Table 1 shows the general characteristics of the study participants. The total number of participants in this study was 10,205. There were 4,737 men and 5,468 women. There were 1,243 (12.2%) participants who on an average slept for less than 5.9 hours per day, 2,511 (24.6%) who slept between 6 and 6.9 hours, 3,454 (33.8%) who slept between 7 and 7.9 hours, 2,110 (20.7%) who slept between 8 and 8.9 hours, and 887 (8.7%) who slept more than 9 hours per day. Regarding the sleep duration ratio, 945 (9.3%) participants had values less than 0.99, 4,873(47.8%) at 1.0, and 4,387 (43.0%) more than 1.01. There were 657 (13.9%) men and 1,270 (23.2%) women with depression.
Table 1
General characteristics of the study participants
Variables | | | | Depression (PHQ-9 > = 5) | |
| | | Male (n = 4737) | | | Female (n = 5468) | |
TOTAL | | YES | NO | | | YES | NO | |
N | % | | N | % | N | % | P | | N | % | N | % | |
Total | 10,205 | 100.0 | | 657 | 13.9 | 4,080 | 86.1 | | | 1,270 | 23.2 | 4,198 | 76.8 | |
Sleep Duration (Hours) | | | | | | | | < .0001 | | | | | < .0001 |
~ 5.9 | 1,243 | 12.2 | | 109 | 19.5 | 449 | 80.5 | | | 232 | 33.9 | 453 | 66.1 | |
6 ~ 6.9 | 2,511 | 24.6 | | 159 | 13.2 | 1,043 | 86.8 | | | 269 | 20.6 | 1,040 | 79.4 | |
7 ~ 7.9 | 3,454 | 33.8 | | 194 | 11.8 | 1,455 | 88.2 | | | 398 | 22.0 | 1,407 | 78.0 | |
8 ~ 8.9 | 2,110 | 20.7 | | 113 | 12.2 | 813 | 87.8 | | | 241 | 20.4 | 943 | 79.6 | |
9 ~ | 887 | 8.7 | | 82 | 20.4 | 320 | 79.6 | | | 130 | 26.8 | 355 | 73.2 | |
Sleep Duration ratio (weekend/weekday) | | | | | | | | 0.0506 | | | | | < .0001 |
~ 0.99 | 945 | 9.3 | | 66 | 15.9 | 348 | 84.1 | | | 129 | 24.3 | 402 | 75.7 | |
1 | 4,873 | 47.8 | | 332 | 13.7 | 2,089 | 86.3 | | | 619 | 25.2 | 1,833 | 74.8 | |
1.01 ~ | 4,387 | 43.0 | | 259 | 15.8 | 1,643 | 84.2 | | | 522 | 21.0 | 1963 | 79.0 | |
Age | | | | | | | | 0.1851 | | | | | < .0001 |
20 ~ 29 | 1,243 | 12.2 | | 86 | 15.4 | 471 | 84.6 | | | 235 | 34.3 | 451 | 65.7 | |
30 ~ 39 | 1,859 | 18.2 | | 128 | 15.6 | 694 | 84.4 | | | 250 | 24.1 | 787 | 75.9 | |
40 ~ 49 | 2,050 | 20.1 | | 124 | 13.8 | 772 | 86.2 | | | 214 | 18.5 | 940 | 81.5 | |
50 ~ 59 | 1,957 | 19.2 | | 109 | 12.7 | 747 | 87.3 | | | 219 | 19.9 | 882 | 80.1 | |
60 ~ 69 | 1,701 | 16.7 | | 100 | 11.8 | 750 | 88.2 | | | 187 | 22.0 | 664 | 78.0 | |
70 ~ | 1,395 | 13.7 | | 110 | 14.6 | 646 | 85.4 | | | 165 | 25.8 | 474 | 74.2 | |
Region | | | | | | | | 0.0654 | | | | | 0.525 |
Metropolitans | 4,862 | 47.6 | | 332 | 14.8 | 1,904 | 85.2 | | | 600 | 22.8 | 2,026 | 77.2 | |
Rurals | 5,343 | 52.4 | | 325 | 13.0 | 2,176 | 87.0 | | | 670 | 23.6 | 2,172 | 76.4 | |
Educational level | | | | | | | | 0.0052 | | | | | 0.002 |
Under highschool | 6,143 | 60.2 | | 413 | 15.1 | 2,328 | 84.9 | | | 837 | 24.6 | 2,565 | 75.4 | |
College | 4,062 | 39.8 | | 244 | 12.2 | 1,752 | 87.8 | | | 433 | 21.0 | 1,633 | 79.0 | |
Job | | | | | | | | < .0001 | | | | | < .0001 |
White | 2,721 | 26.7 | | 164 | 11.5 | 1,260 | 88.5 | | | 254 | 19.6 | 1,043 | 80.4 | |
Pink | 1,460 | 14.3 | | 93 | 17.7 | 433 | 82.3 | | | 200 | 21.4 | 734 | 78.6 | |
Blue | 2,347 | 23.0 | | 191 | 12.2 | 1,377 | 87.8 | | | 153 | 19.6 | 626 | 80.4 | |
None | 3,677 | 36.0 | | 209 | 17.1 | 1,010 | 82.9 | | | 663 | 27.0 | 1,795 | 73.0 | |
Household income | | | | | | | | < .0001 | | | | | < .0001 |
High | 3,123 | 30.6 | | 156 | 10.6 | 1,309 | 89.4 | | | 285 | 17.2 | 1,373 | 82.8 | |
Middle high | 2,895 | 28.4 | | 158 | 11.6 | 1,200 | 88.4 | | | 348 | 22.6 | 1,189 | 77.4 | |
Middle low | 2,491 | 24.4 | | 181 | 15.8 | 964 | 84.2 | | | 329 | 24.4 | 1,017 | 75.6 | |
Low | 1,696 | 16.6 | | 162 | 21.1 | 607 | 78.9 | | | 308 | 33.2 | 619 | 66.8 | |
Marriage | | | | | | | | < .0001 | | | | | < .0001 |
Yes | 7,257 | 71.1 | | 407 | 11.6 | 3,087 | 88.4 | | | 731 | 19.4 | 3,032 | 80.6 | |
No | 2,948 | 28.9 | | 250 | 20.1 | 993 | 79.9 | | | 539 | 31.6 | 1,166 | 68.4 | |
Smoke | | | | | | | | 0.0442 | | | | | < .0001 |
Yes | 4,431 | 43.4 | | 536 | 14.4 | 3,187 | 85.6 | | | 299 | 42.2 | 409 | 57.8 | |
No | 5,774 | 56.6 | | 121 | 11.9 | 893 | 88.1 | | | 971 | 20.4 | 3,789 | 79.6 | |
Drink | | | | | | | | 0.4018 | | | | | 0.0001 |
2 ~ 4 times / week | 2,552 | 25.0 | | 249 | 14.1 | 1,519 | 85.9 | | | 228 | 29.1 | 556 | 70.9 | |
2 ~ 4 times / month | 2,557 | 25.1 | | 166 | 12.8 | 1,131 | 87.2 | | | 291 | 23.1 | 969 | 76.9 | |
Never or occasionally | 5,096 | 49.9 | | 242 | 14.5 | 1,430 | 85.5 | | | 751 | 21.9 | 2,673 | 78.1 | |
BMI† | | | | | | | | 0.6075 | | | | | 0.2846 |
Obese(≥ 25) | 3,532 | 34.6 | | 278 | 14.2 | 1,683 | 85.8 | | | 380 | 24.2 | 1,191 | 75.8 | |
Normal or under-weight(< 25) | 6,673 | 65.4 | | 379 | 13.7 | 2,397 | 86.3 | | | 890 | 22.8 | 3,007 | 77.2 | |
Physical activity | | | | | | | | 0.1757 | | | | | 0.8939 |
Yes | 3,922 | 38.4 | | 291 | 13.1 | 1,923 | 86.9 | | | 534 | 31.3 | 1,174 | 68.7 | |
No | 5,683 | 55.7 | | 366 | 14.5 | 2,157 | 85.5 | | | 736 | 23.3 | 2,424 | 76.7 | |
Stress | | | | | | | | < .0001 | | | | | < .0001 |
Lot | 2,740 | 26.8 | | 374 | 32.9 | 762 | 67.1 | | | 782 | 48.8 | 822 | 51.2 | |
Little | 7,465 | 73.2 | | 283 | 7.9 | 3,318 | 92.1 | | | 488 | 12.6 | 3,376 | 87.4 | |
BMI body mass index | | | | | | | | | | | | | | |
†Obesity status defined by BMI based on 2014 Clinical Practice Guidelines for Overweight and Obesity in Korea | | | |
Table 2 shows the odd ratio results of multiple logistic regression model between depression and sleep duration or sleep duration ratio when other covariates were controlled. For men, the odds ratio among those with sleep duration less than 5.9 hours per day (Odds Ratio [OR] = 1.32, 95% confidence interval [CI] = 0.94–1.87) was much higher, and the odds ratio among those with sleep duration between 6 and 6.9 hours per day (OR = 1.04, 95% CI = 0.77–1.40) was slightly higher than that of men who slept between 7 and 7.9 hours per day (reference group). Additionally, the odds ratio for men with sleep duration of more than 9 hours per day (OR = 1.51, 95% CI = 1.01–2.26) was much higher and the odds ratio for those with sleep duration between 6 and 6.9 hours per day (OR = 1.02, 95% CI = 0.74–1.40) was slightly higher than that of those with sleep duration between 7 and 7.9 hours per day. Thus, the odds ratios were associated with sleep duration in a U-shaped, that is, both shorter and longer sleep durations resulted in higher odds ratios in men. In women, the odds ratios among those with sleep duration less than 5.9 hours per day (OR = 1.60, 95% CI = 1.23–2.08) and more than 9 hours per day (OR = 1.26, 95% CI = 0.94–1.70) were higher than that among those with sleep duration between 7 and 7.9 hours per day. The odds ratio among men with high stress (OR = 6.67, 95% CI = 5.38–8.26) was significantly higher than that among men with low stress (reference group). The odds ratio of women with high stress (OR = 5.84, 95% CI = 5.01–6.82) was also significantly higher than that of women with low stress. Similar results in men and women increase the credibility of this finding. Other covariates such as age, job, household income, marriage, and smoking also showed statistical significance.
Table 2
Multiple logistic regression analysis of depression
Variables | Depression (PHQ-9 > = 5) |
Male | | Female | |
OR | | 95% CI | | | OR | | 95%CI | | |
Sleep Duration (Hours) | | | | | | | | | | | | | | |
~ 5.9 | 1.32 | ( | 0.94 | - | 1.87 | ) | | 1.60 | ( | 1.23 | - | 2.08 | ) | |
6 ~ 6.9 | 1.04 | ( | 0.77 | - | 1.40 | ) | | 0.98 | ( | 0.79 | - | 1.22 | ) | |
7 ~ 7.9 | 1.00 | | | | | | | 1.00 | | | | | | |
8 ~ 8.9 | 1.02 | ( | 0.74 | - | 1.40 | ) | | 0.96 | ( | 0.77 | - | 1.19 | ) | |
9 ~ | 1.51 | ( | 1.01 | - | 2.26 | ) | | 1.26 | ( | 0.94 | - | 1.70 | ) | |
Sleep Duration ratio (weekend/weekday) | | | | | | | | | | | | | | |
~ 0.99 | 1.29 | ( | 0.88 | - | 1.89 | ) | | 0.96 | ( | 0.71 | - | 1.30 | ) | |
1 | 1.00 | | | | | | | 1.00 | | | | | | |
1.01 ~ | 0.98 | ( | 0.88 | - | 1.13 | ) | | 0.88 | ( | 0.68 | - | 0.99 | ) | |
Age | | | | | | | | | | | | | | |
20 ~ 29 | 1.00 | | | | | | | 1.00 | | | | | | |
30 ~ 39 | 1.73 | ( | 1.15 | - | 2.62 | ) | | 0.82 | ( | 0.60 | - | 1.12 | ) | |
40 ~ 49 | 1.98 | ( | 1.26 | - | 3.10 | ) | | 0.73 | ( | 0.53 | - | 0.99 | ) | |
50 ~ 59 | 1.72 | ( | 1.09 | - | 2.71 | ) | | 0.93 | ( | 0.68 | - | 1.28 | ) | |
60 ~ 69 | 1.53 | ( | 0.96 | - | 2.44 | ) | | 0.84 | ( | 0.58 | - | 1.21 | ) | |
70 ~ | 1.58 | ( | 0.95 | - | 2.63 | ) | | 0.68 | ( | 0.46 | - | 1.03 | ) | |
Region | | | | | | | | | | | | | | |
Metropolitans | 1.00 | | | | | | | 1.00 | | | | | | |
Rurals | 0.86 | ( | 0.69 | - | 1.06 | ) | | 1.01 | ( | 0.84 | - | 1.21 | ) | |
Educational level | | | | | | | | | | | | | | |
Under highschool | 1.00 | | | | | | | 1.00 | | | | | | |
College | 1.04 | ( | 0.81 | - | 1.34 | ) | | 0.95 | ( | 0.77 | - | 1.18 | ) | |
Job | | | | | | | | | | | | | | |
White | 1.00 | | | | | | | 1.00 | | | | | | |
Pink | 1.62 | ( | 1.16 | - | 2.28 | ) | | 0.98 | ( | 0.73 | - | 1.32 | ) | |
Blue | 1.16 | ( | 0.84 | - | 1.62 | ) | | 1.04 | ( | 0.76 | - | 1.42 | ) | |
None | 1.51 | ( | 1.06 | - | 2.15 | ) | | 1.63 | ( | 1.29 | - | 2.06 | ) | |
Household income | | | | | | | | | | | | | | |
High | 1.00 | | | | | | | 1.00 | | | | | | |
Middle high | 0.99 | ( | 0.73 | - | 1.35 | ) | | 1.29 | ( | 1.02 | - | 1.61 | ) | |
Middle low | 1.45 | ( | 1.07 | - | 1.97 | ) | | 1.33 | ( | 1.06 | - | 1.67 | ) | |
Low | 2.01 | ( | 1.37 | - | 2.94 | ) | | 1.89 | ( | 1.40 | - | 2.57 | ) | |
Marriage | | | | | | | | | | | | | | |
Yes | 1.00 | | | | | | | 1.00 | | | | | | |
No | 2.16 | ( | 1.68 | - | 2.78 | ) | | 1.63 | ( | 1.34 | - | 1.98 | ) | |
Smoke | | | | | | | | | | | | | | |
Yes | 1.22 | ( | 0.89 | - | 1.68 | ) | | 2.03 | ( | 1.62 | - | 2.54 | ) | |
No | 1.00 | | | | | | | 1.00 | | | | | | |
Drink | | | | | | | | | | | | | | |
2 ~ 4 times / week | 0.90 | ( | 0.69 | - | 1.17 | ) | | 1.23 | ( | 0.97 | - | 1.56 | ) | |
2 ~ 4 times / month | 0.92 | ( | 0.70 | - | 1.21 | ) | | 1.10 | ( | 0.88 | - | 1.36 | ) | |
Never or occasionally | 1.00 | | | | | | | 1.00 | | | | | | |
BMI† | | | | | | | | | | | | | | |
Obese(≥ 25) | 1.07 | ( | 0.86 | - | 1.34 | ) | | 0.97 | ( | 0.80 | - | 1.16 | ) | |
Normal or under-weight(< 25) | 1.00 | | | | | | | 1.00 | | | | | | |
Physical activity | | | | | | | | | | | | | | |
Yes | 1.00 | | | | | | | 1.00 | | | | | | |
No | 1.03 | ( | 0.85 | - | 1.25 | ) | | 0.94 | ( | 0.78 | - | 1.13 | ) | |
Stress | | | | | | | | | | | | | | |
Lot | 6.67 | ( | 5.38 | - | 8.26 | ) | | 5.84 | ( | 5.01 | - | 6.82 | ) | |
Little | 1.00 | | | | | | | 1.00 | | | | | | |
BMI, body mass index; CI, confidence interval; OR, odds ratio; PHQ-9, Patient Health Questionnaire |
Table 3 shows the results of the subgroup analysis by covariates for the sleep duration ratio in men and women. In men who slept more than 9 hours per day on average, the odds ratio was slightly higher in the group with a sleep duration ratio of 1.00 (OR = 1.45, 95% CI = 0.82–2.57) and much higher in the group with a sleep duration ratio of over 1.01 (OR = 2.33, 95% CI = 1.08–5.03) than in the group with a sleep duration ratio less than 0.99 (OR = 1.37, 95% CI = 0.47–4.04). Among women who slept more than 9 hours per day on average, the odds ratio was slightly higher in the group with a sleep duration ratio of 1.00 (OR = 1.74, 95% CI = 1.21–2.51) and much higher in the group with a sleep duration ratio less than 0.99 (OR = 4.94, 95% CI = 1.98–12.37) than in the group with a sleep duration ratio over 1.01 (OR = 0.87, 95% CI = 0.34–2.21).
Table 3
Subgroup analysis of depression
Variables | ~ 5.9 Hours | | 6 ~ 6.9 Hours | | 7 ~ 7.9 Hours | 8 ~ 8.9 Hours | | 9 Hours ~ |
OR | | 95% CI | | | OR | | 95%CI | | | OR | | OR | | 95%CI | | | OR | | 95%CI | |
Male | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Sleep Duration ratio (weekend/weekday) | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
~ 0.99 | 0.80 | ( | 0.25 | - | 2.58 | ) | | 1.30 | ( | 0.53 | - | 3.16 | ) | | 1.00 | | 1.25 | ( | 0.39 | - | 4.05 | ) | | 1.37 | ( | 0.47 | - | 4.04 | ) |
1 | 1.87 | ( | 1.15 | - | 3.05 | ) | | 1.17 | ( | 0.75 | - | 1.84 | ) | | 1.00 | | 0.94 | ( | 0.61 | - | 1.45 | ) | | 1.45 | ( | 0.82 | - | 2.57 | ) |
1.01 ~ | 0.93 | ( | 0.66 | - | 1.70 | ) | | 0.83 | ( | 0.51 | - | 1.48 | ) | | 1.00 | | 1.33 | ( | 0.83 | - | 2.21 | ) | | 2.03 | ( | 0.95 | - | 4.03 | ) |
Drink | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
2 ~ 4 times / week | 1.82 | ( | 1.04 | - | 3.19 | ) | | 1.02 | ( | 0.61 | - | 1.70 | ) | | 1.00 | | 1.34 | ( | 0.81 | - | 2.23 | ) | | 1.96 | ( | 0.98 | - | 3.94 | ) |
2 ~ 4 times / month | 1.56 | ( | 0.82 | - | 2.95 | ) | | 1.19 | ( | 0.66 | - | 2.13 | ) | | 1.00 | | 1.30 | ( | 0.71 | - | 2.38 | ) | | 2.65 | ( | 1.26 | - | 5.60 | ) |
Never or occasionally | 1.00 | ( | 0.58 | - | 1.72 | ) | | 1.13 | ( | 0.73 | - | 1.74 | ) | | 1.00 | | 0.64 | ( | 0.36 | - | 1.14 | ) | | 1.01 | ( | 0.54 | - | 1.87 | ) |
BMI† | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Obese(≥ 25) | 1.02 | ( | 0.59 | - | 1.76 | ) | | 1.14 | ( | 0.73 | - | 1.80 | ) | | 1.00 | | 0.87 | ( | 0.51 | - | 1.47 | ) | | 1.82 | ( | 1.03 | - | 3.23 | ) |
Normal or under-weight(< 25) | 1.71 | ( | 1.11 | - | 2.63 | ) | | 1.08 | ( | 0.73 | - | 1.60 | ) | | 1.00 | | 1.24 | ( | 0.82 | - | 1.88 | ) | | 1.41 | ( | 0.78 | - | 2.54 | ) |
Physical activity | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Yes | 1.29 | ( | 0.83 | - | 2.01 | ) | | 1.04 | ( | 0.69 | - | 1.58 | ) | | 1.00 | | 0.96 | ( | 0.63 | - | 1.46 | ) | | 1.44 | ( | 0.78 | - | 2.68 | ) |
No | 1.50 | ( | 0.91 | - | 2.48 | ) | | 1.13 | ( | 0.76 | - | 1.70 | ) | | 1.00 | | 1.11 | ( | 0.70 | - | 1.74 | ) | | 1.65 | ( | 0.97 | - | 2.79 | ) |
Female | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Sleep Duration ratio (weekend/weekday) | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
~ 0.99 | 4.94 | ( | 1.98 | - | 12.37 | ) | | 2.34 | ( | 1.08 | - | 5.07 | ) | | 1.00 | | 0.90 | ( | 0.40 | - | 2.00 | ) | | 0.28 | ( | 0.06 | - | 1.18 | ) |
1 | 1.74 | ( | 1.21 | - | 2.51 | ) | | 0.91 | ( | 0.65 | - | 1.29 | ) | | 1.00 | | 1.07 | ( | 0.76 | - | 1.48 | ) | | 1.55 | ( | 1.04 | - | 2.31 | ) |
1.01 ~ | 0.99 | ( | 0.74 | - | 1.51 | ) | | 0.90 | ( | 0.61 | - | 1.37 | ) | | 1.00 | | 0.94 | ( | 0.72 | - | 1.46 | ) | | 1.06 | ( | 0.65 | - | 2.09 | ) |
Drink | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
2 ~ 4 times / week | 2.00 | ( | 1.08 | - | 3.69 | ) | | 0.87 | ( | 0.49 | - | 1.55 | ) | | 1.00 | | 1.69 | ( | 0.98 | - | 2.93 | ) | | 2.07 | ( | 0.97 | - | 4.42 | ) |
2 ~ 4 times / month | 2.45 | ( | 1.32 | - | 4.54 | ) | | 0.92 | ( | 0.55 | - | 1.52 | ) | | 1.00 | | 0.89 | ( | 0.57 | - | 1.38 | ) | | 0.91 | ( | 0.47 | - | 1.76 | ) |
Never or occasionally | 1.30 | ( | 0.95 | - | 1.76 | ) | | 1.05 | ( | 0.79 | - | 1.41 | ) | | 1.00 | | 0.82 | ( | 0.61 | - | 1.09 | ) | | 1.15 | ( | 0.81 | - | 1.63 | ) |
BMI† | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Obese(≥ 25) | 1.59 | ( | 0.98 | - | 2.56 | ) | | 1.04 | ( | 0.69 | - | 1.57 | ) | | 1.00 | | 1.04 | ( | 0.69 | - | 1.57 | ) | | 2.67 | ( | 1.52 | - | 4.68 | ) |
Normal or under-weight(< 25) | 1.62 | ( | 1.19 | - | 2.21 | ) | | 0.98 | ( | 0.75 | - | 1.28 | ) | | 1.00 | | 0.82 | ( | 0.63 | - | 1.07 | ) | | 0.97 | ( | 0.68 | - | 1.37 | ) |
Physical activity | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Yes | 1.86 | ( | 1.23 | - | 2.82 | ) | | 1.03 | ( | 0.73 | - | 1.46 | ) | | 1.00 | | 1.17 | ( | 0.83 | - | 1.65 | ) | | 1.24 | ( | 0.76 | - | 2.00 | ) |
No | 1.39 | ( | 0.98 | - | 1.98 | ) | | 0.92 | ( | 0.68 | - | 1.24 | ) | | 1.00 | | 0.79 | ( | 0.58 | - | 1.07 | ) | | 1.22 | ( | 0.84 | - | 1.78 | ) |
BMI, body mass index, CI, confidence interval, OR, odds ratio |
Among men who slept less than 5.9 hours per day on average, the odds ratio was the highest in the group that consumed alcohol between 2 and 4 times per week (OR = 1.82, 95% CI = 1.04–3.19), followed by the group that drank between 2 and 4 times per month (OR = 1.56, 95% CI = 0.82–2.95), and the lowest in the group that drank between 2 and 4 times per week (OR = 1.00, 95% CI = 0.58–1.72), compared to those who slept between 7 and 7.9 hours per day (reference group). Moreover, for men who slept for more than 9 hours per day, the odds ratio was higher in the group with no physical activity (OR = 1.65, 95% CI = 0.97–2.79) than in the physically active group (OR = 1.44, 95% CI = 0.78–2.68), and it was higher in the obese group (OR = 1.82, 95% CI = 1.03–3.23) than in the group that had a normal weight or was underweight (OR = 1.41, 95% CI = 0.78–2.54), compared to those who slept between 7 and 7.9 hours per day on average.