Hormonal Status and Bone Health in Bulgarian Adolescents with Secondary Amenorrhoea

Abstract

A prospective study was conducted including 67 girls with secondary amenorrhoea (excluding cases with PCOS, medical disorders and steroid therapy) and 38 healthy controls. The following indicators were compared between the two groups: serum levels of LH, FSH, estradiol, Ca, P and vitamin D, z- scores for bone mineral density, osteocalcin and β-CrossLaps, and prevalence of vitamin D deficiency. The group with secondary amenorrhoea was additionally subdivided according to the main cause – alimentary deficiency, excessive physical exercise and stress-induced. LH, FSH and estradiol levels were compared between the three subgroups. Ca, P and vitamin D levels in the studied and the control groups were not significantly different. The following indicators were significantly lower in the studied group compared to the control one: prolactin (291.74 mIU/ml and 336.24 mIU/ml), estradiol (322.43 pmol/ml and 475.45 pmol/ml) and LH (3.79 IU/L and 4.99 IU/L) levels, LH/FSH ratio (0.55 and 0.96) and z-score (−0.48 and 0.47). FSH was significantly higher in the studied group (6.90 IU/L) compared to the control one (5.44 IU/L). The serum levels of LH and estradiol were significantly lower in the subgroup with secondary stress-induced amenorrhoea (1.73 IU/L and 220.60 pmol/ml) compared to the subgroups with amenorrhoea due to alimentary deficiency (4.68 IU/L and 394.68 pmol/ml) or extreme physical exercise (3.74 IU/L and 323.91 pmol/ml). In girls with secondary amenorrhea, the levels of osteocalcin were significantly lower compared to the ones in the control group (26.41 and 30.99 ng/ml) while β-CrossLaps levels were similar (0.34 and 0.98 ng/mL). High prevalence of vitamin D deficiency was observed in both the patients with secondary amenorrhoea (71.6%) and the control group (65.8%). Significant changes in hormone levels and bone health were observed in Bulgarian adolescent girls with secondary amenorrhoea as well as high prevalence of vitamin D deficiency in both the studied and the control groups. Early diagnosis and timely interventions are needed to improve bone health in adolescents with secondary amenorrhoea.