Interaction between adolescent sleep rhythms and gender in an obese population

Table 1 Comparison of obesity, overweight, and normal weight among adolescents by gender and age (n = 2942)

Characteristic	Obesity	Overweight	Normal	P value	F/χ2
Age (years), mean ± SD	14.94 (1.442)	15.22 (1.454)	15.30 (1.412)	0.000	69.996
Sex				0.000	231.522
Boy, n (%)	1692 (25.1)	1275 (18.9)	3778 (56.0)
Girl, n (%)	1250 (18.9)	829 (12.5)	4550 (68.6)
Sum, n (%)	2942 (22.0)	2104 (15.7)	8328 (62.3)

Table 2 Comparison of demographic information on obesity in adolescents of different gender (n = 2942)

Characteristic		Sum obesity	Girl obesity	Boy obesity
One-child family	Yes, n (%)	925 (23.1)a	278 (18.5)	647 (25.8)
	No, n (%)	2017 (21.5)	972 (19.0)	1045 (24.6)
School residential experience within 6 mo	Yes, n (%)	695 (17.3)c	317 (15.4)c	378 (19.38)c
	No, n (%)	2247 (24.0)	933 (20.4)	1314 (27.5)
Parents' marital status	Normal, n (%)	2560 (21.8)	1061 (18.4)a	1499 (25.1)
	Single parent or remarriage, n (%)	382 (23.3)	189 (22.0)	193 (24.8)
Family economic situation	Family economic prosperity, n (%)	235 (21.3)a	89 (17.1)a	146 (25.0)
	No family economic pressure, n (%)	2189 (21.6)	924 (18.4)	1265 (24.9)
	High family economic pressure, n (%)	518 (24.0)	237 (21.9)	281 (26.1)
Sleep rhythm	ITs, n (%)	2327 (21.4)b	1012 (18.6)	1315 (24.3)a
	MTs, n (%)	200 (22.9)	76 (18.4)	124 (27.0)
	ETs, n (%)	415 (25.2)	162 (21.2)	253 (28.7)

^aP < 0.05.

^bP < 0.01.

^cP < 0.001.

MTs: Morning-type sleep; ETs: Evening-type sleep; ITs: Intermediate-type sleep.

Table 3 Comparison of sleep rhythm in age, gender and body mass index (n = 13374)

Characteristic	Sleep rhythm			P value
	ITs	MTs	ETs
Age (years), mean ± SD	15.23 (1.433)	14.94 (1.461)	15.19 (1.403)	0.000
BMI (kg/m2), mean ± SD	23.41 (7.022)	23.46 (7.160)	23.81 (7.504)	0.000
Sex				0.005
Boy, n (%)	5403 (80.1)	460 (6.8)	882 (13.1)
Girl, n (%)	5454 (82.3)	412 (6.2)	763 (11.5)
Sum, n (%)	10857 (81.2)	872 (6.5)	1674 (12.3)

MTs: Morning-type sleep; ETs: Evening-type sleep; ITs: Intermediate-type sleep; BMI: Body mass index.

Table 4 Multi-element analysis of obesity in adolescents of different sexes

Characteristic	Characteristic	AOR (95%CI)	P value
Girl	Age	0.818 (0.783-0.854)	0.000
	Self-evaluation of family experience pressure	1.280 (1.125-1.456)	0.000
Boy	Age	0.903 (0.863-0.944)	0.000
	No school residential experience within 6 mo	1.337 (1.153-1.550)	0.000
	Sleep rhythm (ITs)
	(MTs)	1.095 (0.882-1.360)	0.412
	(ETs)	1.250 (1.067-1.468)	0.006

MTs: Morning-type sleep; ETs: Evening-type sleep; ITs: Intermediate-type sleep.

Table 5 Interaction of adolescent sleep rhythms and gender on obesity

Characteristic	AOR (95%CI)	P value
Age	0.869 (0.841-0.898)	0.000
Self-evaluation of family experience pressure	1.173 (1.077-1.1.278)	0.000
Student's way of study	1.223 (1.095-1.368)	0.000
Sex	1.406 (1.292-1.530)	0.000
Sex*ITs
Sex*MTs	1.028 (0.930-1.136)	0.590
Sex*ETs	1.122 (1.043-1.208)	0.002

MTs: Morning-type sleep; ETs: Evening-type sleep; ITs: Intermediate-type sleep.