Table 3.

Pairwise differences in waist gain during follow-up between leisure-time physical activity discordant twin pairs.

	All same sex twin pairs	Waist gain during follow-up				Monozygotic twin pairs	Waist gain during follow-up
		Twin 1	Twin 2				Twin 1	Twin 2
	Pairs, N	Mean (SD), cm	Mean (SD), cm	Mean difference (95%CI)	P	Pairs, N	Mean (SD), cm	Mean (SD), cm	Mean difference (95%CI)	P
Decreased activity (twin 1) vs. increased activity (twin 2)	85 (men=31)	7.7 (9.5)	5.0 (7.5)	2.8 (0.4 to 5.1)	0.009	43 (men=16)	8.3 (10.3)	4.2 (7.3)	4.2 (1.2 to 7.2)	0.008
Persistently inactive (twin 1) vs. from inactive to moderately active or active (twin 2)	41 (men=16)	9.7 (8.8)	5.1 (7.6)	4.7 (1.3 to 8.0)	0.007	22 (men=9)	10.2 (10.1)	6.2 (8.8)	4.0 (−0.8 to 8.8)	0.10
From active to moderately active or inactive (twin 1) vs. persistently active (twin 2)	63 (men=30)	8.3 (9.8)	5.4 (4.5)	2.9 (0.5 to 5.3)	0.02	34 (men=15)	6.6 (9.5)	5.4 (4.4)	1.2 (−1.9 to 4.4)	0.44

Abbreviations: SD, standard deviation; CI, confidence interval