Energy balance, early life body size, and plasma prolactin levels in postmenopausal women.
OBJECTIVE
We examined the relationships of prolactin with birth weight; childhood, adolescent and adult body size measures; adult physical activity and inactivity; and alcohol consumption among 1,423 postmenopausal women from the Nurses' Health Study.


METHODS
Information on exposures was collected on biennial questionnaires beginning in 1976. Blood was collected from 32,826 participants in 1990; prolactin was measured in a subset of women who were controls for a nested breast cancer case-control study. Generalized linear models were adjusted for assay batch, medication use at blood draw, and other potential predictors of prolactin.


RESULTS
No associations were observed for adult factors (p-trend >or= 0.17), body mass index at age 18, birth weight, or height (p-trend >or= 0.27). There was an inverse association between body size at ages 5 (p-trend = 0.03) and 10 (p-trend = 0.05) and prolactin, with levels 9% lower among women with the heaviest versus leanest average childhood body size. This association was more pronounced among women with a birth weight <7 pounds (p-trend = 0.004; p-interaction between birth weight and childhood body size = 0.01).


CONCLUSIONS
Our results suggest that few adult lifestyle risk factors are associated with prolactin levels in postmenopausal women; however, childhood body size may be a predictor of levels later in life.
Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Ave., 3rd Floor, Boston, MA 02115, USA.
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Su
Susan E
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Hankinson
Charles V
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Clevenger
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Eliassen
Shelley S
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Tworoger
D000428:Alcohol Drinking / Q000009:adverse effects; D001724:Birth Weight / Q000502:physiology*; D049628:Body Size / Q000502:physiology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D017698:Postmenopause; D011388:Prolactin / Q000097:blood*; D012307:Risk Factors
D011388:Prolactin