21/78. Evidence that the insulin resistance of pregnancy may not involve a post-receptor defect in human adipocytes.Insulin binding and the capacity of insulin to stimulate the conversion of glucose to carbon dioxide and lipid, and to activate the protein tyrosine kinase associated with the insulin receptor have been investigated in adipocytes isolated from pregnant and non-pregnant women. Insulin binding and the conversion of glucose to lipid were the same for both groups. However, conversion of glucose to CO2 was higher in the non-pregnant group due to an elevated basal activity, and the increase produced by insulin was similar in both groups. The tyrosine kinase activity of the isolated receptor preparations was higher in the pregnant group due to an increase in the basal non-insulin dependent activity, and the increase produced by insulin was similar in both groups. These findings show the in vitro insulin responsiveness of isolated adipocytes is similar for both groups, and suggests that the in vivo insulin resistance of late pregnancy, as far as adipose tissue is concerned, is not due to any inherent defect in insulin action at the receptor or post-receptor level. In vivo insulin resistance may result from an increased level of circulating insulin antagonists.- - - - - - - - - - ranking = 1keywords = adipose (Clic here for more details about this article) |
22/78. Hormonal and metabolic study of a case of adiposis dolorosa (Dercum's disease).A case of a 43-year-old nonobese woman with adiposis dolorosa (Dercum's disease) is reported. Muscle glucose uptake and oxidation before and after ingestion of 75 g of glucose were similar to control group values, although a greater insulin release (16,578 vs 6,242 /- 1,136 microU/3 h) occurred simultaneously. in vitro studies of abdominal normal and painful subcutaneous adipose tissue of the patient revealed lower responsiveness to norepinephrine and lack of response to the antilipolytic effect of insulin in the painful adipose tissue (0.98 vs 1.43 microM FFA/10(6) cells at 5.0 microM of norepinephrine). The disease was not correlated with the HLA system and there were no alterations in hormonal secretion at the pituitary, adrenal, gonadal, and thyroid levels. These findings indicate the presence of peripheral insulin resistance in this patient with adiposis dolorosa.- - - - - - - - - - ranking = 2keywords = adipose (Clic here for more details about this article) |
23/78. Type A-insulin resistance with lipopexia on extremities: a case report.We present the unusual case of a 17-year-old female with insulin-resistant diabetes, acanthosis nigricans, hirsutism, amenorrhea, dental dysplasia and lipopexia on the extremities. She had been diagnosed as having border line diabetes with hyperinsulinemia at age 12 when she was not obese and diabetes mellitus at age 13. On admission, she was obese and had lipopexia only on the extremities. The presence of hyperinsulinemia and poor response to exogenous insulin suggested severe insulin resistance. Insulin binding to transformed B-lymphoblasts derived from her was extremely low compared to the normal control, showing decreased receptor affinity. Her parents and sister exhibited hypersecretion of insulin in response to a 75 g oral glucose tolerance test. Her mother was diabetic, and her father and sister had border line diabetes, whereas her brother had a normal response. These findings support strongly the diagnosis of a type A syndrome with severe insulin resistance associated with lipopexia on the extremities. A genetic defect in the insulin receptor gene may be responsible.- - - - - - - - - - ranking = 0.022676407538keywords = fat (Clic here for more details about this article) |
24/78. Response to treatment with rosiglitazone in familial partial lipodystrophy due to a mutation in the LMNA gene.BACKGROUND: Familial partial lipodystrophy (FPLD) is a monogenic form of diabetes characterised by a dominantly inherited disorder of adipose tissue associated with the loss of subcutaneous fat from the limbs and trunk, with excess fat deposited around the face and neck. The lipodystrophy causes severe insulin resistance, resulting in acanthosis nigricans, diabetes, dyslipidaemia, and increased risk of cardiovascular disease. Preliminary results from animals and man suggest that increasing subcutaneous fat by treatment with thiazolidinediones should improve insulin resistance and the associated features of this syndrome. CASE REPORT: We report a 24-year-old patient with FPLD caused by a mutation in the LMNA gene (R482W) treated with 12 months of rosiglitazone. subcutaneous fat increased following rosiglitazone treatment as demonstrated by a 29% generalised increase in skin-fold thickness. leptin levels increased from 5.8 to 11.2 ng/ml. Compared with treatment on metformin, there was an increase in insulin sensitivity (HOMA S% 17.2-31.6) but no change in glycaemic control. The lipid profile worsened during the follow-up period. CONCLUSION: This initial case suggests that, for modification of cardiovascular risk factors, there are no clear advantages in treating patients with FPLD with rosiglitazone despite increases in subcutaneous adipose tissue. Larger series will be needed to identify moderate beneficial effects and treatment may be more effective in patients with generalised forms of lipodystrophy.- - - - - - - - - - ranking = 8.9789891557232keywords = subcutaneous fat, adipose, fat (Clic here for more details about this article) |
25/78. Is this patient insulin resistant? How much does it matter?Alex was an obese 10-year-old girl with a family history of type 2 diabetes, hypertension, and perhaps polycystic ovarian syndrome. Her physical examination was significant for a central accumulation of body fat and acanthosis nigricans. Although the laboratory studies indicated that Alex was not diabetic and probably not glucose intolerant, she could be insulin resistant (IR). Should any further evaluation be done? If Alex is IR, what kind of treatment should be offered? The following discussion addresses these questions by reviewing the pathophysiology, diagnosis, and consequences of isolated IR.- - - - - - - - - - ranking = 0.022676407538keywords = fat (Clic here for more details about this article) |
26/78. Tall stature, insulin resistance, and disturbed behavior in a girl with the triple X syndrome harboring three SHOX genes: offspring of a father with mosaic klinefelter syndrome but with two maternal X chromosomes.AIMS: To describe the tall stature and its possible underlying mechanism in a Caucasian girl (age 12 years and 10 months) with 46,XX (28%)/47,XXX (72%) mosaicism and to identify the parental origin of her extra x chromosome. methods: The fasting glucose-to-insulin ratio was studied. The karyotypes of the girl and her parents as well as the presence of SHOX copies and the parental origin of her extra x chromosome were assessed. RESULTS: Clinical examination revealed a tall stature and severe acne, and endocrinological/metabolic assessment revealed insulin resistance. fluorescence in situ hybridization cytogenetic analysis depicted the presence of three SHOX genes in the 47,XXX cell line of the patient. karyotyping of her parents showed a normal 46,XX karyotype in the mother and 46,XY(93%)/47,XXY(7%) Klinefelter mosaicism in the father. However, dna analysis unequivocally showed maternal origin of the extra x chromosome of the patient. CONCLUSIONS: This report suggests that SHOX gene triplication may produce a tall stature, even in the presence of preserved ovarian function. X triplication might predispose to insulin resistance and behavioral disorders.- - - - - - - - - - ranking = 0.11338203769keywords = fat (Clic here for more details about this article) |
27/78. Improvement of fat redistribution, insulin resistance and hepatic fatty infiltration in hiv-associated lipodystrophy syndrome by pioglitazone: a case report.hiv-associated lipodystrophy syndrome is a syndrome occurring in HIV-infected patients who were treated with highly-active antiretroviral therapy (HAART), especially regimen containing protease inhibitors. The syndrome consists of fat redistribution, with loss of subcutaneous fat and increase in visceral fat, and metabolic disturbances, including glucose intolerance or overt diabetes and dyslipidemia. No standard treatment has been established for this syndrome. Pioglitazone is an oral antidiabetic agent that acts primarily on adipose tissue to reduce insulin resistance. The authors report a 50-year old HIV-infected woman who developed hiv-associated lipodystrophy syndrome after 3 months of HAART. She had significant weight loss with obvious loss of subcutaneous fat, together with development of hypertension, diabetes and dyslipidemia. After treatment with 30 milligrams of pioglitazone daily, her body weight increased within the first month of treatment. subcutaneous fat loss was restored. Improvement in glycemic and lipid control was also noted. CT scan of the abdomen revealed that fatty infiltration in the liver was markedly decreased. Visceral fat as assessed by CT scan had also decreased. Pioglitazone appeared to have beneficial effects in this patient.- - - - - - - - - - ranking = 8.2284296386412keywords = subcutaneous fat, adipose, fat (Clic here for more details about this article) |
28/78. Efficacy of recombinant methionyl human leptin therapy for the extreme insulin resistance of the Rabson-Mendenhall syndrome.Recombinant methionyl human leptin (r-metHuLeptin) therapy has shown clear efficacy in the treatment of severe insulin resistance associated with lipodystrophy syndromes and low leptin levels. We treated two siblings with Rabson-Mendenhall syndrome (severe insulin resistance and presumed insulin receptor mutations). The brother and sister, aged 13 and 11 yr, respectively, had severe acanthosis nigricans, insulin resistance, and diabetes. Both were taking 2000 mg metformin and 2 mg rosiglitazone daily; the brother was also taking 300 U regular insulin daily. In contrast to our lipoatrophic patients treated with r-metHuLeptin, these two patients had a higher percent body fat and low-normal fasting triglycerides [42 mg/dl (0.37 mmol/liter), male sibling, and 33 mg/dl (0.47 mmol/liter), female sibling]. The siblings were treated with r-metHuLeptin therapy for 10 months and demonstrated a 40-60% decrease in fasting serum glucose and insulin levels and improved glycosylated hemoglobin. There was corresponding improvement in glucose and insulin tolerance during leptin therapy. This is the first report of a partial, but significant, effect of r-metHuLeptin administration in patients with extreme insulin resistance with a presumed insulin receptor mutation and low serum triglyceride levels.- - - - - - - - - - ranking = 0.022676407538keywords = fat (Clic here for more details about this article) |
29/78. Familial juvenile autoimmune hypothyroidism, pituitary enlargement, obesity, and insulin resistance.The proband, a 9-year-old Hispanic female, presented with hair loss, strabismus, and weight gain. On magnetic resonance imaging (MRI) she was found to have severe primary hypothyroidism and a large pituitary mass. In addition, acanthosis nigricans, obesity, and hyperinsulinism were observed. Findings were similar in three of four siblings. Thyroid peroxidase antibodies were detected in the father and three of four siblings. Although all family members were obese, and hyperinsulinemia with high proinsulin and c-peptide was found in all except one sibling, only the mother and one child had overt type 2 diabetes mellitus. Because of the unusual association of autoimmune thyroid disease, insulin resistance and obesity rather than insulin deficiency, we searched for possible genetic abnormalities. The HLA haplotypes did not cosegregate with autoimmune thyroid disease or insulin resistance. Mutational analysis of known obesity genes was done. leptin was not deficient, and sequencing of the proband's dna showed no mutations in the perixisome proliferator activated receptor (PPAR)-gamma, PPAR-gamma(2), PPAR-alpha or melanocortin 4 receptor genes. Maternally inherited diabetes and deafness was ruled out since no mutations were found in mitochondria dna. Insulin receptor antibodies were not detected. In conclusion, the remarkably high incidence of childhood autoimmune hypothyroidism, pituitary enlargement, insulin resistance and obesity in this family is not linked to known HLA types or known gene defects.- - - - - - - - - - ranking = 0.022676407538keywords = fat (Clic here for more details about this article) |
30/78. The beneficial effect of effective control of anemia on hyperinsulinemia and hypoxemia in a hemodialysis patient with corrected transposition of the great arteries.We report the beneficial effect of control of anemia on hyperinsulinemia and hypoxemia in a hemodialysis patient with corrected transposition of the great arteries. The patient's hemoglobin (Hb) level of 10.3 g/dl on admission represents good control for hemodialysis (HD) patients, but it was too low for this patient with secondary polycythemia because of a right-to-left shunt. Control of anemia for a 10-month period was followed by a marked increase in Hb level (from 10.3 g/dl to 13.9 g/dl) and in aerobic work capacity, while the fasted insulin level decreased from 36.7 microU/ml to 8.0 microU/ml, without changes in leptin level, body mass index (BMI), fat mass, Kt/V, or protein catabolic rate (PCR). Additionally, hypoxemia was ameliorated, from PO2 33.1 mmHg to PO2 56.2 mmHg, and the hyperdynamic cardiac state was improved. The degree of anemia, together with deteriorating tissue oxygenation, may have predisposed this patient to developing insulin resistance and consequent hyperinsulinemia. The most appropriate target Hb concentration should be tailored for the clinical condition of each individual patient, bearing in mind an insulin-resistance state, especially in hemodialysis patients with hypoxemia. A more complete understanding of what regulates insulin resistance and consequent hyperinsulinemia in endstage renal disease (ESRD) awaits the elucidation of carbohydrate and insulin metabolism.- - - - - - - - - - ranking = 0.022676407538keywords = fat (Clic here for more details about this article) |
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