Table 5.

Regression results of testing the effect of number of CAG repeats and total surface area

Predictors	Estimates	SE	Std. Beta	Standardized SE	Standardized CI	Statistic	P  *
Males (N = 210; 169 twinid; Observations = 396)
CAGrepeat	32.32	246.86	0.00	0.02	−0.03– 0.04	0.13	0.896
CAGrepeat: age (linear)	5656.71	2614.84	0.39	0.18	0.04–0.75	2.16	0.031 *
CAGrepeat: age (quadratic)	−1133.32	2473.77	−0.08	0.18	−0.43– 0.27	−0.46	0.647
Females (N = 191; 150 twinid; Observations = 363)
CAGrepeat	−100.65	339.58	−0.01	0.02	−0.04– 0.03	−0.30	0.767
CAGrepeat: age (linear)	4809.25	3440.29	0.27	0.20	−0.12– 0.66	1.40	0.162
CAGrepeat: age (quadratic)	−4413.30	3412.23	−0.26	0.20	−0.64– 0.13	−1.29	0.196

^* P value <0.05 “*” and <0.002 “**” (P value for significance after correction for multiple comparison).