Table 1.

Participant Characteristics and their Correlation with Chronotype and Social Jetlag

Variable		Chronotype r	SJL r
Demographics
Age	42.7 (7.4)	−0.20**	0.01
Sex	47.0% male	−0.05a	0.04a
Race	83.2% white	−0.01a	0.04a
Education, y	17.0 (2.8)	−0.04	−0.10*
Family income	17.7% > $110 000	−0.11*	−0.03
Employment status	89.7% full-time	0.03a	−0.08a
Marital status	63.1% married	0.08a	0.05a
Sleep characteristics
Chronotype	39.3 (7.2)		0.13**
Wake time	6:31 am (1 h 8 min)	0.49**	0.03
Bed time	11:41 pm (1 h 11 min)	0.52**	0.05
Sleep duration	6.8h (54 min)	−0.06	−0.03
Sleep debt, h	1.2 (1.0)	0.11*	0.44**
Sleep efficiency, %	83.2 (5.2)	0.00	−0.02
PSQI total	5.0 (2.6)	0.13**	0.12**
Depression and health behaviors
CES-D total	8.5 (7.9)	0.13**	0.02
Physical activity, kcal/d	2810.0 (2132.1)	−0.18**	−0.10*
Caloric intake, kcal/d	1873.6 (829.9)	0.05	0.00
Alcohol intake, drinks/wk	1.6 (2.5)	0.07	0.03
Smoking status	11.6% current smoker	0.05a	0.08a
Health outcomes
Heart rate, bpm	33.4 (4.2)	0.10*	0.04
Systolic BP, mm Hg	115.0 (11.1)	−0.03	−0.06
Diastolic BP, mm Hg	72.1 (8.2)	−0.01	0.02
Total cholesterol, mg/dL	200.66 (38.7)	0.00	0.09
HDL, mg/dL	55.8 (15.1)	−0.11*	−0.06
LDL, mg/dL	122.8 (32.4)	0.01	0.09
Triglycerides, mg/dL	109 (68.2)	0.11*	0.10*
Waist circumference, cm	90.1 (14.2)	0.05	0.12**
BMI, kg/m2	26.8 (5.2)	0.04	0.15**
Fasting glucose, mg/dL	98.1 (10.2)	0.06	0.09
Fasting insulin, μU/mL	12.4 (6.2)	0.06	0.09
HOMA-IR	3.0 (1.7)	0.07	0.10*

Data are expressed as mean (SD) unless stated otherwise. Correlations with chronotype were conducted with an inversed CSM total score for ease of interpretation (a higher score represents greater eveningness).

^aPoint biserial r conducted with the described category of each variable serving as the comparison group.

^*P < .05.

^**P < .01.