Table 1.
Bogalusa Heart Study participant characteristics overall and by chronotype group ( ± sd or n(%)) (n=1180)
| Variables | Total | Morning typea | Neither typea | Evening typea | P value |
|---|---|---|---|---|---|
| N (%) | 1180 (100%) | 498(42.2) | 551(46.7) | 131(11.1) | |
| Sex | *0.001 | ||||
| Male | 494(41.9) | 234(47.0) | 220(39.9) | 40(30.5) | |
| Female | 686(58.1) | 264(53.0) | 331(60.1) | 91(69.5) | |
| Mean Age(yrs) | 48.2±5.3 | 48.7±5.2 | 48.1±5.1 | 46.6±5.7 | †<0.001 |
| #Race | *0.705 | ||||
| White | 780(66.1) | 324(65.1) | 371(67.3) | 85(64.9) | |
| Black | 400(33.9) | 174(34.9) | 180(32.7) | 46(35.1) | |
| Education level | *0.723 | ||||
| Elementary (≤8th grade) | 28(2.4) | 11(2.2) | 14(2.5) | 3(2.3) | |
| High school (9–12th grade) | 562(47.6) | 242(48.6) | 262(47.5) | 58(44.3) | |
| College (13–16th grade) | 488(41.4) | 197(39.6) | 229(41.6) | 62(47.3) | |
| Master’s or above (≥17th grade) | 102(8.6) | 48(9.6) | 46(8.3) | 8(6.1) | |
| Work Schedule | *<0.001 | ||||
| Regular work | 594(50.3) | 288(57.8) | 271(49.2) | 35(26.7) | |
| Shift workb | 164(13.9) | 51(10.2) | 84(15.2) | 29(22.1) | |
| Not working | 422(35.8) | 159(31.9) | 196(35.6) | 67(51.1) | |
| Smoking Exposure | *0.007 | ||||
| Current smoker | 324(27.5) | 126(25.3) | 147(26.7) | 51(38.9) | |
| Never/Ex-Smoker | 856(72.5) | 372(74.7) | 404(73.3) | 80(61.1) | |
| Current alcohol use | *0.356 | ||||
| Yes | 668(56.6) | 294(59.0) | 302(54.8) | 72(55.0) | |
| No | 512(43.4) | 204(41.0) | 249(45.2) | 59(45.0) | |
| Illicit Drug usec | 423(35.8) | 163(32.7) | 193(35.0) | 67(51.1) | *<0.001 |
| Physical activityd | *0.009 | ||||
| High | 417(35.3) | 195(39.2) | 185(33.6) | 37(28.2) | |
| Moderate | 451(38.2) | 191(38.4) | 199(36.1) | 61(46.6) | |
| Low | 312(26.4) | 112(22.5) | 167(30.3) | 33(25.2) | |
| BMI(kg/cm2) | 31.4±7.7 | 31.1±7.3 | 31.1±7.5 | 33.9±9.7 | †0.001 |
| BMI ≥30 | 615(52.1) | 244(49.0) | 290(52.6) | 81(61.8) | *0.031 |
| Mean CESD Depression scoref | 9.8±4.6 | 9.0±4.4 | 10.0±4.7 | 11.7±4.8 | <0.001 |
| Depression (CESD >10)g | 536(45.4) | 195(39.2) | 257(46.6) | 84(64.1) | *<0.001 |
| Sleep durationh | *0.033 | ||||
| Short (<6h/night) | 182(15.4) | 68(13.7) | 85(15.4) | 29(22.1) | |
| Medium (6–8h/night) | 824(69.8) | 366(73.5) | 380(69.0) | 78(59.5) | |
| Long (>8h/night) | 174(14.7) | 64(12.9) | 86(15.6) | 24(18.3) |
Note: sd: standard deviation
Two sample t-test.
Pearson’s Chi-square test.
Chronotype: cumulative scores of reduced Morningness-Eveningness Questionnaire (rMEQ), ≤11 was categorized as evening type, 12–17 was categorized as Neither type, ≥18 was categorized as morning type.
Shift work: comprised of “Afternoon shift”, “Night shift”, “Split shift”, “Irregular shift/On call” and “Rotating shift”.
Consumption of drugs (ever or not) includes having used at least one of the following drugs: marijuana, crack/cocaine, heroin, methadone/codeine, speed/ecstasy/diet pills, LSD/acid/mushrooms/PCP/Special K.
Physical activity: Categorized by International Physical Activity Questionnaire (IPAQ) long form.
Depression scores: cumulated scores of all questions from a combined depression questionnaire (derived from Center for Epidemiologic Studies Depression Scale (CES-D10)). People with higher scores are more likely to be depressed.
Depression: defined by CES-D10 score ≥ 10.
Sleep duration: hours of sleep per night was calculated by [(hours of sleep on weekdays or workdays*5) + (hours of sleep on weekends*2)]/7, all self-reported. Sleep duration was categorized by short (<6h/night), medium (6–8h/night) and long (>8h/night).