TABLE 1
Demographic Characteristics of Subject Pairs
Characteristic
Monozygotic twins
Dizygotic twins
Pairs (
n
)
40 (12 M/28 F)
18 (9 M/9 F)
Mean age ± SD (y)
Male
59.2 ± 13.2
73.7 ± 10.6
Female
60.7 ± 11.6
56.1 ± 14.5