The calcimimetic cinacalcet normalizes serum calcium in renal transplant patients with persistent hyperparathyroidism.

BACKGROUND: Treatment of persistent hyperparathyroidism in renal transplant patients resistant to calcium and vitamin D sterols is limited and often requires parathyroidectomy. Given the potential hazards linked to surgery, an alternative approach to manage excess parathyroid hormone (PTH) secretion is needed. Calcimimetics inhibit PTH secretion by modulating the calcium-sensing receptor in the parathyroid. Lowering of the serum calcium concentration with the calcimimetic cinacalcet has previously been demonstrated in patients with primary hyperparathyroidism or with secondary hyperparathyroidism on dialysis. Here we present the first clinical observations of a calcimimetic in patients with persistent hyperparathyroidism. METHODS: A 30 mg dose of cinacalcet was prescribed once daily for 3 months to seven female and seven male stable renal transplant patients, aged 23-65 years, 7 months to 14 years after transplantation, with a serum creatinine ranging from 89 to 229 micromol/l and persistent hyperparathyroidism. Concomitant medication included cyclosporin and low-dose prednisone in all patients. RESULTS: On cinacalcet, serum calcium decreased and normalized in all but two patients (baseline 2.72+/-0.03 mmol/l; 1 month 2.42+/-0.04 mmol/l, P<0.001), whereas serum PTH and phosphate levels did not change significantly. A slight reduction in renal function, as assessed by serum creatinine concentration, was observed at months 2 and 3 (P<0.05). An immunoglobulin-deficient patient developed colitis after 1 week of treatment and cinacalcet was withdrawn. No patient stopped cinacalcet because of other presumed side effects. CONCLUSION: Calcimimetics are a promising therapy in renal transplant patients with persistent hyperparathyroidism. Prospective controlled studies must now be designed focusing on functionally relevant musculo-skeletal end-points and allowing the exclusion of negative effects on long-term renal and general outcome of such patients.     

Intravenous calcitriol lowers serum calcium concentrations in uraemic patients with severe hyperparathyroidism and hypercalcaemia

We studied the effects of intravenous calcitriol in four persistently hypercalcaemic patients established on haemodialysis. All had marked hyperparathyroidism and had been previously shown to be intolerant to vitamin D by mouth. Calcitriol was administered at the end of each dialysis session in doses of 0.5-2.5 micrograms for 2 months and continued for 7 and 8 months in two patients. A significant decrease in serum calcium was observed after 2 weeks, which was maintained throughout treatment despite increasing the dose of calcitriol. This was associated with a decrease in serum concentrations of iPTH (28% of the initial value at 4 weeks), suggesting a shift in the set-point for PTH secretion. During longer-term treatment, serum calcium values increased, but lower concentrations of iPTH were maintained. We conclude that an increment in serum calcium is not a prerequisite for the suppressive action of calcitriol on parathyroid secretion and that the presence of hypercalcaemia does not preclude its use. Longer-term studies on a larger number of patients are required to assess the therapeutic potential of intravenous calcitriol in hypercalcaemic patients.     

2 224例女性月经史及绝经年龄、绝经年限与骨质疏松症相关性研究

目的 分析兰州市两社区45岁以上女性初潮年龄、月经周期、月经天数及绝经年龄、绝经年限与骨质疏松症相关性。方法 采用现场问卷调查方式获取初潮年龄、月经周期、月经天数及绝经年龄、绝经年限等相关资料,应用双能X线骨密度检测仪测定骨密度。结果 ①骨质疏松症患病率为32.73 %,患病率随初潮年龄增加（P<0.01）及月经周期延长（P<0.05）而上升;患病率随月经天数增加而逐渐降低,但差异无统计学意义（P=0.104）;②绝经后女性患病率（35.91 %）显著高于未绝经女性（5.22 %）,组间差异存在统计学意义（P＜0.01）;不同绝经年龄与绝经年限组间差异存在统计学意义（P＜0.01）。③单因素Logistic分析显示,初潮年龄、绝经史、绝经年龄、绝经年限与骨质疏松相关（P<0.05）。结论 兰州市两社区45岁以上女性骨质疏松症发生与初潮年龄、绝经史、绝经年龄、绝经年限相关,初潮年龄早、月经周期长、绝经年龄早、绝经年限长的绝经后女性应提早筛查、预防骨质疏松症的发生。     

Adverse implications of acid phosphatase levels in the upper range of normal

A retrospective review of 102 consecutive patients with surgically staged, clinically localized prostatic carcinoma was performed to determine the relationship between pre-treatment enzymatic acid phosphatase values and histopathological extent of the tumor. Of 96 patients with normal pretreatment acid phosphatase titers (thymolphthalein monophosphate substrate) 77 (80 per cent) had values in the lower and 19 (20 per cent) had values in the upper half of the normal range. Of the latter 19 patients 16 (84 per cent) had histological evidence of extraprostatic tumor extension. Similarly, 5 of 6 patients (83 per cent) with elevated pre-treatment acid phosphatase titers had extraprostatic extension and 1 had a persistent postoperative acid phosphatase elevation that normalized with megestrol acetate therapy. Thus, 22 of 25 patients (88 per cent) with acid phosphatase values in or above the upper half of the normal range had either histological or clinical evidence of extracapsular tumor extension. By contrast, 41 of the 77 patients (53 per cent) with acid phosphatase titers in the lower half of the normal range had extracapsular extension. The predictive value for extraprostatic tumor extension of an acid phosphatase level in the upper half of the normal range was 84 per cent. Furthermore, in the 96 patients with normal acid phosphatase titers the incidence of extraprostatic tumor extension was significantly greater (p less than 0.01, chi-square) in those with values in the upper rather than the lower half of the normal range. Acid phosphatase titers in the upper half of the normal range were proportionately more common among patients with high grade and high clinical stage tumors. However, among patients with low grade and low stage tumors an acid phosphatase value in the upper half of the normal range was an independent variable that correlated with the presence of extracapsular tumor extension. These results confirm previously reported adverse prognostic implications of enzymatic acid phosphatase titers in or above the upper half of the normal range.     

Seasonal changes in serum calcium,PTH and vitamin D levels in patients with primary hyperparathyroidism

BackgroundSeasonal variations of 25-hydroxyvitamin D, PTH and calcium levels are not well characterized in primary hyperparathyroidism (PHPT). Our objectives were to characterize seasonal changes in these parameters in PHPT patients, and to assess whether these seasonal changes affect clinical decision making.MethodsThis is a retrospective study based on the electronic medical records of Clalit Health service in the south of Israel between 2000 and 2012. Patients 18 years and older with PHPT (PTH > upper limit of norm (ULN) and serum calcium > 10.5 mg%) were included. Patients with renal failure or on Thiazide diuretics were excluded. All serum levels of calcium, PTH and 25-hydroxyvitamin D were collected and then stratified according to season.Results792 patients were classified as PHPT (72.2% female) and had a total of 2659 PTH tests, 1395 25-hydroxyvitamin D tests and 7426 calcium test. Fifty six percent of 25-hydroxyvitamin D levels were < 50 nmol/L. Seasonality was demonstrated in all three parameters: mean 25-hydroxyvitamin D was 13% higher in the summer compared to the winter (P < 0.001), median PTH values showed opposite trend with a fall of about 8.4% in summer compared to winter (P < 0.001). Calcium levels were higher during the autumn with a rise of about 0.2 mg/dL in the mean calcium levels compared to spring and summer (P < 0.001). The odds ratio of calcium level above 11.5 mg/dL is highest in the autumn (OR = 1.275, P = 0.018).ConclusionWe show seasonal variation in serum 25-hydroxyvitamin D, PTH, and calcium levels in patients with PHPT. These seasonal variations cause transition to pathological values that may influence diagnosis and treatment of PHPT patients.     

Primary hyperparathyroidism. Relationship between surgical technique and postoperative calcium levels in patients with single parathyroid adenomas

The relationship between extent of surgery and calcium levels 6-12 months postoperatively has been analysed in 177 patients in whom a parathyroid adenoma was found at exploratory surgery of the neck. The analysis showed that the frequency of postoperative hypocalcaemia and the need of longterm calcium and vitamin D supplements increased if macroscopically normal glands were extirpated and/or biopsied in addition to removal of the adenoma. It was also shown that the frequency of postoperative hypercalcaemia was similar in patients in whom the peroperative histopathological examination of macroscopically normal glands showed normal cellularity or hyperplasia. The data favour a more conservative approach in parathyroid surgery.     

Correlates of intestinal calcium absorption in women 10 years past the menopause

Summary Because intestinal calcium absorption may be an important independent determinant of calcium balance and therefore bone mass, we have studied this factor and other potential predictors in 196 healthy postmenopausal women. Gut calcium absorption was measured in each subject by a stable strontium method and expressed as a fractional absorption. The fractional absorption was significantly negatively correlated with years since menopause (YSM) (r=-0.15 P<0.05), and dietary calcium intake (r=-0.15 P<0.05), and significantly positively correlated with 24-hour urine calcium excretion (r=0.31 P<0.001) and body mass index (r=0.20 P<0.01). Apart from YSM, these factors remained as correlates in multiple regression analysis; the standardized regression coefficient was largest for 24-hour urine calcium excretion (0.32). Fractional absorption of calcium was not correlated with vertebral bone density. Thus, intestinal calcium absorption, although falling with increasing menopausal age and increasing calcium intake, is best correlated with the urine calcium excretion. This indicates either that gut calcium absorption is regulated in response to the magnitude of the urine calcium excretion or that the kidney maintains calcium balance by excreting what is absorbed by the intestine. The mechanisms whereby gut and renal calcium handling are correlated are uncertain.     

Primary hyperparathyroidism is associated with abnormal cortical and trabecular microstructure and reduced bone stiffness in postmenopausal women

Typically, in the milder form of primary hyperparathyroidism (PHPT), now seen in most countries, bone density by dual‐energy X‐ray absorptiometry (DXA) and detailed analyses of iliac crest bone biopsies by histomorphometry and micro–computed tomography (µCT) show detrimental effects in cortical bone, whereas the trabecular site (lumbar spine by DXA) and the trabecular compartment (by bone biopsy) appear to be relatively well preserved. Despite these findings, fracture risk at both vertebral and nonvertebral sites is increased in PHPT. Emerging technologies, such as high‐resolution peripheral quantitative computed tomography (HRpQCT), may provide additional insight into microstructural features at sites such as the forearm and tibia that have heretofore not been easily accessible. Using HRpQCT, we determined cortical and trabecular microstructure at the radius and tibia in 51 postmenopausal women with PHPT and 120 controls. Individual trabecula segmentation (ITS) and micro–finite element (µFE) analyses of the HRpQCT images were also performed to further understand how the abnormalities seen by HRpQCT might translate into effects on bone strength. Women with PHPT showed, at both sites, decreased volumetric densities at trabecular and cortical compartments, thinner cortices, and more widely spaced and heterogeneously distributed trabeculae. At the radius, trabeculae were thinner and fewer in PHPT. The radius was affected to a greater extent in the trabecular compartment than the tibia. ITS analyses revealed, at both sites, that plate‐like trabeculae were depleted, with a resultant reduction in the plate/rod ratio. Microarchitectural abnormalities were evident by decreased plate‐rod and plate‐plate junctions at the radius and tibia, and rod‐rod junctions at the radius. These trabecular and cortical abnormalities resulted in decreased whole‐bone stiffness and trabecular stiffness. These results provide evidence that in PHPT, microstructural abnormalities are pervasive and not limited to the cortical compartment, which may help to account for increased global fracture risk in PHPT. © 2013 American Society for Bone and Mineral Research.     

Decrease of serum calcium concentration and lost influence of calcium on parathyroid hormone release in a patient with primary hyperparathyroidism after treatment with diphosphonates

Summary Prolonged decrease of elevated serum calcium levels after treatment with diphosphonates in patients with primary hyperparathyroidism (pHPT) is very rare. A patient with water clear cell hyperplasia and five enlarged glands is presented who received diphosphonates (day 1 through day 8 dichloromethylene diphosphonate orally and a single dose of 60 mg pamidronate on day 8 intravenously) leading to a significant fall in serum calcium levels. Surprisingly, there was no reactive increase in intact parathyroid hormone (PTH) in the following 18 days. Patients with missing PTH regulation to hypocalcemia after diphosphonates who need a period of stabilization prior to parathyroid surgery might benefit most from this therapy.     

Primary hyperparathyroidism: Renal calcium excretion in patients with and without renal stone disease before and after parathyroidectomy

The effect of parathyroidectomy on renal calcium excretion per 24 hours in patients with primary hyperparathyroidism with and without a history of renal stone disease was evaluated. Altogether, 91 patients operated on for primary hyperparathyroidism formed the study group for preoperative analysis. Of these patients, 42 were evaluated 1 to 3 years postoperatively. The median preoperative serum calcium level was 2.92 mmol/L, and it was the same for patients with or without renal stones. Preoperatively we found no differences in renal calcium excretion between patients with and without renal stone disease. The median renal calcium excretion was 6.80 mmol/24 hr. At 1 to 3 years after successful parathyroidectomy the group with renal stone disease had higher renal calcium excretion than the group without renal stones (p = 0.03). The reduced effect of parathyroidectomy on renal calcium excretion in the patients with renal stone disease indicates that factors not related to the hyperparathyroid state could contribute to disturbances in renal calcium excretion and hence stone formation. In conclusion, the pathologic basis for renal stone formation in patients with primary hyperparathyroidism might not be the hyperparathyroid state alone; stone formation could be related to other predisposing factors as well. Therefore, although parathyroidectomy can cure hyperparathyroidism, the curative effect on renal stone disease should be reconsidered.     

Lifestyle factors are associated with osteoporosis in lean women but not in normal and overweight women: a population-based cohort study of 1222 women

The aim of the present population-based cohort study was to evaluate the contribution of lifelong lifestyle factors to calcaneal and distal forearm bone mass in elderly women. We studied 1222 of the 1689 eligible home-dwelling women aged 70–73 years. Lifelong occupational and leisure time physical activity, calcium intake, smoking, alcohol intake and medical history were obtained by a self-completed questionnaire. Main outcome measures were broadband ultrasound attenuation (BUA) of the calcaneus and bone mineral density (BMD) of the radius measured once in 1997–1998. The women with BMI ≤ 25.1 kg m² had lower BUA (p < 0.0001) and radial BMD values (p < 0.0001) than women with higher BMI. Lifestyle factors associated with BUA in the leanest women were: low physical activity at work (RR 0.4; 95% confidence interval 0.2 to 0.8), low habitual exercise at the ages 30 years , 50 years and currently (RR 1.5; 1.0 to 2.4; RR 1.5; 1.1 to 2.6; RR 1.7; 1.1 to 2.7), poor mobility (RR 1.9; 1.2 to 3.0), coffee intake ≥ 5 cups/day (RR 1.7; 1.1 to 2.7), type 2 diabetes (RR 0.3; 0.1 to 0.9) and hypertension (RR 0.5; 0.3 to 0.8). Type 2 diabetes protected lean women from lower distal and ultradistal radial bone density (RR 0.3; 0.1 to 0.8; RR 0.1; 0.1 to 0.5). The selected lifestyle factors were not associated with lowered calcaneal or radial bone density in the higher categories of BMI. In conclusion, risk factors for lower calcaneal and radial bone density appear to be different among lean and normal/obese women. Lifelong recreational physical activity, low physical activity at work, type 2 diabetes and hypertension seem to be associated with increased bone density, while high coffee intake may increase the risk of lower bone density in lean elderly women. These factors are potentially modifiable, and intervention studies targeted at this risk category of women are needed.     

Breast magnetic resonance imaging as a problem solving tool in women recalled at biennial screening mammography: A population-based study in the Netherlands

PurposeProblem solving magnetic resonance imaging (MRI) is used to exclude malignancy in women with equivocal findings on conventional imaging. However, recommendations on its use for women recalled after screening are lacking. This study evaluates the impact of problem solving MRI on diagnostic workup among women recalled from the Dutch screening program, as well as time trends and inter-hospital variation in its use.MethodsWomen who were recalled at screening mammography in the South of the Netherlands (2008–2017) were included. Two-year follow-up data were collected. Diagnostic-workup and accuracy of problem solving MRI were evaluated and time trends and inter-hospital variation in its use were examined.ResultsIn the study period 16,175 women were recalled, of whom 906 underwent problem solving MRI. Almost half of the women (45.4%) who underwent problem solving MRI were referred back to the screening program without further workup. The sensitivity, specificity, and positive and negative predictive values of problem solving MRI were 98.2%, 70.0%, 31.1%, and 99.6%, respectively. The percentage of recalled women receiving problem solving MRI fluctuated over time (4.7%–7.2%) and significantly varied among hospitals (2.2%–7.0%).ConclusionThe use of problem solving MRI may exclude malignancy in recalled women. The use of problem solving MRI varied over time and among hospitals, which indicates the need for guidelines on problem solving MRI.     

Estimation of the risk of lung cancer in women participating in a population-based breast cancer screening program

IntroductionLung cancer mortality is increasing in women. In Spain, estimates suggest that lung cancer mortality may soon surpass breast cancer mortality, the main cause of cancer mortality among women. The aim of this study was to estimate the proportion of women at high risk of developing lung cancer in a group of participants in a population-based breast cancer screening program.MethodsCross-sectional study in a sample of women who participated in a population-based breast cancer screening program in 2016 in Hospitalet de Llobregat n = 1,601. High risk of lung cancer was defined according to the inclusion criteria of the National Lung Screening Trial (NLST) and the Dutch-Belgian randomized lung cancer screening trial (NELSON).ResultsAround 20% of smokers according to NLST and 40% of smokers according to NELSON criteria, and around 20% of former smokers according to both criteria, are at high risk of developing lung cancer. A positive and statistically significant trend is observed between the proportion of women at high risk and nicotine dependence measured with the brief Fagerström Test.ConclusionsA high proportion of participants in this breast cancer screening program have a high risk of developing lung cancer and would be eligible to participate in a lung cancer screening program. Population-based breast cancer screening programs may be useful to implement lung cancer primary prevention activities.     

A comparative study of serum ultrafiltrable, ionized, and total calcium in the diagnosis of primary hyperparathyroidism in patients with intermittent or no elevation in total calcium

Measurement of serum ionized calcium has been shown to be more sensitive a method of diagnosing primary hyperparathyroidism than total calcium in patients with subtle or intermittent elevations of total calcium. The measurement of ionized calcium, however, is technically difficult. The measurement of serum ultrafiltrable calcium would circumvent technical difficulties because atomic absorption spectroscopy would be used to measure the calcium of a filtrate produced by passing serum through a filter which excludes protein-complexed calcium (Worthington ultrafree filter). The normal range for ultrafiltrable calcium (4.7 to 6.8 mg/dl) was determined in 138 patients by nonlinear least-squares analysis and chart review. The serum concentration of ultrafiltrable calcium correlated well with ionized calcium (r = 0.91). Previous studies have demonstrated no benefit in measuring ionized calcium, as opposed to total calcium, in the diagnosis of primary hyperparathyroidism unless there was subtle, intermittent, or no elevation of the total calcium. This comparative study of ultrafiltrable, ionized, and total calcium was, therefore, done in six patients with primary hyperparathyroidism who exhibited intermittent, minimal, or no elevations in serum total calcium. All six patients had symptoms referrable to hyperparathyroidism. All six underwent parathyroid surgery, and a parathyroid adenoma was found in each case. These six patients had a total of 24 concurrent preoperative determinations of ionized, ultrafiltrable, and total calcium levels. The total calcium value was elevated in only 9 of these 24 determinations (38%), ultrafiltrable calcium was elevated in 15 (63%), and ionized calcium was elevated in 23 (96%). The values of ionized calcium were elevated more frequently than both total calcium (p less than 0.0005) and ultrafiltrable calcium (p less than 0.025). The values for ultrafiltrable calcium were more frequently elevated than those for total calcium; this difference, however, was not significant. This study confirms our previous reports showing that ionized calcium is a more sensitive indicator of primary hyperparathyroidism in patients with intermittent or borderline elevation of the total calcium and extends those observations to show that ionized calcium is also a more sensitive indicator of primary hyperparathyroidism than ultrafiltrable calcium in this group of patients.     

Urodynamic characterisation of women with naive urinary incontinence: a population-based study in subjectively incontinent and healthy 53-63 years old women

OBJECTIVES: To compare the urodynamic characteristics in a group of middle-aged women with untreated urinary incontinence with the findings in a control group of healthy women. METHODS: Sixty women with mild-to-moderate urinary incontinence and 28 symptom-free women, 53-63 years old, were randomly chosen out of a large health questionnaire study. All were investigated with a detailed history, gynaecological examination, urinalysis, frequency-volume chart, and urodynamics including cystometry and pressure-flow analysis. RESULTS: The maximum urinary flow was significantly higher in the incontinent group of women, 22+/-1ml/s, than in the healthy controls, 16+/-2ml/s (p<0.01). The acceleration of flow, with a theoretical maximum of 0 degrees, was also significantly faster in the incontinent, 20 degrees, than in the healthy women, 32 degrees (p=0.01). In the five women with urge incontinence only, maximum urinary flow was 26+/-2.4ml/s and the flow acceleration 7 degrees. In incontinent women, both a lower opening pressure and detrusor pressure at maximum flow were seen compared with the healthy women, though the difference did not reach statistical significance. The incontinent and the healthy women did not differ regarding bladder volumes or pressures during filling. CONCLUSION: The findings of this study indicate the presence of an increased efficiency of the urethral opening mechanism in incontinent women compared to normal, irrespective of the type(s) of symptoms present.     

Suppressibility of serum levels of PTH by calcium in the immediate postoperative period after surgery for primary hyperparathyroidism

The ability of calcium to suppress the secretion of parathyroid hormone (PTH) is impaired in primary hyperparathyroidism (pHPT). Whether the nonadenomatous glands in pHPT also exhibit altered calcium/PTH homeostasis is not known, but this may be the case since in the immediate postoperative period after surgery for pHPT, hypocalcemia often evolves in spite of a rapid normalization of serum levels of PTH. In this study, therefore, the suppression of serum levels of PTH by an oral calcium load was investigated pre- and postoperatively in 12 patients operated on for parathyroid adenoma. There was no difference in the calcemic response during the calcium load pre- and postoperatively. We found that the suppression of serum levels of PTH by calcium was increased already on the first postoperative day. However, postoperatively, the suppression of serum levels of PTH corrrelated positively to serum levels of ionized calcium and, furthermore, negatively to the weight of the excised parathyroid adenoma and the preoperative serum levels of ionized calcium. The results indicate that the function of the remaining parathyroid glands in patients with parathyroid adenoma could have been altered during the hyperparathyroid state and that postoperative hypocalcemia more readily evolves in patients with severe pHPT and impaired suppressibility of PTH (by calcium) in the remaining parathyroid glands.

---

Resumen La capacidad que posee el calcio de suprimir la secreción de hormona paratiroídea (HPT) se encuentra alterada en el híperparatiroidismo primario (pHPT). No se sabe si las glándulas paratiroídes no adenomatosas en pacientes con PHPT también exhiben alteración en la homeostais calcio/HPT; pero bien puede ser así, puesto que en el período postoperatorio inmediato, después de cirugía por pHPT, con frecuencia se desarrolla hipocalcemía a pesar de la rápida nomalización de los niveles séricos de HPT. En el présente estudio se investigó la supresión de los niveles séricos de HPT por una carga oral de calcio en los períodos pre y postoperatorios en 12 pacientes intervenidos por adenoma paratiroídeo. No se encontró diferencia en la respuesta calcémica pre y postoperatoria. Encontramos que la supresión de los niveles sérico de HPT por el calcio se incrementó en el primer día postoperatorío. Sin embargo, en el postopertorío la supresión de los niveles séricos de HPT se correlacionaron positivamente con los niveles séricos de calcio ionizado y negativamente con el peso del adenoma paratiroídeo resecado y los niveles preoperatorios de calcio ionizado. Estos resultados indican que la función en las glándulas paratiroídes residuales en pacientes con adenomas paratiroídeas pueden haber sido alterados en el curso del estado hiperparatiroideo, y que la hipocalcemía postoperatoria se desarrolla más fácilmente en pacientes con severo pHPT y con supresión alterada de la secreción de HPT por calcio en las glándulas residuales.

---

Résumé L'hyperparathyroïdie primitive (HPT_p) est caractérisée par une altération du freinage de la sécrétion de la parathormone (PTH) par le calcium. On ne siat pas si les parathyroïdes non adénomateuses présentent aussi une altération dans l'homéostasie calcium/PTH, mais ceci est probable car dans la période postopératoire immédiate après chirurgie sur la parathyroïde pour HPT_p, il existe une hypocalcémie malgré une normalisation rapide des taux sériques de PTH. Nous avons étudié la variation des taux de PTH sérique après une charge en calcium per os chez 12 patients, avant et après intervention pour un adénome de la parathyroïde. Il n'y avait aucune différence entre les calcémies pré-et postopératoire après charge calcique chez ces 12 patients. La diminution des taux sériques de PTH par le calcium était exacerbée le lendemain de l'intervention. Après cette date, cependant, la diminution des taux sériques de la PTH corrélait positivement avec les taux sériques de calcium ionisé et négativement avec le poids de l'adénome excisé et les taux sériques préopératoires du calcium ionisé. Ces résultats indiquent que la fonction des glandes parathyroïdes restantes chez le patient ayant un adénome parathyroïde pourrait être altérée pendant l'HPT_p et que l'hypocalcémie postopératoire est plus prononcée chez le patient ayant une HPTp sévère et qui présente une incapacité à déprimer la sécrétion de PTH par le calcium dans les glandes parathyroïdes restantes.

     

Higher serum bicarbonate levels within the normal range are associated with better survival and renal outcomes in African Americans

Recent studies suggest that correcting low serum bicarbonate levels may reduce the progression of kidney disease; however, few patients with chronic kidney disease have low serum bicarbonate. Therefore, we examined whether higher levels of serum bicarbonate within the normal range (20-30 mmol/l) were associated with better kidney outcomes in the African American Study of Kidney Disease and Hypertension (AASK) trial. At baseline and during follow-up of 1094 patients, the glomerular filtration rates (GFR) were measured by iothalamate clearances and events were adjudicated by the outcomes committee. Mean baseline serum bicarbonate, measured GFR, and proteinuria were 25.1 mmol/l, 46 ml/min per 1.73 m(2), and 326 mg/g of creatinine, respectively. Each 1 mmol/l increase in serum bicarbonate within the normal range was associated with reduced risk of death, dialysis, or GFR event and with dialysis or GFR event (hazard ratios of 0.942 and 0.932, respectively) in separate multivariable Cox regression models that included errors-in-variables calibration. Cubic spline regression showed that the lowest risk of GFR event or dialysis was found at serum bicarbonate levels near 28-30 mmol/l. Thus, our study suggests that serum bicarbonate is an independent predictor of CKD progression. Whether increasing serum bicarbonate into the high-normal range will improve kidney outcomes during interventional studies will need to be considered.