SULT1A1 and hematocrit: Linear regression models and ANOVA were used to test for association of SULT1A1 copy number, rs3760091, rs750155, and rs9282861 (SULT1A1∗2), with age at menopause and symptoms, levels of estrogens (estrone [E1], estrone sulfate [E1S], E2, and estradiol sulfate [E2S]), before and after HT.