Adiponectin expression and metabolic markers in obesity and Type 2 diabetes.

BACKGROUND: Adiponectin has emerged over the last decade as a key adipokine linking obesity, insulin resistance, and Type 2 diabetes. However, the molecular mechanisms controlling adiponectin expression in adipose tissue are not fully elucidated. Furthermore, increasing evidence indicates that peroxisome proliferator-activated receptor- γ (PPAR-γ) plays an important, and beneficial, role in modulating adiponectin expression. AIM: The aim of the present study was to assess the separate role of obesity and Type 2 diabetes in the relationship between endogenous PPAR-γ signaling and adiponectin expression in subcutaneous adipose tissue. SUBJECTS AND METHODS: Enzyme-linked immuno sor bent assay and real time quantitative PCR analysis were carried out in overweight, obese, and/or diabetic Tunisian patients who underwent an abdominal surgery. RESULTS: These results collectively indicate that circulating levels of adiponectin were decreased in all overweight, obese, and/or diabetic (p<0.001). However, the subcutaneous mRNA expression of adiponectin was reduced only in diabetics (p<0.01) but presents some discrepancies in obese individuals. Moreover, mRNA levels of adiponectin were positively correlated with levels of mRNA encoding PPARγ and its heterodimeric partner retinoid X receptor-α (RXR-α), in both obese and diabetic patients. CONCLUSION: Our study on Tunisian patients shows impaired regulation of circulating and mRNA adiponectin levels dependent of metabolic disorders in obesity and Type 2 diabetes. The data suggest that subcutaneous adipose tissue may play an important role in modulating adiponectin expression in diabetes and obesity. Moreover, adiponectin mRNA could be potentially regulated by endogenous PPARγ/RXRα-dependent pathways.

[Clinical spectrum of cobalamin deficiency in Tunisia]. / Le spectre clinique des déficits en cobalamines en Tunisie.

PURPOSE: the aim of this study was to determine the prevalence of cobalamin (vitamin B12) deficiency in different populations of patients with clinical manifestations associated or secondary to cobalamin or folates deficiency and to analyse the demographic, clinical, paraclinical investigations in cobalamin deficient patients in Tunisia. METHODS: it was a prospective (1999-2001) multicenter study of 604 patients divided into four groups. The first group is composed of 478 consecutive patients with anaemia and/or macrocytosis with megaloblastic haemopoiesis on bone marrow examination without myelodyslasic or malignancy signs. The second group is made up of 34 patients with unexplained neurological symptoms without the presence of anaemia. The third group was composed of 82 invidious with isolated psychiatric disorders and the 10 patients with Hashimoto thyroïditis constituted the last group. RESULTS: serum cobalamin level was low in 98 %, 23%, 14% of cases, respectively, in the first three groups. Only one case of patients with Hashimoto thyroiditis has serum cobalamin deficiency. Pernicious anaemia (Biermer's disease) was established by dual isotope schilling examination in 103 patients among a sample of 120 serum cobalamin deficient patients (86%). The median age at presentation was 45.5 years. Severe chronic atrophic gastritis was diagnosed in 97.5% of patients with Biermer's disease. Serum antibodies against intrinsic factor and gastric parietal cells were detected in (42.5%) and (60.6%) patients, respectively; (25.5%) patients had the both types of antibodies. 23.4% patients were positive for antithyroid antibodies. Anti-nuclear antibodies were detected in 3% patients. CONCLUSION: an interesting finding of our study was the high frequency of cobalamin deficiency in Tunisia, particularly in relative young patients. Our patients had classic features of florid cobalamin deficiency (severe haematological manifestations and neuro-psychiatric disorders). The main underlying causes of such deficiencies were Biermer's disease. Subtle clinical manifestations should be recognized and investigated even in young patients at risk.

Effect of training on GH and IGF-1 responses to a submaximal exercise in football players.

To study the effects of regular football training on basal and exercise induced levels of growth hormone (GH) and insulin-like growth factor (IGF-1), 13 young football players were investigated by a submaximal exercise at the beginning of the sporting season in October (S1), at the middle of the season in January (S2) and at the end in May (S3). At each session, an exercise test on an ergogycle was performed for 25 min, beginning with an incremental exercise to reach 90% of theoretical maximal heart, which was maintained for the last 10 min of the test. Venous blood samples were collected at rest, at the end of the exercise and at 30 and 60 min during the recovery period. Plasma lactate and glucose concentrations increased during exercise with no difference found between sessions. GH level increased with exercise at each session but the response was significantly higher in S1 than in S2 and S3 (P<0.01). The GH area under the curve decreased significantly all along the football season (P<0.01); the IGF-1 level did not significantly change during exercise nor with training. Basal insulin-like growth factor binding protein-3 (IGFBP3) remained stable during the three sessions. Football training decreased significantly the exercise-stimulated GH levels all along the football season but did not have any significant effect on IGF-1 levels or on basal IGFBP3 levels.

[Cortisol rhythm during Ramadan]

We studied the nyctohemeral cortisol secretion rhythm and the cortisol response to 1-24 corticotropin during Ramadan in 11 healthy, male volunteers aged 20-35 years. Their response to 250 mg 1-24 corticotropin was investigated 2 weeks before Ramadan by testing daily at 08:00 and 20:00 hours. After 16-22 days of fasting, their cortisol levels were measured at 08:00 hours and their response to 1-24 corticotropin at 20:00 hours. Before Ramadan, the baseline cortisol level was significantly higher at 08:00 hours than at 20:00 hours and the cortisol response to 1-24 corticotropin was also higher at 08:00 hours but this difference was not significant. During Ramadan, the cortisol level at 08:00 hours was lower than at the same time before Ramadan; the level at 20:00 hours was slightly higher than at the same time before Ramadan. There was no significant difference between the cortisol response to 1-24 corticotropin at 20:00 hours during Ramadan and the responses before Ramadan at 20:00 hours and 08:00 hours

[Circadian rhythm of cortisol and its responsiveness to ACTH during Ramadan]. / Variations de la cortisolémie et de sa réponse à l'ACTH pendant le mois de Ramadan.

UNLABELLED: Changes in the nyctemeral pattern observed during Ramadan include diurnal fasting from sunrise to sunset and delayed and shortened periods of sleep. The purpose of the present study was to investigate the possible effect of these changes on the circadian rhythm of cortisol and its response to exogenous ACTH. SUBJECTS AND METHODS: Eleven healthy male volunteers aged 20 to 35 years were studied for two weeks prior to Ramadan. Two short ACTH stimulation tests (250 microg ACTH 1-24 intravenously) at 8 a.m. and 8 p.m. An average 17 days after the beginning of the month of Ramadan, basal cortisol was measured at 8 a.m. and a short stimulation test was performed at 8 p.m. RESULTS: Before Ramadan, cortisol level was higher at 8 a.m. (749.5 +/- 207 nmol/l) than at 8 p.m. (195.18 +/- 79 nmol/l, p<0.001) and the incremental cortisol response to exo genous ACTH was higher at 8 a.m. (peak at 1.167 +/- 46 nmol/l) than at 8 p.m. (peak at 950 nmol/l) (NS). During Ramadan, morning cortisol level (646.3 81 nmol/l) was lower than before Ramadan (NS). The 8 p.m. cortisol level (319 193 nmol/l) increased slightly during Ramadan (p=0.08) but remained lower than the morning level during Ramadan (p=0.001) and before Ramadan (p<0.001). There was not significant difference between cortisol responsiveness to exogenous ACTH at 8 p.m. during Ramadan (peak at 1.102 51 nmol) and at 8 a.m. and 8 p.m. during Ramadan. DISCUSSION: Changes in eating and sleeping schedule was found to reduce morning cortisol level and raise the evening cortisol level. Adrenal sensitiveness to corticotropin stimulation did not appear to be impaired during Ramadan.

[Antithyroid antibodies. Prevalence in primary hypothyroidism in Central Tunisia]. / Les anticorps antithyroïdiens. Prévalence dans l'hypothyroïdie primaire en Tunisie Centrale.

Thyroid microsomal (AAM) and thyroglobulin antibodies (AAT) were studied in sera of 112 patients with overt primary hypothyroidism in Central Tunisia. Thyroid antibodies were detected by an agglutination method. AAM and AAT were found respectively in 78.6% and 42%. The data confirm that there is a high prevalence of antibodies in primary hypothyroidism of short duration (AAM: 90%, AAT: 56.7%). The study reflect the prevalence of Hashimoto's thyroiditis and point to the usefulness of thyroid auto-antibodies in early screening of symptomless autoimmune thyroiditis.

[The role of phadiatop in the screening of respiratory allergy]. / Place du phadiatop dans le dépistage de l'allergie respiratoire.

Phadiatop is a new in vitro screening test for respiratory allergy. This test, based on the RAST procedure, detects in serum, the presence of specific IgE to a mixture of common inhalent allergens. Among 70 patients (26 children and 44 adults) consulting for respiratory syndrome, Phadiatop was positive in 31 cases. There were a good correlation between this new test and skin tests (59% for adults and 92% for children), total IgE (70% for adults and 65% for children) and RAST (93% for adults and 96% for children). Phadiatop, with a specificity of 100%, a sensitivity of 82% (76% for adults and 92% for children) and an efficiency of 90% (86% for adults and 96% for children), is a more accurate test than total IgE and could be an excellent in vitro screening test for respiratory allergy.

[Serum IgE in allergy examinations using in vitro radioimmunologic tests]. / IgE sériques dans l'exploration allergologique par tests radioimmunologiques in vitro.

Allergy is a real public health problem and specially respiratory allergy; it concerns 10-15% of the tunisian population according to a WHO data. Besides clinical history, allergy exploration consists of in vivo tests i.e. skin tests and in vitro tests i.e. total and specific, circulating and tissular IgE. A judicious prescription of laboratory tests can supply physician with important data for diagnosis, prediction, prevention and therapeutic control. With O.R.L. or bronchial symptoms, Phadiatop allows the physician to make a trustful screening of an IgE mediated sensitisation towards the most common inhalation allergens, so he can direct the patient towards an allergologist for a specialised investigation. In a clinical context, a well integrated measure of IgE is very helpful for diagnosis, prediction of risk and prevention for children with familial atopy. The RAST, identification of the involved allergen(s), will allow the specific desensitisation and its control.

[Preliminary note on anti-insulin antibody formation in diabetics treated with porcine insulin]. / Note préliminaire sur la production d'anticorps anti-insuline chez les diabétiques traités par l'insuline porcine.

In the present study, we have tested the sera of sixty five diabetic patients treated with insulin, researching the action of some physiologic and therapeutic factors (sex, age, insulin dose and time of treatment), to production of anti-insulin antibodies. Our results have shown that an important percentage of diabetic patients treated by porcine insulin produce antibodies: 72% of studied patients, concerning chiefly all the women and patients under-fourty years old. However our results have not pointed out any relation between the administered insulin dose versus the anti-insulin antibodies production, in spite of the early production of these antibodies in a great part of the patients.