Table 3. Differences in effects of smoking and BMI on LTL between race and sex groups.

	Total effect: Smoking→LTL ©a	Indirect effect 1: Smoking→BMI (β1)	Indirect effect 2: BMI→LTL (β2)	Direct effect: Smoking→LTL (c’)b
Whites (n=729)	-0.076 *	-0.136 *	-0.113 *	-0.091 *
African Americans (n=308)	-0.010	-0.141 *	-0.041	-0.016
P for race difference	0.539	0.477	0.104	0.421
Males (n=437)	-0.053	-0.196 *	-0.099 *	-0.072
Females (n=600)	-0.064	-0.104 *	-0.073	-0.072
P for sex difference	0.865	0.244	0.515	0.971

β, c and c’ are standardized regression coefficients.

BMI=body mass index; LTL=leukocyte telomere length

a, BMI was not included in the models for adjustment.

b, BMI was included in the models for adjustment.

*, P<0.05