Table 1 Characteristics of European UK Biobank participants with self-reported sleep trait data and genetic data and in subgroups: (a) with QC-checked accelerometer-derived sleep data; and (b) without accelerometer data.

From: The role of accelerometer-derived sleep traits on glycated haemoglobin and glucose levels: a Mendelian randomization study

Variable

Participants with QC-checked accelerometer-derived sleep traits

Participants without accelerometer data*

All participants

Mean (SD) (%)

Mean (SD) (%)

Mean (SD) (%)

n

73,797

306,317

385,163

Age (years)

56.3 (7.8)

56.8 (8.1)

56.7 (8.0)

Female, Sex (%)

56.0%

53.6%

54.0%

Body mass index (kg/m2)

26.7 (4.5)

27.6 (4.8)

27.4 (4.8)

Accelerometer-derived sleep traits

 Sleep duration (h)

7.29 (0.86)

–

–

 Fragmentation (episode, times)

17.2 (3.6)

–

–

 Efficiency (%)

76% (7%)

–

–

 L5 timing (hour; time)

27.3 (1.1); 3:18 a.m.

–

–

 M10 timing (hour; time)

13.7 (1.2); 1:42 p.m.

–

–

Self-reported sleep duration

7.2 (1.0)

7.2 (1.1)

7.2 (1.1)

 Insomnia

  Never/rarely or sometimes (%)

73

71

72

  Usually (%)

27

29

28

 Chronotype

  Morning (%)

23

24

24

  More ‘morning’ than ‘evening’ (%)

34

32

32

  Do not know (%)

10

10

10

  More ‘’evening’ ‘than ‘morning’ (%)

25

26

26

  Evening (%)

8

8

8

HbA1c (mmol/mol)/log(hbA1c)

35.3 (5.5)/3.55 (0.14)

36.1 (6.8)/3.57 (0.15)

35.9 (6.5)/3.57 (0.15)

HbA1c ≥ 48 mmol/l (%)

2.3

3.7

3.4

Glucose (mmol/L)/log(glucose)

5.1 (1.1)/1.61 (0.16)

5.1 (1.2)/1.62 (0.18)

5.1 (1.2)/1.61 (0.17)

Diabetes defined by Eastwood algorithm (%)

3.2

5.0

4.6

Diagnosed sleep apnoea§ (%)

0.4

0.5

0.5

Townsend deprivation index†

− 1.8 (2.8)

− 1.4 (3.1)

− 1.5 (3.0)

 Most affluent (the lowest 10%)

11%

10%

ref (≤ − 4.6)

 Most deprived (the highest 10%)

7%

11%

ref ≥ 3.1)

Smoking

 Never (%)

56.7

53.3

54.0

 Former (%)

36.5

35.4

35.6

 Current (%)

6.8

11.3

10.4

Alcohol intake‡

 Daily (%)

23.5

20.7

21.3

 One to four times a week (%)

51.6

49.6

50.0

 One to three times a month (%)

10.8

11.2

11.1

 Never/occasionally (%)

14.1

18.4

17.6

Education (ISCED codes)

 College or university degree/NVQ or HND or HNC or equivalent (%)

58.3

46.4

48.8

 Other prof. equal. Eg: nursing, teaching (%)

12.7

12.1

12.2

 A levels/AS levels or equivalent (%)

6.3

5.5

5.7

 O levels/GCSEs or equivalent/CSEs or equivalent (%)

14.6

17.2

16.7

 None of the above (%)

8.1

18.8

16.6

Days of vigorous physical activity per week‡ (%)

 0–1 day

49.9

52.1

51.6

 2–3 days (%)

32.4

29.0

29.7

 4–7 days (%)

17.7

18.8

18.6

  1. *The number of European participants with self-reported sleep trait data and genetic data but without accelerometer-derived data (n = 306,317) is obtained from the whole European sample with self-reported sleep trait data and genetic data (n = 385,163) minus the number with accelerometer data (n = 78,846) and minus those who failed the accelerometer data quality control check (n = 5049).
  2. †Townsend deprivation index was calculated using data from the preceding national census output areas, where each participant was assigned, a continuous score corresponding to the output area of their postcode location. A higher index indicates a greater level of deprivation.
  3. ‡Alcohol intake was categorized and adjusted as “Daily”, “One or four times a week”, “Once or twice a week”, “One to three times a month”, “Occasionally”, “Never”; vigorous physical activity was categorized as days from 0 to 7 per week. (Details in Supplementary Information).
  4. §Sleep apnea (ICD-10) was diagnosed from the Hospital Episode Statistics (HES) data.
Back to article page