Table 3.

Within-pair correlation coefficients with 95% confidence intervals (CI) of differences between self-reported and measured height, weight, body mass index (BMI) and waist circumference (WC) in all twin pairs and by zygosity and sex.

Differences between self-reported and measured variablea	ALL pairs			MEN pairs				WOMEN pairs
	All (n = 220)	MZ (n = 125)	DZ (n = 93)	All (n = 89)	MZ (n = 49)	DZ (n = 39)		All (n = 131)	MZ (n = 76)	DZ (n = 54)
	r (95% CI)	r (95% CI)	r (95% CI)	r (95% CI)	r (95% CI)	r (95% CI)	p-valuec	r (95% CI)	r (95% CI)	r (95% CI)	p-valuec
Height (cm)	0.32 (0.19, 0.43)	0.42 (0.27, 0.56)	0.16 (−0.04, 0.36)	0.29 (0.09, 0.47)	0.29 (0.01, 0.53)	0.28 (−0.04, 0.55)	0.961	0.35 (0.19, 0.49)	0.55 (0.37, 0.69)	0.09 (−0.19, 0.35)	0.004
Weight (kg)b	0.23b (0.10, 0.36)	0.26 (0.09, 0.42)	0.21b (0.01, 0.40)	0.15 (−0.06, 0.35)	0.06 (−0.22, 0.34)	0.29 (−0.03, 0.56)	0.284	0.28b (0.11, 0.43)	0.39 (0.18, 0.56)	0.17b (−0.10, 0.42)	0.191
BMI (kg/m2)	0.30b (0.17, 0.42)	0.40 (0.24, 0.54)	0.19b (−0.01, 0.38)	0.22 (0.01, 0.41)	0.16 (−0.13, 0.42)	0.37 (0.06, 0.61)	0.459	0.33b (0.17, 0.48)	0.52 (0.34, 0.67)	0.12b (−0.16, 0.38)	0.013
WC (cm)b	0.39b (0.27, 0.50)	0.34b (0.17, 0.49)	0.43 (0.25, 0.58)	0.42b (0.23, 0.58)	0.42b (0.15, 0.63)	0.44 (0.14, 0.66)	0.913	0.37b (0.21, 0.51)	0.30b (0.08, 0.50)	0.43 (0.18, 0.63)	0.411

MZ = monozygotic; DZ = dizygotic; r = correlation coefficient; BMI = body mass index; WC = waist circumference; 95 % CI = 95% confidence intervals.

Note: Zygosity was unknown in one male pair and in one female pair.

^aDifference variable (self-reported value − measured value) of twin 1 correlated to difference variable (self-reported value − measured value) of twin 2.

^bMissing values: Weight in one DZ woman, BMI in one DZ woman, and waist in one MZ man and one MZ woman.

^cP-values for differences in correlation coefficients between MZ and DZ pairs within sex.