TABLE 1.

Baseline characteristics by dietary GI quintile and incidence of insomnia 3 y later, continuous variables¹

	Dietary GI quintiles						Incident insomnia 3 y later
Baseline characteristics	1 (Low)	2	3	4	5 (High)	P 2	Yes	No	P 2
Mean insomnia WHIIRS	5.064 ±  3.66	5.263 ± 3.70	5.296 ± 3.63	5.413 ± 3.73	5.501 ± 3.80	<0.0001	11.278 ± 2.36	3.957 ± 2.39	<0.0001
Age, y	63.77 ± 7.3	63.56 ± 7.3	63.48 ± 7.3	63.32 ± 7.3	62.63 ± 7.2	<0.0001	63.39 ± 7.3	63.35 ± 7.3	0.5837
BMI, kg/m2	26.41 ± 5.3	26.46 ± 5.4	26.78 ± 5.5	27.13 ± 5.7	27.77 ± 6.1	<0.0001	27.36 ± 5.9	26.81 ± 5.6	<0.0001
Physical activity,MET-h/wk	17.72 ± 16.0	16.06 ± 14.8	14.71 ± 14.3	13.27 ± 13.7	11.10 ± 13.0	<0.0001	13.57 ± 14.1	14.80 ± 14.7	<0.0001

¹Values are means ± SDs unless stated otherwise. GI, glycemic index; MET, metabolic equivalent; WHIIRS, Women's Health Initiative Insomnia Rating Scale.

²Differences by insomnia and GI quintiles were tested with t tests for continuous variables.