El laboratorio en el diagnóstico multidisciplinar del desarrollo sexual anómalo o diferente (DSD)

Objetivos

El desarrollo de las características sexuales femeninas o masculinas acontece durante la vida fetal, determinándose el sexo genético, el gonadal y el sexo genital interno y externo (femenino o masculino). Cualquier discordancia en las etapas de diferenciación ocasiona un desarrollo sexual anómalo o diferente (DSD) que se clasifica según la composición de los cromosomas sexuales del cariotipo.

Contenido

En este capítulo se abordan la fisiología de la determinación y el desarrollo de las características sexuales femeninas o masculinas durante la vida fetal, la clasificación general de los DSD y su estudio diagnóstico clínico, bioquímico y genético que debe ser multidisciplinar. Los estudios bioquímicos deben incluir, además de las determinaciones bioquímicas generales, análisis de hormonas esteroideas y peptídicas, en condiciones basales o en pruebas funcionales de estimulación. El estudio genético debe comenzar con la determinación del cariotipo al que seguirá un estudio molecular en los cariotipos 46,XX ó 46,XY, orientado a la caracterización de un gen candidato. Además, se expondrán de manera específica los marcadores bioquímicos y genéticos en los DSD 46,XX, que incluyen el desarrollo gonadal anómalo (disgenesias, ovotestes y testes), el exceso de andrógenos de origen fetal (el más frecuente), fetoplacentario o materno y las anomalías del desarrollo de los genitales internos.

Perspectivas

El diagnóstico de un DSD requiere la contribución de un equipo multidisciplinar coordinado por un clínico y que incluya los servicios de bioquímica y genética clínica y molecular, un servicio de radiología e imagen y un servicio de anatomía patológica.

The laboratory in the multidisciplinary diagnosis of differences or disorders of sex development (DSD): III) Biochemical and genetic markers in the 46,XYIV) Proposals for the differential diagnosis of DSD

Objectives

46,XY differences/disorders of sex development (DSD) involve an abnormal gonadal and/or genital (external and/or internal) development caused by lack or incomplete intrauterine virilization, with or without the presence of Müllerian ducts remnants.

Content

Useful biochemical markers for differential diagnosis of 46,XY DSD include hypothalamic-pituitary-gonadal hormones such as luteinizing and follicle-stimulating hormones (LH and FSH; in baseline or after LHRH stimulation conditions), the anti-Müllerian hormone (AMH), inhibin B, insulin-like 3 (INSL3), adrenal and gonadal steroid hormones (including cortisol, aldosterone, testosterone and their precursors, dihydrotestosterone and estradiol) and the pituitary ACTH hormone. Steroid hormones are measured at baseline or after stimulation with ACTH (adrenal hormones) and/or with HCG (gonadal hormones).

Summary

Different patterns of hormone profiles depend on the etiology and the severity of the underlying disorder and the age of the patient at diagnosis. Molecular diagnosis includes detection of gene dosage or copy number variations, analysis of candidate genes or high-throughput DNA sequencing of panels of candidate genes or the whole exome or genome.

Outlook

Differential diagnosis of 46,XX or 46,XY DSD requires a multidisciplinary approach, including patient history and clinical, morphological, imaging, biochemical and genetic data. We propose a diagnostic algorithm suitable for a newborn with DSD that focuses mainly on biochemical and genetic data.

The laboratory in the multidisciplinary diagnosis of differences or disorders of sex development (DSD): I) Physiology, classification, approach, and methodologyII) Biochemical and genetic markers in 46,XX DSD

Objectives

The development of female or male sex characteristics occurs during fetal life, when the genetic, gonadal, and internal and external genital sex is determined (female or male). Any discordance among sex determination and differentiation stages results in differences/disorders of sex development (DSD), which are classified based on the sex chromosomes found on the karyotype.

Content

This chapter addresses the physiological mechanisms that determine the development of female or male sex characteristics during fetal life, provides a general classification of DSD, and offers guidance for clinical, biochemical, and genetic diagnosis, which must be established by a multidisciplinary team. Biochemical studies should include general biochemistry, steroid and peptide hormone testing either at baseline or by stimulation testing. The genetic study should start with the determination of the karyotype, followed by a molecular study of the 46,XX or 46,XY karyotypes for the identification of candidate genes.

Summary

46,XX DSD include an abnormal gonadal development (dysgenesis, ovotestes, or testes), an androgen excess (the most frequent) of fetal, fetoplacental, or maternal origin and an abnormal development of the internal genitalia. Biochemical and genetic markers are specific for each group.

Outlook

Diagnosis of DSD requires the involvement of a multidisciplinary team coordinated by a clinician, including a service of biochemistry, clinical, and molecular genetic testing, radiology and imaging, and a service of pathological anatomy.

El laboratorio en el diagnóstico multidisciplinar del desarrollo sexual anómalo o diferente (DSD): III) Marcadores bioquímicos y genéticos en los 46,XY IV) Propuestas para el diagnóstico diferencial de los DSD

Objetivos

El desarrollo sexual anómalo o diferente (DSD) con cariotipo 46,XY incluye anomalías en el desarrollo gonadal y/o genital (externo y/o interno).

Contenido

Los marcadores bioquímicos útiles para el diagnóstico diferencial de los DSD con cariotipo 46,XY incluyen las hormonas del eje hipotálamo-hipófiso gonadal como son las gonadotropinas LH y FSH (en condiciones basales o tras la estimulación con LHRH), la hormona anti-Mülleriana, la inhibina B, el factor insulinoide tipo 3 y las hormonas esteroideas de origen suprarrenal (se incluirá la hormona hipofisaria ACTH) y testicular (cortisol, aldosterona y sus precursores, testosterona y sus precursores, dihidrotestosterona y estradiol). Las hormonas esteroideas se analizarán en condiciones basales o tras la estimulación con ACTH (hormonas adrenales) y/o con HCG (hormonas testiculares). Los patrones de variación de las distintas hormonas dependerán de la causa y la edad de cada paciente. El diagnóstico molecular debe incluir el análisis de un gen candidato, un panel de genes o el análisis de un exoma completo.

Perspectivas

El diagnóstico diferencial de los DSD con cariotipos 46,XX ó 46,XY debe ser multidisciplinar, incluyendo los antecedentes clínicos, morfológicos, de imagen, bioquímicos y genéticos. Se han elaborado numerosos algoritmos diagnósticos.

Chronic proton pump inhibition therapy in the diagnostic accuracy of serum pepsinogen I and gastrin concentrations to identify pernicious anaemia

BACKGROUND

Chronic use of proton pump inhibitors (PPIs) leads to increases in gastrin and pepsinogen-I serum concentrations.

AIM

To asses if chronic treatment with PPIs has an effect on serum gastrin and pepsinogen-I concentrations for the diagnosis of pernicious anaemia (PA).

MATERIALS AND METHODS

Serum gastrin and pepsinogen-I were measured in 38 patients with PA and 74 without PA (controls); 17/38 PA patients and 36/74 controls were treated with PPIs. Receiver Operating Curves (ROC) were used to compare diagnostic accuracy of gastrin and pepsinogen-I for PA in patients under chronic treatment with PPIs and in untreated patients.

RESULTS

PPI treatment increased pepsinogen-I in patients and in controls, while gastrin increased only in controls. In untreated patients, a pepsinogen-I <8.3ng/mL had 95.2% sensitivity and 100% specificity, whereas a gastrin >115pg/mL had 100% sensitivity and 92.11% specificity for PA diagnosis. In PPI-treated patients, a pepsinogen I<24.1ng/mL had a lower sensitivity (82.4%) but retained 100% specificity, however the best cut-off point for gastrin, 610pg/mL, had a very low sensitivity (58%).

CONCLUSIONS

PPI chronic treatment decreased the diagnostic accuracy for the studied biomarkers, particularly of gastrin. In PPI-treated patients, serum pepsinogen-I concentrations >24.1ng/mL allowed rejecting a PA diagnosis with 100% specificity.

Breaking Therapeutic Inertia in Type 2 Diabetes: Active Detection of In-Patient Cases Allows Improvement of Metabolic Control at Midterm

Type 2 diabetes (T2D) exists in 25-40% of hospitalized patients. Therapeutic inertia is the delay in the intensification of a treatment and it is frequent in T2D. The objectives of this study were to detect patients admitted to surgical wards with hyperglycaemia (HH; fasting glycaemia > 140 mg/dL) as well as those with T2D and suboptimal chronic glycaemic control (SCGC) and to assess the midterm impact of treatment modifications indicated at discharge. A total of 412 HH patients were detected in a period of 18 months; 86.6% (357) had a diagnosed T2D. Their preadmittance HbA1c was 7.7 ± 1.5%; 47% (189) had HbA1c ≥ 7.4% (SCGC) and were moved to the upper step in the therapeutic algorithm at discharge. Another 15 subjects (3.6% of the cohort) had T2D according to their current HbA1c. Ninety-four of the 189 SCGC patients were evaluated 3-6 months later. Their HbA1c before in-hospital-intervention was 8.6 ± 1.2% and 7.5 ± 1.2% at follow-up (P < 0.004). Active detection of hyperglycaemia in patients admitted in conventional surgical beds permits the identification of T2D patients with SCGC as well as previously unknown cases. A shift to the upper step in the therapeutic algorithm at discharge improves this control. Hospitalization is an opportunity to break therapeutic inertia.

Similarly high prevalence of hypovitaminosis D in HIV-infected subjects with and without low bone mineral density

Background: Hypovitaminosis D is highly prevalent among HIV-infected patients. Since hypovitaminosis D is a secondary cause of low bone mineral density (BMD), we assessed its prevalence and associated factors in HIV-infected patients with osteopenia/osteoporosis, compared with HIV-infected patients with normal BMD. Materials & methods: Serum 25-hydroxy vitamin D (25[OH]D) concentration were collected from 149 HIV-infected subjects with low BMD and 36 with normal BMD from April to October, 2010. Regression analyses were fitted to predict the probability of hypovitaminosis D in all patients. Results: Of the 149 patients with low BMD (51.8 ± 8 years old, 76.5% men), 83% had vitamin D insufficiency (<30 ng/ml) and 7.4% had severe deficiency (<10 ng/ml). In comparison, insufficiency was present in 75% of subjects from the group with normal BMD (p = 0.60) and no subject was severely deficient (p = 0.13). Among subjects with low BMD, 1.8% of men had low levels of testosterone, 5.4% of patients had high levels of thyroid-stimulating hormone, (all with normal free thyroxine levels) and 14.6% had high levels of parathyroid hormone. Univariate analysis showed significant associations between hypovitaminosis D and the current use of non-nucleosides (β-coefficient: -3.797; standard deviation: 1.538; p = 0.015), whereas protease inhibitors were associated with higher levels of vitamin D (β-coefficient: 4.640; standard deviation: 1.673; p = 0.006). Conclusion: Hypovitaminosis D was highly prevalent in our patients with low BMD but also in those with normal bone dual x-ray energy absorptionmetry scan. 25(OH)D should be periodically monitored, although the benefit of vitamin D and calcium supplements on bone mineralization has not yet been investigated in this population.

Regulatory role of vitamin D in T-cell reactivity against myelin peptides in relapsing-remitting multiple sclerosis patients

Background

Low levels of plasma 25-hydroxyvitaminD (25(OH)D) are associated with a higher incidence of multiple sclerosis (MS) due to the immune suppressive properties of vitamin D.

The aim of this study was to determine the correlation between plasma 25(OH)D concentrations and clinical and immunological variables in a cohort of multiple sclerosis patients.

Methods

Plasma 25(OH)D concentrations were evaluated in summer and winter in 15 primary progressive MS (PPMS) patients, 40 relapsing- remitting MS (RRMS) patients and 40 controls (HC). Protocol variables included demographic and clinical data, radiological findings and immunological variables (oligoclonal bands, HLADR15 and T-lymphocyte proliferation to a definite mix of 7 myelin peptides).

Results

During the winter, plasma concentrations were significantly lower in RRMS patients compared to HC, whereas no differences were found in summer. No relationships were found between plasma 25(OH)D concentrations and clinical or radiological variables. RRMS patients with a positive T-cell proliferation to a mix of myelin peptides (n = 31) had lower 25(OH)D concentrations.

Conclusions

25(OH)D is an immunomodulatory molecule that might have a regulatory role in T-cell proliferation to myelin peptides in RRMS patients.

SRD5A2 gene mutations and polymorphisms in Spanish 46,XY patients with a disorder of sex differentiation

One hundred and forty-six index patients with 46,XY DSD in whom gonads were confirmed as testes were consecutively studied for a molecular diagnosis during the period 2002-2010. AR gene was analysed in all patients as the first candidate gene, yielding a mutation in 42.5% of cases and SRD5A2 gene was analysed as the second candidate gene, resulting in the characterization of 10 different mutations (p.Y91D, p.G115D, p.Q126R, p.R171S, p.Y188CfsX9, p.N193S, p.A207D, p.F219SfsX60, p.R227Q and p.R246W) in nine index patients (6.2% of the total number of 46,XY DSD patients). One of the mutations (p.Y188CfsX9) has never been reported. In addition, we genotyped SRD5A2 gene p.V89L and c.281+15T>C polymorphisms in 46,XY DSD and in 156 normal adult males and found that patients with SRD5A2 mutations or without a known molecular diagnosis presented a higher frequency of homozygous p.L89, homozygous TT and combined CCTT genotypes compared with controls. This result suggests that 46,XY DSD patient phenotypes may be influenced by SRD5A2 polymorphism genotypes. SRD5A2 gene mutations may not be as infrequent as previously considered in 46,XY DSD patients with variable degrees of external genitalia virilization at birth and normal T production and appears to be the second aetiology in our series.

Serum autoimmune gastritis markers, pepsinogen I and parietal cell antibodies, in patients with type 1 diabetes mellitus: a 5-year prospective study

BACKGROUND AND AIM

To determine the temporal evolution of serum markers of autoimmune gastritis, mainly pepsinogen I (PI) and parietal cell antibodies (PCA), in patients with Type 1 diabetes mellitus (DM1).

MATERIALS AND METHODS

A 5-yr prospective follow-up study of 168 DM1 patients (87 men, aged 31 ± 9.3 yr) attending the endocrinology outpatient clinic of a university hospital evaluated in 2001 and 2006. Serum PI, gastrin, hemoglobin, cobalamin concentrations, PCA and antibodies to intrinsic factor were measured.

RESULTS

In 2001, 11 patients had low PI concentrations and positive PCA (group I), 11 had only low PI concentrations (group II), and 33 had only positive PCA (group III). After 5 yr, PI remained low and PCA positive in all patients from group I. In group II, PI remained low in 4 and normalized in 7. In group III, 4 patients presented low PI concentrations after 5 yr, which remained normal in the other 29 subjects. PCA became negative in 17 patients from group III. In 2001, 3 of the 11 patients of group I had low cobalamin concentrations. In 2006, 2 additional patients from this group presented low cobalamin concentrations.

CONCLUSIONS

These results show the importance of determining PI together with PCA, since the presence of abnormal results in both tests, that is low PI and positive PCA, is the association that best identifies patients with a higher risk to decrease cobalamin concentrations during follow-up.

Novel (60%) and recurrent (40%) androgen receptor gene mutations in a series of 59 patients with a 46,XY disorder of sex development

BACKGROUND

Androgen receptor (AR) gene mutations are the most frequent cause of 46,XY disorders of sex development (DSD) and are associated with a variety of phenotypes, ranging from phenotypic women [complete androgen insensitivity syndrome (CAIS)] to milder degrees of undervirilization (partial form or PAIS) or men with only infertility (mild form or MAIS).

OBJECTIVE

The aim of the study was to characterize the contribution of the AR gene to the molecular cause of 46,XY DSD in a series of Spanish patients.

SETTING

We studied a series of 133 index patients with 46,XY DSD in whom gonads were differentiated as testes, with phenotypes including varying degrees of undervirilization, and in whom the AR gene was the first candidate for a molecular analysis.

METHODS

The AR gene was sequenced (exons 1 to 8 with intronic flanking regions) in all patients and in family members of 61% of AR-mutated gene patients.

RESULTS

AR gene mutations were found in 59 individuals (44.4% of index patients), of whom 46 (78%) were CAIS and 13 (22%) PAIS. Fifty-seven different mutations were found: 21.0% located in exon 1, 15.8% in exons 2 and 3, 57.9% in exons 4-8, and 5.3% intronic. Twenty-three mutations (40.4%) had been previously described and 34 (59.6%) were novel.

CONCLUSIONS

AR gene mutation is the most frequent cause of 46,XY DSD, with a clearly higher frequency in the complete phenotype. Mutations spread along the whole coding sequence, including exon 1. This series shows that 60% of mutations detected during the period 2002-2009 were novel.

Vitamin D and growth hormone regulate growth hormone/insulin-like growth factor (GH-IGF) axis gene expression in human fetal epiphyseal chondrocytes

OBJECTIVE

Cell proliferation and gene expression regulation were studied in human fetal epiphyseal chondrocytes to ascertain the involvement of GH-IGF axis components in human fetal growth regulation by 1,25-dihydroxyvitamin D(3) (VitD) and growth hormone (GH).

DESIGN

Chondrocytes from primary cultures were plated in serum-free medium for 48 h and incubated for a further 48 h with VitD (10(-11) to 10(-6)M) and/or IGF-I (100 ng/ml) and/or GH (500 ng/ml). We analyzed (3)H-thymidine incorporation into DNA and IGF-I, IGFBP-3, GHR, SOX9, COL2A1, aggrecan and COMP gene expression by real-time quantitative PCR.

RESULTS

VitD dose-dependently and significantly inhibited (3)H-thymidine incorporation whereas GH had no effect on proliferation and, when combined with VitD, the same inhibition was observed as with VitD alone. IGF-I (100 ng/ml) significantly stimulated proliferation and opposed inhibition by VitD. VitD dose-dependently stimulated IGF-I (11.1+/-19.8 at VitD10(-6)M), IGFBP-3 (2.6+/-0.9), GHR (3.8+/-2.8) and COMP (1.5+/-0.6) expression whereas it inhibited SOX9 (0.7+/-0.2), COL2A1 (0.6+/-0.3) and aggrecan (0.6+/-0.2) expression and had no significant effect on IGF-II. IGF-I stimulated IGF-I, IGFBP-3, SOX9, COL2A1 and aggrecan expression and opposed COL2A1 and aggrecan gene expression inhibition by VitD. GH alone had no effect on gene expression whereas, in the presence of VitD, significantly-increased IGF-I expression stimulation was observed above values obtained with VitD alone (17.5+/-7.4).

CONCLUSIONS

Our results suggest that VitD regulation of fetal growth cartilage could have consisted of parallel enhancing of cell differentiation and conditioning to a phenotype more sensitive to regulation by other hormones such as GH as shown by increased GHR and IGF-I expression, but not by IGF-II expression which was not regulated.

The exon 3-deleted/full-length growth hormone receptor polymorphism does not influence the effect of puberty or growth hormone therapy on glucose homeostasis in short non-growth hormone-deficient small-for-gestational-age children: results from a two-year controlled prospective study

CONTEXT

The exon 3-deleted/full-length (d3/fl) GH receptor polymorphism (d3/fl-GHR) has been associated with responsiveness to GH therapy in short small-for-gestational-age (SGA) patients, although consensus is lacking. However, its influence on glucose homeostasis, at baseline or under GH therapy, has not been investigated.

OBJECTIVE

Our objective was to evaluate whether the d3/fl-GHR genotypes influence insulin sensitivity in short SGA children before or after puberty onset or during GH therapy.

DESIGN

We conducted a 2-yr prospective, controlled, randomized trial.

SETTING

Thirty Spanish hospitals participated. Auxological, GH secretion, and glucose homeostasis evaluation was hospital based, whereas molecular analyses and data computation were centralized.

PATIENTS

Patients included 219 short SGA children [body mass index sd score (SDS) < or = 2.0]; 159 were prepubertal (group 1), and 60 had entered puberty (group 2).

INTERVENTION

Seventy-eight patients from group 1 were treated with GH (66 microg/kg.d) for 2 yr (group 3).

MAIN OUTCOME MEASURES

Previous and 2-yr follow-up auxological and biochemical data were recorded, d3/fl-GHR genotypes determined, and data analyzed.

RESULTS

In groups 1 and 2, fasting glucose, insulin, homeostasis model assessment (HOMA), and quantitative insulin sensitivity check index (QUICKI) were similar in each d3/fl-GHR genotype. Group 2 glucose, insulin, and HOMA were significantly higher and QUICKI lower than in group 1. In group 3 GH-treated patients, height SDS, growth velocity SDS, fasting glucose, insulin, and HOMA significantly increased as did body mass index SDS at the end of the second year, and QUICKI decreased during the first and second years, with no differences among the d3/fl-GHR genotypes.

CONCLUSION

In short SGA patients, the d3/fl-GHR genotypes do not seem to influence prepubertal or pubertal insulin sensitivity indexes or their changes over 2 yr of GH therapy (66 mug/kg.d).

Serum IGF-I measured by four different immunoassays in patients with adult GH deficiency or acromegaly and in a control population

BACKGROUND

IGF-I is a useful tool in GH disorders diagnosis, however, the use of commercially available kits needs to be validated.

OBJECTIVE

To validate the use of serum IGF-I concentrations measured by four immunoassays in the diagnosis of adult GH deficiency and acromegaly.

DESIGN

Cross-sectional study.

PATIENTS

Fifty GH-deficient (GHD) patients, 41 acromegaly patients and 405 controls.

MEASUREMENTS

Serum IGF-I concentrations were measured by four commercial immunoassays: (1) RIA-NICHOLS; (2) ICMA-IMMULITE; (3) IRMA-IMMUNOTECH; and (4) non-extraction-IRMA-DSL. Reference values were established from the control population in six age groups. Individual results were transformed to standard deviation score (SD score) from the age-related reference population and reference data provided by each assay manufacturer. Diagnostic sensitivity for GH deficiency was calculated.

RESULTS

IGF-I measured by the four assays differed significantly. In controls, assay 2 yielded the lowest results, followed by assays 1, 3 and 4 (P < 0.0001 for all comparisons). IGF-I declined with age, but no sex-related differences were observed. When IGF-I was standardized with respect to reference data obtained from the manufacturers, it showed better sensitivity in assays 1 and 2, than with our controls (65%vs. 77.5% and 58%vs. 70%, respectively) for GHD diagnosis. With assays 3 and 4, higher sensitivity was obtained when standardized with our controls (62%vs. 52% and 56%vs. 36%, respectively). In acromegaly, IGF-I was > 2 SD score with all assays.

CONCLUSIONS

IGF-I SD score for GHD diagnosis differed according to the normative data used. All assays proved to be useful for active acromegaly diagnosis.

Effects of GH treatment in GH-deficient adults on adiponectin, leptin and pregnancy-associated plasma protein-A

OBJECTIVE

GH deficiency (GHD) in adults is associated with adverse effects on metabolism and increased cardiovascular risk. Pregnancy-associated plasma protein-A (PAPP-A) is a protease that promotes IGF-I availability in vascular tissues. PAPP-A levels appear to correlate with carotid intima-media thickness and have been proposed as an early predictor of cardiac events. The aim of our study was to evaluate PAPP-A levels in GHD adults at baseline and after GH replacement and correlate them with changes in body composition, lipid profile, glucose homeostasis, inflammatory markers and in leptin and adiponectin.

PATIENTS AND METHODS

Fourteen GHD adults were evaluated at baseline and after 1 year of GH therapy. All patients were compared at baseline with 28 age-, sex- and body mass index (BMI)-matched control subjects.

RESULTS

At baseline, GHD adults showed higher PAPP-A levels (P=0.03) and higher leptin (P=0.04), fibrinogen (P=0.002) and highly sensitive C-reactive protein (P=0.01) values than controls. Therapy with GH reduced PAPP-A (P=0.03) and fibrinogen levels (P=0.002) while increased BMI (P=0.01) and reduced waist-hip ratio (WHR; P=0.05) were observed. Insulin and homeostasis model assessment of insulin resistance index increased after treatment (P<0.004/P=0.007), without changes in leptin or adiponectin levels. PAPP-A values correlated positively with BMI and WHR and negatively with adiponectin before and after treatment, with no correlation with glucose homeostasis parameters, lipid profile or leptin.

CONCLUSIONS

Our study suggests that PAPP-A expression is increased in GHD adults, and that 1 year of GH replacement therapy is able to reduce PAPP-A levels in this population. However, further studies are required to determine whether this decrease correlates with an improvement in atherosclerosis.

[Post-transplant diabetes mellitus depending on the pre-transplant dialysis technique]

Post-transplant diabetes mellitus (PTDM) is one of the most important complications in kidney transplant patients because it has a significant impact on graft and patient survival. Diagnosis of PTDM should be based on the American Diabetic Association criteria. Recent studies show the value of performing an oral glucose tolerance test in all patients. Multiple risk factors promote PTDM. PTDM incidence may be reduced by controlling modifiable factors (immunosuppression, obesity, infections...). According to RMRC data, patients on peritoneal dialysis are younger, but have a greater incidence rate of dyslipidemia and obesity. Recent data suggest that subclinical information, adiponectin, and ghrelin may be a significant pathogenetic factor in development of insulin resistance and diabetes mellitus. There is no clear evidence that the dialysis procedure influences the subclinical inflammatory state and adipocytokines. According to data from the Spanish group for the study of PTDM, a relationship exists between ghrelin levels and sex in patients on peritoneal dialysis. The most common metabolic complication in patients on peritoneal dialysis is hyperglycemia. Pre-transplant hyperglycemia promotes the occurrence of PTDM. There is no clear evidence in the literature showing that the dialysis procedure is a risk factor for the occurrence of PTDM. Additional multicenter studies are required to analyze the clinical and biological characteristics of renal patients and their relationship to PTDM.

Do Anti-CD25 Monoclonal Antibodies Potentiate Posttransplant Diabetes Mellitus?

Anti-CD25 monoclonal antibodies (MAbs) are directed against the IL-2 (CD-25) receptor, which is associated with the pathogenesis of diabetes mellitus (DM). Measuring CD25 on peripheral blood lymphocytes could be a new immunologic marker to identify patients with prediabetes.

OBJECTIVE

The study aimed to analyze whether administration of anti-CD25 MAbs was an independent risk factor for posttransplant diabetes mellitus (PTDM) in kidney transplant (KT) patients at 3 months after transplantation.

PATIENTS AND METHODS

Seventy-four stable, nondiabetic KT patients were included in the study. The overall sex distribution was 70% men and mean overall age, 52 +/- 10 years. Thirty-eight subjects where treated with anti-CD25 antibodies (basiliximab). The diagnosis of PTDM was made if patients required insulin or oral antidiabetic drugs and/or had glycemia >200 mg/dL at 120 minutes after an oral glucose tolerance test (75 g glucose). We determined the age, weight, body mass index, acute rejection, chronic hepatitis C virus (HCV) infection, and type of calcineurin inhibitor.

RESULTS

Thirty-four percent of patients developed PTDM. Patients treated with anti-CD25 antibodies were older (P = .022) and showed a greater incidence of PTDM (P = .041). The logistic regression analysis (dependent variable: PTDM; independent variables: age, anti-CD25, tacrolimus vs cyclosporine) showed that treatment with anti-CD25 is an independent risk factor for PTDM (P = .041; OR 3.28; CI 95% 1.04-10.31).

CONCLUSION

Patients treated with anti-CD25 MAbs showed greater incidence of PTDM.

Obesity, adiponectin and inflammation as predictors of new-onset diabetes mellitus after kidney transplantation

The high incidence of new-onset diabetes mellitus after transplantation (NODAT) suggests the need to find new factors to explain the pathogenesis. Our objectives were (1) to confirm that low levels of pre-transplant adiponectin are an independent risk factor for the development of NODAT in a larger transplanted population; (2) to analyze whether adiponectin is a better predictor of NODAT than other inflammatory markers (C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) and pregnancy-associated plasma protein A (PAPP-A)) and (3) to assess the relationship between obesity, inflammatory markers and NODAT. One hundred ninety-nine non-diabetic patients (128 men; age: 53 +/- 11 years; body mass index (BMI) 24.98 +/- 3.76 kg/m2) were included. Pre-transplant plasma glucose, insulin, adiponectin, CRP, TNF-alpha, IL-6 and PAPP-A were measured. Forty-five patients developed NODAT. Patients with NODAT had a greater BMI (p = 0.005). Adiponectin was lower (p < 0.001) and CRP higher (p = 0.032) in patients with NODAT. Multivariate logistic regression and Cox analysis showed that the calcineurin inhibitor used, pre-transplant BMI and adiponectin were predictors of NODAT. ROC analysis showed that an adiponectin concentration of 11.4 microg/mL had a significant negative prediction for NODAT risk (sensitivity: 81% and specificity: 70%). Of the inflammatory markers studied, adiponectin proved to be an independent predictor of NODAT.

Detection of early abnormalities in gastric function in first-degree relatives of patients with pernicious anemia

BACKGROUND

Pernicious anemia (PA), as many other autoimmune disorders, has a trend to appear in other members of the family of the affected patients. Although this fact has been recognized since some decades ago, less is known about the frequency with which the abnormalities detected in the patients appear also in their relatives, the correlations that exist among these abnormalities and to what extent these markers of the disease relate to serum cobalamin concentration.

SUBJECTS AND RESULTS

For these reasons we studied the values of some markers of PA in a group of 79 first-degree relatives and we detected that the most frequent abnormalities are a decrease in serum pepsinogen I (22.7% of cases), an increase in serum gastrin (16.5% of cases) and in parietal cell antibody at a titer >or=40 (23.4% of cases). From a functional point of view, a decrease in hydrogen excretion in a magnesium breath test, indicative of achlorhydria, is also frequent (29.1%). The fall in cobalamin concentration runs in parallel with these abnormalities. The concentration of this vitamin was below normal levels in as much as 15.2% of cases.

CONCLUSION

These findings emphasize the need for searching for the presence of occult or latent PA in relatives of patients with this diagnosis, not only to prevent the development of anemia but also to avoid other undesirable consequences of cobalamin deficiency.

The effect of bariatric surgery on adipocytokines, renal parameters and other cardiovascular risk factors in severe and very severe obesity: 1-year follow-up

AIMS

To evaluate the effect of weight loss after bariatric surgery (BS) on peripheral adipocytokines, renal parameters and other cardiovascular risk factors (CVRFs).

METHODS

A total of 70 (41 women) extremely obese adults were prospectively studied before and 12 months after surgery.

CONTROLS

24 (15 women) normal-weight adults. Anthropometric, biochemical and renal parameters were recorded.

RESULTS

Presurgery, adiponectin (ADPN) was lower, whereas leptin, insulin resistance, C-reactive protein, creatinine clearance and albuminuria were higher in patients than controls (P<0.001). All parameters improved postsurgery. Changes in ADPN correlated negatively with leptin, insulin resistance, albumin, C-reactive protein, and creatinine clearance. Multiple regression analysis: using changes in ADPN as the dependent variable, only changes in insulin resistance (P=0.005) and albumin (P=0.019) were significant independent determinants for changes in ADPN. No statistical differences were found in relation to the degree of obesity.

CONCLUSION

Patients changed to obesity type I after surgery. This implies a substantial improvement of CVRFs including ADPN, creatinine clearance and albuminuria. Changes in plasma ADPN correlated negatively with insulin resistance and with albuminemia but not with renal parameters. The lack of differences between different degrees of obesity suggests that the relationship between weight and CVRFs no longer exists when obesity becomes very extreme.

Effect of low doses of atorvastatin on adiponectin, glucose homeostasis, and clinical inflammatory markers in kidney transplant recipients

INTRODUCTION

Various studies describe the pleiotropic antiinflammatory and antioxidant effects of atorvastatin, in addition to its hypolipemic effects. It has been suggested that statins modify glucose homeostasis via their antiinflammatory effects. A further hypothesis suggests that the incidence of posttransplantation diabetes is lower in statin-treated patients. This study sought to ascertain whether atorvastatin modifies glucose homeostasis, adiponectin, and inflammatory markers in kidney transplant recipients.

PATIENTS AND METHODS

Sixty-eight kidney transplant recipients (41 men, 27 women; mean age, 53 +/- 12 years) with stable renal function and dyslipidemia were treated with atorvastatin (10 mg/d) for 12 weeks. Glucose, insulin, homeostasis model assessment (HOMA-IR) index, adiponectin, tumor necrosis factor (TNF)-alpha, and serum C-reactive protein (CRP) concentrations were determined at baseline and at 3 months. The lipid profile, renal function parameters (creatinine, creatinine clearance, and proteinuria), as well as GOT, GPT, and CK were determined at baseline and at 3 months.

RESULTS

Treatment with atorvastatin achieved a statistically significant decrease in lipid profile. After 3 months of treatment, 74.6% of patients had total cholesterol and 78.7% low-density lipoprotein (LDL) cholesterol concentrations within reference range (<5.2 and 3.3 mmol/L, respectively). Furthermore, 47.5% of patients attained an LDL concentration <2.59 mmol/L. A greater reduction in total cholesterol (P = .05) and LDL cholesterol (P = .04) was achieved in patients with creatinine clearance <60 mL/min. Atorvastatin did not modify glucose homeostasis parameters, adiponectin, TNF-alpha, or CRP. At baseline and after 3 months of treatment, an inverse correlation was found between adiponectin and glucose, insulin, HOMA- IR index, and creatinine clearance, and a positive correlation was found between adiponectin and high-density lipoprotein (HDL) cholesterol.

CONCLUSION

Atorvastatin at a dose of 10 mg/d in kidney transplant recipients does not modify glucose homeostasis or alter inflammatory markers, despite its hypolipemic effects. Its efficacy to reduce total cholesterol and LDL cholesterol was greater in patients with worse renal function.

Lack of deleterious effect on bone mineral density of long-term thyroxine suppressive therapy for differentiated thyroid carcinoma

The effect of subclinical hyperthyroidism on bone mineral density is controversial and could be significant in patients with differentiated thyroid carcinoma who receive suppressive doses of levothyroxine (LT4). To ascertain whether prolonged treatment with LT4 to suppress thyrotropin had a deleterious effect on bone mineral density and/or calcium metabolism in patients thyroidectomized for differentiated thyroid cancer we have performed a cross-sectional study in a group of 88 women (mean +/- SD age: 51 +/- 12 years) treated with LT4 after near-total thyroidectomy and in a control group of 88 healthy women (51 +/- 11 years) matched for body mass index and menopausal status. We determined calcium metabolism parameters, bone turnover marker N-telopeptide and bone mass density by dual-energy X-ray absorptiometry. No differences were found between patients and controls in calcium metabolism parameters or N-telopeptide except for PTH, which was significantly increased in controls. No differences were found between groups in bone mineral density in femoral neck (0.971 +/- 0.148 gr/cm(2) vs 0.956 +/- 0.130 gr/cm(2) in patients and controls respectively, P = 0.5). In lumbar spine, bone mineral density values were lower in controls than in patients (1.058 +/- 0.329 gr/cm(2) vs 1.155 +/- 0.224 gr/cm(2) respectively, P < 0.05). When premenopausal (n = 44) and postmenopausal (n = 44) patients were compared with their respective controls, bone mineral density was similar both in femoral neck and lumbar spine. The proportion of women with normal bone mass density, osteopenia and osteoporosis in patient and control groups was similar in pre- and postmenopausal women. In conclusion, long-term suppressive LT4 treatment does not appear to affect skeletal integrity in women with differentiated thyroid carcinoma.

Adiponectin and risk of new-onset diabetes mellitus after kidney transplantation

BACKGROUND

New-onset diabetes mellitus after transplantation (NODAT) is a severe complication of kidney transplantation (KTx) with negative effects upon patient and graft survival. Several risk factors for NODAT have been described; however, the search for an early predictive marker is ongoing. It has recently been demonstrated that high concentrations of adiponectin (APN), which is an adipocyte-derived peptide with antiinflammatory and insulin-sensitizing properties, protect against future development of type 2 diabetes in healthy individuals. The purpose of this report was to study pretransplant insulin resistance and analyze pretransplant serum leptin and APN levels as independent risk factors for the development of NODAT.

METHODS

A total of 68 KTx patients were studied [mean age, 48 +/- 11 years; 70% males; body mass index (BMI), 25 +/- 3 kg/m]; 31 KTx patients with NODAT and 37 KTx patients without NODAT (non-NODAT) with similar age, sex, BMI, immunosuppression, and posttransplant time were studied. All patients received prednisone and calcineurin inhibitors (75% tacrolimus and 25% cyclosporine A), and 76% of patients received mycophenolate mofetil. Family history of diabetes mellitus was recorded. Pretransplant homeostasis model assessment for insulin resistance (HOMA-IR) index was calculated from fasting plasma glucose and insulin. Pretransplant serum leptin and APN levels were determined by radioimmunoassay.

RESULTS

NODAT patients showed higher pretransplant plasma insulin concentrations [NODAT, 13.4 (11-22.7) microIU/mL; non-NODAT, 10.05 (7.45-18.4) microIU/mL; P=0.049], HOMA-IR index [NODAT, 4.18 (2.49-5.75); non-NODAT, 2.63 (1.52-4.68); P=0.043], and lower pretransplant serum APN concentration [NODAT, 8.78 (7.2-11.38) microg/mL; non-NODAT, 11.4 (8.56-15.27) microg/mL, P=0.012]. Inverse correlations between APN and BMI (r=-0.33; P=0.014) and APN and HOMA-IR index (r=-0.39; P=0.002) and between APN and NODAT (r=-0.31; P=0.011) were observed. Multiple logistic regression analysis showed the patients with lower pretransplant APN concentrations to be those at greater risk of developing NODAT [Odds Ratio=0.832 (0.71-0.96); P=0.01].

CONCLUSION

Pretransplant serum APN concentration is an independent predictive factor for NODAT development in kidney-transplanted patients.

Evaluation of two replacement regimens in primary adrenal insufficiency patients. effect on clinical symptoms, health-related quality of life and biochemical parameters

OBJECTIVE

To evaluate clinical symptoms, health-related quality of life (HRQL) and biochemical parameters in patients with primary adrenal insufficiency under treatment with two different hydrocortisone regimens (20 mg-0 mg-10 mg/day and 10 mg-5 mg-5 mg/day), each maintained for 3 months and compare results obtained with those in healthy controls.

DESIGN, PATIENTS AND METHODS

Twelve patients with primary adrenal insufficiency were studied. Clinical symptoms and HRQL with the Nottingham Health Profile (NHP) were evaluated and Na, K and serum cortisol determined at 09:00 h, 12:30 h and 17:30 h and urinary free cortisol (UFC) throughout the day. Control group comprised 19 healthy subjects.

RESULTS

No differences in specific adrenal insufficiency symptoms were detected between the two regimens. HRQL was worse in energy dimension assessed by the NHP compared to the general population, regardless of 20 mg-0 mg-10 mg/day or 10 mg-5 mg-5 mg/day treatment (p=0.03 and p=0.013). The total NHP score was only adversely affected when patients were on the 10 mg-5 mg-5 mg/day hydrocortisone replacement regimen (p=0.008). Serum cortisol concentrations were higher than controls at 09:00 h, and lower at 17:30 h with both regimens, whereas serum cortisol at 12:30 h and UFC were within the 5th-95th percentile normal range only with the 10 mg-5 mg-5 mg/day regimen.

CONCLUSIONS

Patients with primary adrenal insufficiency had worse HRQL in the NHP energy dimension compared with the general population, regardless of the hydrocortisone regimen although total score for HRQL was worse only with the 10 mg-5 mg-5 mg/day regimen. Patients on the thrice-daily hydrocortisone regimen showed a more physiological cortisol profile, leading us to recommend initially treating patients with this dose and increasing it in the case of impaired HRQL.

Spironolactone alone or in combination with furosemide in the treatment of moderate ascites in nonazotemic cirrhosis. A randomized comparative study of efficacy and safety

BACKGROUND/AIMS

The most rational treatment of moderate ascites is spironolactone alone or in combination with furosemide. However, it is unknown which of these two treatment schedules is preferable.

METHODS

One hundred nonazotemic cirrhotic patients with moderate ascites were randomly assigned to be treated with spironolactone and furosemide (Group 1: 50 patients) or with spironolactone alone (Group 2: 50 patients). If no response was obtained, the doses of diuretics were increased up to 400 mg/day of spironolactone and 160 mg/day of furosemide. In patients of group 2 not responding to 400 mg/day of spironolactone, furosemide was added. In cases with an excessive response, the dosage of diuretics was reduced.

RESULTS

The response rate (98% in Group 1 vs. 94% in Group 2), the rapidity of ascites mobilization and the incidence of complications induced by diuretic therapy was similar in both groups. The need to reduce the diuretic dosage was significantly higher in Group 1 than Group 2 (68% vs. 34%; P=0.002).

CONCLUSIONS

In the treatment of moderate ascites, spironolactone alone seems to be as safe and effective as spironolactone associated with furosemide. Since spironolactone alone requires less dose adjustment, it would be more suitable for treating ascites on an outpatient basis.

Postpartum thyroid dysfunction and postpartum depression: are they two linked disorders?

OBJECTIVE

Postpartum has been considered as a period of risk for developing postpartum depression (PD) by some but not all authors, and this PD has been linked with postpartum thyroid dysfunction (PPTD). The major aim of this study was to evaluate the relation between the presence of PPTD and PD.

DESIGN AND PATIENTS

Six hundred and forty-one healthy Caucasian women recruited between their 36th week of pregnancy and fourth day postpartum underwent clinical and laboratory evaluation and were checked again at 1 (n = 605), 3 (n = 552), 6 (n = 574), 9 (n = 431), and 12 (n = 444) months postpartum.

MEASUREMENTS

At baseline and at each clinical evaluation, Beck Depression Inventory (BDI) was administered to screen PD. The definitive diagnoses of PD was performed by a psychiatrist according to the DSM-III-R criteria. At each visit, we determined serum free T4 and TSH concentrations. Thyroperoxidase and thyroglobulin antibodies were determined only in patients with abnormal hormone concentrations. Postpartum thyroiditis (PPT) was considered to be present in women with overt or subclinical transient hyperthyroidism between 1 and 3 months postpartum and/or overt or subclinical hypothyroidism between 3 and 6 months postpartum.

RESULTS

Fifty-six women developed postpartum thyroid dysfunction (PPTD), corresponding to an incidence rate of 11%: 45 with PPT [incidence rate 7.8%; confidence interval (CI) 5.6-10%], eight with Graves' disease (incidence rate 1.5%; CI 0.5-2.5%) and three with nonpalpable toxic thyroid adenoma (incidence rate 0.5%; CI 0-1.5%). Five hundred and eighty of the evaluated women (incidence rate 90.5%; CI 95% 88.2-92.8) presented BDI scores below 21 and therefore the PD diagnoses was excluded. In 50 cases (incidence rate 7.8%; Cl 95% 5.7-9.8), we detected a BDI score over 21 in some evaluations, but the PD diagnosis was not confirmed. Another 11 (incidence rate 1.7%; CI 95% 0.7-2.7) were diagnosed as having PD and required psychiatric treatment. None of the PPTD was diagnosed as having PD. The BDI scores frequency over 21 was similar between healthy women and those with PPTD. Patients with a previous history of depression developed PD more often (P < 0.0001). One hundred and ninety women breast fed their babies for more than 2 months, without observing a higher PD rate or BDI scores over 21 (P = 0.5).

CONCLUSIONS

We found a general PD incidence rate of 1.7% in our group of patients. This figure is not higher in women with hormone abnormalities caused by PPTD. Women with a past history of depression present a higher risk of PD while those who breast fed did not have an increased risk.

Short-term effects of a hypocaloric diet on nitrogen excretion in morbid obese women

OBJECTIVE

To determine whether the daily pattern of urine excretion of N wastes is affected by obesity and very low-calorie diets (VLCD).

DESIGN

The plasma amino acid, urea and other energy parameters, as well as the urinary excretion of total nitrogen, urea and creatinine were studied in obese and normal-weight women. The obese women's data were obtained under hospital basal controlled conditions (8.1 MJ/day) and after 3 days of VLCD diet (1.9 MJ/day) controls were studied only once (5.8 MJ/day). The hourly excretion patterns of total N, urea and creatinine were determined from the composition of each bladder voiding.

SUBJECTS

Twenty morbidly obese and 10 age-matched normal-weight control women.

RESULTS

Plasma amino acid levels were higher in obese women, which showed a limited ability to metabolize amino acid hydrocarbon skeletons. Neither differences in the patterns between groups nor total 24 h values for urine volume were found. Total N and urea excretion diminished under VLCD diet. Hourly creatinine excretion showed a flat pattern and was higher in obese women than in the controls, VLCD diet diminished the amount of creatinine excreted in 24 h.

CONCLUSIONS

The early change in energy availability that the creatinine excretion figures reflect may result from the energy conservation mechanisms induced in response to energy restriction. The early onset of this effect (3 days, and the extent of decrease (approximately 19%) also suggest that the impact of VLCD on the muscle energy budget of the obese is more marked than usually assumed.

Urinary free cortisol excretion pattern in morbid obese women

The urinary excretion of free cortisol in a group of 10 control and 20 morbidly obese women was measured in all bladder voidings during 24 h. The data from obese women were measured under Hospital basal controlled conditions and after 3 days of very low calorie diet (VLCD, 1.9 MJ/d). The hourly cortisol excretion pattern was determined for each woman, and means of each group were computed in order to obtain a 24 h excretion pattern. In controls, the highest excretion rate was in the morning (8-9 h) and the lowest at 21-22 h. Inbasal conditions, the obese showed a similar but flatter pattern; the highest peak was also in the morning (9-10 h), but the lowest rate was between 21 and 24 h. The VLCD diet flattened the pattern even more, in away that no clear peak was observed from the early morning until the afternoon; however, the nadir coincided with that found in basal conditions. These patterns resulted in significant differences between VLCD, basal diet and control. The amount of free cortisol excreted was 93.0 +/- 6.9 nmol/ day in controls, 70.1 +/- 4.7 nmol/day in obese under basal conditions and 62.6 +/- 3.0 nmol/day when subjected to VLCD. The results presented are consistent with a lower overall cortisol secretion in the morbid obese women, which also show a narrower margin of variation in cortisol secretion than non-obese controls. The data also show the significant influence of dietary energy on the pattern of cortisol excretion in obese women.

The relationship between idiopathic thrombocytopenic purpura and pernicious anaemia

Some reports on the simultaneous presence of chronic idiopathic thrombocytopenic purpura (ITP) and pernicious anaemia (PA) may be found in the literature. However, little is known about the coexistence of these autoimmune disorders. For this reason, we studied the prevalence of PA in a series of patients with a diagnosis of chronic ITP by means of the analysis of the concentration of the most sensitive marker of type A atrophic (autoimmune) gastritis, serum pepsinogen I. Serum pepsinogen I was low in 20.3% of the 133 patients studied. Gastrin was elevated in 15. 2% of patients, but the coexistence of both abnormalities was rather low (7.6% of patients). However, the progressive decrease in serum cobalamin as biochemical abnormalities related with atrophic gastritis appeared was noticeable. The time to progression to frank PA from type A atrophic gastritis may span some years.

Diagnostic efficiency of serum IGF-I, IGF-binding protein-3 (IGFBP-3), IGF-I/IGFBP-3 molar ratio and urinary GH measurements in the diagnosis of adult GH deficiency: importance of an appropriate reference population

OBJECTIVE

To analyse the diagnostic role of serum IGF-I, IGF-binding protein-3 (IGFBP-3), IGF-I/IGFBP-3 molar ratio and urinary GH (uGH) excretion in adult GH deficiency (GHD).

DESIGN

Twenty-seven adults (age range: 18-71 years) with severe GHD, defined by a peak GH response to an insulin tolerance test below 3microg/l in patients with at least one additional pituitary hypofunction. Reference values were established from a selected age- and body mass index-matched population (154 healthy adults grouped in four age groups).

METHODS

IGF-I and IGFBP-3 were measured by RIA (Nichols) and results expressed as standard deviation (s.d.) scores from our reference population and assay normative data (s.d. score Nichols). uGH was measured by IRMA.

RESULTS

Within the control group, IGF-I, IGFBP-3, IGF-I/IGFBP-3 ratio standardisation regarding our control population and IGF-I with respect to the assay normative data resulted in disappearance of age-related differences. However, IGFBP-3 s.d. score Nichols resulted in mean values between +1.4 and +2.5 s.d. score. Greatest diagnostic efficiency was for IGF-I standardised with respect to our controls (97.2%), followed by s.d. score IGFBP-3 (92.9%). s.d. score IGF/IGFBP-3 ratio and uGH showed poor diagnostic efficiency. Any combination of at least two abnormal parameters raised specificity to 100%. IGF-I standardised with respect to assay reference (s.d. score Nichols) showed similar diagnostic value (95.0%) whereas IGFBP-3 showed low sensitivity (33. 3%). Within the GHD patients, those with three or more additional deficiencies had lower s.d. score IGF-I than those with only two or one.

CONCLUSION

We underline the importance of an appropriate reference population for correct interpretation of GH secretion markers. Considering our results, specificity obtained with two simultaneous abnormal parameters when referred to an adequate reference population may add valuable information to alternative GH stimulation tests to confirm adult GHD.

Insulin sensitivity and secretion influence the relationship between growth hormone-binding-protein and leptin

BACKGROUND

A direct relationship between body mass index (BMI), visceral adipose tissue, insulin levels and growth hormone-binding protein (GHBP) activity has consistently been reported. It was recently described that GHBP directly depends on serum leptin levels. Since leptin co-varies with insulin secretion and/or sensitivity, we aimed to study the influence of these variables on plasma GHBP activity.

SUBJECTS

In order to isolate the effects of obesity per se from those of insulin secretion, three groups of subjects were prospectively studied: 14 lean, 10 obese and nine obese subjects with glucose intolerance.

MEASUREMENTS

The percentage of body fat was measured through bioelectric impedance. Insulin sensitivity and secretion were determined through a frequently sampled intravenous glucose tolerance test with minimal model analysis. Serum leptin was measured by radioimmunoassay. GHBP activity was determined by the high performance liquid chromatography-gel filtration method.

RESULTS

Plasma GHBP activity was found to correlate with BMI (r = 0. 65, P < 0.0001), fat mass (r = 0.51, P = 0.003), waist circumference (r = 0.64, P < 0.0001), waist-to-hip ratio (r = 0.42, P = 0.01), insulin sensitivity (SI, r = - 0.61, P = 0.0001), insulin secretion (expressed as the acute insulin response to intravenous glucose, AIRg) (r = 0.48, P = 0.006) and leptin concentration (r = 0.49, P = 0.004). The associations with SI (r = - 0.42, P = 0.02) and AIRg (r = 0.38, P = 0.03) persisted even after controlling for fat mass. Since insulin secretion and insulin sensitivity usually covary in glucose tolerant subjects (an increased insulin secretion is necessary to compensate a decreased insulin sensitivity), we constructed a multiple linear regression to predict GHBP activity. In this model, SI (P = 0.005), AIRg (P = 0.02) and SD score-leptin (P = 0.03) independently contributed to 34, 10 and 8% of the variability in serum GHBP activity.

CONCLUSIONS

Our results suggest that plasma GHBP activity is simultaneouslly influenced by insulin secretion and sensitivity and leptin. Perhaps leptin, through increased insulin secretion, might induce GHBP/GH secretion, explaining the normal to high insulin-like growth factor (IGF)-I levels found in overnutrition.

Postpartum thyroiditis: epidemiology and clinical evolution in a nonselected population

Postpartum thyroiditis (PPT) presents in approximately 5% of women. Its incidence, clinical characteristics, and evolution were studied in a nonselected population of Mediterranean women. Six hundred five healthy women, recruited between the 36th week of pregnancy and the 4th postpartum day, underwent initial clinical and biological evaluation and postpartum at 1 (n = 605), 3 (n = 552), 6 (n = 574), 9 (n = 431), and 12 (n = 444) months. PPT was diagnosed in women with transient hyperthyroidism between 1 and 3 months postpartum and/or hypothyroidism between 3 and 6 months postpartum. Permanent hypothyroidism was considered if it was overt and persisted one year after diagnosis. The incidence rate of PPT was 7.8%. Eighty-two percent of PPT patients had hormone abnormalities at the 6th month postpartum, 8.8% showed depression and 51% goiter. PPT was manifest as hyperthyroidism plus hypothyroidism in 35.5% of patients, because only transient hyperthyroidism in 22.2% and as hypothyroidism alone in 42.3%. Five patients with hypothyroidism during PPT (0.82% of the initial population, 11.1% of PPT patients, and 15.6% of hypothyroidism PPT patients) presented permanent hypothyroidism after a follow-up of 39.8 (4.2) months. PPT was found in 7.8% of general Mediterranean population. We recommend evaluation at the 6th postpartum month to diagnose the majority of PPT women and indefinite follow-up of hypothyroid PPT patients to detect permanent hypothyroidism.

[Genetic study of a new family with Hippel-Lindau type IIB disease]

BACKGROUND

Von Hippel-Lindau disease is characterized by the variable presence of cerebellar and retinal haemangioblastomas, phaeocromocytomas and hypernephromas, beginning at early stages of life. Von Hippel-Lindau gene has been located in the short arm of chromosome 3 (3p25.5) and has been involved in the regulation of DNA transcription acting as a suppressor gene. More than 500 different mutations have been described.

SUBJECTS AND METHODS

We describe a new family with the type IIB Von Hippel-Lindau disease in which, apart from clinical studies, we performed a genetic screening trying to identify germinal mutations.

RESULTS

So far, we have point out 6 patients with the G-->A transversion at codon 167 (R167Q). Two of them with overt clinical disease (phaeocromocytoma in case II.1 and haemangioblastoma in the II.2) at the beginning of the study and one with a non-suspected clinical presentation (phaeocromocytoma and renal carcinoma in case I.1) out of 8 family members studied in three generations.

CONCLUSIONS

The genetic screening in this family permitted us to identify three subjects before their clinical onset. The absence of the mutation in two of the younger patients will simplify the clinical follow-up of this family. Genetic screening must be generalized in the follow-up of Von Hippel-Lindau disease families, because of economic advantages and clinical efficacy.

Growth hormone-binding protein directly depends on serum leptin levels in adults with different nutritional status

The aim of this work was to assess the relationship between GH-binding protein (GHBP) and leptin. Both peptides are nutritionally regulated, but the recent implication of a role for leptin in the GH axis requires further study. To avoid the sexual dimorphism in leptin values, we performed leptin standardization according to gender (SD score-leptin). The relationship between SD score-leptin and GHBP was studied in 128 adults with different nutritional status [8 groups according to body mass index (BMI)], ranging from severely underweight anorexia nervosa to highly morbid obesity. Both GHBP and SD score-leptin significantly increased according to BMI within the range from 18-27 kg/m2, whereas no significant differences were found among underweight groups (BMI, < 18 kg/m2) or among obesity grades (BMI, > 27 kg/m2). We found a strong correlation between GHBP and SD score-leptin (r = 0.8; P < 0.0001). Multiple regression analysis revealed SD score-leptin to be a significant determinant of GHBP, accounting for 64% of the variation, whereas BMI did not contribute further to explaining changes in GHBP. This suggests a physiological pathway involving both GHBP (the soluble fraction of GH receptor) and leptin. Thus, we might speculate that leptin could be the signal that induces the related nutritional changes observed in GHBP/GH receptor expression.

Increased leptin production in vivo and insulin cleavage by the omental adipose tissue of morbidly obese patients

OBJECTIVE

The aim of this investigation was to assess the insulin cleavage capacity in obese humans. Increased insulin degradation by visceral adipose tissue has previously been demonstrated in obese rats and could be interpreted as a physiological response to hyperinsulinaemia. The recent characterization of leptin receptors in pancreatic beta cells, liver and muscle suggests that leptin may influence insulin function and metabolism. Our study focuses on the possible relationship between leptin secretion and adipose tissue insulin-degrading capacity.

DESIGN AND PATIENTS

Insulin and leptin were measured in arterial blood and in the epiploic vein of morbidly obese (n = 7) and non-obese patients (n = 7) who were undergoing abdominal surgery. Arteriovenous insulin difference (AV insulin) was considered an in vivo marker of insulin degradation by the omental fat tissue. Statistical comparison between venous and arterial leptin was used to assess endogenous leptin production.

MEASUREMENTS

Insulin was measured using an oligoclonal IRMA and leptin levels were determined by using a specific radioimmunoassay.

RESULTS

Morbidly obese patients were hyperinsulinaemic compared to non-obese patients according to arterial insulin levels (P = 0.049) but not to venous levels. Insulin cleavage capacity, nil in the control group, was clearly significant in the morbidly obese patients (P = 0.001). In the morbidly obese group, leptin levels in venous epiploic samples were significantly higher (P = 0.028) than in the arterial samples, confirming in situ the synthesis of leptin by human white adipose tissue. We also observed a correlation between insulin arterial levels and venous leptin concentrations (P = 0.009) which supports the chronic leptinogenic effect of insulin suggested in previous works. Finally, our results show that venous leptin levels are correlated with the extent of insulin cleavage by omental tissue (P = 0.033).

CONCLUSIONS

Morbidly obese patients have a higher white adipose tissue insulin cleavage capacity, which could partially diminish hyperinsulinaemia-derived adverse effects. High leptin production, a consequence of high insulin levels, may act as a signal to the insulin-degrading tissues in order to lower insulinaemia.

Analytical performance and clinical usefulness of two binding assays for growth hormone binding protein (GHBP) measurement: high performance liquid chromatography (HPLC)-gel filtration and dextran-coated charcoal adsorption

We compared two binding assays for growth hormone binding protein (GHBP) measurements, which differ in the method of bound and free GH separation: HPLC-gel filtration or dextran coated-charcoal adsorption (DCC). Two pools of sera (high and medium GHBP activity) were used for quality-control assessment. Moreover, 62 samples from 34 children and 28 adults with different nutritional status were studied. Total, between- and intra-iodination coefficients of variation (CVs) from the two methods were not different. Although percentage binding measured in the pool sera significantly differed, the concentrations assessed by Scatchard plot were comparable. Results obtained by the two methods in the 62 sera were significantly correlated (r = 0.77, P < 0.001). With both methods GHBP activity correlated with chronological age and body mass index (BMI) and differed among groups with different nutritional status. Although HPLC and DCC separation methods for GHBP measurement differ in their practicability, our study demonstrates that performance and the clinical usefulness of the two methods are comparable.

Medical therapy of Graves' disease: does thyroxine prevent recurrence of hyperthyroidism?

Sixty patients with Graves' disease (GD) hyperthyroidism were distributed in two randomized groups. Patients in group A (n = 30) received carbimazole by a titration regimen, and patients in group B (n = 30) were treated with higher doses of carbimazole plus T4. Clinical and analytical evaluations were done at baseline, during treatment (18.4 +/- 2.6 months), and after, until the relapse of hyperthyroidism, or for 4.98 +/- 1.6 yr in patients who did not relapse. There were no differences in clinical parameters, thyroid hormones, or TSH binding inhibitory immunoglobulins (TBII) levels between the two groups, either at baseline or at the end of treatment. Serum TSH persisted undetectable in 16 out of 60 patients (group A: 9; group B: 7), after treatment. Relapse occurred in 38 patients (63.3%), (group A: 18 (60%) vs. group B: 20 (66.7%)). Patients who relapsed had bigger goiters at baseline (P = 0.02) and at the end of treatment (P = 0.03). Eighty-seven percent (14/16) of patients with undetectable TSH after therapy relapsed, vs. 54.5% (24/44) of those with normal TSH (P = 0.01). Undetectable TSH at the end of treatment was the only independent variable in the logistic analysis to predict relapse. Treatment modality did not influence the relapse rate. This study has found that, in Spanish patients, the use of high doses of carbimazole with T4 offers no advantages in the treatment of GD hyperthyroidism.

Growth hormone secretion assessment in the diagnosis of short stature

Growth hormone (GH) secretion assessment in the diagnosis of short stature presents certain problems in relation to the protocols designed for it and the interpretation of results. GH measurement in serum may be accompanied by IGF-I and IGFBP-3 measurements, and in some patients by GHBP measurement. Protocols for evaluating GH response to acute stimuli or spontaneous secretion are tedious, sometimes hazardous and difficult to interpret. This is due to the wide variation in responses observed in normally-growing children, to the age-dependent changes in these parameters and, in the case of GH, to the wide variation in immunoassay results. New techniques able to measure biologically-active GH molecules circulating in blood may help to simplify diagnosis. Severe idiopathic or organic GH deficiency poses no diagnostic problems. GH secretory insufficiency may be diagnosed as partial, idiopathic, isolated GH deficiency or as neurosecretory dysfunction. Clear cut-off values for these diagnoses and the possibility of a transient reversible pathology are not well established. Analysis of large series of children with different diagnoses in whom the growth pattern, either spontaneous or under rhGH treatment, final height and GH secretion re-evaluation at the end of growth were studied will help to clarify GH secretion or action abnormalities in these patients.

Clinical usefulness of urinary growth hormone measurements in normal and short children according to different expressions of urinary growth hormone data

To assess the clinical usefulness of urinary growth hormone (UGH) measurements, a UGH determination technique, including dialysis, ultrafiltration, and measurement by polyclonal-coated tube RIA, was established. Sixty-three short children were studied: 56 idiopathic growth retarded (37 prepubertal and 19 pubertal) and seven prepubertal with classic GH (growth hormone) deficiency. Forty-two healthy children (32 prepubertal and 10 pubertal) served as controls. Two groups of adults were studied: eight with active acromegaly and 11 healthy controls. UGH was measured in 24-h urine samples from all patients and controls. Mean +/- SD UGH excretion expressed as ng/24 h was significantly lower in the GH-deficient group compared with prepubertal growth-retarded and control children (p less than 0.01). No differences were found between UGH excreted by controls and by the growth-retarded groups. Pubertal children excreted significantly higher amounts of GH when UGH was expressed as ng/24 h (p less than 0.02 and p less than 0.03, respectively), but this difference disappeared when UGH was expressed as ng/g creatinine. UGH was significantly higher in acromegalic patients compared with adult controls (p less than 0.001). Differences between day, night, and 24-h UGH were studied in 23 children. UGH in night urine was significantly lower whether expressed as the total amount or as ng/g creatinine. The effect of recombinant hGH administration on UGH was studied in 13 children after 6 and 12 mo of treatment. UGH increased significantly under recombinant hGH treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Assay-dependent results of immunoassayable spontaneous 24-hour growth hormone secretion in short children

Forty-eight children, referred for evaluation of short stature, underwent 24-hour spontaneous growth hormone (GH) secretion studies. The GH level in pooled sera was assessed for each child, using up to 11 commercial immunoassays. In a group of 15 children, the mean GH values obtained by nine of the assays were compared with the mean value given by a polyclonal radioimmunoassay (RIA) from Sorin: four gave higher results (p less than 0.0001), three gave comparable results and two gave lower results (p less than 0.001). The assay yielding the highest results (Nichols: 5.9 +/- 2.3 ng/ml, mean +/- SD) gave values that were approximately triple those obtained by the assay yielding the lowest results (Hybritech: 1.8 +/- 0.8 ng/ml; p less than 0.0001); both of these are monoclonal immunoradiometric assays (IRMAs). The GH concentrations measured in 24-hour pools from 32 children using a monoclonal IRMA from Biomérieux were similar to those obtained using a polyclonal RIA from Farmos (2.8 +/- 1.1 ng/ml and 2.9 +/- 1.4 ng/ml, respectively) but significantly lower than those measured by another polyclonal RIA from Sorin (3.5 +/- 1.5 ng/ml). Two polyclonal assays (Biomérieux and Sorin) were then used to measure the GH levels in all of the 30-minute samples and in the day, night and 24-hour pools from the secretion studies of 22 children. The ratio of the results of the two assays remained fairly constant for a given child (although the GH levels in different 30-minute samples differed considerably). However, the ratios between different children showed quite wide variation (from 2.03 to 1.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of chronic clonidine treatment on urinary growth hormone excretion and linear growth in children with short stature

Eleven prepubertal children with short stature were treated with clonidine (0.15 mg/m2 daily) for a period of 1 year. The effect of this drug was evaluated on both clinical (growth velocity, height standard deviation scores for chronological age and bone age) and hormonal (urinary growth hormone excretion and insulin-like growth factor I) parameters. Our study shows that long-term clonidine administration in children with short stature did not result in significant differences in growth velocity, height standard deviation scores for chronological age and bone age, insulin-like growth factor I or in urinary growth hormone excretion.