Material and Methods: 40 women -including 16 with HP surgically confirmed, 12 OP affected and 12 healthy as control group were studied. b-ALP serum values were determined by IRMA assay (Tandem-R OstaseTM, Hybritech) and urinary CTx values also were determined using RIA assay corrected by urinary creatinine (CrossLapsTM, Osteometer Biotech), in addition to routinely biochemical protocol. In every case, bone mineral density (BMD) was determined by dual X-ray densitometry on lumbar spine (LS), femoral neck (FN) and Ward's triangle (WT) areas, and moreover, on HP patients in tree radius zones: medial (M), distal (D) and ultradistal (UD).

Results: HP patients showed b-ALP values significantly elevated respect to OP patients (p < 0.01) and in comparison to control group (p < 0.01). Significant differences were found in HP patients CTx levels respect to control group (p < 0.03), but no differences were observed as we compared this values respect OP group. Both markers showed good correlations in HP group (p=0.008). OP patients showed a significantly diminished Z-score (p < 0.001) on three more affected regions in trabecular zone. HP patients showed a Z-score significantly diminish on predominant trabecular radial region and a significantly diminution (p < 0.02) on axial skeleton. No diminution was observed on predominant trabecular radial area. In the comparison of three axial skeleton areas in HP and OP groups, no significant difference was detected.

Conclusions: Ours results evidence a bone remodelation increase either HP as OP. That shows a balance between bone formation and resorption on HP, but not on OP. Moreover, axial skeleton affectation is similar both on OP and HP groups. Forearm bone mass determinations allow classic patron of skeleton affectation identification in primary hyperparathyroidism.