Mannstadt, Michael

ABSTRACT The efficacy and safety of parathyroid hormone (PTH) therapy for managing long-term hypoparathyroidism is being evaluated in ongoing clinical trials. We undertook a systematic review and meta-analysis of currently available randomized controlled trials to investigate the benefits and harms of PTH therapy and conventional therapy in the management of patients with chronic hypoparathyroidism. To identify eligible studies, published in English, we searched Embase, PubMed, and Cochrane CENTRAL from inception to May 2022. Two reviewers independently extracted data and assessed the risk of bias. We defined patients' important outcomes and used grading of recommendations, assessment, development, and evaluation (GRADE) to provide the structure for quantifying absolute effects and rating the quality of evidence. Seven randomized trials of 12 publications that enrolled a total of 386 patients proved eligible. The follow-up duration ranged from 1 to 36 months. Compared with conventional therapy, PTH therapy probably achieves a small improvement in physical health-related quality of life (mean difference [MD] 3.4, 95% confidence interval [CI] 1.5–5.3, minimally important difference 3.0, moderate certainty). PTH therapy results in more patients reaching 50% or greater reduction in the dose of active vitamin D and calcium (relative risk [RR] = 6.5, 95% CI 2.5–16.4, 385 more per 1000 patients, high certainty). PTH therapy may increase hypercalcemia (RR =2.4, 95% CI 1.2–5.04, low certainty). The findings may support the use of PTH therapy in patients with chronic hypoparathyroidism. Because of limitations of short duration and small sample size, evidence from randomized trials is limited regarding important benefits of PTH therapy compared with conventional therapy. Establishing such benefits will require further studies. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

ABSTRACT The complications and symptoms of hypoparathyroidism remain incompletely defined. Measuring serum parathyroid hormone (PTH) and calcium levels early after total thyroidectomy may predict the development of chronic hypoparathyroidism. The study aimed (i) to identify symptoms and complications associated with chronic hypoparathyroidism and determine the prevalence of those symptoms and complications (Part I), and (ii) to examine the utility of early postoperative measurements of PTH and calcium in predicting chronic hypoparathyroidism (Part II). We searched Medline, Medline In-Process, EMBASE, and Cochrane CENTRAL to identify complications and symptoms associated with chronic hypoparathyroidism. We used two predefined criteria (at least three studies reported the complication and symptom and had statistically significantly greater pooled relative estimates). To estimate prevalence, we used the median and interquartile range (IQR) of the studies reporting complications and symptoms. For testing the predictive values of early postoperative measurements of PTH and calcium, we used a bivariate model to perform diagnostic test meta-analysis. In Part I, the 93 eligible studies enrolled a total of 18,973 patients and reported on 170 complications and symptoms. We identified nine most common complications or symptoms probably associated with chronic hypoparathyroidism. The complications or symptoms and the prevalence are as follows: nephrocalcinosis/nephrolithiasis (median prevalence among all studies 15%), renal insufficiency (12%), cataract (17%), seizures (11%), arrhythmia (7%), ischemic heart disease (7%), depression (9%), infection (11%), and all-cause mortality (6%). In Part II, 18 studies with 4325 patients proved eligible. For PTH measurement, regarding the posttest probability, PTH values above 10 pg/mL 12–24 hours postsurgery virtually exclude chronic hypoparathyroidism irrespective of pretest probability (100%). When PTH values are below 10 pg/mL, posttest probabilities range from 3% to 64%. Nine complications and symptoms are probably associated with chronic hypoparathyroidism. A PTH value above a threshold of 10 pg/mL 12–24 hours after total thyroidectomy is a strong predictor that the patients will not develop chronic hypoparathyroidism. Patients with PTH values below the threshold need careful monitoring as some will develop chronic hypoparathyroidism. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Abstract PARADIGHM is an actively recruiting, prospective, observational registry (NCT01922440/EUPAS16927). The primary objective is to evaluate the safety and effectiveness of recombinant human parathyroid hormone, rhPTH(1-84), treatment in patients with chronic hypoparathyroidism (HypoPT) under routine clinical care. The secondary objective is to characterize the clinical course of chronic HypoPT under conditions of routine clinical practice. At enrollment, registry inclusion criteria are patients having a HypoPT diagnosis >6 months and receiving conventional therapy (CT; eg, calcium supplements and active vitamin D), rhPTH(1-84) plus CT, or rhPTH(1-84). We present baseline characteristics of patients as of a June 30 2019 data cut. Baseline was defined as the value entered at the time of enrollment (Visit 1). Baseline symptom data exclude patients who initiated rhPTH(1-84) prior to enrollment (n=68) and are herein presented as two groups: those subsequently prescribed with rhPTH(1-84) after enrollment or those treated with CT. All data are summarized descriptively. Patient data from 64 centers in Europe and North America were analyzed. In the analysis population (n=737), 587 patients (79.6%) were female, 620 (84.1%) were white, and the mean (SD) age was 49.1 (16.45) years. The mean (SD) BMI was 19.3 (5.73) kg/m2 and 30.0 (7.72) kg/m2 in patients aged <18 (n=25) and ≥18 (n=587) years, respectively. The primary cause of HypoPT was thyroid surgery (n=547 [74.2%]; of these, 281 [60.0%] underwent surgery for thyroid cancer). Endocrinologists were the prescribing specialists for most patients (n=660 [89.6%]). Vitamin D and analogs were prescribed for 90.1% of patients (calcitriol, 74.2%, native vitamin D, 47.4%, alfacalcidol, 7.9%,), calcium for 81.0% (calcium carbonate, 57.9%, calcium citrate, 27.1%), and thyroid hormones for 71.2% (levothyroxine, 73.4%; liothyronine, 5.8%). Symptoms reported at enrollment for the rhPTH(1-84) (n=66) and the CT groups (n=603), respectively, included fatigue (53.0%, 39.3%), paresthesia (48.5%, 29.2%), muscle twitching (48.5%, 21.1%), muscle cramping (40.9%, 33.0%), headaches (33.3%, 17.6%), anxiety (28.8%, 20.1%), muscle pain (28.8%, 19.2%), tetany (28.8%, 12.1%), and brain fog (27.3%, 16.3%). The baseline data for the overall population appear to be representative of patients with chronic HypoPT. Baseline data suggest that at enrollment patients prescribed rhPTH(1-84) after enrollment appear to have an increased burden of disease than patients receiving CT based on symptoms. PARADIGHM will be a valuable resource of real-world longitudinal data for patients with chronic HypoPT.

Abstract Context Conventional hypoparathyroidism treatment with oral calcium and active vitamin D is aimed at correcting hypocalcemia but does not address other physiologic defects caused by PTH deficiency. Objective To evaluate long-term safety and tolerability of recombinant human PTH (1-84) [rhPTH(1-84)]. Design Open-label extension study; 5-year interim analysis. Setting 12 US centers. Patients Adults (N = 49) with chronic hypoparathyroidism. Intervention(s) rhPTH(1-84) 25 or 50 µg/d initially, with 25-µg adjustments permitted to a 100 µg/d maximum. Main Outcome Measure(s) Safety parameters; composite efficacy outcome was the proportion of patients with ≥50% reduction in oral calcium (or ≤500 mg/d) and calcitriol (or ≤0.25 µg/d) doses, and albumin-corrected serum calcium normalized or maintained compared with baseline, not exceeding upper limit of normal. Results Forty patients completed 60 months of treatment. Mean albumin-corrected serum calcium levels remained between 8.2 and 8.7 mg/dL. Between baseline and month 60, levels ± SD of urinary calcium, serum phosphorus, and calcium-phosphorus product decreased by 101.2 ± 236.24 mg/24 hours, 1.0 ± 0.78 mg/dL, and 8.5 ± 8.29 mg2/dL2, respectively. Serum creatinine level and estimated glomerular filtration rate were unchanged. Treatment-emergent adverse events (AEs) were reported in 48 patients (98.0%; hypocalcemia, 36.7%; muscle spasms, 32.7%; paresthesia, 30.6%; sinusitis, 30.6%; nausea, 30.6%) and serious AEs in 13 (26.5%). At month 60, 28 patients (70.0%) achieved the composite efficacy outcome. Bone turnover markers increased, peaked at ∼12 months, and then declined to values that remained above baseline. Conclusion Treatment with rhPTH(1-84) for 5 years demonstrated a safety profile consistent with previous studies and improved key biochemical parameters.