Background: Premature ovarian insufficiency(POI), gonadal failure ≤40 years, occurs secondary to medical(M-POI) or surgical(S-POI) therapies or is spontaneous(SP-POI). Bone loss and fractures are increased in POI. However, trabecular bone score(TBS), an indirect measure of spinal bone microarchitecture, has not been investigated in POI.
Aim: Prevalence of low BMD, degraded TBS and fractures in women with POI.
Method: Cross-sectional and longitudinal study of 70 POI women aged 20-50 years at a tertiary centre from 2005-2018. Medical history, including fracture and oestrogen replacement therapy(ERT) were obtained. Dual-energy X-ray absorptiometry(DXA) spine and femoral neck(FN) BMD and TBS(TBSiNsight v18.104.22.168) were measured. Low bone mass defined as Z-score<-2.0. Partially degraded and degraded TBS defined as TBS=1.20-1.35, and TBS<1.20, respectively. Analysis included logistic regression and linear mixed models.
Results: Women with SP-POI (n=25), M-POI (n=16) and S-POI (n=29) were identified. Median(range) age of POI diagnosis was 33(11-40)years with baseline DXA performed median 1(0-13)year after diagnosis. ERT was used by 68.8%[lower rates in M-POI women secondary to breast cancer(p=0.001)]. Prevalence of low bone mass at the spine and FN was 8.6%: SP-POI women had lower spine BMD, FN BMD and FN Z-score than S-POI women(p<0.05). Normal, partially degraded, and degraded TBS occurred in 51.4%, 41.4%, and 7.1%, respectively, and were similar across POI groups. Longitudinal analysis of 28 POI women[median follow-up 5(1-12) years], where 15/28 had continued ERT, revealed a decline in FN BMD[-0.006g/cm2/year (95%CI -0.010, -0.002), p<0.05] but no significant change in spine BMD or TBS. Fractures occurred in 5/70(7.1%) women following POI onset, of which 4/5(80%) fractures occurred in bone with high trabecular component. No significant difference in BMD or TBS between fracture and non-fracture groups was observed.
Conclusion: Higher prevalence of abnormal TBS was observed in women with POI versus abnormal BMD Z-score. Further research is required to elucidate the role of TBS.