Maintained Bone Density in Young Hypoestrogenized Women with a High BMI: Case Series

Estrogen deficiency and obesity are factors that affect bone mass in a manner that is independent and in opposing directions. Obesity favours higher bone mass and increased bone formation whereas estrogen deficiency leads to significant bone loss in leaner individuals. To report the impact of the competing effects of a hypoestrogenized state and obesity on long-term bone health, we present two cases of young chronically hypoestrogenized females whose bone parameters were assessed with high-resolution peripheral quantitative computed tomography (HR-pQCT) and revealed a bone mineral density and microstructure that did not change despite the long history of a low estrogen state. As evidenced by the outcomes for these patients, the obesity-related effect on bone mass may be dominant when obesity is marked and appears to be highly protective even in the setting of sub-physiologic circulating estrogen. Recognition of this interaction should be considered in decisions around estrogen replacement therapy in such cases.