W18 – HT Hormone Pretest

This page provides study documentation for Core Study W18. For description of the specimen results, see Specimen Results Description (open to public). Data sets of the specimen results are included in the existing WHI datasets located on the WHI Data on this site (sign in and a completed Data Distribution Agreement are required; see details on the Data site).

Investigator Names and Contact Information

Core study approved by WHI Steering Committee


The WHI hormone trials were designed to evaluate the hypothesis that postmenopausal hormone therapy would reduce coronary heart disease risk.  Epidemiologic studies suggested an increase in breast cancer with hormone therapy, so breast cancer was monitored as a ‘primary adverse’ outcome.
The primary objective for this project is to determine the effect of Estrogen plus Progestin and Estrogen Alone treatment on the blood levels of the following hormones: 
Estrogen Alone:  Estrone, Estradiol, and SHBG;
Estrogen plus Progestin:  Estrone, Estradiol, SHBG, Testosterone, Progesterone
Participant blood samples at baseline and Year 1 will be tested for these analytes and results compared. This pretest will be carried out before moving forward with the HT Breast Cancer and HT Fracture biomarker proposals.
See publications: 795. WHI publications by study lists published WHI papers that have been generated by ancillary studies. A complete list of WHI papers is available in the Bibliography section of this website