Women's Health Initiative (WHI)

Introduction

The Women's Health Initiative has generated several studies. Some conclusions are described below, others in Related.

Key points: 2006

• Estrogen, alone or in combination with progestin
  • does NOT reduce incidence of heart disease
  • increases risk for strokes & blood clots

• breast cancer
  • small increase in risk for breast cancer in women taking both estrogen & progestin
  • estrogen alone does NOT increase risk of breast cancer

• estrogen reduces risk of fractures

• estrogen use for hot flashes
  • use lower possible dose
  • periodically review need for continuation

• dietary intake of fruits & vegetables may not reduce risk of breast cancer or colon cancer

• Ca+2 & vitamin D increase bone density & may reduce risk of fractures

Other key points:

• history of miscarriage or stillbirth is associated with increased risk for coronary heart disease

Conclusions:

• NSAIDS
  • women taking at least 2 tablets of NSAIDs/week for 5 years or longer have a 20% lower risk of breast cancer low-dose aspirin 100 mg QOD does not lower risk of cancer
  • aspirin 100 mg QOD vs placebo (40,000 women > 45, mean age 55) with average follow-up of 10 years
    • significant decrease in combined endpoint of MI, stroke or cardiovascular death for women > 65 ONLY
    • decrease in stroke 1.1% vs 1.3%/10 years (P=0.4) & TIA 0.9% vs 1.2% (P=0.01)
    • increased risk of GI bleeding 4.6% > 3.8%
    • does NOT prevent cognitive decline
• Vit E
  • vitamin E 600 IU QOD of no benefit in reducing risk of cardiovascular disease or cancer
  • vitamin E 600 IU QOD diminished risk of venous thromboembolism & pulmonary embolism, especially in high-risk women
• Folate
  • higher plasma folate & vitamin B6 levels are associated with a lower risk of breast cancer
• Estrogen
  • women taking Prempro have a high risk of heart disease, breast cancer, stroke & dementia
    • acute coronary syndrome less common in women age 50-59 taking conjugated equine estrogens than placebo (21 vs 34 events in 10,739 women over 7 years)
  • premarin alone does NOT increase the risk of heart disease or breast cancer, but does increase the risk of stroke
  • recipients of Prempro were less likely than placebo to be diagnosed with colon cancer (43 vs 72 per 16,000 women over average of 5 years)
    • HOWEVER; Prempro recipients were significantly more likely than placebo recipients to present with positive lymph nodes (59% vs 29%) & with regional or metastatic disease (76% vs 29%)
    • NO difference in number of deaths from colorectal cancer
  • estrogen alone of little to no benefit for postmenopausal women
  • HRT started 14 years after menopause increases risk of cardiovascular disease & thromboembolic events
• Calcium plus vitamin D supplementation
  • 36,000 women, 7 year trial
  • 1000 mg of calcium plus 400 IU of vitamin D3
  • Results: no effect on fracture no risk reduction for colorectal cancer

More general terms

• clinical trial

Additional terms

• hormone replacement therapy (HRT); estrogen replacement therapy; postmenopausal hormone replacement therapy
• Women's Health Initiative: Antihypertensives and Cardiovascular Death
• Women's Health Initiative: Dietary Modification Trial
• Womens Health Initiative (WHI) memory study