Results
Table 1 shows the baseline characteristics of our study patients. A total of 56 patients were included, of which 54 were women (96.4%). The mean age was 68.1 ± 8.2 years. The most frequently observed concomitant diseases were arterial hypertension (32.1%), dyslipidemia (32.1%) and hypothyroidism (16.1%). Most of the patients had not previously suffered vertebral fractures (73.2%) and their risk of fracture calculated at 10 years using the FRAX risk assessment tool after having suffered multiple vertebral fractures was 11% for major fractures (95% CI 6.1% -16%) and 3.9% for hip fractures (1.2% -6.6%). Patients had been taking DMAB for a median of 30.5 months (95% CI: 24-43.5 months) and had injected a median of 6 doses (95% CI: 4-8 doses). 56 patients accumulated 192 new vertebral fractures.
Table 3 shows the reasons why DMAB was discontinued. Medical prescription was the main cause of suspending treatment, which occurred in 62.7% of cases.
Table 4 shows the biochemical values studied, including the biochemical markers of bone remodeling, obtained before and after DMAB suspension and the appearance of multiple vertebral fractures. Values of calcium, phosphorus, total proteins, vitamin D (25 hydroxycholecalciferol) and PTH do not change substantially, but the biochemical markers of bone remodeling increase significantly, both beta-crosslaps, P1NP and osteocalcin (p <0.006 in all cases). The greatest increase occurs in the beta-crosslaps, from 0.071 to 0.520 ng/mL median, a 14-fold increase in baseline values. Osteocalcin values almost tripled while those of P1NP quadrupled.
Finally, Table 5 shows the logistic regression analysis to study the possible association between the various clinical, analytical and densitometric parameters and the number of vertebral fractures. The length of time of previous DMAB use is the only parameter that was associated in a statistically significant way (p= 0.04).