Table 3.

Odds ratios of incident obesity^* at 1-year follow-up as a function of sleep duration at baseline (2006) in men (n = 20,023) and women (n =3,189)

	Number (%)	P value	Model 1‡			Model 2§			Model 3¶
			OR	95%CI	P value	OR	95%CI	P value	OR	95%CI	P value
Sleep Duration (Hours)
Men
< 5	43 (9.4)	< 0.001	1.96	1.40, 2.74	< 0.001	1.97	1.41, 2.75	< 0.001	1.91	1.36, 2.67	< 0.001
5 to < 6	209 (7.4)	< 0.001	1.50	1.24, 1.80	< 0.001	1.51	1.26, 1.82	< 0.001	1.50	1.25, 1.80	< 0.001
6 to < 7	554 (5.7)	0.13	1.13	0.98, 1.30	0.10	1.14	0.98, 1.32	0.08	1.14	0.98, 1.32	0.08
7 to < 8	294 (5.1)	1.00	1.00			1.00			1.00
8 to < 9	63 (6.0)	0.20	1.19	0.90, 1.58	0.22	1.17	0.89, 1.56	0.26	1.17	0.88, 1.55	0.27
≥ 9	8 (7.3)	0.29	1.48	0.71, 3.06	0.30	1.46	0.70, 3.03	0.31	1.42	0.69, 2.96	0.34
total	1171 (5.8)
Women
< 5	1 (1.0)	0.50	0.36	0.05, 2.73	0.32	0.36	0.05, 2.75	0.33	0.35	0.05, 2.69	0.31
5 to < 6	14 (2.1)	0.86	0.83	0.40, 1.69	0.60	0.83	0.41, 1.70	0.62	0.82	0.40, 1.68	0.59
6 to < 7	40 (2.6)	0.89	1.03	0.59, 1.82	0.91	1.04	0.59, 1.83	0.90	1.04	0.59, 1.84	0.88
7 to < 8	18 (2.4)	1.00	1.00			1.00			1.00
8 to < 9	2 (1.5)	0.75	0.62	0.14, 2.70	0.52	0.62	0.14, 2.72	0.53	0.64	0.15, 2.79	0.55
≥ 9	0 (0.0)	0.59	0.00		1.00	0.00		1.00	0.00		1.00
total	75 (2.4)

Abbreviations: OR, odds ratio; 95%CI, 95% confidence interval.

^*“Obesity” defined as a body mass index ≥ 25 kg/m².

^†Analysis of obesity was conducted among participants who were not obese at baseline.

^‡Model 1: adjusted for age.

^§Model 2: adjusted for the variables in model 1 plus shift-worker, smoking, alcohol consumption, and physical activity.

^¶Model 3: adjusted for the variables in model 2 plus depressive symptoms.