Endoscopic third ventriculostomy in the treatment of hydrocephalus in posterior fossa tumors in children

OBJECT

The purpose of the present study is to assess the effectiveness of endoscopic third ventriculostomy (ETV) in children with hydrocephalus related to posterior fossa tumors.

METHODS

Between September 1999 and December 2002, 63 children with posterior fossa tumors were treated at Santobono Hospital in Naples, Italy. Twenty-six patients had severe hydrocephalus. In order to relieve intracranial hypertension before tumor removal, 20 were treated with ETV, and 6 with ventriculo-peritoneal (VP) shunts. Twenty patients with mild hydrocephalus were treated with diuretics, corticosteroid agents, and early posterior fossa surgery, and 17 patients who did not have hydrocephalus were treated by elective posterior fossa surgery. Another 4 ETV were performed in the management of postoperative hydrocephalus.

RESULTS

Preoperative ETV procedures were technically successful. One was complicated by intraventricular bleeding. The successful 19 preoperative ETV resolved intracranial hypertension before posterior fossa surgery in all cases. Three of these 19 patients developed postoperative hydrocephalus and were treated by VP shunt insertion after posterior fossa surgery. Out of the 4 ETV performed after posterior fossa surgery, only 2 were successful, both when the shunt malfunctioned.

CONCLUSIONS

Endoscopic third ventriculostomy should be considered as an alternative procedure to ventriculo-peritoneal shunting and external ventricular draining for the emergency control of severe hydrocephalus caused by posterior fossa tumors, since it can quickly eliminate symptoms, and hence, can delay surgery scheduling if required. Even though ETV does not prevent postoperative hydrocephalus in all cases, it does protect against acute postoperative hydrocephalus due to cerebellar swelling. In addition, it eliminates the risks of cerebrospinal fluid (CSF) infection related to external drainage and minimizes the risk of overdrainage because it provides more physiological CSF drainage than the other procedures. Since postoperative hydrocephalus is very often physically obstructive, ETV should always be considered a possible treatment procedure.

The +276 G/T single nucleotide polymorphism of the adiponectin gene is associated with coronary artery disease in type 2 diabetic patients

OBJECTIVE

Two single nucleotide polymorphisms (SNPs) at the adiponectin locus (+45T>G and +276G>T) have been associated with low circulating adiponectin levels, insulin resistance, and type 2 diabetes. We investigated whether these genetic markers are determinants of coronary artery disease (CAD) in type 2 diabetic patients.

RESEARCH DESIGN AND METHODS

A total of 376 consecutive type 2 diabetic patients were studied: 142 case subjects with coronary stenosis >50% or previous myocardial infarction and 234 control subjects with no symptoms, no electrocardiogram (ECG) signs of myocardial ischemia, and a normal ECG stress test (n = 189) and/or (n = 45) with coronary stenosis <or=50%.

RESULTS

No association with CAD was observed for the +45 SNP (P = 0.48). By contrast, a significant association was observed for the +276 SNP, with T/T homozygotes having a lower risk of CAD than carriers of other genotypes (adjusted odds ratio [OR] 0.13 [95% CI 0.037-0.46], P = 0.002). A similarly protective effect of the +276 T/T genotype was observed in 110 case and 45 control subjects for whom the CAD status had been determined by angiography (0.04 [0.006-0.30], P = 0.002). Serum adiponectin, although clearly related to several features of the proatherogenic/insulin-resistant phenotype, was not different between control subjects and CAD patients (26 +/- 17 vs. 25 +/- 13 microg/ml).

CONCLUSIONS

In conclusion, the +276 G>T polymorphism is a determinant of CAD risk in type 2 diabetic patients. This marker may assist in the identification of diabetic individuals at especially high risk of CAD, so that preventive programs can be targeted at these subjects.

A common haplotype at the CD36 locus is associated with high free fatty acid levels and increased cardiovascular risk in Caucasians

CD36 is a class B scavenger receptor recognizing a variety of ligands including long-chain fatty acids and modified LDL. We investigated whether genetic variability at this locus is a determinant of free fatty acid (FFA) plasma levels and risk of coronary artery disease (CAD) in Caucasians. Typing of 21 polymorphic markers, evenly spanning the CD36 gene, revealed two linkage disequilibrium (LD) blocks that could be tagged by five polymorphisms (-33137A>G, -31118G>A, 25444G>A, 27645del>ins and 30294G>C). In 585 non-diabetic individuals of Caucasian origin, the 30294G>C polymorphism was significantly associated with FFA levels (P = 0.02)--an effect that was especially visible among men (P = 0.009). A similar association was observed in this gender at -33137 (P = 0.008) and -31118 (P = 0.028). When the five tag polymorphisms were considered together, men carrying the AGGIG haplotype had 31% higher FFA (P = 0.0002) and 20% higher triglycerides (P = 0.025) than non-carriers. The same haplotype was associated with increased risk of CAD in 197 type 2 diabetic individuals from the US (OR = 2.3, 95% CI 1.2-4.2). A similar tendency was observed in a group of 321 type 2 diabetic individuals from Italy (OR = 1.4, 0.9-2.3), resulting in an overall relative risk of 1.6 (1.1-2.3, P = 0.015) in the two populations considered together. By targeted resequencing, we identified a common variant in the CD36 promoter that is in strong LD with the AGGIG haplotype and could be partly responsible for these findings. In conclusion, this comprehensive study of CD36 variability indicates that the common polymorphisms at this locus modulate lipid metabolism and cardiovascular risk in Caucasians.

Multigenic control of serum adiponectin levels: evidence for a role of the APM1 gene and a locus on 14q13

Adiponectin is a circulating enhancer of insulin action that is secreted by the adipose tissue. In epidemiological studies, serum levels of this protein predict the risk of type 2 diabetes and cardiovascular events. Serum adiponectin levels have been associated with variants at the adiponectin (APM1) and PPARgamma2 loci and have also been linked to markers on 5p15 and 14q13. We investigated the role of these four loci in regulating serum adiponectin in a Caucasian population from Italy. Four haplotype-tagging single-nucleotide polymorphisms (ht-SNPs) (-11377 C>G, -4041 A>C, +45 T>G, and +276 G>T) at the APM1 locus and the PPARgamma2 Pro12Ala polymorphism were examined for association with serum adiponectin in 413 unrelated, nondiabetic individuals. Of the five SNPs tested, +276G>T was the only one to be associated with serum adiponectin (P = 0.032), with "TT" individuals having higher adiponectin levels than other subjects. In a variance-components analysis of 737 nondiabetic members of 264 nuclear families, adiponectin heritability was 30%, with a small but significant proportion explained by the +276 genotype ( P = 0.0034). Suggestive evidence of linkage with adiponectin levels was observed on chromosome 14q13, with a LOD of 2.92 (P = 0.000057) after including the APM1 +276 genotype in the model. No linkage was observed at 5p15. Our data indicate a strong genetic control of serum adiponectin. A small proportion of this can be attributed in our population to variability at the APM1 locus, but an as yet unidentified gene on 14q13 appears to play a much bigger role.

The allelic variant of LAR gene promoter –127 bp T→A is associated with reduced risk of obesity and other features related to insulin resistance

Insulin resistance, which is pathogenic for type 2 diabetes (T2D), is under the control of largely unknown genetic determinants. LAR, a protein-tyrosine phosphatase which inhibits insulin signalling, is overexpressed in animal and human models of insulin resistance. We studied the entire sequence of the LAR gene by SSCP analysis and automatic DNA sequencing, with the aim of verifying whether its sequence variants might be associated with insulin resistance. In the 276 bp sequence upstream of the transcriptional start site (i.e. a region we have identified as having basal promoter activity) a -127 bp T-->A SNP (5% frequency) was associated with lower body mass index (BMI) ( P=0.03), waist circumference ( P=0.01), blood pressure ( P=0.01) and urinary albumin/creatinine ratio ( P=0.04) in 589 non-diabetic unrelated individuals from the Gargano region (central east coast of Italy). To quantify the risk for a high body weight conferred by the -127 T-->A SNP, the whole cohort was divided into tertiles according to the individual BMI. The risk of belonging to the heavier tertile, as compared to the leaner one, was reduced by approximately 60%. In a population from East Sicily ( n=307), T/A genotype carriers ( n=13) showed lower triglyceride levels ( P=0.04) and higher insulin sensitivity as indicated by lower plasma glucose ( P=0.03) and serum insulin ( P=0.006) during oral glucose tolerance testing (OGTT). Promoter activity, studied by cDNA transfection experiments, was similar for the A and T alleles. In conclusion, a genetic variant of the LAR gene promoter is consistently associated with features of insulin resistance in two different Caucasian populations. Although the biological relevance of this variant has yet to be determined, this finding underlines the potential importance of the LAR gene in dysregulation of insulin sensitivity and related disorders.

Spinal volumetric bone mineral density and vertebral fractures in female patients with adrenal incidentalomas: the effects of subclinical hypercortisolism and gonadal status

Although adrenal incidentalomas (AI) are not associated with clinically evident syndromes, some patients display biochemical features of subclinical hypercortisolism (SH). Previous studies indicated a negative effect of SH on bone in AI patients, but the prevalence of vertebral fractures and the roles of SH and gonadal status in volumetric bone mineral density are unknown. In 70 female AI patients and 84 controls, the prevalence of vertebral fractures and spinal bone mineral density (by quantitative computed tomography) were evaluated. Subjects were subdivided according to menopausal status into groups Pre (21 patients and 23 controls) and Post (49 patients and 61 controls); there were 14 and 35 patients without SH (SH(-)) and 7 and 14 patients with SH (SH(+)) in groups Pre and Post, respectively. The prevalence of fractures was higher in SH(+) than in controls and in SH(-) subjects in both groups Pre [SH(+), 42.9%; controls, 0% (P = 0.001); SH(-), 7.1% (P = 0.049)] and post [SH(+), 78.6%; controls, 37.7% (P = 0.006); SH(-) 42.9% (P = 0.024)]. In group Post, the mean z-score quantitative computed tomography values were lower in SH(+) patients (-0.78 +/- 0.29) than in controls (0.06 +/- 0.14; P = 0.011) and SH(-) patients (0.02 +/- 0.19; P = 0.034). Evaluation of spinal bone is indicated in female AI patients with SH.

Association of the human adiponectin gene and insulin resistance

Adiponectin is an adipocyte-secreted protein that modulates insulin sensitivity and whose low circulating concentration is associated with insulin resistance. In the present study, we analysed the association between two single-nucleotide polymorphisms (SNPs) in the adiponectin gene and insulin resistance in 253 nondiabetic subjects. In addition, we investigated whether this association is modulated by body mass index (BMI) levels. The SNPs +45T>G and +276G>T in the human adiponectin gene were detected in real-time PCR with LightCycler. No association was found with the +45T>G SNP. The +276G>T SNP was associated with higher BMI (P<0.01), plasma insulin (P<0.02) and HOMA(IR) (P<0.02). To analyse the possible interaction between BMI and the adiponectin gene on insulin resistance, the study group was divided into two subgroups, according to the BMI below or above the median of 26.2 kg/m(2). In both subgroups, subjects carrying the +276G>T SNP had higher HOMA(IR); however, the difference was highly significant among leaner (P<0.001), but not among heavier individuals, indicating that BMI status and the adiponectin gene interact in modulating insulin resistance. Among individuals with BMI <26.2 kg/m(2), the relative risk of insulin resistance was 9.7 (CI: 1.32-87.7, P<0.035). In a subgroup of 67 subjects, carriers of the +276G>T SNP had significantly (P<0.05) lower mean serum adiponectin levels (25.7 ng/ml) compared to noncarriers (37.0 ng/ml), suggesting a possible influence of the +276G>T SNP on adiponectin levels. In summary, we observed an association between the +276G>T SNP in the adiponectin gene and insulin resistance. In particular, among leaner individuals, the adiponectin gene appears to determine an increased risk to develop insulin resistance.

Evidence for genetic epistasis in human insulin resistance: the combined effect of PC-1 (K121Q) and PPAR?2 (P12A) polymorphisms

Insulin resistance is believed to be under the control of several genes often interacting each other. However, whether genetic epistasis does in fact modulate human insulin sensitivity is unknown. In 338 healthy unrelated subjects from Sicily, all nondiabetic and not morbidly obese, we investigated whether two gene polymorphisms previously associated with insulin resistance (namely PC-1 K121Q and PPARgamma2 P12A) affect insulin sensitivity by interacting. PC-1 X121Q subjects showed higher level of fasting glucose, lower insulin sensitivity (by both the Matsuda insulin sensitivity index and M values at clamp, the latter performed in a subgroup of 113 subjects representative of the overall cohort) and higher insulin levels during the oral glucose tolerance test (OGTT) than PC-1 K121K subjects. In contrast, no difference in any of the measured variables was observed between PPARgamma2 P12P and X12A individuals. The deleterious effect of the PC-1 X121Q genotype on each of these three variables was significant and entirely dependent upon the coexistence of the PPARgamma2 P12P genotype. Among PPARgamma2 P12P carriers also fasting insulin and glucose levels during OGTT were higher in PC-1 X121Q than in K121K individuals. In contrast, no deleterious effect of the PC-1 X121Q genotype was observed among PPARgamma2 X12A carriers; rather, in these subjects a lower body mass index and consequently lower fasting insulin level was observed in PC-1 X121Q than in K121K carriers. Overall, a significant interaction between the two genes was observed on body mass index, insulin levels (both fasting and after OGTT) and both insulin sensitivity (i.e., insulin sensitivity index and M value) and insulin secretion (i.e., HOMA-B%) indexes.

PC-1 amino acid variant Q121 is associated with a lower glomerular filtration rate in type 2 diabetic patients with abnormal albumin excretion rates

OBJECTIVE

To study the relationships between the PC-1 K121Q variant and diabetic nephropathy (DN) in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 125 patients with type 2 diabetes and abnormal albumin excretion rate (AER) (range 20-5416 microg/min) were followed up for 4 years with repeated measurements of glomerular filtration rate (GFR). Genomic DNA was extracted from all patients, and the PC-1 K121Q polymorphism was determined by the PCR AvaII restriction enzyme. A subset of 64 patients underwent a percutaneous kidney biopsy at baseline, and glomerular structure was analyzed by electron microscopic morphometric analysis. At baseline, age (56 +/- 8 vs. 59 +/- 7 years), BMI (28.3 +/- 4.3 vs. 28.6 +/- 3.7 kg/m(2)), known duration of type 2 diabetes (11.1 +/- 7 vs. 11.9 +/- 8 years), and HbA(1c) (8.6 +/- 1.8 vs. 8.4 +/- 1.7%) were similar in K121K (KK, n = 87, 73 men/14 women) and XQ (35 K121Q + 3 Q121Q, n = 38, 27 men/11 women) patients. Baseline GFR was 96 +/- 28 ml. min(-1). 1.73 m(-2) and was related (P = 0.01-0.001) to age, known diabetes duration, and systolic blood pressure.

RESULTS

XQ patients had lower GFR (P < 0.05) than KK patients (88 +/- 30 vs. 100 +/- 26 ml. min(-1). 1.73 m(-2)); this difference persisted also after factoring in age and known diabetes duration. The rate of progression of DN was similar in KK and XQ patients: %deltaGFR was 4.1/year (median, range: 22.9-30.6) vs. 4.2/year (9.8-26.7). Morphometric parameters of diabetic glomerulopathy were similar in the two genotype groups.

CONCLUSIONS

Among patients with type 2 diabetes with abnormal AER, those carrying the Q PC-1 genotype have more severe DN but not a faster GFR decline than KK patients, thus suggesting faster DN development since diabetes diagnosis in XQ patients.

Glucose homeostasis in acromegaly: effects of long-acting somatostatin analogues treatment

OBJECTIVE

Acromegaly is a syndrome with a high risk of impaired glucose tolerance (IGT) and diabetes mellitus (DM). Somatostatin analogues, which are used for medical treatment of acromegaly, may exert different hormonal effects on glucose homeostasis. Twenty-four active acromegalic patients were studied in order to determine the long-term effects of octreotide-LAR and SR-lanreotide on insulin sensitivity and carbohydrate metabolism.

DESIGN

Prospective study.

PATIENTS

We studied 24 patients with active acromegaly, 11 males and 13 females, aged 50.7 +/- 12.7 years, body mass index (BMI) 30.1 +/- 4.8 (kg/m2).

MEASUREMENTS

All patients underwent an oral glucose tolerance test (OGTT) and 12 also had an euglycaemic hyperinsulinaemic clamp. All patients were evaluated at baseline and after 6 months of somatostatin analogues therapy.

RESULTS

Acromegalic patients showed low M-values in respect to the control group at baseline (P<0.05), followed by a significant improvement after 6 months of therapy (P<0.005 vs. baseline). Serum glucose levels at 120 min during OGTT worsened (P<0.05) during somatostatin analogs therapy in patients with normal glucose tolerance, but not in those with impaired glucose tolerance or diabetes mellitus. This was associated with a reduced (P<0.05) and 30 min delayed insulin secretion during OGTT. Also, HbA1c significantly deteriorated in all subjects after treatment (4.7 +/- 0.6% and 5.1 +/- 0.5%, basal and after six months, respectively, P<0.005).

CONCLUSION

In acromegalic patients, somatostatin analogues treatment reduces insulin resistance, and also impairs insulin secretion. This may suggest that the use of oral secretagogue hypoglycaemic agents and/or insulin therapy should be considered rather than insulin sensitizers, as the treatment of choice in acromegalic patients who develop frank hyperglycaemia during somatostatin analogues therapy.

Rats that are made insulin resistant by glucosamine treatment have impaired skeletal muscle insulin receptor phosphorylation

The current study sought to verify whether glucosamine (GlcN)-induced insulin resistance is associated with impaired insulin receptor (IR) autophosphorylation. Rats were given either saline or primed continuous GlcN infusion (5 micromol x kg(-1) x min(-1)) 10 minutes prior to and during euglycemic hyperinsulinemic clamp (primed continuous infusion of 20 mU x kg(-1) x min(-1) insulin for 2 hours). IR autophosphorylation was measured in skeletal muscle after in vivo insulin stimulation (ie, during clamp) by Western blot and then retested after subsequent in vitro 0.1 to 100 nmol/L insulin stimulation (by enzyme-linked immunosorbent assay [ELISA]). Tissue PC-1 enzymatic activity was also measured. In vivo, insulin/GlcN rats had decreased (P <.01) whole body glucose uptake (37.7 +/- 2.1 v 49.7 +/- 2.7 mg x kg(-1) x min(-1) in respect to insulin/saline), receptor autophosphorylation (37 +/- 5 v 82 +/-.0 arbitrary units/mg protein), and insulin receptor substrate-1 (IRS-1) phosphorylation (112% +/- 15% v 198% +/- 23% of saline infusion rats). Receptor autophosphorylation was correlated with whole body glucose uptake (r = 0.62, P <.05). Skeletal muscle PC-1 activity (58.8 +/- 10.7 v 55.7 +/- 5.8 nmol x mg(-1) x min(-1)) was not different in the 2 groups. Our data show that GlcN-induced insulin resistance is mediated, at least in part, by impaired skeletal muscle IR autophosphorylation.

Bone mineral density in acromegaly: the effect of gender, disease activity and gonadal status

OBJECTIVE

Data on bone mineral density (BMD) in acromegaly are conflicting as most previous studies collectively evaluated eugonadal and hypogonadal patients of both sexes, with or without active disease. We have evaluated BMD in 152 acromegalic patients of both sexes with varying disease activity and gonadal status.

DESIGN

Cross-sectional, retrospective.

PATIENTS

We studied 152 acromegalic patients (99 women aged 26-72 years, and 53 men aged 21-75 years), 107 with active and 45 with controlled disease. Eighty-five patients had normal gonadal status and 67 were hypogonadal.

MEASUREMENTS

In all patients we measured serum GH levels by immunoenzimometric assay, and serum IGF-I levels by radioimmunoassay. BMD was assessed at spine L2-L4 (LS) and at femoral neck (FN) by dual energy X-ray absorptiometry; results are expressed as Z-values.

RESULTS

We evaluated the effect of GH excess on bone at different sites in relation to gonadal status, disease activity and gender. At LS, in respect to the reference population, BMD (mean +/- SE) values were higher in eugonadal patients (active: 0.71 +/- 0.29, P < 0.02; controlled: 0.65 +/- 0.28, P < 0.05) and lower in hypogonadal ones (active: -0.64 +/- 0.35, 0.1 < P < 0.05; controlled: -1.05 +/- 0.36, P < 0.01), regardless of disease activity. On the contrary, at FN, BMD was higher than in the reference population, both in eugonadal (1.01 +/- 0.22, P < 0.001) and hypogonadal (0.63 +/- 0.17, P < 0.001) patients only in subjects with active disease, but not in those in which the disease was controlled (eugonadal: 0.31 +/- 0.23, P = ns; hypogonadal 0.04 +/- 0.28, P = ns). We did not observe any difference in BMD values according to gender both at LS (males vs. females -0.02 +/- 0.30 vs. 0.01 +/- 0.24, P = ns) or at FN (0.77 +/- 0.19 vs. 0.63 +/- 0.15, P = ns).

CONCLUSIONS

The anabolic effect of GH excess on bone in acromegalic patients is: (i) gender-independent; (ii) evident at the spine only in eugonadal regardless of disease activity; (iii) evident at femoral neck only in the presence of active disease regardless of gonadal status.

Insulin modulates PC-1 processing and recruitment in cultured human cells

We evaluated whether insulin signaling modulates plasma cell glycoprotein (PC-1) plasma membrane recruitment, posttranslational processing, and gene expression in human cultured cell lines. Insulin induced a fourfold increase (P < 0.01) of membrane PC-1 expression by rapid and sensitive mechanism(s). This effect was reduced (P < 0.05-0.01) by inhibition of phosphatidylinositol 3-kinase (200 nmol/l wortmannin) and S6 kinase (50 nmol/l rapamycin) activities and intracellular trafficking (50 micromol/l monensin) and was not accompanied by PC-1 gene expression changes. Moreover, at Western blot, insulin elicited the appearance, in both plasma membrane and cytosol, of a PC-1-related 146-kDa band (in addition to bands of 163, 117, 106, and 97 kDa observed also in absence of insulin) that was sensitive to endoglycosidase H. Finally, inhibition of PC-1 translocation to plasma membrane, by wortmannin pretreatment, increases insulin-stimulated receptor autophosphorylation. Our data indicate that insulin stimulates PC-1 posttranslational processing and translocation to the plasma membrane, which in turn impairs insulin receptor signaling. Bidirectional cross talk between insulin and PC-1, therefore, takes place, which may be part of the hormone self-desensitization mechanism.

Percutaneous ethanol injection plus radioiodine versus radioiodine alone in the treatment of large toxic thyroid nodules

Therapeutic options for toxic thyroid nodules (TTNs) are surgery, radioiodine (RAI), and percutaneous ethanol injection (PEI). Surgery is generally considered for TTNs larger than 4 cm. However, some patients may be at high surgical risk. The purpose of the study was to evaluate the efficacy of 2 nonsurgical modalities for these TTNs.

METHODS

Twenty-two patients with TTNs larger than 4 cm were randomly assigned to 2 different treatments: to 11 (subgroup A), RAI was administered at a dose of 12,580 kBq/mL of nodular volume (NV) and was corrected for 100% 24-h (131)I uptake (RAIU); to 11 (subgroup B), 2-4 PEI sessions (ethanol injected = 30% NV) preceded 2 mo of 24-h RAIU and RAI dosing. Inclusion criteria were clinical and biochemical hyperthyroidism; a single palpable, hot nodule at (99m)Tc scintigraphy; and high surgical risk or refusal to have surgery. Patients gave informed consent. Local symptoms were evaluated by a previously validated score (symptom score, or SYS).

RESULTS

Both treatments were well tolerated. Subgroup B showed a significant reduction of NV 2 mo after PEI: 33.6 +/- 18.5 versus 60.8 +/- 29.5 mL. Their 24-h RAIU was similar to that of subgroup A: 53.9 +/- 13.9 versus 61.8% +/- 11.0%. Consequently, the administered RAI dose was significantly lower for subgroup B (730 +/- 245 MBq) than for subgroup A (1,048 +/- 392 MBq). Twelve months after RAI, subgroup B had a higher NV reduction and a lower SYS than did subgroup A. In subgroup A, 1 patient was subclinically hyperthyroid, 2 showed a slight increase of thyroid-stimulating hormone, and 1 was clinically hypothyroid. In subgroup B, 1 patient had a slight increase of thyroid-stimulating hormone.

CONCLUSION

We demonstrated that RAI, alone or with PEI, can be considered a valid alternative for TTNs larger than 4 cm when surgery is either refused or contraindicated. PEI plus RAI can be considered when marked shrinkage of a nodule is required or when reduction of the RAI dose can prevent hospitalization.

Serum thyroglobulin and 131I whole body scan after recombinant human TSH stimulation in the follow-up of low-risk patients with differentiated thyroid cancer

OBJECTIVE

The 'standard' postoperative follow-up of patients with differentiated thyroid cancer (DTC) has been based upon serum thyroglobulin (Tg) measurement and (131)I whole body scan ((131)I-WBS) after thyroid hormone (T(4)) treatment withdrawal. However, (131)I-WBS sensitivity has been reported to be low. Thyroid hormone withdrawal, often associated with hypothyroidism-related side effects, may now be replaced by recombinant human thyroid stimulating hormone (rhTSH). The aim of our study was to evaluate the diagnostic accuracy of (131)I-WBS and serum Tg measurement obtained after rhTSH stimulation and of neck ultrasonography in the first follow-up of DTC patients.

DESIGN

Ninety-nine consecutive patients previously treated with total thyroidectomy and (131)I ablation, with no uptake outside the thyroid bed on the post-ablative (131)I-WBS (low-risk patients) were enrolled.

METHODS

Measurement of serum Tg and (131)I-WBS after rhTSH stimulation, and ultrasound examination (US) of the neck.

RESULTS

rhTSH-stimulated Tg was <or=1 ng/ml in 78 patients (Tg-) and >1 ng/ml (Tg+) in 21 patients, including 6 patients with Tg levels >5 ng/ml. (131)I-WBS was negative for persistent or recurrent disease in all patients (i.e. sensitivity = 0%). US identified lymph-node metastases (confirmed at surgery) in 4/6 (67%) patients with stimulated Tg levels >5 ng/ml, in 2/15 (13%) with Tg >1<5 ng/ml, and in 2/78 (3%) who were Tg-negative.

CONCLUSIONS

(i) diagnostic (131)I-WBS performed after rhTSH stimulation is useless in the first follow-up of DTC patients; (ii) US may identify lymph node metastases even in patients with low or undetectable serum Tg levels.

Polymorphisms of the insulin receptor substrate-2 in patients with type 2 diabetes

We investigated the significance of Gly1057Asp and Leu647Val insulin receptor substrate (IRS)-2 polymorphisms in two Italian cohorts comprising 186 glucose-tolerant subjects and 240 subjects with type 2 diabetes from the Lazio region (i.e. representative of central Italy), and 123 glucose-tolerant subjects from the Sicily region (i.e. representative of south Italy). The allelic frequency of Gly1057Asp variant did not differ between diabetics (32.9%) and nondiabetic subjects, whatever their ethnicity was (35.8% and 33.7% from Lazio and Sicily, respectively). As compared with Gly/Gly subjects within each group, Asp/Asp individuals showed no differences in quantitative traits, including fasting insulin and C-peptide, and several indices of insulin sensitivity and secretion. Only one of the diabetic patients was heterozygous for the Leu647Val variant, and none of the control subjects carried this variant. This patient had three children who were also heterozygous for this variant. They were glucose tolerant, and their insulin sensitivity and insulin secretion indices were within the range of age-matched controls. We also analyzed IRS-2 function in fibroblasts from carriers of Gly1057Asp or Leu647Val variant. No defects in IRS-2 expression, insulin-stimulated phosphorylation, or binding to the p85 subunit of phosphatidylinositol 3-kinase were observed. These results strongly argue against a major role of IRS-2 polymorphisms in the pathogenesis of type 2 diabetes.

Relationship between obesity-related metabolic abnormalities and sexual function

Obesity is increasing worldwide. In fact, within the next 20 years it is likely to become an epidemic condition. As obesity is characterized by a variety of severe co-morbidities, it imposes a tremendous burden to health care systems of western societies. Among these, although less recognised, there is also sexual dysfunction. This short review will first give some details about the prevalence of sexual dysfunction among obese people, and then focus on the role of obesity in the negative modulation of sexuality. In detail, it will be reported about the 3 possible mechanisms through which obese people may suffer from sexual dysfunction: a) insulin resistance and associated hormonal changes, b) dyslipidemia and related drugs, and c) psychological problems.

Bone involvement in eugonadal male patients with adrenal incidentaloma and subclinical hypercortisolism

Adrenal incidentalomas (AI) are not associated, by definition, with clinically evident syndromes; however, some AI patients may show biochemical indexes of subclinical hypercortisolism (SH). Previous data on female AI patients indicated that SH may lead to bone loss, at least at spine. No data are available on bone involvement in samples of only AI male patients. We measured bone metabolism and bone mineral density at spine and femur by dual-energy x-ray absorptiometry in 38 consecutive eugonadal male AI patients and 38 healthy matched control subjects. Patients were subdivided according to the presence or absence of SH (group SH+ and group SH-, respectively). Mean Z-score levels of spinal bone mineral density measured by dual-energy x-ray absorptiometry were lower (P < 0.05) in group SH+ (-0.42 +/- 1.62) in comparison with group SH- (0.6 +/- 1.13) and controls (0.47 +/- 1.06). Thus, in order for the most appropriate management to be individually tailored, bone mass evaluation is strongly indicated in AI male patients with SH, irrespective of their gonadal status.

Screening for silent myocardial ischaemia in type 2 diabetic patients with additional atherogenic risk factors: applicability and accuracy of the exercise stress test

OBJECTIVE

Coronary artery disease (CAD), a major cause of mortality in patients with type 2 diabetes (T2D), is often diagnosed late because of silent myocardial ischaemia (SMI). Exercise electrocardiogram testing (ECG) stress is the most utilized screening test for SMI. Its applicability and accuracy, which have never been reported in asymptomatic high-risk T2D patients, have been investigated in this study.

DESIGN

A cross-sectional study with coronary angiography as the gold standard for detecting CAD was used.

METHODS

Two hundred and six consecutive T2D patients, without symptoms and resting ECG signs of ischaemia but with peripheral vascular disease (PVD) and/or > or = two atherogenic factors, were studied. Ischaemia at ECG stress was indicated by horizontal or downsloping ST segment depression > or =1 mm at 0.08 s after the J point. CAD was defined by stenosis > or =70%.

RESULTS

Only 141/206 (68%) patients had a diagnostic test: 27 (19%) tested positive and 114 (81%) tested negative. Coronary angiography in 71 patients (the 27 who tested positive and 44 randomly selected patients who tested negative) indicated a CAD prevalence of 29% and the ECG stress accuracy was 79%. 'False negative' patients (18%) had a higher prevalence (P<0.01) of long duration of diabetes and PVD.

CONCLUSIONS

This is the first study which provides insights into the applicability and accuracy of ECG stress in screening SMI in high-risk patients with T2D. Due to the high prevalence of CAD, alternative screening tests in patients unable to perform the test and in those with a high chance of being 'false negative' should be looked for and validated.

Genetics of specific phenotypes of congenital hypothyroidism: a population-based approach

Congenital hypothyroidism (CH) may cause severe and irreversible neurologic and developmental abnormalities when not recognized early. Many millions of newborns have now been screened and many thousands of patients with CH have been identified. Approximately 80%-85% have defects of thyroid gland development, while 15%-20% have congenital errors of thyroid hormone biosynthesis. An entire population screened for CH over a long period of time, was studied in the present report, using a population-based approach. In particular, two CH phenotypes, both presenting with in situ thyroid gland (patients with either goiter or with thyroid gland volume ranging from normal to hypoplasic) were analyzed. Mutations were searched in some of the most likely candidate genes: thyroperoxidase (TPO) in patients with CH goiter, Pax8 and thyrotropin receptor (TSHR) in the other group. In the former group (n = 8), four TPO gene mutations were identified in three patients. One patient was a compound heterozygous. In two cases an already described mutation (1277(insGGCC)) was present; in two other cases mutations not previously described (1996(G-->T) and 2295(G-->A)), which induced aminoacid variations with a Glu --> Stop and Val --> Ile changes, respectively, were identified. In all patients mutations were inherited from one of the parents. In the case of the compound heterozygous patient, one mutation was inherited from the mother (1277(insGGCC)) and the other from the father (1996(G-->T), Glu --> Stop). In the latter group (n = 8), a patient with a 16-base pair C(T)(13)CC deletion in TSHR gene intron 8, 42-bp distal to exon/intron 8 splice junction, was identified. No mutation was identified in Pax8 gene.

Global skeletal uptake of 99mTc-methylene diphosphonate (GSU) in patients affected by endocrine diseases: comparison with biochemical markers of bone turnover

This study aimed to clinically validate the global skeletal uptake (GSU) of (99m)Tc-methylene diphosphonate ((99m)Tc-MDP), and to compare it with a marker of bone formation (i.e. serum osteocalcin or OC) and an index of bone resorption (i.e. urinary deoxypyridinoline or U-DPD) in different endocrine disorders affecting the skeleton. We studied 29 female patients with thyrotoxicosis (TT), 27 with primary hyperparathyroidism (PHPT), 16 with acromegaly (AC), 15 with Cushing's syndrome (CS), and altogether 110 healthy women matched for age, BMI and menstrual status. In all subjects total body digital scan images (TBDS) were acquired at 5 min and at 4 h after the administration of (99m)Tc-MDP; the whole body retention (WBR) of the tracer was measured by counting two identical sets of rectangular ROIs, and GSU was subsequently calculated by drawing an irregular ROI on 4 h TBDS images. Serum OC was assessed by IRMA and urinary DPD by fluorometric detection after reverse phase high pressure chromatography. In TT patients GSU (40.0 +/- 5.1 vs 36.5 +/- 4.8%), OC (19.1 +/- 11.8 vs 7.1 +/- 2.9 microg/l) and U-DPD (62.4 +/- 42.7 vs 19.5 +/- 5.3 pmol/pmol) were significantly ( p<0.01) higher than in controls. PHPT patients showed GSU (47.2 +/- 6.6 vs 37.8 +/- 5.3%), OC (38.6 +/- 40.9 vs 8.2 +/- 2.5 microg/l), and U-DPD (55.0 +/- 51.3 vs 21.9 +/- 6.1 pmol/pmol) values significantly ( p<0.001) higher than controls. In CS patients, GSU (39.6 +/- 6.4 vs 32.7 +/- 3.5%; p<0.01) and U-DPD (22.8 +/- 8.4 vs 16.5 +/- 2.7 pmol/pmol; p<0.05) were higher, whereas OC (3.6 +/- 2.4 vs 5.2 +/- 1.9 mg/l; p<0,05) was lower than in controls. In AC patients, GSU (34.9 +/- 5.3 vs 35.2 +/- 3.4%) did not differ significantly from controls, whereas OC (16.8 +/- 8.8 vs 6.9 +/- 2.9 microg/l; p<0.001) and U-DPD (30.9 +/- 13.6 vs 21.0 +/- 5.7 pmol/pmol; p<0.01) were higher. Stepwise multivariate linear regression analysis was performed with disease activity, creatinine clearance, age, and years since menopause as predictor variables and GSU or OC or U-DPD as dependent variables. The significant partial regression coefficients ( r) were: in TT, free triiodothyronine (fT3) with GSU ( r = 0.37; p<0.005), Ln OC ( r = 0.30; p = NS), Ln U-DPD ( r = 0.76; p<0.0001), respectively; in PHPT, PTH with GSU ( r = 0.74; p<0.001), Ln OC ( r = 0.50; p<0.05), Ln U-DPD ( r = 0.64; p<0.001); in CS Ln urinary free cortisol with OC ( r = -0.68; p<0.001) and U-DPD ( r = 0.66; p<0.05). Our data suggest that GSU could represent a valuable clinical tool for evaluating bone turnover rate in PHPT, CS, TT but not in AC. The behavior of GSU and OC and U-DPD is non-uniform in disorders characterized by a marked uncoupling between bone formation and resorption.

The Decorin gene 179 allelic variant is associated with a slower progression of renal disease in patients with type 1 diabetes

Background genetic factors may influence the variability in the rate of progression of kidney disease in type 1 diabetes. In diabetes, progressive mesangial matrix expansion and glomerular sclerosis are, to a large extent, mediated by TGF-beta1. Decorin, a proteoglycan which is a component of the extracellular matrix, regulates TGF-beta1 activity and expression. We have examined the relationship between the 179/183/185 polymorphism of the Decorin gene and the progression of diabetic nephropathy.

METHODS

From a cohort of 175 European patients with diabetic nephropathy, we studied 79 patients who were selected because they had a follow-up of at least 2 years (average 6.5 years; range: 2.5-15 years), and regular measurements of serum creatinine on 5 or more occasions. Creatinine clearance (CrCl) calculated from serum creatinine concentration was used as a measure of derived glomerular filtration rate (dGFR). All patients were on antihypertensive therapy.

RESULTS

The rate of dGFR decline in the whole cohort was [median (range)] 4.6 (-3.8 to 18) ml/min/year. No patient with 185 allele was found. Patients with 179/183 and 179/179 genotype (n = 14), who were considered together and named 179 carriers, had a slower rate of GFR decline [2.1 (0.06-11.7) ml/min/year] as compared to patients with Decorin 183/183 genotype (n = 65) [5.6 (-3.8 to 18) ml/min/year; p < 0.001]. In addition, when considering individual data, patients carrying the 179 allele had a 3.0 (95%CI: 1.8-4.2)-fold higher probability to be slow progressors (i.e. GFR decline below the median). This difference could not be accounted for by differences in duration of disease, type and duration of antihypertensive therapy, albumin excretion rate, blood glucose or blood pressure control. In a multivariate logistic analysis albumin excretion rate (p < 0.001), mean arterial pressure (p = 0.07) and Decorin gene polymorphism (p = 0.036), but not HbA1c, were independently correlated with the rate of dGFR fall.

CONCLUSION

The 179 allele variant of the Decorin gene is related to a slower progression of DN in type 1 diabetic patients with albuminuria and receiving antihypertensive therapy.