Post on 25-Dec-2015
Linda Snetselaar, PhD, RDProfessor
Interim Chair of the Department of Community and Behavioral Health
College of Public HealthUniversity of Iowa
Background15- year, $625 million national health study
funded by NHLBIFocused on chronic disease prevention in
postmenopausal women of all racesHeart diseaseBreast cancerColorectal cancerOsteoporotic fractures
161,808 women aged 50-79
WHI Sites40 clinics throughout the USThree locations in Iowa:
Iowa CityDavenportDes Moines
Two Main Study ComponentsRandomized clinical trial
3 prevention strategies-women could enroll in any or all (if eligible) Hormone therapy Dietary modification Calcium and Vitamin D
Observational studyExamines relationships between lifestyle,
health, risk factors, and disease outcomes
Hormone Therapy TrialsEstrogen plus progestinEstrogen alonePlaceboHormone groups stopped treatment early,
but all participants continued to be followed until the end of the study
Dietary Modifications (DM) TrialEvaluated impact of diet on prevention of
breast and colorectal cancer and heart diseaseLow fatHigh fruitHigh vegetableHigh grain
DM Comparison GroupFollow regular eating habits
Keep a food record a few days each year
Attend a clinic visit one time each year
Dietary Change GroupAttend nutrition sessions to:
Lower fat (20% kcal from fat) Increase fruits and vegetables
(> 5 servings per day)
Increase grains (> 6 servings per day)
Frequently keep a food recordOne clinic visit per year
DM Nutrition SessionsThe first year
18 nutrition classes Once a week for 6 weeks Every other week for 6 weeks Once a month for 9 months 1 clinic and 1 phone visit
The second year and beyond4 nutrition classes each year1 clinic and 1 phone visit
Calcium and Vitamin D TrialEvaluated the effect of calcium and vitamin D
supplementation on osteoporotic fractures and colorectal cancer
Calcium and vitamin D supplements group
Placebo group
Observational Study GroupCompleted questionnaires reporting changes
in health and activities over time
No other required study activities
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