. Author manuscript; available in PMC: 2016 May 1.

Published in final edited form as: Int J Obes (Lond). 2014 Dec 22;39(5):842–848. doi: 10.1038/ijo.2014.201

Table 2.

Associations between social jetlag and weight and metabolic measures are increased by controlling for smoking and decreased by controlling for socioeconomic status (SES)

Weight and metabolic measures	Controlling for sex, chronotype and sleep duration		Controlling for smoking^a		Controlling for smoking and SES^b
	β (s.e.)	P-value	β (s.e.)	P-value	β (s.e.)	P-value
BMI	0.10 (0.24)	0.012	0.13 (0.24)	0.002	0.12 (0.24)	0.004
Fat mass	0.084 (0.48)	0.031	0.11 (0.48)	0.005	0.10 (0.48)	0.009
Waist circumference	0.072 (5.2)	0.052	0.09 (5.2)	0.017	0.08 (5.2)	0.034
	OR (95% CI)	P-value	OR (95% CI)	P-value	OR (95% CI)	P-value

Obesity	1.2 (1.0–1.5)	0.045	1.3 (1.0–1.5)	0.019	1.2 (1.0–1.5)	0.035
Metabolic syndrome	1.3 (1.0–1.6)	0.031	1.3 (1.0–1.6)	0.043	1.2 (1.0–1.5)	0.063

Abbreviations: BMI, body mass index; CI, confidence interval; OR, odds ratio. We used linear regression models to test associations between social jetlag and continuous outcome measures of BMI, fat mass and waist circumference; the table shows the standardized coefficient (β), s.e. and P-value for social jetlag as a predictor variable. We used logistic regressions to test associations between social jetlag and binary outcome measures of obesity and the metabolic syndrome; the table shows the OR, 95% confidence interval for the OR (95% CI) and P-values for social jetlag as a predictor variable. The OR associated with social jetlag reflects the effect of a one-unit (s.d.) increase in social jetlag. Significant P-values (P < 0.05) are shown in bold.

Individuals who smoked had lower BMI (r = −0.13, P < 0.001), less fat mass (r = −0.14, P < 0.001), smaller waist circumference (r = −0.09, P = 0.003) and lower risk for obesity (r = −0.08, P = 0.02). Smoking was not associated with risk for metabolic syndrome (r = 0.02, P = 0.51).

Lower SES status was significantly associated with higher BMI (r = −0.09, P = 0.009), greater waist circumference (r = −0.08, P = 0.02) and higher risk for obesity (r = −0.08, P = 0.03). Lower SES status was also marginally significantly associated with more fat mass (r = −0.06, P = 0.09), but not with risk for the metabolic syndrome (r = −0.05, P = 0.13).