Endocrine Abstracts

Chronic hypoparathyroidism is a rare mineral homeostasis disorder managed by conventional therapy (oral calcium and active vitamin D), alone or with adjunctive rhPTH(1-84). Chronic hypoparathyroidism is associated with considerable symptom burden, which can interfere with daily living. We report results from a web-based, cross-sectional survey conducted among adults with chronic hypoparathyroidism. The objectives were to quantify the impact on overall life interference of (1) time from diagnosis to rhPTH(1-84) initiation and (2) rhPTH(1-84) treatment vs conventional therapy. Overall life interference of hypoparathyroidism was patient self-reported upon considering all aspects of their condition using a 7-point rating scale (1=none to 7=very significant interference). Hypoparathyroidism-associated symptom severity was assessed through the disease-specific, patient-reported Hypoparathyroidism Symptom Diary. The study included 90 patients treated with rhPTH(1-84) (mean±SD age, 54.5±11.3 years; 83% female) and 57 patients treated but not adequately controlled with conventional therapy (mean±SD age, 50.0±11.7 years; 93% female). Among rhPTH(1-84)-treated patients, time from hypoparathyroidism diagnosis to rhPTH(1-84) initiation was ≤12 months, >12–≤48 months, and >48 months in 28%, 38%, and 34% of patients, respectively. Initiation of rhPTH(1-84) >48 months after diagnosis was associated with higher overall life interference compared with initiation ≤12 months after diagnosis (P<0.001 for the unadjusted and P=0.02 for multivariable regression analysis adjusted for potential confounders). The life interference mean±SE score was 2.0±0.54 points higher (unadjusted) and 0.8±0.34 points higher (multivariable regression) for patients who initiated rhPTH(1-84) >48 months vs ≤12 months after diagnosis. Self-reported severity of hypoparathyroidism was rated as no symptoms, mild, moderate, and severe in 42%, 49%, 8%, and 1% of patients treated with rhPTH(1-84), respectively, and in 11%, 37%, 49%, and 3% of patients treated with conventional therapy. Treatment with rhPTH(1-84) was associated with lower overall hypoparathyroidism-related life interference compared with conventional therapy that did not adequately control hypoparathyroidism (P<0.001 for both unadjusted and adjusted multivariable regression analyses). Mean±SE life interference score for rhPTH(1-84)-treated patients was 1.5±0.33 points lower (unadjusted) and 1.1±0.29 points lower (multivariable regression) vs patients treated with conventional therapy. A strength of this study is the multivariable analysis adjusting for potential confounders; limitations include cross-sectional study design, inaccessibility of patient characteristics before treatment initiation, and recall bias. In a real-world setting, rhPTH(1-84) initiation >48 months after hypoparathyroidism diagnosis was associated with greater overall life interference vs rhPTH(1-84) initiation ≤12 months after diagnosis. Compared with conventional therapy, rhPTH(1-84) treatment was associated with lower overall life interference after adjusting for confounding variables.