Osteopenia in Sheehan’s Syndrome N .Belhamri, S .El Baki ,G .El Mghari, N .El Ansari Endocrinology and Diabetes Department, University Hospital Mohamed VI Marrakesh, Morocco

Introduction : Patients and Methods: Sheehan’s syndrome (SS) is a pituitary failure caused by pituitary infarction, which is generally secondary to a postpartum hemorrhage. Its prevalence is decreasing thanks to the improvement of obstetric care . SS is still an important cause of hypopituitarism in Morocco. Patients and Methods: In the present study, we aimed to evaluate bone mineral density (BMD) in premenopasal patients. we reviewed 15 cases retrospectively who were diagnosed and followed as SS in endocrinology department from 2010 to 2015. BMD evaluations were carried out in all patients.  The BMD was measured in all patients by dual-energy X-ray absorptiometry at 2 sites: the lumbar spine L1–L4 and the femoral neck. T- and Z-scores were determined according to the Italian specific reference database that was used for geographic and sociocultural considerations. Osteopenia was defined as a T-score between −1.0 SD and −2.5 SD. Osteoporosis was defined as a T-score equal to or less than −2.5 SD.

Results The patients aged 38 to 42 years . The serum calcium and phosphorus levels were normal in all patients (94.1 ± 4.3 mg/L and 34.4 ± 9.3 mg/L, respectively), A deficiency of vitamin D was found in all patients. Endocrine testing of the pituitary revealed secondary hypothyroidism in (86%) 13 patients , adrenal cortex failure in all patients, hypogonadotrophic hypogonadism in (93%) 14 patients. All patients had corticotropin deficiency and were treated with hydrocortisone. The daily dose of hydrocortisone was usually 20 mg and was then reduced to 15 mg. The mean dose was 20 ± 4.1 mg/d. 14 patients (95%) had gonadotropin deficiency. All patients, aged less than 50 yr with gonadotropin deficiency , had estrogen–progesterone substitution. Low bone mineral mass was present in 15 patients : osteopenia in 08 (53%) and osteoporosis in 7 (46 %). The lumbar spine was more frequently affected by low bone mineral mass.

Discussion Only a few studies evaluated BMD in SS. The literature has dealt with other causes of hypopituitarism affecting one or more axes, especially GH deficiency. Our study showed a significantly higher frequency of osteoporosis and osteopenia in 15 patients with SS. BMD, T-score, and Z-score at both the femoral neck and the lumbar spine were significantly lower in the patients with SS. The low bone mass could be explained by different mechanisms: GH deficiency, estrogen deficiency, or thyroxine or hydrocortisone overdose. However, these latter factors are often associated with patients with SS, so the role of each factor can be difficult to demonstrate Hypogonadism was present in 95% of our patients and in 58%–76% of cases of SS in the literature . Hypogonadism is a known cause of bone mineral loss . In our study, no correlation was noted between BMD and the use of oestrogen–progesterone replacement therapy before the age of natural menopause in patients with hypogonadism. GH deficiency is present in 88%–100% of cases of SS . In our series, GH deficiency was not checked , as it is not substituted in adults in morocoo.

Conclusion Osteoporosis and osteopenia were very frequent in patients with SS. The age of the patient, the duration of the disease, and the daily doses of hydrocortisone and thyroxine replacement therapy were associated with lower BMD. Estrogen–progesterone replacement therapy did not reduce the risk of low BMD. Patients with SS should be screened for osteoporosis by a BMD measurement upon the diagnosis of the disease. Hormone replacement therapy of all pituitary deficits should be instituted. Accurate doses of hydrocortisone and thyroxine should avoid iatrogenic risk factors of bone mineral loss.