Gender-dependent association between sleep duration and overweight incidence in CHINESE school children: a national follow-up study

Table 3 HRs for overweight incidence according to sleep duration group among Chinese normal weight children in 6–9 months follow-up

Group	No. of Participants	No. of new overweight	Model 1^a	Model 2^b
Male
> 9 h	1735	47	1	1
7–9 h	3950	112	1.09(0.77–1.54)	1.03(0.67–1.59)
< 7 h	855	38	1.38(0.87–2.21)	1.21(0.65–2.24)
Female
> 9 h	1888	46	1	1
7–9 h	4563	140	1.23(0.87–1.74)	1.60(1.02–2.52)*
< 7 h	1667	50	1.28(0.81–2.00)	1.71(0.95–3.08)
Stratified by age and gender
Before adolescents
Male (6–11 years)
> 9 h	1416	43	1	1
7–9 h	2148	66	1.04(0.71–1.53)	1.05(0.65–1.70)
< 7 h	302	7	0.84(0.38–1.86)	0.84(0.29–2.40)
Female (6–10 years)
> 9 h	1499	34	1	1
7–9 h	2086	64	1.41(0.93–2.13)	2.13(1.20–3.77)*
< 7 h	247	8	1.46(0.68–3.16)	1.78(0.65–4.87)
Young adolescents
Male (12–15 years)
> 9 h	287	3	1	1
7–9 h	1411	34	2.14(0.65–7.01)	1.41(0.41–4.87)
< 7 h	450	17	3.58(1.02–12.49)*	2.19(0.56–8.51)
Female (11–14 years)
> 9 h	346	7	1	1
7–9 h	1595	44	1.12(0.50–2.52)	1.31(0.49–3.47)
< 7 h	366	12	1.31(0.50–3.40)	1.28(0.38–4.28)
Elder adolescents
Male (15–17 years)
> 9 h	32	1	1	1
7–9 h	391	12	1.42(0.18–10.98)	0.36(0.04–3.46)
< 7 h	405	14	1.87(0.24–14.40)	0.28(0.03–2.89)
Female (16–17 years)
> 9 h	43	5	1	1
7–9 h	882	32	0.50(0.19–1.29)	0.24(0.06–0.93)*
< 7 h	970	30	0.53(0.20–1.37)	0.28(0.07–1.12)

HRs hazard ratios, risk for overweight are displayed as HR (95%CI)
^*P < 0.05 compared with ‘> 9 h’ group
^aModel 1 was adjusted for age
^bModel 2 was adjusted Model 1 covariates plus puberty on-set, food intake, physical activity& sedentary, domestic income and mother’s year of education

ISSN: 1471-2458