Fragile bones in patients with stroke? : bone mineral density in acute stroke patients and changes during one year of follow up

This thesis highlights several clinically important questions related to bone loss the first year following stroke and with regard to bone mass at stroke onset: Lack of mobility and weight bearing early after stroke is an important factor for the greater bone loss in the proximal femur on the paretic side. Relearning to walk within the first two month after stroke, even with support of another person may, however, reduce the bone loss after immobilisation. The reduction in BMD in the femoral neck appears mainly to occur in the lower part of the neck and on the paretic side. It depends on when or if the patients start to walk after stroke, but also on the amount of body weight born through the paretic leg. Thus, measuring the lower part of the femoral neck may give a better estimate of the impact of gait and weight bearing than measuring the total femoral neck. During the first year after stroke bone mineral is lost in the proximal humerus of the paretic arm, but the loss depends on the initial degree of the paresis. However, stroke patients who regain almost normal arm function within one year, despite being severely impaired initially, loose less bone mineral than patients where a severe paresis persists. Female, but not male, stroke patients have lower femoral neck BMD than population controls. At present it is unclear if low BMD actually increases the risk of stroke in women or reflects a poor health with both high stroke risk and low BMD.