Table 1.

Baseline and Follow-up Characteristics of the Physical Activity–Discordant Twin Pairs Healthy at Baseline

CharacteristicInactive (n=16)Active (n=16)P*
Baseline 1975
Male sex, n (%)11 (69)11 (69)
Age, mean (minimum–maximum), y28 (18–42)28 (18–42)
Body mass index, mean (SD), kg/m223.0 (4.2)22.3 (2.0)0.88
Leisure time MET index, mean (SD), during follow-up from 1980 to 2005, MET-h/d
19801.8 (1.8)14.2 (6.9)<0.001
19851.5 (1.8)13.5 (6.6)<0.001
19903.0 (6.0)11.5 (5.7)0.002
19953.1 (5.1)11.7 (5.7)0.005
20001.9 (1.5)9.1 (4.8)0.001
20052.4 (1.9)8.6 (4.4)0.001
Mean from 1980–20052.2 (2.3)11.0 (4.1)<0.001
Follow-up end point 2007
Age, mean (minimum–maximum), y60 (50–74)60 (50–74)
Leisure time MET index, mean (SD), MET h/d1.6 (1.4)8.4 (4.1)<0.001
Body mass index, mean (SD), kg/m226.7 (3.5)24.8 (2.6)0.088
Total body fat percent, mean (SD), %27.0 (5.3)21.5 (6.4)0.004
Total body fat mass, mean (SD), kg21.6 (7.7)15.6 (5.0)0.015
Total body fat-free mass, mean (SD), kg57.7 (12.4)57.2 (11.1)1.00
Visceral adipose tissue area, mean (SD), cm2171 (103)115 (73)0.010
Intramuscular fat infiltration area, mean (SD), cm214.0 (7.0)9.1 (4.8)0.002
Estimated Vo2peak, mean (SD), mL·kg−1·min−126.4 (4.9)32.5 (5.5)<0.001
Type 2 diabetes mellitus, n (%)3 (19)1 (6)0.16
Coronary heart disease, n (%)3 (19)1 (6)0.16
Nutrient intake and use of alcoholic drinks before follow-up visit†
Energy, mean (SD), MJ/d6.4 (1.5)7.1 (1.9)0.20
Protein E%, mean (SD), %18.1 (1.9)17.5 (2.3)0.26
Carbohydrate E%, mean (SD), %45.2 (6.0)46.7 (6.8)0.48
Fat E%, mean (SD), %33.6 (6.2)31.7 (6.2)0.38
Saturated fat E%, mean (SD), %12.5 (3.2)11.4 (2.9)0.40
Monounsaturated fat E%, mean (SD), %11.6 (2.4)11.1 (3.1)0.56
Polyunsaturated fat E%, mean (SD), %6.0 (1.3)6.0 (1.6)0.64
Dietary fiber, mean (SD), g/d19.8 (5.4)21.6 (6.1)0.31
Alcoholic drinks, mean (SD), g/d122 (251)147 (183)0.55
  • E% indicates percentage of total energy intake per day; and MET, metabolic equivalent.

  • *P values derived from paired t test (normal distribution), Wilcoxon signed-rank test (nonnormal distribution), or exact symmetry test (categorical variables; Stata).

  • †Calculated on the basis of 5-day (3 weekdays and weekend) food diary.