PRL and osteoporosis: For gonadal hormone levels, patients with osteoporosis had a significantly higher PRL level (90.9 ± 20.5 vs 44.1 ± 17.2, Z =  − 10.6, P <0.001), a lower E2 level (55.3 ± 24.6 vs 88.0 ± 45.3, Z =  − 5.3, P <0.001) and a higher FSH level (7.6 ± 4.1 vs 6.6 ± 4.0, Z =  − 2.2, P = 0.026) than patients without osteoporosis (Table 2).