Abstract Objective: To estimate the prevalence of vitamin D deficiency and severe deficiency in children and adolescents, in a large Brazilian sample. Methodology: Results of 413,988 25(OH)D measurements in children and adolescents aged 0 to 18 years collected between 01/2014 and 10/2018 were obtained from the database of a Clinical Laboratory. In this population, 25 hydroxyvitamin D concentrations below 20 ng/mL are considered deficient, and below 12 ng/mL as severe deficiency. All measurements were performed by immunoassay and the results were distributed by gender, age group, seasonality, and latitude. Results: The mean of 25(OH)D levels was 29.2 ng/mL with a standard deviation of 9.2 ng/mL. Of the total samples, 0.8% had a concentration < 12 ng/mL, and 12.5% of the samples had a concentration < 20 ng/mL, with a higher prevalence in females. Children under 2 years of age had the lowest prevalence. The effects of latitude and seasonality were quite evident. In samples of female adolescents from the southern region in winter, 36% of vitamin D deficiency and 5% of severe deficiency were found. Conclusion: In this large number of measurements of 25(OH)D in children and adolescents, 12.5% had a deficiency and 0.8% had severe deficiency. A greater deficiency was observed among adolescents, especially females, which raises questions about the need for supplementation during this period of life. Objective sample Methodology 413988 413 988 413,98 25OHD OHD OH 1 012014 01 2014 01/201 102018 10 2018 10/201 Laboratory population ngmL ng mL deficient gender group 292 29 29. 92 9 9. 08 8 0.8 125 5 12.5 females evident winter 36 found Conclusion life 41398 41 98 413,9 01201 201 01/20 10201 10/20 0. 12. 3 4139 4 413, 0120 01/2 1020 10/2 012 01/ 102 10/

ABSTRACT Objective: This study aimed to investigate the association between 25OHD (total, bioavailable and free) with bone mass and microarchitecture among primary hyperparathyroidism (PHPT) patients and controls. Subjects and methods: Sixty-four patients in the preoperative period of PHPT and 63 matched controls, who had not taken vitamin D in the last three months. To calculate the bioavailable and free 25OHD, the genetic variants of the vitamin D-binding protein (DBP) were determined. Bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry (DXA). The distributions of total, bioavailable and free 25OHD and their correlation with TBS and DXA were evaluated. Results: PHPT showed BMD and TBS values lower than CTRL in all locations (p < 0.05). There were no statistical differences in the levels of free, bioavailable and total 25OHD between the PHPT and CTRL groups [mean, min-max: 3.4 (1.4-8.6) vs. 3.1 (1.0-9.8) pg/mL, 1.51 (0.43-3.58) vs. 1.41 (0.38-3.48) ng/mL, 22.6 (11.0-39.9) vs. 20.6 (8.9-35.3) ng/dL, respectively; (p > 0.05). The distribution of DBP haplotypes was similar between groups. DXA showed no correlation with any form of 25OHD in both groups. TBS presented a weak correlation with the total 25OHD in PHPT (r = 0.28; p = 0.02) and a moderate correlation with the total, free and bioavailable 25OHD in CTRL (r = 0.42; r = 0.42; r = 0.43; respectively, p < 0.01). Conclusion: The concentrations of total, free and bioavailable 25OHD were similar in both the PHPT and control groups. 25OHD concentrations correlated positively with TBS and not with DXA, especially in controls, suggesting that this method may be more sensitive to assessing the consequences of vitamin D deficiency on bone quality in individuals without PHPT. Objective OHD (total (PHPT controls methods Sixtyfour Sixty four 6 months Dbinding binding (DBP (BMD dualenergy dual energy Xray X ray DXA. . (DXA) evaluated Results 0.05. 005 0.05 0 05 0.05) mean, mean [mean minmax min max min-max 34 3 4 3. 1.48.6 1486 1.4 8.6 1 8 (1.4-8.6 vs 31 1.09.8 1098 1.0 9.8 9 (1.0-9.8 pgmL pg mL pg/mL 151 51 1.5 0.433.58 043358 0.43 3.58 43 58 (0.43-3.58 141 41 0.383.48 038348 0.38 3.48 38 48 (0.38-3.48 ngmL ng ng/mL 226 22 22. 11.039.9 110399 11.0 39.9 11 39 (11.0-39.9 206 20 20. 8.935.3 89353 8.9 35.3 35 (8.9-35.3 ngdL dL ng/dL respectively 0.28 028 28 0.02 002 02 0.42 042 42 043 0.01. 001 0.01 01 0.01) Conclusion (DXA 00 0.0 1.48. 148 14 1. 86 8. (1.4-8. 09 1.09. 109 10 98 9. (1.0-9. 15 5 433 0.433.5 04335 0.4 358 3.5 (0.43-3.5 383 0.383.4 03834 038 0.3 348 (0.38-3.4 2 039 11.039. 11039 110 11. 399 39. (11.0-39. 935 8.935. 8935 89 353 35. (8.9-35. 0.2 04 0. 1.48 (1.4-8 1.09 (1.0-9 0.433. 0433 (0.43-3. 0.383. 0383 03 (0.38-3. 11.039 1103 (11.0-39 93 8.935 893 (8.9-35 (1.4- (1.0- 0.433 (0.43-3 0.383 (0.38-3 11.03 (11.0-3 8.93 (8.9-3 (1.4 (1.0 (0.43- (0.38- (11.0- (8.9- (1. (0.43 (0.38 (11.0 (8.9 (1 (0.4 (0.3 (11. (8. ( (0. (11 (8 (0

ABSTRACT Trabecular bone score (TBS) is an indirect and noninvasive measure of bone quality. A low TBS indicates degraded bone microarchitecture, predicts osteoporotic fracture, and is partially independent of clinical risk factors and bone mineral density (BMD). There is substantial evidence supporting the use of TBS to assess vertebral, hip, and major osteoporotic fracture risk in postmenopausal women, as well as to assess hip and major osteoporotic fracture risk in men aged > 50 years. TBS complements BMD information and can be used to adjust the FRAX (Fracture Risk Assessment) score to improve risk stratification. While TBS should not be used to monitor antiresorptive therapy, it may be potentially useful for monitoring anabolic therapy. There is also a growing body of evidence indicating that TBS is particularly useful as an adjunct to BMD for fracture risk assessment in conditions associated with increased fracture risk, such as type-2 diabetes, chronic corticosteroid excess, and other conditions wherein BMD readings are often misleading. The interference of abdominal soft tissue thickness (STT) on TBS should also be considered when interpreting these findings because image noise can impact TBS evaluation. A new TBS software version based on an algorithm that accounts for STT rather than BMI seems to correct this technical limitation and is under development. In this paper, we review the current state of TBS, its technical aspects, and its evolving role in the assessment and management of several clinical conditions.

ABSTRACT In recent years the immunomodulatory actions of vitamin D, a steroid hormone, have been extensively studied. In 2020, due to the COVID-19 pandemic, the question arose as to 25(OH)D status would be related to susceptibility to SARS-CoV-2 infection, since several studies pointed out a higher prevalence and severity of the disease in populations with low levels of 25(OH)D. Thus, we investigated the 25(OH)D levels in adults “Detected” positive for SARS CoV-2 by RT-PCR (reverse transcriptase polymerase chain reaction) test, and in negative controls, “not Detected”, using the Fleury Group's examination database, in Sao Paulo, Brazil. Of a total of 14.692 people with recent assessments of 25(OH)D and RT-PCR tests for COVID-19, 2.345 were positive and 11.585 were negative for the infection. The groups did not differ in the percentage of men and women, or in the age distribution. There were no differences in the distribution of 25(OH)D between the two groups (p = 0.08); mean 25(OH)D of 28.8 ± 21.4 ng/mL and 29.6 ± 18.1 ng/mL, respectively. In the specific population studied, clinical, environmental, socioeconomic and cultural factors should have greater relevance than 25(OH)D in determining the susceptibility to COVID-19.

ABSTRACT Objective To evaluate the usefulness of a third-generation PTH assay in the diagnosis of primary hyperparathyroidism (PHPT). Subjects and methods Forty-one PHPT patients (4 men and 37 women) with 61.2 ± 10.9 (mean ± SD) years, were studied and had PTH levels measured with two different methods using the same immunochemiluminescent assay plataform (Elecsys 2010 System, Roche). We compared a second-generation assay (I-PTH) with a third-generation PTH assay (Bio-PTH). Two populations of 423 and 120 healthy adults with serum 25OHD levels above 25 ng/mL were used to define normal values in the I-PTH and Bio-PTH assays respectively. Results Normal PTH values based in the healthy adults population were 24.2-78.0 pg/mL for the I-PTH assay and 19.9-58.5 pg/mL for Bio-PTH assay. In PHPT patients, PTH values ranged from 67 to 553 pg/mL (median: 168 pg/mL) using the I-PTH assay and from 55 to 328 pg/mL (median: 111 pg/mL) using the Bio-PTH assay. Results obtained with the Bio-PTH assay were significantly lower (p < 0.0001, Wilcoxon). In general I-PTH and Bio-PTH showed highly significant correlation (r = 0.952, p < 0.0001). Passing–Bablok analysis gave a regression equation of Bio PTH = 13.44 + 0.59 x intact PTH. PHPT patients had 25OHD levels ranging from 4 to 36 ng/mL (mean 16.2 ng/mL); 35 subjects (85.3%) had values bellow 25 ng/mL. Conclusion Our results demonstrate that both second and third generation PTH methods are strongly correlated in PHPT patients and control subjects. Lower results with Bio-PTH tests are expected in function of the assay specificity determined by the amino-terminal antibody used.

The aim of this study was to determine whether the plasma CTX bone remodeling marker is useful for indicating the bone metabolic activity level of the mandible. Thirty-six patients were selected; all were postmenopausal and aged 50 years or over. In accordance with the WHO criteria for osteoporosis, a control group was set up (n = 10) in which the T-score was greater than -1 and a diseased group with T-score less than -1. Using MDP-99mTc samples, the radioisotope uptake in the femoral neck (R2) and mandibular body (R1) was analyzed. A third examination was performed using the plasma CTX biochemical bone-modeling marker. The inferential results for the diseased group showed that Ln(R1) presented a statistically significant linear relationship with Ln(CTx) (p = 0.067) and with the T-score (p = 0.018). The plasma CTX bone remodeling marker is useful for monitoring the bone metabolic activity of the mandible.

OBJETIVO: Diante de um paciente portador de hiperparatiroidismo primário com indicação de tratamento cirúrgico, a localização pré-operatória da paratiroide é de fundamental importância para definir a melhor abordagem cirúrgica. MATERIAIS E MÉTODOS: A realização adicional de imagens SPECT e da cintilografia com 99mTc durante a cintilografia das paratiroides com Setamibi não é rotina em nosso meio, sendo comum a aquisição apenas das imagens planas − precoce (15 minutos) e tardia (2 horas). RESULTADOS: Na nossa experiência, tem-se percebido que a realização do protocolo completo contribui de maneira decisiva na sensibilidade da localização pré-operatória da paratiroide. CONCLUSÃO: A aplicação completa de todos os métodos cintilográficos disponíveis (SPECT e 99mTc) e a análise cuidadosa das imagens em um contexto multidisciplinar podem aumentar a acurácia da cintilografia das paratiroides.

OBJECTIVE: In patients with primary hyperparathyroidism, candidates for surgical intervention, the parathyroid pre-operative localization is of fundamental importance in planning the appropriate surgical approach. MATERIALS AND METHODS: The additional acquisition of SPECT and Technetium-99m images, during parathyroid scintigraphy with Sestamibi, is not common practice. Usually, only planar image acquisition, 15 minutes prior and 2 hours after radiopharmaceutical administration, is performed. RESULTS: In our experience, the complete protocol in parathyroid scintigraphy increases the accuracy of pre-operative parathyroid localization. CONCLUSION: The complete utilization of all available nuclear medicine methods (SPECT e 99mTc) and image interpretation in a multidisciplinary context can improve the accuracy of parathyroid scintigraphy.

A evolução dos métodos de avaliação da massa óssea trouxe diferentes tecnologias, modos de aquisição de imagens, bancos de dados de referência, terminologias, critérios diagnósticos fez com que a International Society for Bone Densitometry (ISCD) tomasse a iniciativa de promover reuniões periódicas de consenso, a última em 2007. A Sociedade Brasileira de Densitometria Clínica (SBDens), com apoio de várias sociedades brasileiras ligadas ao estudo da saúde óssea, reuniu diversos especialistas para discutir as propostas da ISCD e validar a aplicação destas normas à população brasileira. A reunião de Posições Oficiais da SBDens produziu um documento extremamente útil para a compreensão e interpretação da densitometria e de outros métodos de avaliação da massa óssea.

With the evolution of bone densitometry, differences in technologies, acquisition techniques, reference databases, reporting methods, diagnostic criteria and terminology have developed and the International Society for Clinical Densitometry (ISCD) periodically holds Position Development Conferences, the latest in 2007. The Brazilian Society for Clinical Densitometry (SBDens), with support from many Brazilian societies interested in bone health, gathered numerous specialists to discuss the ISCD proposals and to evaluate the validity of the extension of those norms to Brazilian population. The SBDens reunion of consensus made a very utile document to help the understanding and interpretation of bone densitometry and other methods of bone assessment.

A cintilografia das paratireóides tem sido utilizada para detectar glândulas paratireóides patológicas tanto antes quanto após (em caso de insucesso) a cirurgia de ressecção em pacientes com hiperparatireoidismo. Uma das técnicas mais utilizadas para realizar este exame é a de duas fases utilizando como radiofármaco o sestamibi-99mTc, a qual tem se mostrado acurada na localização de glândulas paratireóides aumentadas. Similarmente ao sestamibi-99mTc, o tetrofosmin-99mTc é um radiofármaco que foi inicialmente desenvolvido para a realização de cintilografia de perfusão do miocárdio e que tem sido utilizado para a realização de cintilografia das paratireóides. Apesar de muitos artigos sugerirem que as sensibilidades dos dois radiofármacos são idênticas, alguns poucos trabalhos questionam a acurácia do tetrofosmin-99mTc para a localização de glândulas paratireóides anômalas. No presente artigo, relatamos um caso em que foi observado resultado discordante pelos dois métodos.

Parathyroid scintigraphies have been used to detect pathological parathyroid glands either before as well as after the parathyroid resection surgery in patients with hyperparathyroidism. One of the most utilized techniques to perform the studies is the double-phase images with Tc-99m sestamibi, which has been shown to be very accurate in the localization of enlarged parathyroid glands. Similar to Tc-99m sestamibi, Tc-99m tetrofosmin is a radiopharmaceutical initially developed to perform myocardial perfusion study that has been used to perform parathyroid scintigraphies. Although most of the papers suggest that the overall sensitivities of both radiopharmaceuticals are similar, there are some papers questioning the accuracy of Tc-99m tetrofosmin to detect abnormal parathyroid glands. In the present article, we report a case with discordant results by both methods.

A cintilografia das paratireóides tem sido utilizada para detectar glândulas patológicas em pacientes com hiperparatireoidismo, tanto antes quanto após a cirurgia de paratireoidectomia. Apesar da elevada especificidade, a cintilografia das paratireóides pode apresentar resultados falso-positivos. Neste artigo, relatamos o caso de uma paciente transplantada renal, com múltiplas lesões osteolíticas na bacia, interpretadas como tumores marrons, que à cintilografia das paratireóides com sestamibi-99mTc apresentou hipercaptação focal do radiofármaco em topografia de porção anterior do mediastino superior. Esta área hipercaptante foi inicialmente interpretada como glândula paratireóide ectópica, porém, após realização de outros exames de imagem e análise mais detalhada, mostrou-se corresponder a tumor marrom em esterno.

Parathyroid scintigraphies have been used to detect pathological parathyroid glands either before as well as after the parathyroid resection surgery in patients with hyperparathyroidism. Although this test presents high specificity for detection of increased parathyroid glands, there exist causes of false positive results. In the present article, we report a case of a renal transplanted patient, with multiple lytic lesions on pelvic bones reported as brown tumors, who presented a focal uptake in the anterior portion of the superior mediastinum on Tc-99m sestamibi scintigraphy. This focal uptake, initially thought to be an ectopic parathyroid gland, after a more detailed analysis and the performance of other imaging diagnostic tests was demonstrated to be a brown tumor of the sternum.

Osteoporose é uma doença caracterizada pela baixa massa óssea e alterações de micro arquitetura do tecido ósseo, levando ao aumento da fragilidade óssea e aumento do risco de fratura. Apesar da pesquisa em osteoporose ter focalizado principalmente no papel da perda óssea na população idosa, está começando a ficar claro que a quantidade de osso que é ganho durante o crescimento é também um determinante importante de resistência futura para fraturas. Portanto, interesse considerável está sendo colocado na definição de estratégias preventivas que otimizam o ganho de massa óssea durante a infância e adolescência. O conhecimento dos determinantes responsáveis pelas variações fisiológicas e genéticas, na acumulação óssea nas crianças, irá levar aos melhores meios para o diagnóstico precoce e tratamento da osteoporose. Este artigo revê as técnicas disponíveis para a medida da massa óssea em crianças e os maiores determinantes e doenças que influenciam a aquisição óssea durante a infância e adolescência.

Osteoporosis is a disease characterized by low bone mass and micro architectural alterations of bone tissue leading to enhanced bone fragility and increased fracture risk. Although research in osteoporosis has focused mainly on the role of bone loss in the elderly population, it is becoming increasingly clear that the amount of bone that is gained during growth is also an important determinant of future resistance to fractures. Thus, considerable interest is being placed on defining preventive strategies that optimize the gain of bone mass during childhood and adolescence. Knowledge of the determinants accounting for the physiologic and genetic variations in bone accumulation in children will provide the best means toward the early diagnosis and treatment of osteoporosis. This article reviews the techniques available for bone mass measurements in children and the major determinants and diseases influencing bone accretion during childhood and adolescence.

Com o objetivo de correlacionar os níveis séricos de cálcio e PTH com a porcentagem de resultados positivos na cintilografia das paratiróides (CP), analisamos retrospectivamente 194 pacientes submetidos à CP. Avaliou-se visualmente a distribuição dos resultados das CP em um diagrama de dispersão cujos eixos eram os níveis de cálcio (eixo Y) e PTH (eixo X) séricos. Foram definidos 6 grupos de pacientes: 1) cálcio > 12mg/dL; 2) 11mg/dL < cálcio < 12mg/dL; 3) 9,9mg/dL < cálcio < 11mg/dL com PTH > 120pg/mL; 4) 9,9mg/dL < cálcio < 11mg/dL com 65pg/mL < PTH < 120pg/mL; 5) 9,9mg/dL < cálcio < 11mg/dL com PTH < 65pg/mL; e 6) cálcio < 9,9mg/dL. A porcentagem de exames positivos nestes 6 grupos foram respectivamente: 10/10 (100%), 18/29 (62%), 7/9 (78%), 18/45 (40%), 2/21 (10%) e 1/80 (1%). Em conclusão, nos pacientes com suspeita de hiperparatiroidismo primário, as CPs realizadas antes da cirurgia de paratiroidectomia naqueles com níveis de cálcio acima de 11mg/dL são, na maioria das vezes, positivas. Para pacientes com níveis de cálcio sérico entre 9,9mg/dL e 11mg/dL, a pertinência da realização da cintilografia vai depender dos níveis de PTH sérico, sendo esta pertinência alta para pacientes com níveis de PTH acima de 120pg/mL e muito baixa para pacientes com PTH abaixo de 65pg/mL. Pacientes com cálcio sérico abaixo de 9,9mg/dL raramente apresentam cintilografia das paratiróides positivas.

To correlate PTH and calcium serum levels with the percentages of positive results on the parathyroid scintigraphy, we retrospectively analyzed 194 patients who performed parathyroid scintigraphy. The distribution of the parathyroid scintigraphy results was visually analyzed in a scatter plot, being calcium (Y axis) and PTH (X axis) serum levels the axes. Six groups of patients were defined: 1) calcium > 12mg/dL; 2) 11mg/dL ¾ calcium < 12mg/dL; 3) 9.9mg/dL < calcium < 11mg/dL with PTH > 120pg/mL; 4) 9.9mg/dL < calcium < 11mg/dL with 65pg/mL < PTH < 120pg/mL; 5) 9.9mg/dL < calcium < 11mg/dL with PTH < 65pg/mL; and 6) calcium < 9.9mg/dL. The percentage of positive scintigraphy in these groups were respectively: 10/10 (100%), 18/29 (62%), 7/9 (78%), 18/45 (40%), 2/21 (10%) and 1/80 (1%). We conclude that in patients with suspected primary hyperparathyroidism, parathyroid scintigraphies performed before surgery on those with calcium level above 11mg/dL are frequently positive. In patients with calcium levels between 9.9mg/dL and 11mg/dL the pertinence of performing the scintigraphy will depend on the PTH levels, and it will be high for patients with PTH serum level above 120pg/mL and very low for patients with PTH level below 65pg/mL. Patients with calcium level below 9.9mg/dL rarely present positive results on parathyroid scintigraphies.

RACIONAL: Existe associação entre doença óssea metabólica e doença hepática colestática. Contudo, a associação com cirrose não-colestática ainda é pouco conhecida. OBJETIVOS: Determinar a prevalência e a gravidade da perda de densidade mineral óssea na cirrose não-colestática e investigar fatores preditivos do seu diagnóstico. MÉTODOS: Oitenta e nove pacientes e 20 controles foram estudados de março a setembro de 1998. Todos foram submetidos a exames laboratoriais e densitometria óssea da coluna lombar e do colo do fêmur. RESULTADOS: A massa óssea estava significativamente reduzida em ambos os sítios nos pacientes quando comparado aos controles. A prevalência da perda de massa óssea na cirrose não-colestática, de acordo com os critérios da Organização Mundial da Saúde, foi de 78% na coluna lombar e 71% no colo do fêmur. A massa óssea diminuiu significativamente com a idade em ambos os sítios, especialmente em pacientes acima de 50 anos. Pacientes mulheres pós-menopausa tinham massa óssea significativamente menor do que pacientes mulheres pré-menopausa e homens em ambos os sítios. Não houve diferença significativa na massa óssea entre as etiologias não-colestáticas. A massa óssea da coluna lombar diminuiu significativamente com a progressão da disfunção hepática. Nenhuma variável bioquímica foi associada com a perda da massa óssea. CONCLUSÕES: A perda de massa óssea foi freqüente em pacientes com cirrose não-colestática. Pacientes idosos, do sexo feminino na pós-menopausa e com disfunção hepática grave apresentaram doença óssea mais avançada. Os exames laboratoriais rotineiramente dosados nos pacientes com doença hepática não puderam predizer com segurança a presença de redução na massa óssea.

BACKGROUND: Metabolic bone disease has long been associated with cholestatic disorders. However, data in noncholestatic cirrhosis are relatively scant. AIMS: To determine prevalence and severity of low bone mineral density in noncholestatic cirrhosis and to investigate whether age, gender, etiology, severity of underlying liver disease, and/or laboratory tests are predictive of the diagnosis. PATIENTS/METHODS: Between March and September/1998, 89 patients with noncholestatic cirrhosis and 20 healthy controls were enrolled in a cross-sectional study. All subjects underwent standard laboratory tests and bone densitometry at lumbar spine and femoral neck by dual X-ray absorptiometry. RESULTS: Bone mass was significantly reduced at both sites in patients compared to controls. The prevalence of low bone mineral density in noncholestatic cirrhosis, defined by the World Health Organization criteria, was 78% at lumbar spine and 71% at femoral neck. Bone density significantly decreased with age at both sites, especially in patients older than 50 years. Bone density was significantly lower in post-menopausal women patients compared to pre-menopausal and men at both sites. There was no significant difference in bone mineral density among noncholestatic etiologies. Lumbar spine bone density significantly decreased with the progression of liver dysfunction. No biochemical variable was significantly associated with low bone mineral density. CONCLUSIONS: Low bone mineral density is highly prevalent in patients with noncholestatic cirrhosis. Older patients, post-menopausal women and patients with severe hepatic dysfunction experienced more advanced bone disease. The laboratory tests routinely determined in patients with liver disease did not reliably predict low bone mineral density.

O hiperparatiroidismo primário (HPP) é caracterizado pelo aumento da secreção de PTH, com conseqüente aumento da concentração sérica de cálcio. O diagnóstico é realizado pela dosagem de cálcio e PTH. A cintilografia das paratiróides é solicitada, classicamente, em pacientes com recorrência de HPP após paratiroidectomia, na tentativa de detectar glândulas patológicas ectópicas ou remanescentes. Algumas vezes este exame tem sido solicitado antes do primeiro ato cirúrgico, na tentativa de localizar as glândulas comprometidas e abreviar a duração da cirurgia; na nossa casuística, no entanto, a maioria dos exames solicitados com esta indicação resulta negativa. Comparamos os níveis séricos de cálcio e PTH nos pacientes com cintilografia das paratiróides positiva, com aqueles dos pacientes com cintilografia negativa, a fim de tentar definir níveis com índice maior de positividade na cintilografia. Foram estudados retrospectivamente 74 pacientes consecutivos submetidos à cintilografia das paratiróides. Avaliou-se a utilização dos valores mais baixos de PTH (79pg/mL) e cálcio (10mg/dL) registrados no grupo com cintilografia positiva como referência para a indicação do exame. No grupo total de pacientes, 17 (23%) apresentaram cintilografia positiva. No subgrupo com valores de PTH > ou = 79pg/mL e de cálcio > ou = 10 mg/dL a porcentagem de exames positivos foi de 49%. Concluímos que cintilografias das paratiróides realizadas antes da cirurgia de paratiroidectomia em pacientes com níveis de cálcio sérico abaixo do limite superior da normalidade ou níveis de PTH pouco aumentados são, na maioria das vezes, negativas.

Primary hyperparathyroidism (PHP) is characterized by increased secretion of PTH and consequent increase in plasma calcium concentration. Diagnosis is based on the measurement of serum calcium and PTH concentrations. Parathyroid scintigraphy is classically performed in patients with recurrent PHP after resection of the parathyroids, aiming the detection of remnants or ectopically located parathyroid adenomas. Sometimes, parathyroid scintigraphy is requested before the first surgery, in order to localize the pathological glands and abbreviate the duration of the surgical procedure; however, in our series of patients, most of the exams performed with this purpose were negative. We compared serum calcium and PTH levels in a group of patients with positive or negative scintigraphy in order to define the best calcium and PTH levels to perform scintigraphy. Seventy-four consecutive parathyroid scintigraphies were retrospectively analyzed. The use of the lower values of PTH (79pg/mL) and calcium (10mg/dL) in the group of patients with positive scintigraphy were assessed as a reference level for the indication of parathyroid scintigraphy. For the whole group of patients, 17 (23%) presented positive scintigraphy. For the subgroup of patients with PTH > or = 79pg/mL and calcium > or = 10mg/dL, the percentage of positive exams is 49%. We conclude that parathyroid scintigraphies performed before the initial surgery in patients with serum calcium levels below the superior limit of normality or slightly increased PTH level, are mostly negative.

A massa óssea de um indivíduo adulto, que está estreitamente relacionada ao risco de fraturas osteoporóticas, depende da diferença entre o pico de massa óssea alcançado no final do período de maturação sexual e esquelética, e as perdas acumuladas durante a vida. A enorme variabilidade observada no pico de massa óssea da adolescência está relacionada, principalmente, a fatores genéticos, mas também a parâmetros antropométricos, como peso e altura, hábitos dietéticas, influências hormonais diversas, atividade física, uso de medicamentos e doenças intercorrentes. A identificação dos fatores envolvidos na aquisição do pico de massa óssea na infância e adolescência e a compreensão deste longo período de maturação esquelética, permitirão a criação de estratégias para prevenção da osteoporose.

Bone mass in the adult life, which is closely related to osteoporotic fracture risk, depends on the differences between the peak bone mass attained at the end of the sexual and skeletal maturation and the rate of involutional bone mass. The great variability in peak bone mass observed at adolescence is related not only to genetic factors, but also to diet, hormonal status, anthropometric variables, as weight and height, physical activity, drugs and intercurrent diseases. The identification of the factors involved with the acquisition of the peak bone mass and the comprehension of this long period of skeletal maturation will indicate strategies for prevention of osteoporosis.