A novel truncated form of apolipoprotein A-I transported by dense LDL is increased in diabetic patients.

Diabetic (DM) patients have exacerbated atherosclerosis and high CVD burden. Changes in lipid metabolism, lipoprotein structure, and dysfunctional HDL are characteristics of diabetes. Our aim was to investigate whether serum ApoA-I, the main protein in HDL, was biochemically modified in DM patients. By using proteomic technologies, we have identified a 26 kDa ApoA-I form in serum. MS analysis revealed this 26 kDa form as a novel truncated variant lacking amino acids 1-38, ApoA-IΔ(1-38). DM patients show a 2-fold increase in ApoA-IΔ(1-38) over nondiabetic individuals. ApoA-IΔ(1-38) is found in LDL, but not in VLDL or HDL, with an increase in LDL3 and LDL4 subfractions. To identify candidate mechanisms of ApoA-I truncation, we investigated potentially involved enzymes by in silico data mining, and tested the most probable molecule in an established animal model of diabetes. We have found increased hepatic cathepsin D activity as one of the potential proteases involved in ApoA-I truncation. Cathepsin D-cleaved ApoA-I exhibited increased LDL binding affinity and decreased antioxidant activity against LDL oxidation. In conclusion, we show for the first time: a) presence of a novel truncated ApoA-I form, ApoA-IΔ(1-38), in human serum; b) ApoA-IΔ(1-38) is transported by LDL; c) ApoA-IΔ(1-38) is increased in dense LDL fractions of DM patients; and d) cathepsin D-ApoA-I truncation may lead to ApoA-IΔ(1-38) binding to LDLs, increasing their susceptibility to oxidation and contributing to the high cardiovascular risk of DM patients.

Stem cells isolated from adipose tissue of obese patients show changes in their transcriptomic profile that indicate loss in stemcellness and increased commitment to an adipocyte-like phenotype.

BACKGROUND: The adipose tissue is an endocrine regulator and a risk factor for atherosclerosis and cardiovascular disease when by excessive accumulation induces obesity. Although the adipose tissue is also a reservoir for stem cells (ASC) their function and "stemcellness" has been questioned. Our aim was to investigate the mechanisms by which obesity affects subcutaneous white adipose tissue (WAT) stem cells. RESULTS: Transcriptomics, in silico analysis, real-time polymerase chain reaction (PCR) and western blots were performed on isolated stem cells from subcutaneous abdominal WAT of morbidly obese patients (ASCmo) and of non-obese individuals (ASCn). ASCmo and ASCn gene expression clustered separately from each other. ASCmo showed downregulation of "stemness" genes and upregulation of adipogenic and inflammatory genes with respect to ASCn. Moreover, the application of bioinformatics and Ingenuity Pathway Analysis (IPA) showed that the transcription factor Smad3 was tentatively affected in obese ASCmo. Validation of this target confirmed a significantly reduced Smad3 nuclear translocation in the isolated ASCmo. CONCLUSIONS: The transcriptomic profile of the stem cells reservoir in obese subcutaneous WAT is highly modified with significant changes in genes regulating stemcellness, lineage commitment and inflammation. In addition to body mass index, cardiovascular risk factor clustering further affect the ASC transcriptomic profile inducing loss of multipotency and, hence, capacity for tissue repair. In summary, the stem cells in the subcutaneous WAT niche of obese patients are already committed to adipocyte differentiation and show an upregulated inflammatory gene expression associated to their loss of stemcellness.

The subcutaneous adipose tissue reservoir of functionally active stem cells is reduced in obese patients.

It has been demonstrated that the adipose tissue, a highly functional metabolic tissue, is a reservoir of mesenchymal stem cells. The potential use of adipose-derived stem cells (ADSCs) from white adipose tissue (WAT) for organ repair and regeneration has been considered because of their obvious benefits in terms of accessibility and quantity of available sample. However, the functional capability of ADSCs from subjects with different adiposity has not been investigated. It has been our hypothesis that ADSCs from adipose tissue of patients with metabolic syndrome and high adiposity may be functionally impaired. We report that subcutaneous WAT stromal vascular fraction (SVF) from nonobese individuals had a significantly higher number of CD90+ cells than SVF from obese patients. The isolated ADSCs from WAT of obese patients had reduced differentiation potential and were less proangiogenic. Therefore, ADSCs in adipose tissue of obese patients have lower capacity for spontaneous or therapeutic repair than ADSCs from nonobese metabolically normal individuals.

Immediate and delayed postoperative morbidity in functional and non-functioning pituitary adenomas.

Neurosurgery is the most widely used definite treatment for pituitary tumors, while medical treatments are a good option to improve symptoms, which tend to recur when drugs are stopped. The aim of this study was to assess postsurgical morbidity of secreting pituitary adenomas (adrenocorticotropin hormone -ACTH- and growth hormone -GH- secreting) and non-functioning (NF) adenomas, operated between January 2002 and May 2009. We retrospectively reviewed the data of 94 patients who were operated by the same neurosurgeons and compared the immediate (1st month) and delayed (1st year) complications between the three groups of adenomas. Forty had immediate post-operative complications (42% of NF, 37% of GH-secreting and 48% of ACTH-secreting adenomas). The most frequent complications were transient diabetes insipidus (23%), cerebrospinal fluid leaks (7%), sinusitis and meningitis (2%). Patients with Cushing's disease showed a tendency to have more transient diabetes insipidus and sinusitis compared to NF adenomas (P = 0.071). Ten patients had delayed complications during the first post-operative year (7% of NF, 11% of GH-secreting and 15% of ACTH-secreting), with a greater incidence of arthromyalgias and acute carpal tunnel syndrome in ACTH-secreting adenomas, compared with the other groups (P < 0.05). We conclude, that although ACTH-secreting adenomas are mostly microadenomas (78%) and affect younger patients, they are associated with a greater number of immediate and delayed complications during the first postoperative year (mainly invalidating arthromyalgias and acute carpal tunnel syndrome) compared with larger GH-secreting and NF adenomas, probably related to acute glucocorticoid deprivation after successful surgery.

Relationship between adiponectin and left atrium size in uncomplicated obese patients: adiponectin, a link between fat and heart.

BACKGROUND: It is well known that obesity is a risk factor for severe cardiovascular complications, such as coronary heart disease, heart failure, stroke, venous thromboembolic disease, and atrial fibrillation. Left ventricle (LV) and left atrium (LA) enlargement is a characteristic feature of these patients with the consequent cardiovascular risk. Factors other than hemodynamic may influence LA remodeling. The aim of the study is to evaluate the relationship between adiponectin and LA size in uncomplicated obese patients. METHODS: Seventy-four asymptomatic obese patients and an age- and sex-matched control group (N = 70) were recruited. A detailed clinical, echocardiographic, and analytical study was performed. Insulin resistance was assessed using the homeostasis model assessment for insulin resistance (HOMA-IR) method. Insulin sensitivity was assessed measuring serum total adiponectin concentrations. RESULTS: Adiponectin levels were lower in the obese group (P < 0.001) and particularly so in those obese participants with enlarged LA (32%; P < 0.0005). LA sizes were higher in the obese group (P < 0.0005). Adiponectin displayed significant correlations with body mass index, glucose, insulin, high-density lipoprotein cholesterol, and triglyceride concentrations as well as HOMA-IR (P < 0.001 for all). Adiponectin displayed significant correlations with LV mass and LA size, diastolic and systolic cardiac volumes and diameters, and cardiac output (P < 0.001 for all). Adiponectin correlations with LA size (r = -0.429; P < 0.001) persisted after adjustment for HOMA-IR, age, sex, and LV mass. CONCLUSIONS: A novel inverse relationship between adiponectin and LA size independent of age, sex, insulin resistance, and LV mass appears in our series. Adiponectin could be a link between adipose tissue and the heart, having an influence on cardiac remodeling.

[Role of health-related quality of life in clinical practice: subjectivity in evidence]. / Calidad de vida relacionada con la salud, su lugar en la práctica clínica: lo subjetivo en la evidencia.

The incorporation of subjective elements provided by the patient to medical practice constitutes a new bridge between two historical movements of human culture: naturalism and rationalism. In recent years, medical sciences have identified these movements as patient-centered medicine and evidence-based medicine. By revisiting the paradigms of medicine, theories of causality, doctor-patient relationship models, bioethical principles and examples of clinical studies, their role and meaning has been revised. The applicability for neuroendocrinology has been demonstrated by validating therapeutic results with measurement of health-related quality of life. The need to incorporate the patient's subjective perception poses a challenge that, when accepted, can advance the understanding and care of human beings--ultimately rational, thinking subjects, and therefore subjective--as our species has been defined.

Aminoterminal pro-brain natriuretic peptide (NT-proBNP) and sleep-disordered breathing in morbidly obese females: a cross-sectional study.

Sleep-disordered breathing (SDB) is often encountered in morbid obesity (MO) in conjunction with insulin resistance (IR). Aminoterminal pro-brain natriuretic peptide (NT-proBNP) is a promising marker for left ventricular dysfunction (LVD) in MO. We sought to explore the factors that may influence the relationships of SDB and IR with NT-proBNP in MO women. We performed a cross-sectional pilot study involving 110 asymptomatic MO (44.5+/-0.7 kg/m2) young women. SDB risk was assessed using a modified version of the Berlin Questionnaire (BQ). IR was assessed using the homeostasis model assessment (HOMA) index and adiponectin levels. LVD was assessed using NT-proBNP and echocardiograms. In this study, NT-proBNP levels and LVD increased significantly along the BQ strata. Multiple regression analysis identified BQ and log-transformed HOMA as the independent variables predicting as much as 48.0% of the variability of logNT-proBNP. In conclusion, NT-pro-BNP levels are independently predicted by SDB and IR in asymptomatic MO women. Larger prospective studies are warranted.

Rapid and reversible alterations in thyroid function tests in dehydrated patients.

Dehydration commonly leads to hypovolemia and hemoconcentration. Changes in thyroid hormone-binding proteins secondary to hemoconcentration profoundly affect total serum thyroid hormone concentrations. The authors sought to determine the acute effects of mild to moderate dehydration on thyroid hormone levels/thyroid function tests and its reversibility upon rehydration. Total thyroxine, total triiodothyronine, free thyroxine, and the free-thyroxine index decreased significantly after hydration, in parallel with the decrease in extra cellular fluid volume status markers. Triiodothyronine-resin uptake increased after hydration. Thyrotropin levels decreased by 8% after hydration. Hypovolemia leads to simultaneous alterations in extracellular fluid volume markers and thyroid hormone serum concentrations that reverse rapidly upon rehydration. This constitutes, by itself, a distinct and new clinical entity.

Hypovitaminosis D and morbid obesity.

There is scarce and flawed data regarding vitamin D status in morbidly obese patients. More often than not, vitamin D deficits have been linked with bariatric surgery, not considering that the deficit may well precede surgery. Moreover, several pathophysiologic mechanism might explain, in part, vitamin D deficits. Conversely, the association between vitamin D deficits and secondary hyperparathyroidism in morbidly obese patients has been reported before and after bariatric surgery. Taking into account the elevated prevalence of vitamin D deficits in morbidly obese patients, its associated comorbidity, and the efficacy and low cost of its treatment to restore normal serum values of 25-OH-vitamin D, it seems advisable to recommend routine monitoring of serum calcium, phosphorus, and 25-OH-vitamin D levels in morbidly obese patients and to implement calcium and vitamin D supplementation whenever necessary.

Isolated use of vibration perception thresholds and semmes-weinstein monofilament in diagnosing diabetic polyneuropathy: "the North Catalonia diabetes study".

Several systems are used for the diagnosis of diabeticpolyneuropathy (DPN). We analyzed the isolated use of vibration perception thresholds (VPTs) or monofilament (MF) for the diagnosis of DPN. A group of 400 patients who had type 2 diabetes was selected from the North Catalonia Study Group. A clinical neurologic evaluation was performed based on three categories of the San Antonio Consensus. Neurothesiometer and quantitative tuning fork explored VPT, and MF was assessed by Olmos and Michigan Diabetic Neuropathy Score (MDNS) criteria. The use of VPT and MF showed a high specificity and low sensitivity. MF, by MDNS criteria, was more sensitive and specific, and showed more accurate positive and negative predictive values. The predicted probability of DPN diagnosis was higher with a tuning fork evaluation.

Hypogonadal hypogonadism and osteoporosis in men.

In recent years, osteoporosis in men has become increasingly recognized as an important clinical and public health problem. Many similarities exist in various aspects of osteoporosis in men and women, but this article focuses on the sex difference, bone biology, epidemiology, and consequences of fractures. Although maintenance of bone integrity depends on the action of sex hormones in both sexes, menopause is a much more obvious indicator of estrogen deficiency than is the subtle decrease of testosterone in aging men. This often leads to delay and neglect of diagnosis. The need to identify and screen men at a particular risk for osteoporosis, as when hypogonadism is induced for treatment of prostate cancer, has become important.

Primary hyperparathyroidism, insulin resistance, and cardiovascular disease: a review.

The presentation of primary hyperthyroidism (PHPT) has changed substantially in the last decade. Before the introduction of routine calcium measurement in most automated biochemistry serum analyzers, it usually was diagnosed after renal and bony lesions already were present. Nowadays, its presentation is practically asymptomatic. Nevertheless, the cardiovascular morbidity and mortality of mild to moderate forms of PHPT reportedly are increasing. Individuals who have mild to moderate forms of PHPT have an increased risk for enduring cardiovascular disease, arterial hypertension, left ventricular hypertrophy, myocardial and valvular calcifications, altered vascular reactivity, and cardiac conduction. Finally, they also reveal alterations in carbohydrate metabolism, insulin resistance, dyslipidemia, and body composition.

Comparison of the BD MAX MRSA XT to the Cepheid™ Xpert® MRSA assay for the molecular detection of methicillin-resistant Staphylococcus aureus from nasal swabs.

INTRODUCTION: Variation in MRSA genotypes may affect the sensitivity of molecular assays to detect this organism. METHODS: We compared 2 commonly used screening assays, the Cepheid™ Xpert® MRSA and the BD MAX™ MRSA XT on consecutively obtained nasal swabs from 479 subjects. Specimens giving discordant results were subjected to additional microbiologic and molecular testing. RESULTS: Six hundred forty-two (97.6%) of the 658 test results were concordant. Of the 16 discordant results from 12 subjects, additional results suggested that 9 (60%) of the 15 MRSA XT assays were likely correct, and 6 (40%) of the 15 Xpert® assays were likely correct. One discordant result could not be resolved. A mecA dropout and novel mec right-extremity junction (MREJ) sites led to false-positive and negative results by Xpert®. CONCLUSION: While both assays performed well, continued vigilance is needed to monitor for Staphylococcus aureus with novel MREJ sites, mecA dropouts, and mecC, leading to inaccurate results in screening assays.

PTEN promoter methylation in sporadic thyroid carcinomas.

The tumor-suppressor gene PTEN/MMAC1, on chromosome 10q23.3, has been implicated in an important number of human tumors, such as thyroid carcinomas. PTEN somatic mutations occur in sporadic tumors of the endometrium, brain, prostate, or melanomas, while germline mutations predispose to development of the multiple hamartoma syndromes (i.e., Cowden's disease and Bannayan-Zonana syndrome). Activation of the two alleles of PTEN is required for its tumor-suppression role. Because the frequency of PTEN suppression in thyroid tumors exceeds that of PTEN mutations or deletions, it is very likely that epigenetic mechanisms, such as promoter hypermethylation, may account for its inactivation in a subset of tumors. The main aim of this study was to assess the frequency of promoter hypermethylation of PTEN in thyroid tumors. We studied frozen tissue samples from 46 papillary carcinomas, 7 follicular carcinomas, 6 follicular adenomas as well as 39 normal thyroid tissue samples. Methylation-specific polymerase-chain reaction (PCR) with three different sets of primers was used. Two of the primer sets were designed to avoid any interference with PTEN pseudogene promoter. PTEN promoter hypermethylation was detected in 21 of 46 (45.7%) papillary carcinomas, 6 of 7 follicular carcinomas, and 5 of 6 follicular adenomas. It was negative in all normal tissues. Negative immunohistochemical staining for PTEN was significantly associated with the presence of promoter hypermethylation (p < 0.001). These results show a high frequency of PTEN promoter hypermethylation, especially in follicular tumors, suggesting its possible role in thyroid tumorigenesis.

A new educational program for patients suffering from sleep apnea syndrome.

OBJECTIVE: Patients' knowledge and beliefs about their chronic illnesses such as OSAS are known to influence a range of health related variables, including treatment compliance. It is for that reason that this interdisciplinary program centred on the therapeutic education of the patients was conceived by two medical teams with the aim of creating a new coverage of the patients affected of OSAS. METHODS: Thirty-five OSAS patients were consecutively collected among those regularly followed at the Service of pneumology outpatient facility. The psycho-educational methodology as well as the courses are described in detail. Patients were admitted for 36 h at the Service of Therapeutic Education for Chronic Diseases for both individual and group multidisciplinary approach to their disease. Groups of 3-4 patients discuss benefits, inconvenience as well as CPAP representations and manipulation of the device in small workshops. RESULTS: The therapeutic objectives, the educational methods, the program evaluation are presented. Preliminary results show a clinical improvement of the duration of CPAP use (0.7 +/- 0.2 h/night). 24% of patients increased the CPAP use more than one hour per night 3 months later. The Epworth sleepiness scale is significantly improved 3 months later (p < 0.05). CONCLUSION: We describe a new therapeutic educational interdisciplinary program for patients affected by OSAS. Its efficacy will be tested prospectively in a larger group and in the long term. PRACTICE IMPLICATIONS: The educational methods were applicable to the patients affected of OSAS bringing new specific strategies to improve the CPAP use. Patients had a positive attitude towards the CPAP treatment.

Differential associations between glomerular filtration rate and duration of obesity depending on the presence or absence of left ventricular diastolic dysfunction.

BACKGROUND: A robust and consistent association between increasing body mass index (BMI) and chronic kidney disease (CKD) has been reported in several observational studies. Obesity remains the main preventable risk factor for CKD because it largely mediates diabetes and hypertension, the 2 most common etiologies for end-stage kidney disease (ESKD). Obesity is associated weakly with early stages of kidney disease but strongly with kidney progression to ESKD, even after adjustment for hypertension and diabetes. AIM: To assess the relationship between estimated glomerular filtration rate (eGFR) and trans-thoracic echocardiography left ventricular function parameters in a cohort of patients with obesity. MATERIALS & METHODS: Cross-sectional study involving 324 obese (BMI=44.0±2.2Kg/m(2)) apparently healthy asymptomatic patients with an eGFR >60ml/min/1.73m(2). Each patient underwent transthoracic echocardiography and a blood testing. The eGFR was addressed by the CKD-EPI formula. RESULTS: All patients had a normal systolic function whereas 24.5% disclosed diastolic dysfunction (DD). Hypertension and type 2 diabetes mellitus prevalence were 34.5% and 4.5% (respectively). All patients disclosed an eGFR >60ml/min while none of them disclosed hyperfiltration (eGFR >120ml/min). eGFR correlated inversely with BMI and the duration of obesity and positively with diastolic function parameters (P<0.001 for all, respectively). Patients with diastolic dysfunction displayed lower eGFR (P<0.0005) and longer duration of obesity (P<0.0005). CONCLUSIONS: Obesity and its duration are likely to impose hemodynamic changes affecting simultaneously both heart (diastolic dysfunction) and kidney (decreased glomerular filtration rate). Larger prospective studies are warranted.

Microparticle Shedding by Erythrocytes, Monocytes and Vascular Smooth Muscular Cells Is Reduced by Aspirin in Diabetic Patients.

INTRODUCTION AND OBJECTIVES: Diabetes mellitus is associated with an enhanced risk for cardiovascular disease and its prevalence is increasing. Diabetes induces metabolic stress on blood and vascular cells, promoting platelet activation and vascular dysfunction. The level of vascular cell activation can be measured by the number and phenotype of microparticles found in the circulation. The aim of this study was to investigate the effect of a platelet-inhibitory dose of aspirin on the number and type of microparticles shed to the circulation. METHODS: Forty-three diabetic patients were enrolled in the study and received a daily dose of 100mg of aspirin for 10 days to cover the average platelet life-span in the circulation. Before and after the intervention period, circulating microparticles were characterized and quantified by flow cytometry. RESULTS: Type 1 diabetic patients had about twice the number of tissue factor-positive circulating microparticles (derived both from platelets and monocytes) and endothelial-derived E-selectin positive microparticles than type 2 diabetic patients. Aspirin therapy significantly inhibited platelets since cyclooxygenase 1 derived thromboxane generation levels were reduced by 99%. Microparticles derived from erythrocytes, activated monocytes, and smooth muscle cells were significantly reduced after 10 days of aspirin administration. CONCLUSIONS: These results indicate that: a) vascular and blood cells in type 1 diabetic patients are exposed to more sustained stress shown by their specific microparticle origin and levels; b) aspirin therapy inhibits vascular wall cell activation and microparticle shedding, and c) the effects of aspirin are similar in type 1 and 2 diabetes.

Unchanged hypovitaminosis D and secondary hyperparathyroidism in morbid obesity after bariatric surgery.

BACKGROUND: Morbidly obese patients have been reported to present with vitamin D insufficiency and secondary hyperparathyroidism. We assessed whether bariatric surgery alters the 25-hydroxyvitamin D (calcidiol) and intact parathyroid hormone (iPTH) levels in patients presenting with morbid obesity. METHODS: A cross-sectional survey was conducted on 144 patients of whom 80 had not undergone bariatric surgery, while 64 had bariatric surgery at a mean of 36 months previously. Calcidiol levels were defined as being normal (>50 nmol/L), insufficient (2550 nmol/L) and deficient (<25 nmol/L). Mild secondary hyperparathyroidism was defined as iPTH >7.3 pmol/L with simultaneous normal values for creatinine, calcium and phosphorus. RESULTS: 80% of the patients presented low vitamin D levels and mild secondary hyperparathyroidism. Previous surgery or the presence of diabetes did not influence calcidiol levels. Corrected serum calcium, phosphorus, alkaline phosphatase, iPTH and Calcidiol were similar between subjects with and without surgery. CONCLUSIONS: Vitamin D deficient states with secondary hyperparathyroidism in the morbidly obese precede and are not significantly affected by bariatric surgery. Hypovitaminosis D with secondary hyperparathyroidism due to low calcidiol bio-availability should be added to the crowded list of sequelae of morbid obesity. While further studies are warranted, it seems advisable to support vitamin D supplementation in the morbidly obese population.

Effects of bariatric surgery on vitamin D status and secondary hyperparathyroidism: a prospective study.

BACKGROUND: Morbidly obese patients have been reported to present with vitamin D insufficiency and secondary hyperparathyroidism. Scattered data are available regarding the effects of bariatric surgery on vitamin D status. We studied calcium metabolism and vitamin D status before and after bariatric surgery. METHODS: In this prospective study, 64 patients (M5/F59) fulfilled the inclusion criteria (i.e. 2 calcidiol serum determinations in the winter season) among 457 morbidly obese individuals who underwent Roux-en-Y gastric bypass (RYGBP) a mean of 36 months previously. Laboratory data (serum calcium, phosphorus, creatinine, alkaline phosphatase, albumin, calcidiol, albumin and iPTH) were determined before and after RYGBP. Pre- and postoperative calcidiol levels were categorized as being normal (>50 nmol/L), insufficient (25-50 nmol/L), and deficient (<25 nmol/L). Pre- and postoperative mild secondary hyperparathyroidism was defined as iPTH >7.3 pmol/L with simultaneous normal values for creatinine, calcium and phosphorus. RESULTS: RYGBP produced a significant weight loss coupled with a simultaneous increase in calcidiol (+28%, P<0.0005) and decrements in total alkaline phosphatase (-53%, P<0.0005) and iPTH (-74%, P=0.001). Corrected serum calcium, phosphorus, and creatinine levels were indistinguishable before and after RYGBP. Additionally, 37.5% of the patients maintained their calcidiol category, while 42.2 % improved it and 20.3% lost one category. CONCLUSIONS: RYGBP does not completely correct pre-existing vitamin D deficient states with secondary hyperparathyroidism. Low calcidiol bioavailability and or insufficient sunlight exposure do probably persist after bariatric surgery. While randomized controlled studies are warranted, it seems advisable to support vitamin D supplementation as well as increasing sunlight exposure in the morbidly obese population.

Predicting the effect of intravenous calcitriol on parathyroid gland activity using double-phase technetium Tc 99m-sestamibi scintigraphy.

BACKGROUND: Although intravenous calcitriol is useful for decreasing intact parathyroid hormone (iPTH) blood levels in patients with secondary hyperparathyroidism (SHP) undergoing hemodialysis, approximately half these patients remain refractory to this treatment. The current study measures the diagnostic utility of double-phase technetium Tc 99m-sestamibi (MIBI) scintigraphy in predicting the response to calcitriol treatment. METHODS: Sixty hemodialysis patients with SHP with iPTH blood levels between 240 and 600 pg/mL (ng/L) were selected. Initial intravenous calcitriol pulse therapy was 6 microg/wk (for iPTH levels of 400 to 600 pg/mL [ng/L]) or 3 microg/wk (for iPTH levels of 240 to 400 pg/mL [ng/L]). MIBI scintigraphy was performed before the onset of calcitriol therapy and repeated 1 year later. Patients were injected intravenously with 740 MBq of MIBI. Images were obtained at 15 minutes (thyroid phase) and 2 hours (parathyroid phase) after radiotracer administration. Focal areas of increased MIBI uptake were considered pathological parathyroid glands. RESULTS: Forty-eight patients completed the study. After 1 year, iPTH levels had decreased significantly in 95.2% (47 patients), whereas good control (iPTH < 240 pg/mL [ng/L]) was reached in 70.8% (34 patients) and only 4 patients had iPTH levels greater than 400 pg/mL (ng/L; all were patients with 3 MIBI-positive areas at baseline determination). At baseline, there were 30 patients (62.5%) with MIBI positive areas (1, 2, or 3 areas), which decreased to 14 patients (29%) at the end of the study period. No patient showed 4 positive areas at any time. The 18 patients (37.5%) with no MIBI-positive area at baseline remained unchanged. CONCLUSION: MIBI scintigraphy is a reliable exploratory tool in predicting the response to treatment with intravenous calcitriol in hemodialysis patients with SHP.