Table 3.

Cross-sectional Linear Multiple Regression Model of BMI (kg/m²) Regressed on Actigraph Sleep Fragmentation (per Standard Deviation) and Longitudinal Regression Model of BMI Regressed on Actigraph Sleep Fragmentation and BMI 5 Years Prior, the CARDIA Sleep Study, 2000–2006

	Model 1—Cross-sectional			Model 2—Longitudinal
	Coefficient of BMI (kg/m2)	95% Confidence Interval	P Value	Coefficient of BMI (kg/m2)	95% Confidence Interval	P Value
Unadjusted
Fragmentation, score (per SD)	1.20	0.53, 1.88	<0.001	0.17	−0.03, 0.38	0.09
BMI 5 years prior, kg/m2				1.00	0.96, 1.04	<0.001
Adjusteda
Fragmentation, score (per SD)	0.58	−0.03, 1.19	0.06	0.12	−0.08, 0.31	0.25
Age (per year)	0.02	−0.13, 0.17	0.82	−0.005	−0.06, 0.05	0.84
Race-sex groups
White women	Referent			Referent
White men	1.86	0.74, 2.97	0.001	−0.35	−0.78, 0.08	0.11
Black women	4.35	2.66, 6.04	<0.001	−0.24	−0.83, 0.35	0.43
Black men	1.50	−0.24, 3.23	0.09	−0.59	−1.21, 0.4	0.07
Education (per level)	−0.91	−1.45, −0.37	0.001	−0.27	−0.46, −0.09	0.004
Smoking
Nonsmoker	Referent			Referent
Smoker	−1.76	−3.23, −0.30	0.018	−0.17	−0.78, 0.43	0.57
Former smokerb				0.36	−0.36, 1.09	0.33
New smokerb				−3.10	−5.87, −0.34	0.03
Physical activity, exercise units
Current (per 100 units)	−0.29	−0.48, −0.10	0.003	−0.05	−0.14, 0.04	0.28
5 years prior (per 100 units)				0.03	−0.05, 0.12	0.42
Apnea risk
Snoring	3.53	1.80, 5.27	<0.001	0.76	0.12, 1.40	0.02
Tiredness	0.73	−0.43, 1.90	0.22	−0.17	−0.58, 0.23	0.40
BMI 5 years prior, kg/m2				1.00	0.95, 1.04	<0.001

Abbreviations: BMI, body mass index; CARDIA, Coronary Artery Risk Development in Young Adults; SD, standard deviation.

^aIncludes all listed covariates.

^bChanged smoking status between baseline and follow-up.