Table 1

Partial regression coefficients (β) and standard errors (SE) for the blood pressure predictor variables in the mixed model analyses of monozygotic smoking discordant twin pairs

		Monozygotic men				Monozygotic women
		β (SE)	t(9), p value			β (SE)	t(9), p value
Systolic blood pressure (mm Hg)
Intercept	164.47 (12.43)			157.06 (8.50)
Tobacco smoking	22.10 (13.02)	1.70, 0.12		9.38 (9.51)	0.99, 0.35
Hypertension medication	−11.15 (18.08)	−0.62, 0.55		3.59 (11.56)	0.31, 0.76
Age	−5.55 (5.64)	−0.98, 0.35		1.68 (3.12)	0.54, 0.60
Body mass index	1.29 (2.30)	0.56, 0.59		3.31 (1.61)	2.06, 0.07
Alcohol consumption	−0.12 (0.07)	−1.77, 0.11		0.77 (0.85)	0.90, 0.39
Diastolic blood pressure (mm Hg)
Intercept	78.08 (6.96)			84.92 (4.05)
Tobacco smoking	11.88 (7.00)	1.70, 0.12		2.60 (6.12)	0.42, 0.68
Hypertension medication	0.28 (9.98)	0.03, 0.98		−0.20 (5.93)	−0.03, 0.97
Age	−3.57 (3.19)	−1.12, 0.29		2.96 (1.16)	2.55, 0.03^1-150
Body mass index	0.69 (1.27)	0.54, 0.60		0.48 (0.77)	0.62, 0.55
Alcohol consumption	−0.03 (0.04)	−0.86, 0.41		0.76 (0.36)	2.13, 0.06

↵1-150 p<0.05 (statistically significant). The continuous regressors age (years), body mass index (kg/m²), and alcohol consumption (alcohol servings per month) were centred about their means in the mixed model analyses. The means of these regressors were 83.58 years, 24.49 kg/m2, and 4.44 servings/month, respectively.