GH/IGF1 axis disturbances in the fibromyalgia syndrome: is there a rationale for GH treatment?

Fibromyalgia Syndrome (FMS) is a frequent idiopathic condition in which patients experience intense pain in specific tender points, profound fatigue and sleep disturbances. Although pain had not account so far in growth hormone deficiency syndrome (GHD) description, symptoms of FMS are very similar; and there is strong evidence of decreased GH secretion at least in a subset of FMS patients. Is there an overlap of the two diseases? A systematic Medline/Embase search for preliminary proof-of-concept trials, but also larger placebo-controlled studies, have shown that GH replacement in low-IGF1 patients can significantly improve some symptoms of FMS and quality of life, suggesting a direct causal effect of GH deficiency. Despite the use of relatively high doses of GH in these patients, treatment seems to be well tolerated. Several mechanisms of action for GH in FMS relief have been suggested, including both central modulation of pain and peripheral musculo-tendinous effects, as already described in classic GHD.

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.

Wernicke's syndrome after bariatric surgery.

Two young females with severe morbid obesity presented with Wernicke's syndrome after Roux-en-Y gastro-jejunum bypass had been performed. The first patient had recurrent vomiting and dyplopia two months post-surgery. Physical examination indicated bilateral ophthalmoparesia with conserved convergence and ataxia. The second patient had frequent vomiting episodes over the previous three months together with lower limb hypotonia, myoclonia and generalised tonicoclonic seizures on two occasions within one year of surgery. In both cases routine blood test, ion levels (sodium, potassium, calcium, phosphates), electroencephalogram and CT scan were normal. Thiamine therapy was instigated on the basis of clinical intuition and the first patient achieved complete remission within 24 hours while the second improved gradually in that two years later only mild lower limb hypotonia and a slight cognitive deficit remains. Erythrocyte transketolase activity determinations were abnormal on two separate occasions for this second patient. Vitamin B1 determinations were not available for the first patient. In conclusion, the restriction in energy intake and the persistent vomiting together with malabsorption induced by the surgical intervention could explain the vitamin deficiency causing Wernicke's encephalopathy. This indicates a need for close monitoring and systematic vitamin supplementation in those patients who undergo bariatric surgery.

[Genetic study of a new family with Hippel-Lindau type IIB disease]. / Estudio genético de una nueva familia con la enfermedad de Von Hippel-Lindau tipo IIB.

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.

High prevalence of growth hormone deficiency in severe fibromyalgia syndromes.

CONTEXT: Fibromyalgia (FM) is characterized by widespread pain and fatigue and is considered a syndrome with different pathogenic mechanisms. Controversial data on GH axis disturbances have been published. Some preliminary trials have shown promising effects of GH therapy on tender points and quality of life in FM. AIM: The aim was to study the patterns of GH secretion/sensitivity in a cohort of severe FM patients. SETTING: The study was conducted in five tertiary hospitals. METHODS: A total of 493 FM women (1990 American College of Rheumatology criteria) recruited from five centers, having more than 16 tender points, Fibromyalgia Impact Questionnaire scores above 75, more than 1 yr of stable medication (serotonin reuptake inhibitors, amitriptyline, and opioids), and body mass index below 35 kg/m(2) underwent baseline IGF-I/GH determinations; an insulin tolerance test (ITT) and a modified IGF-I generation test were performed in those cases showing IGF-I of 150 microg/liter or less. RESULTS: A total of 169 of the 493 patients (34.2%) showed IGF-I of 150 microg/liter or less. Mean peak GH during ITT was 13.3 +/- 9.9 ng/ml in 127 patients in which the test was performed. In 22 of 127 (17.3%), ITT peak GH was 5 microg/ml or less, and in eight of them (6.3%), the peak GH was 3 ng/ml or less. Mean baseline GH (n = 127) was 1.47 +/- 2.58 ng/dl, and eight of 120 (6.8%) showed an insufficient IGF-I response (<50% over baseline) to the IGF-I generation test. CONCLUSION: FM patients show a high prevalence of GH axis dysfunction. A significant number of patients show biochemical patterns of GH deficiency as well as some degree of GH resistance and might be potential candidates for substitution treatment.

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.

Introducción, definición y medida del exceso de peso en adolescentes / No disponible

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Comorbilidades del exceso ponderal en el adolescente / No disponible

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Recomendaciones para el uso clínico de orlistat en el control de la obesidad / Recommendations for the use of orlistat in obesity management

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