Bone mineral density in estrogen-deficient young women.
BACKGROUND
Osteoporosis primarily affects postmenopausal women. However, young women with estrogen deficiency also are at increased risk for low bone density.


OBJECTIVE
The aim of the study was to assess bone density and associated risk factors for reduced bone density in young, estrogen-deficient women using primary ovarian insufficiency (POI) as the disease model.


METHODS
We conducted a cross-sectional study at a tertiary care research center.


METHODS
We studied women with POI (n = 442), concurrent controls (n = 70), and matched controls from NHANES III (n = 353).


METHODS
We measured bone mineral density (BMD) using dual-energy x-ray absorptiometry.


RESULTS
Patients on average had 2-3% lower BMD at L1-L4, femoral neck, and total hip (P < 0.01 at all sites). The modifiable risk factors for BMD below the expected range for age (Z-score <-2) were: more than 1-yr delay in diagnosis of estrogen deficiency (P = 0.018), low (<32 ng/ml) vitamin D levels (P = 0.002), estrogen replacement nonadherence (P = 0.002), low calcium intake (P = 0.005), and lack of exercise (P = 0.005). As compared to Caucasians, African-American and Asian women with POI were 3.18 and 4.34 times more likely, respectively, to have Z-scores below -2 (P = < 0.0001 for both). Race was an overall risk factor, but on regression modeling, not an independent predictor of low bone density.


CONCLUSIONS
Women with POI have lower bone density compared to regularly menstruating women. Compared to Caucasians, minority women with estrogen deficiency are more likely to have BMD below the expected range for age. This racial disparity appears to be related to a combined effect of several modifiable risk factors. Delay in diagnosis of POI also contributes to reduced bone density by delaying proper therapy.
Popat
Vaishali B
VB
Intramural Research Program on Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-1103, USA. popatv@mail.nih.gov
Calis
Karim A
KA
Vanderhoof
Vien H
VH
Cizza
Giovanni
G
Reynolds
James C
JC
Sebring
Nancy
N
Troendle
James F
JF
Nelson
Lawrence M
LM
D000328:Adult; D015519:Bone Density / Q000502:physiology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004967:Estrogens / Q000172:deficiency*; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging; D006615:Hip / Q000000981:diagnostic imaging; D006801:Humans; D007006:Hypogonadism / Q000150:complications / Q000000981:diagnostic imaging / Q000208:ethnology / Q000503:physiopathology*; D008161:Lumbosacral Region / Q000000981:diagnostic imaging; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000208:ethnology / Q000209:etiology; D010049:Ovarian Diseases / Q000150:complications / Q000209:etiology / Q000503:physiopathology; D011859:Radiography; D012307:Risk Factors; D055815:Young Adult
D004967:Estrogens