Adult height, insulin, and 17beta-estradiol in young women.
BACKGROUND
Adult height and insulin are thought to modify the development of breast cancer. However, little is known about the association between height and 17beta-estradiol, a key factor in breast carcinogenesis, and whether insulin modifies such an association.


METHODS
Among 204 healthy women, ages 25 to 35 years, who participated in the Energy Balance and Breast Cancer Aspect I study, adult height (in centimeters) and fasting serum concentrations of insulin (pmol/L) were measured. 17beta-Estradiol concentrations were measured in daily saliva samples throughout an entire menstrual cycle through RIA. Age and multivariate linear regression models were used to study the association between adult height and 17beta-estradiol levels throughout an entire menstrual cycle and whether serum levels of fasting insulin may modify such an association.


RESULTS
The women had a mean age of 30.7 years, adult height of 166.9 cm, and serum insulin of 85.7 pmol/L. For each increase of one SD in insulin levels in the upper tertile of adult height, the adjusted level of 17beta-estradiol increased by 3.1 pmol/L (95% confidence interval, 1.1-5.2), equivalent to a 17.3% higher mean average concentration of 17beta-estradiol. Women with an adult height > or =170 cm (upper tertile) and insulin levels >101 pmol/L (upper quartile) experienced, on average, 41% higher 17beta-estradiol levels throughout the entire menstrual cycle compared with women with the same adult height and insulin levels <101 pmol/L.


CONCLUSIONS
Our findings support that premenopausal levels of 17beta-estradiol vary in response to adult height and insulin levels, of possible importance for breast cancer risk.
Finstad
Sissi Espetvedt
SE
The Cancer Center, Oslo University Hospital, Ullevål, Oslo 0407, Norway. sissi.espetvedt@medisin.uio.no
Emaus
Aina
A
Tretli
Steinar
S
Jasienska
Grazyna
G
Ellison
Peter T
PT
Furberg
Anne-Sofie
AS
Wist
Erik A
EA
Thune
Inger
I
D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D014408:Biomarkers, Tumor / Q000378:metabolism; D001827:Body Height; D001943:Breast Neoplasms / Q000378:metabolism; D016009:Chi-Square Distribution; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood*; D016014:Linear Models; D009664:Norway; D017697:Premenopause; D012463:Saliva / Q000737:chemistry; D011795:Surveys and Questionnaires
D014408:Biomarkers, Tumor; D007328:Insulin; D004958:Estradiol