Table 2.

Unadjusted and multivariable linear regression estimating associations of demographic and cardiac risk factors with endothelin-1 levels (n=1,361)

	Difference in Endothelin-1 Level (pg/mL)
		Univariate			Multivariate
	Difference	(95% CI)	p-value	Difference	(95% CI)	p-value
Age (per 10 years)	−0.8	(−1.3, −0.3)	0.002	−0.8	(−1.4, −0.2)	0.007
Female	0.1	(−0.9, 1.1)	0.84	−0.2	(−1.2, 0.9)	0.75
Body mass index (per 5 kg/m2)	−0.2	(−0.7, 0.3)	0.50	−0.2	(−0.8, 0.4)	0.46
Race
White			Referent			Referent
Chinese	−1.5	(−3.3, 0.2)	0.07	−3.3	(−5.5, −1.2)	0.002
African-American	−0.6	(−1.9, 0.7)	0.36	−0.8	(−2.3, 0.6)	0.26
Hispanic	−0.7	(−2.1, 0.7)	0.35	−2.3	(−4.1, −0.6)	0.008
Educational attainment
< high school degree			Referent			Referent
High school degree	0.9	(−0.9, 2.7)	0.31	0.4	(−1.4, 2.2)	0.67
Some college	0.5	(−1.1, 2.1)	0.53	−0.6	(−2.2, 1.2)	0.54
Bachelor’s Degree	−0.7	(−2.5, 1.0)	0.42	−1.9	(−3.9, 0.0)	0.06
≥ bachelor’s degree	0.1	(−1.7, 1.8)	0.93	−1.6	(−3.5, 0.4)	0.12
Exercise (per 500 MET/min/week)	0.1	(0.0, 0.2)	0.02	0.1	(0.0, 0.2)	0.06
Pack-years (per 10 years)	−0.4	(−0.6, −0.1)	0.003	−0.4	(−0.6, −0.1)	0.003
GFR (per 10 mL/min/1.73m2)	0.2	(−0.2, 0.5)	0.32	0.1	(−0.2, 0.5)	0.46
Hypertension	−0.6	(−1.7, 0.4)	0.24	0.2	(−1.0, 1.3)	0.79
Diabetes mellitus	−1.4	(−2.9, 0.2)	0.09	−1.0	(−2.6, 0.6)	0.22

Multivariate model included all listed variables and also included study site.

Data presented as mean ± standard deviation or percentage as appropriate

Abbreviations: pg=picogram, mL=milliliter, CI= confidence interval, kg=kilograms, m²=meters squared, MET/min/week= Metabolic equivalents per minute per week

A parsimonious backward elimination multivariate model of predictors of endothelin-1 level included only age (−0.8 pg/mL per 10 additional years of age, p=0.004), intentional exercise (0.1 pg/mL per 500 additional MET/min/week, p=0.02), and pack-years of smoking (−0.3 pg/mL per 10 pack-years, p=0.008).