TABLE 3

Best fitting biometric models for metabolic variables in young and older twins

Components of variance
Goodness of fit tests
Additive genetic (a2)Dominant genetic (d2)Common environment (c2)Unique environment (e2)χ2PAIC
Insulin secretion
    Young
        AE0.75 (0.55–0.86)*0.25 (0.14–0.45)*0.01.00−2.0
    Older
        AE0.84 (0.69–0.92)0.16 (0.08–0.31)1.40.24−0.6
HGP
    Young
        DE0.29 (0.08–0.47)0.71 (0.53–0.92)0.01.00−2.0
    Older
        CE0.54 (0.29–0.72)0.46 (0.28–0.71)0.00.90−2.0
Basal glucose uptake
    Young
        AE0.27 (0.07–0.44)*0.73 (0.56–0.93)*0.01.00−2.0
    Older
        AE0.67 (0.39–0.83)0.33 (0.17–0.61)0.00.98−2.0
Insulin-stimulated glucose uptake
    Young
        AE0.53 (0.28–0.71)0.47 (0.29–0.72)0.00.84−2.0
    Older
        AE0.55 (0.20–0.76)0.45 (0.24–0.80)0.01.00−2.0
NOGM
    Young
        AE0.50 (0.32–0.64)0.50 (0.36–0.68)0.160.69−1.8
    Older
        DE0.48 (0.04–0.72)0.52 (0.28–0.96)0.01.00−2.0
  • Data are proportion of total variance (95% CI) adjusted for sex.

  • *

    * P < 0.05 for young vs. old. AIC, Akaike’s information criterion.