shift workers

Sample size, n

13,729

13,721

Age (year)

52.39 ± 7.06

51.18 ± 6.85

Sex/female

7036 (51.2)

4974 (36.3)

Ethnicity/White

12,676 (92.3)

12,287 (89.5)

Education

 Higher

6234 (45.4)

5966 (43.5)

 Upper secondary

1090 (7.9)

974 (7.1)

 Lower secondary

2520 (18.4)

2519 (18.4)

 Vocational

1435 (10.5)

1728 (12.6)

 Other

2450 (17.8)

2534 (18.5)

Townsend deprivation index category

 Low

2676 (19.5)

2642 (19.3)

 Intermediate

6643 (48.4)

6500 (47.4)

 High

4410 (32.1)

4579 (33.4)

 DM

582 (4.2)

645 (4.7)

 HTN

3041 (22.2)

3110 (22.7)

 Stroke

129 (0.9)

104 (0.8)

 CHD

370 (2.7)

405 (3.0)

 Cholesterol-lowering medication

1600 (11.7)

1622 (11.8)

 Antihypertensives

2045 (14.9)

2095 (15.3)

 Aspirin

1411 (10.3)

1415 (10.3)

 BMI (kg/m2)

27.70 ± 4.91

28.21 ± 4.76

 SBP (mmHg)

134.84 ± 17.65

135.63 ± 17.30

 TC (mmol/L)

5.66 ± 1.07

5.63 ± 1.09

 TG (mmol/L)

1.74 ± 1.06

1.87 ± 1.15

 HDL (mmol/L)

1.42 ± 0.37

1.35 ± 0.35

 LDL (mmol/L)

3.56 ± 0.83

3.56 ± 0.84

 HbA1c (%)

5.42 ± 0.61

5.44 ± 0.63

 No current smoking

11,871 (86.5)

11,404 (83.1)

 Alcohol consumption at least weekly

9218 (67.1)

9088 (66.2)

 Healthy diet

8297 (60.4)

7722 (56.3)

 Regular physical activity

8109 (59.1)

8593 (62.6)

Genetic predisposition to dementia by PRS category

 Low

6804 (49.6)

6742 (49.1)

 Intermediate

3596 (26.2)

3630 (26.5)

 High

3329 (24.2)

3349 (24.4)

 Years of work (years)

12.23 ± 10.34

14.07 ± 10.90

Sleep duration category (h/day)

 ≤ 6

3956 (28.8)

4734 (34.5)

 7–8

9054 (65.9)

8283 (60.4)

 ≥ 9

719 (5.2)

704 (5.1)

Chronotype

 Definitely a “morning” person

3835 (27.9)

3410 (24.9)

 More a “morning” than “evening” person

4633 (33.7)

4130 (30.1)

 More an “evening” than a “morning” person

4013 (29.2)

4324 (31.5)

 Definitely an “evening” person

1248 (9.1)

1857 (13.5)

  1. Data are means ± standard deviations, or N (%)
  2. Abbreviation: DM diabetes mellitus, HTN hypertension, CHD coronary heart disease, BMI body mass index, SBP systolic blood pressure, TC total cholesterol, TG triglycerides, HDL high-density lipoprotein, LDL low-density lipoprotein, HbA1c glycated hemoglobin, PRS polygenic risk score