American Diabetes Association

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)	χ²	P	AIC
Insulin secretion
Young
AE	0.75 (0.55–0.86)^*	—	—	0.25 (0.14–0.45)^*	0.0	1.00	−2.0
Older
AE	0.84 (0.69–0.92)	—	—	0.16 (0.08–0.31)	1.4	0.24	−0.6
HGP
Young
DE	—	0.29 (0.08–0.47)	—	0.71 (0.53–0.92)	0.0	1.00	−2.0
Older
CE	—	—	0.54 (0.29–0.72)	0.46 (0.28–0.71)	0.0	0.90	−2.0
Basal glucose uptake
Young
AE	0.27 (0.07–0.44)^*	—	—	0.73 (0.56–0.93)^*	0.0	1.00	−2.0
Older
AE	0.67 (0.39–0.83)	—	—	0.33 (0.17–0.61)	0.0	0.98	−2.0
Insulin-stimulated glucose uptake
Young
AE	0.53 (0.28–0.71)	—	—	0.47 (0.29–0.72)	0.0	0.84	−2.0
Older
AE	0.55 (0.20–0.76)	—	—	0.45 (0.24–0.80)	0.0	1.00	−2.0
NOGM
Young
AE	0.50 (0.32–0.64)	—	—	0.50 (0.36–0.68)	0.16	0.69	−1.8
Older
DE	—	0.48 (0.04–0.72)	—	0.52 (0.28–0.96)	0.0	1.00	−2.0

	Components of variance							Goodness of fit tests
		Additive genetic (a²)	Dominant genetic (d²)	Common environment (c²)	Unique environment (e²)	χ²	P	AIC
Insulin secretion
Young
AE	0.75 (0.55–0.86)^*	—	—	0.25 (0.14–0.45)^*	0.0	1.00	−2.0
Older
AE	0.84 (0.69–0.92)	—	—	0.16 (0.08–0.31)	1.4	0.24	−0.6
HGP
Young
DE	—	0.29 (0.08–0.47)	—	0.71 (0.53–0.92)	0.0	1.00	−2.0
Older
CE	—	—	0.54 (0.29–0.72)	0.46 (0.28–0.71)	0.0	0.90	−2.0
Basal glucose uptake
Young
AE	0.27 (0.07–0.44)^*	—	—	0.73 (0.56–0.93)^*	0.0	1.00	−2.0
Older
AE	0.67 (0.39–0.83)	—	—	0.33 (0.17–0.61)	0.0	0.98	−2.0
Insulin-stimulated glucose uptake
Young
AE	0.53 (0.28–0.71)	—	—	0.47 (0.29–0.72)	0.0	0.84	−2.0
Older
AE	0.55 (0.20–0.76)	—	—	0.45 (0.24–0.80)	0.0	1.00	−2.0
NOGM
Young
AE	0.50 (0.32–0.64)	—	—	0.50 (0.36–0.68)	0.16	0.69	−1.8
Older
DE	—	0.48 (0.04–0.72)	—	0.52 (0.28–0.96)	0.0	1.00	−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.