Characteristics of hypoparathyroidism in Colombia: data from a single center in the city of Medellín

ABSTRACT Objective Hypoparathyroidism is a rare condition, whose most common etiology is complications of neck surgery. The aim of the study was to identify the clinical and biochemical profile of the patients with diagnosis of hypoparathyroidism, including the frequency of symptoms, clinical signs, long-term complications and disease control. Additionally, the study sought to know what the medication profile was, and the doses required by the patients. Subjects and method A retrospective cohort study was conducted wherein all patients with ICD-10 codes associated with hypoparathyroidism between 2011 and 2018 at the Hospital Universitario San Vicente Fundación were included. We investigated the etiology of the disease; biochemical profile including lowest serum calcium, highest serum phosphorus, 25OHD levels, calciuria and calcium/phosphorus product; medication doses, disease control, and presence of complications, especially renal and neurologic complications were also evaluated. Results The cohort included 108 patients (99 women/9 men) with a mean age of 51.6 ± 15.6 years. The main etiology was postoperative (93.5%), the dose of elemental calcium received was relatively low (mean 1,164 mg/day), and in only 9.2% of cases more than 2,500 mg/day of elemental calcium was necessary. We were able to evaluate the follow-up in 89 patients, and found that only 57.3% met the criteria for controlled disease. Conclusion The clinical profile of patients with hypoparathyroidism in our cohort is similar to that described in other international studies, with predominantly postoperative etiology. With standard therapy, only adequate control is achieved in a little more than half of patients. Arch Endocrinol Metab. 2020;64(3):282-9

Hypoparathyroidism and pseudohypoparathyroidism: etiology, laboratory features and complications

ABSTRACT Objectives To identify a clinical profile and laboratory findings of a cohort of hypoparathyroidism patients and determine the prevalence and predictors for renal abnormalities. Materials and methods Data from medical records of five different visits were obtained, focusing on therapeutic doses of calcium and vitamin D, on laboratory tests and renal ultrasonography (USG). Results Fifty-five patients were identified, 42 females and 13 males; mean age of 44.5 and average time of the disease of 11.2 years. The most frequent etiology was post-surgical. Levels of serum calcium and creatinine increased between the first and last visits (p < 0.001 and p < 0.05, respectively); and serum levels of phosphate decreased during the same period (p < 0.001). Out of the 55 patients, 40 had USG, and 10 (25%) presented with kidney calcifications. There was no significant difference in the amount of calcium and vitamin D doses among patients with kidney calcifications and others. No correlation between serum and urinary levels of calcium and the presence of calcification was found. Urinary calcium excretion in 24h was significantly higher in patients with kidney calcification (3.3 mg/kg/d) than in those without calcification (1.8 mg/kg/d) (p < 0.05). Conclusions The reduction of hypocalcemia and hyperphosphatemia suggest an effectiveness of the treatment, and the increase in serum creatinine demonstrates an impairment of renal function during follow-up. Kidney calcifications were prevalent in this cohort, and higher urinary calcium excretion, even if still within the normal range, was associated with development of calcification. These findings suggest that lower rates of urinary calcium excretion should be aimed for in the management of hypoparathyroidism.

The deceptive concept of hypoparathyroidism and recurrence after parathyroidectomy in dialysis patients: are we offering a Procrustean bed to some patients? / O enganoso conceito de hipoparatireoidismo e recidiva após paratireoidectomia em pacientes dialíticos: estamos oferecendo uma cama de Procrustes a alguns pacientes?

ABSTRACT Objective: to analyze the frequency of hypoparathyroidism and of its recurrence after parathyroidectomy in dialysis patients according to different existing classifications. Methods: we conducted a retrospective study of 107 consecutive dialysis patients undergoing total parathyroidectomy with immediate autograft in a tertiary hospital from 2006 to 2010. We studied the changes in PTH levels in the postoperative period over time. Were grouped patients according to different PTH levels targets recommended according to the dosage method and by the American and Japanese Nephrology Societies, and by an International Experts Consortium. Results: after parathyroidectomy, there was sustained reduction in serum calcium and phosphatemia. The median value of PTH decreased from 1904pg/ml to 55pg/ml in 12 months. Depending on the considered target level, the proportion of patients below the target ranged between 17% and 87%. On the other hand, the proportion of patients with levels above the target ranged from 3% to 37%. Conclusion: the application of different recommendations for PTH levels after parathyroidectomy in dialysis patients may lead to incorrect classifications of hypoparathyroidism or recurrent hyperparathyroidism and resultin discordant therapeutic conducts.

RESUMO Objetivo: analisar as frequências de hipoparatireoidismo e de recidiva do hiperparatireoidismo após paratireoidectomia em pacientes dialíticos de acordo com diferentes classificações existentes. Métodos: estudo retrospectivo de 107 pacientes dialíticos consecutivamente submetidos à paratireoidectomia total com autoenxerto imediato em um hospital terciário no período de 2006 a 2010. A variação dos níveis de PTH no pós-operatório foi estudada ao longo do tempo. Os pacientes foram agrupados de acordo com diferentes metas de níveis de PTH recomendados de acordo com o método de dosagem e pelas sociedades de nefrologia americana, japonesa e de um consórcio internacional de especialistas. Resultados: após a paratireoidectomia, houve redução sustentada da calcemia e fosfatemia. O valor mediano do PTH reduziu-se de 1904pg/ml para 55pg/ml, em 12 meses. Dependendo do nível alvo considerado, a proporção de pacientes abaixo da meta variou entre 17% e 87%. Ao contrário, a proporção de pacientes com níveis acima da meta variou de 3% a 37%. Conclusão: O emprego de diferentes recomendações de níveis de PTH em pacientes dialíticos após paratireoidectomia pode levar a classificações incorretas de hipoparatireoidismo ou hiperparatireoidismo recidivado e implicar em condutas terapêuticas discordantes.

Postoperative calcium levels as a diagnostic measure for hypoparathyroidism after total thyroidectomy

ObjectiveThe aim of the present study was to identify a fast, efficient and low-cost method to diagnose hypoparathyroidism after total thyroidectomy.Materials and methodsOne hundred and forty medical records, which contained patients’ clinical and laboratory data, were retrospectively analyzed. Patient parathyroid hormone values, which were obtained immediately following operation, were compared with their ionized calcium levels the morning after surgery. This comparison was used to examine the correlation between the two variables in predicting hypoparathyroidism because measuring calcium levels is low-cost and more available in the hospitals compared to measuring parathormone (PTH) levels.ResultsThere was a positive and statistically significant correlation between PTH and ionized calcium values (Pearson correlation coefficient, r = 0.456; p < 0.0001). The values of first postoperative day ionized calcium levels (stratified by the 1.10 mmol/l cut-off value) were tested as a diagnostic measure for hypoparathyroidism, and a PTH < 15 pg/mL obtained immediately following operation served as a reference. This analysis showed that ionized calcium levels measured on the first postoperative day had a sensitivity of 45.6% (95% CI 30.9-61.0%), a specificity of 88.9% (95% CI 80.5-94.5%) and an accuracy of 76.7% (95% CI 68.7-83.5%) as a diagnostic measure for hypoparathyroidism.ConclusionIn conclusion, we demonstrated that patients who had high ionized calcium levels on the first postoperative day also had high PTH levels immediately following operation and, therefore, they had lower rates of hypoparathyroidism.

Hypoparathyroidism and pseudohypoparathyroidism / Hipoparatiroidismo e pseudohipoparatiroidismo

The principal function of the parathyroid hormone (PTH) is maintenance of calcium plasmatic levels, withdrawing the calcium from bone tissue, reabsorbing it from the glomerular filtrate, and indirectly increasing its intestinal absorption by stimulating active vitamin D (calcitriol) production. Additionally, the PTH prompts an increase in urinary excretion of phosphorus and bicarbonate, seeking a larger quantity of free calcium available in circulation. Two mechanisms may alter its function, limiting its control on calcium: insufficient PTH production by the parathyroids (hypoparathyroidism), or a resistance against its action in target tissues (pseudohypoparathyroidism). In both cases, there are significantly reduced levels of plasmatic calcium associated with hyperphosphatemia. Clinical cases are characterized by nervous hyperexcitability, with paresthesia, cramps, tetany, hyperreflexia, convulsions, and tetanic crisis. Abnormalities such as cataracts and basal ganglia calcification are also typical of these diseases. Treatment consists of oral calcium supplementation associated with increased doses of vitamin D derivatives.

A principal função do paratormônio (PTH) é a manutenção dos níveis plasmáticos de cálcio, retirando-o do tecido ósseo, reabsorvendo-o do filtrado glomerular e, indiretamente, aumentando sua absorção intestinal através do estímulo para a produção de vitamina D ativa (calcitriol). Além disso, o PTH promove um aumento na excreção urinária de fósforo e bicarbonato, objetivando uma maior quantidade de cálcio livre disponível na circulação. Dois mecanismos podem alterar sua função, limitando seu controle sobre o cálcio: produção insuficiente de PTH pelas paratiróides (hipoparatiroidismo), ou uma resistência à sua ação nos órgãos-alvo (pseudohipoparatiroidismo). Em ambos os casos, ocorre uma redução significativa dos níveis plasmáticos de cálcio em associação com hiperfosfatemia. Manifestações clínicas características são: hiperexcitabilidade nervosa, com parestesia, cãimbras, tetania, hiperreflexia, convulsões e crise tetânica. Catarata e calcificação dos gânglios basais são anormalidades típicas dessas doenças. O tratamento consiste da suplementação oral de cálcio, associada com doses elevadas de derivados da vitamina D.

Permanent hypoparathyroidism following radioiodine treatment for hyperthyroidism.

Persistent hypoparathyroidism following 131I treatment is a rare but recognized complication. A case is presented, where a relatively small dose of 131I produced persistent hypocalcaemia.