Efficacy of teriparatide in patients with resolved secondary hyperparathyroidism due to vitamin D deficiency

To determine the efficacy of at least 1 year of teriparatide therapy on bone mineral density (BMD), T-scores, and rates of occurrence of fractures in patients with a history of resolved secondary hyperparathyroidism due to vitamin D deficiency and to compare its efficacy with that in patients without a history of resolved secondary hyperparathyroidism. In this retrospective study based on a search of electronic medical records, we collected the following data: patient demographics, doses of calcium and vitamin D supplementation, duration of teriparatide treatment, history and treatment of secondary hyperparathyroidism, BMD information, T-scores, and any history of fractures. Paired and unpaired t tests, the Fisher exact test, and the Wilcoxon rank sum test were used for statistical analysis. Ninety-five patients (7 with a history of resolved secondary hyperparathyroidism due to vitamin D deficiency and 88 without such a history) fulfilled the study inclusion criteria. Baseline characteristics (demographics, median calcium and vitamin D supplementation doses, mean BMD, mean T-scores, and fracture rates before teriparatide therapy) were similar between the 2 groups. In comparison with baseline data, after a mean of 21 months of teriparatide therapy: (1) hip BMD and T-scores did not change in either study group (with no significant differences between the 2 groups), (2) spine BMD and T-scores significantly improved in both study groups (with no significant differences between them), and (3) wrist T-scores significantly worsened in both study groups (with wrist BMD significantly lower in patients without a history of secondary hyperparathyroidism). No patients with a history of secondary hyperparathyroidism sustained a fracture while receiving teriparatide therapy versus 6 of 88 patients without a history of secondary hyperparathyroidism (P = .624). Patients with a history of resolved secondary hyperparathyroidism attributable to vitamin D deficiency responded to teriparatide therapy in a fashion similar to patients without such a history.