76 postmenopausal women from the climacteric clinic of the regional hospital 1o de Octubre of the Institute of Security and Social Services for State Workers (ISSSTE) were firstly considered, of which 23 presented elimination criteria and only 55 who had received denosumab therapy for an average of 2.5 years without a significant improvement in hip and lumbar spine T-scores were enrolled. First, a general medical evaluation was performed. Serum levels of vitamin D were analysed to find the prevalence of hypovitaminosis D. A bone mineral density test was done to calculate hip and lumbar spine T-scores. Then, vitamin D was administrated daily for one year at a dose of 4,000 IU and the studies were repeated after one year. Statistical analysis was performed using PAST 3.0 and GraphPad Prism 8.4.3. software. The arithmetic median (µ) and standard deviation (S.D.) were calculated using Excel-Word. Graphics were constructed with GraphPad Prism 8.4.3 and tables with Excel Word. Categorical variables were analysed with chi-squared or Fisher exact test depending on the number of participants in each cell. Normality was determined using the Shapiro-Wilk test. To compare two paired samples, the Wilcoxon signed-rank test was utilized. The assigned α value for this study was <0.05. In all cases, if a Montecarlo permutation was available, the exact p-value was taken instead of the raw p-value.
Denosumab is a monoclonal antibody against RANKL ligand, which is used as an alternative treatment for osteoporosis in patients who have a poor response to first-line antiresorptive therapy. However, discontinuation of denosumab produces a rapid increase in bone turnover, bone loss and potentially increased risk of multiple vertebral fractures.