Bone mineral density and sex hormone status in intellectually disabled women on progestin-induced amenorrhea.

Objective: To evaluate bone mineral density (BMD) and hormonal status in female patients with intellectual disability and a history of progestin-induced amenorrhea.

Design: Cross-sectional study.

Setting: Nursing home.

Sample: The study included 51 patients with a history of therapeutic amenorrhea (age 23-77 years, mean 45 years); 115 staff members (age 21-64 years, mean 45 years) at the same nursing homes served as controls.

Methods: Calcaneal BMD was measured for all (Peripheral Instantaneous X-ray Imaging Lunar Bone Densitometer); blood samples for serum levels of estradiol (E(2)), follicle stimulation hormone (FSH) and lutenizing hormone (LH) were obtained only for the patients.

Results: The patients showed significantly lower age and weight-adjusted BMD than the controls (0.35 g/cm(2)+/-0.13 vs. 0.53 g/cm(2)+/-0.09, p<0.001). BMD values did not differ between pre- (N=29) and postmenopausal (N=22) patients. Osteoporosis was observed in 57% of the patients and only in 2% of the controls. Four patients (8%) but none of the controls had sustained a bone fracture during the preceding five years. Most premenopausal patients had hypogonadotropic hypogonadism, as shown by low serum E(2), LH and FSH levels in 83%, 69%, and 59% of the cases. Postmenopausal patients showed normal hormonal status for their age.

Conclusion: Osteoporosis with concomitant fractures is prevalent in women with intellectual disability on therapeutic amenorrhea. Progestin-induced amenorrhea results in hypogonadism, an established risk factor for osteoporosis. New strategies for the management of menstruation should be considered.