The APOA5-1131 T>C variant enhances the association between RBP4 and hypertriglyceridemia in diabetes.

BACKGROUND AND AIM: Type 2 diabetic patients have an increased prevalence of hypertriglyceridemia. RBP4 has been associated with insulin resistance and hypertriglyceridemia in obesity, the metabolic syndrome and type 2 diabetes. APOA5 is proposed to be a genetic modulator of triglycerides. The aim of this study was to evaluate the relationship between RBP4 plasma levels and lipid disturbances and to determine the impact of the APOA5-1131 T>C variant on this relationship in type 2 diabetic patients. METHODS AND RESULTS: A total of 165 type 2 diabetic patients were included in the study. RBP4 plasma levels and the APOA5-1131 T>C variant were determined and the complete lipid profile was assessed by sequential ultracentrifugation. RBP4 was positively correlated with triglyceride levels in plasma and with all the components of triglyceride-rich lipoproteins. Despite the fact that a statistically significant relationship between the APOA5 genetic variant and RBP4 plasma levels was not found, the hypertriglyceridemic effect of high RBP4 levels was enhanced by the presence of the APOA5-1131 T>C genetic variant. Correlation coefficients were 2-fold higher for TC carriers compared to TT carriers with regard to RBP4 plasma levels and all the components of triglyceride-rich lipoproteins. Those type 2 diabetic patients with high RBP4 plasma concentrations and who were TC carriers showed an increased incidence of hypertriglyceridemia (OR=7.46, P=0.010). CONCLUSION: RBP4 is associated with hypertriglyceridemia in type 2 diabetic patients. The RBP4 effect is conditioned by the presence of the APOA5-1131 T>C genetic variant.

A nuclear defect in the 4p16 region predisposes to multiple mitochondrial DNA deletions in families with Wolfram syndrome.

Wolfram syndrome is a progressive neurodegenerative disorder transmitted in an autosomal recessive mode. We report two Wolfram syndrome families harboring multiple deletions of mitochondrial DNA. The deletions reached percentages as high as 85-90% in affected tissues such as the central nervous system of one patient, while in other tissues from the same patient and from other members of the family, the percentages of deleted mitochondrial DNA genomes were only 1-10%. Recently, a Wolfram syndrome gene has been linked to markers on 4p16. In both families linkage between the disease locus and 4p16 markers gave a maximum multipoint lod score of 3.79 at theta = 0 (P<0.03) with respect to D4S431. In these families, the syndrome was caused by mutations in this nucleus-encoded gene which deleteriously interacts with the mitochondrial genome. This is the first evidence of the implication of both genomes in a recessive disease.

Respiratory chain activity and mitochondrial DNA content of nonpurified and purified pancreatic islet cells.

Considerable interest has recently focused on the possible role of alterations in mitochondrial activity and mutations in the mitochondrial genome for the development of non-insulin-dependent diabetes. Our study aimed at investigating the normal mitochondrial respiratory chain activity of nonpurified and purified islet cells to further explore whether some diabetic states are associated with alterations of mitochondrial oxidative processes. For this purpose, pancreatic islets were isolated from Wistar rats. Unpurified islet cells were obtained in the presence of trypsin and DNAse, and purified beta and non-beta cells were prepared by autofluorescence-activated sorting using a flowcytometer. Intact cell respiration and substrate oxidation in digitonin-permeabilized cells were measured polarographically with a Clark oxygen electrode in a micro-water-jacketed cell. Specific activity of the individual complexes of the respiratory chain was determined spectrophotometrically in unpurified islet cells. The relative amount of mitochondrial (mtDNA) and nuclear (nDNA) DNA in all three cell populations and in rat brain and skeletal muscle was estimated by dot blotting. The intact cell respiration of unpurified islet cells corresponds to the mean of values obtained for beta and non-beta islet cells. Oxidation rates of different substrates by permeabilized beta cells were lower than those for unpurified and non-beta cells. The amount of mtDNA relative to nDNA was similar in all three groups of cells, and was also similar to that obtained from brain and skeletal muscle. In summary, we have described mitochondrial respiratory chain activity in unpurified, beta, and non-beta islet cells. Our results represent an initial step in investigating the potential pathogenic role that alterations in oxidative phosphorylation could play in some diabetic states.

High-monounsaturated fat, olive oil-rich diet has effects similar to a high-carbohydrate diet on fasting and postprandial state and metabolic profiles of patients with type 2 diabetes.

Whether metabolic control in type 2 diabetes mellitus (DM) is best achieved with the traditional high-carbohydrate (CHO), low-fat diet or a low-CHO, high-fat diet is still controversial. In a randomized crossover study, we compared the effects of a low-fat (30% of daily energy) diet and a high-fat (40% of daily energy), high-monounsaturated-fat diet for 6 weeks each on fasting and postprandial glucose, insulin, and lipoprotein concentrations in 12 patients with well-controlled type 2 DM (fasting blood glucose, 176 +/- 54 mg/dL; hemoglobin A1c, 6.4% +/- 0.7%) and no overt dyslipidemia (serum total cholesterol, 235 +/- 43 mg/dL; triglycerides, 180 +/- 63 mg/dL). Home-prepared foods were used and olive oil was the main edible fat, accounting for 8% and 25% of daily energy requirements in the low-fat and high-fat diets, respectively. For postprandial studies, the same mixed meal containing 36% fat was used in both dietary periods. Body weight and fasting and 6-hour postprandial blood glucose, insulin, and lipoprotein levels were similar after the two diets. The mean incremental area under the curve of serum triglycerides 0 to 6 hours after the challenge meal, adjusted for baseline levels, did not change significantly after the high-fat diet compared with the low-fat diet (1,484 +/- 546 v 1,714 +/- 709 mg x 6 h/dL, respectively, P = .099). Mean postprandial triglyceride levels at 6 hours were increased about 2 times over fasting levels and were still greater than 300 mg/dL after either diet. A diet high in total and monounsaturated fat at the expense of olive oil is a good alternative diet to the traditional low-fat diet for patients with type 2 DM. However, ongoing postprandial hypertriglyceridemia with either diet points to the need for other therapies to decrease triglyceride-rich lipoproteins (TRL) and the inherent atherogenic risk in type 2 diabetics.

Follow-up study of the revascularization process of purified rat islet beta-cell grafts.

The revascularization of islets of Langerhans transplanted in heterotopic sites like the liver by portal vein embolization or the renal subcapsular space is a major process necessary for the viability of grafted cells. This process has been extensively studied by different techniques and the results have shown that islet revascularization is an early phenomenon that takes place soon after transplantation. In this report we have analyzed by a double indirect immunofluorescence technique, the revascularization process of purified endocrine islet beta-cells transplanted in the renal subcapsular space of syngeneic rats. Lewis rats were grafted with islets cultured for 24 h, with a suspension of purified beta-cells cultured for 24 h, and with a suspension of purified beta plus nonbeta-cells cultured for 24 h. Rats were killed at different days after implantation and the kidney bearing the grafts were snap frozen and immunohistochemically stained with a rabbit anti factor VIII antiserum (which labels endothelial cells). Immunocytochemical analysis revealed that cultured islets completed revascularization by days 3-5 after transplantation, as shown by the detection of capillary endothelial cells within and surrounding the islets. Within purified endocrine beta-cell grafts, the presence of numerous endothelial cells was not observed until days 10-14, indicating that revascularization of beta-cells with host vessels is not such an early phenomenon as it takes place in whole isolated islets. Conversely, the addition of a population of endocrine nonbeta-cells to the purified islet cell grafts, partially accelerated the revascularization of pure beta-cell grafts, which showed the presence of abundant capillary endothelial cells already at day 7 after transplantation, indicating that some other unidentified factors besides the absence of endothelial cells may explain the retardation of beta-cell grafts revascularization.

High proinsulin levels in late PRE-IDDM stage.

AIM: To analyse the fasting proinsulin levels in first degree relatives of patients with insulin-dependent diabetes mellitus (IDDM) with different risk for developing the disease. PATIENTS AND METHODS: Non siblings first degree relatives, 33, of IDDM patients were separated into three groups with different risk for developing IDDM: Group 1, 14 first degree relatives (eight male/six female), aged from 18 to 57 years, normal first phase insulin release (FPIR) in the intravenous glucose tolerance test, negative ICA; Group 2, 11 first degree relatives (six male/five female), aged from 16 to 62 years, normal FPIR and ICA < 20 JDF U; Group 3, eight first degree (six male/two female), from 16 to 52 years, FPIR diminished and ICA > 20 JDF U. All patients had normal oral glucose tolerance test at the initiation of the study. We tested fasting proinsulin (PRO) and insulin (IRI) levels by radioimmunoassay (RIA) and the PRO/IRI ratio. RESULTS: Four first degree from the group 3 developed IDDM after 2-32 months. No differences were observed in-fasting PRO levels and PRO/IRI ratio between the groups. However, the PRO (21.7 +/- 5.8 pmol/l) and PRO/IRI ratio (0.29 +/- 0.10) levels of the subjects who developed IDDM were significantly higher (P < 0.05) than those values obtained in subjects who did not developed the disease. CONCLUSION: these data indicate that fasting PRO levels and the PRO/IRI ratio may be an additional marker in post-puberty first-degree relatives of IDDM patients with immunological and metabolic evidence of high risk for developing the disease.

Effects of an individual intensive educational control program for insulin-dependent diabetic subjects with poor metabolic control.

The aim of our study was to evaluate the efficiency of an individual intensive educational control program on improving the metabolic control of insulin-dependent diabetic patients at short- and long-term follow-up. Fifteen insulin-dependent diabetic subjects with poor metabolic control (hemoglobin A1c > 9%) were included. At entry, their knowledge of diabetes (DKQ2 test), total energy intake and its distribution, insulin schedule, technical skill for insulin administration and self monitoring of blood glucose were evaluated. According to the initial evaluation, individual goals were stipulated and monitored in weekly visits. Individual life-style was particularly kept in mind. Thereafter, patients were switched to our ambulatory clinic for outpatients. At 1, 6, 12 and 24 months of follow-up, the items analyzed at the beginning were reevaluated. After 1 month, the program produced a significant decrease in hemoglobin A1c and an increase in knowledge of diabetes. The same beneficial effects were present at 6, 12 and 24 months evaluation compared to those values recorded at entry. There were neither major changes in dietary intake nor insulin schedule nor any increase in the frequency of hypoglycemic episodes. In conclusion, our program (5.2 +/- 0.8 weekly visits) significantly reduced and sustained hemoglobin A1c values close to those levels recommended by multicenter controlled trials. We consider that our program produced two major changes: a long-lasting improvement in knowledge of diabetes and an increase in self-monitoring blood glucose which provided the key for optimal self-regulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Cushing's disease and pregnancy: report of six cases.

We describe six pregnancies in five patients with Cushing's disease --four had undergone transsphenoidal surgery, with improvement but no cure of their hypercortisolism; the other woman became pregnant during initial work up. At conception, none of the patients were receiving specific treatment for hypercortisolism. Mean free urinary cortisol (FUC) prior to pregnancy was 430 nmol/24 h (normal range: 51-280). In two patients, FUC throughout pregnancy increased significantly, but no clinical progression was observed. FUC measured in 20 healthy pregnant women was found to rise above the normal non-pregnant range ( < 280 nmol/24 h) in the second (mean +/- 2 S.D. = 463 +/- 256 nmol/24 h; P < 0.01) and third trimester (424 +/- 210 nmol/24 h; P < 0.05). However, in the Cushing patients values were higher. Two pregnancies ended in spontaneous abortions, one resulted in an ectopic pregnancy, and the remaining three were followed to term of which one developed third trimester gestational diabetes, and her baby developed neonatal sepsis which resolved uneventfully. We conclude that despite high abortion and ectopic pregnancy rates, a remarkably uneventful and uncomplicated outcome with no clinical progression of cushingoid symptoms, was observed in two of the three pregnancies followed to term, despite significant increases in FUC.

[Diagnosis of Cushing's disease in pregnancy]. / Diagnóstico de la enfermedad de Cushing en la gestación.

The Cushing syndrome during pregnancy is very infrequent, being even more so that of hypophysary etiology despite corticotropic adenomas being more prevalent in fertile-aged women. Its diagnosis is difficult since it may be confused with the physiologic alterations of the cortisol and the ACTH which occur during pregnancy. The treatment is controversial. In the cases reported to date, pregnancy represented a worsening of the picture. The case of a patient diagnosed with Cushing disease during the first trimester of pregnancy is presented. The hypercorticism improved clinically and biochemically during the pregnancy with no maternofetal complications observed. The disease activity continued following delivery.

[Insulin treatment in diabetes mellitus type II: the usefulness of the breakfast test]. / Insulinización en la diabetes tipo II: utilidad de la prueba del desayuno.

BACKGROUND: Insulin treatment in patients with type-II diabetes mellitus (DMII) is normally undertaken by clinical criteria. The aim of the present was to study the efficacy of a standard mixed meal (breakfast test) to predict the need for insulin therapy to thereby evaluate whether it is possible to obtain more objective criteria for the indication of insulin treatment. METHODS: Fifty-six patients with DMII were studied to evaluate the need for insulin therapy over a one-year period. Serum glucose and basal C peptide and their maximum values were determined in all the patients following stimulation with the breakfast test. Insulin treatment was initiated according to exclusively clinical criteria during admission. The patients were followed as out patients for a minimum of 3 months. Treatment at the end of follow up (insulin or no insulin) was evaluated and the results of the test were retrospectively analyzed. RESULTS: The basal C peptide (BCP) values were significantly lower in the individuals requiring insulin in comparison to those who did not require insulin (mean +/- SD 0.64 +/- 0.28 versus 1.18 +/- 0.41 nmol/l, p < 0.0001) similar to what was found with the stimulated maximum C peptide values (MCP) (1.48 +/- 0.77 versus 2.49 +/- 0.63 nmol/l, p < 0.0001). On considering a BCP of less than 0.9 nmol/l for the patients with insulin treatment the sensitivity of BCP was 83.6% and the specificity 78.9%. For a BCP value of less than 1.9 nmol/l sensitivity was 77.7% and specificity 78.9%. Using the values together, sensitivity was 66.6% and specificity 84.4%. CONCLUSIONS: The breakfast test is useful to indicate the need for insulin therapy in patients with type II diabetes mellitus but is not more useful than a determination of isolated basal C peptide.

Fatty acid binding protein 4 is increased in metabolic syndrome and with thiazolidinedione treatment in diabetic patients.

OBJECTIVE: To study the role of FABP4 in the plasma of type 2 diabetic (T2D) subjects with and without metabolic syndrome (MS) and the impact of thiazolidinedione (TZD) treatment. METHODS AND RESULTS: FABP4 was analyzed in 274 individuals (169 T2D subjects and 105 controls). MS-T2D subjects had higher FABP4 levels than non-MS-T2D subjects and controls (53% and 76% increase, respectively, p<0.005). FABP4 levels in T2D subjects were positively correlated to the number of MS elements, obesity degree, adiponectin, triglycerides, lipoperoxides, C-reactive protein, age, systolic blood pressure and diabetes duration (p<0.05). Neither clinical or subclinical atherosclerosis, nor plasma levels of insulin, glucose or RBP4 were associated to FABP4. TZD-treated T2D subjects showed >30% higher FABP4 levels (p<0.05) than non-TZD-treated T2D. A subgroup study confirmed that TZD treatment prospectively increased FABP4 levels (p<0.05) along with an increase of peripheral blood mononuclear cell PPARgamma activity (p<0.05). Furthermore, in vitro studies showed that TZD treatment increased FABP4 mRNA, intracellular protein levels and extracellular secretion from human adipocytes. CONCLUSIONS/INTERPRETATION: FABP4 plasma concentrations are increased with the early presence of MS components, as well as inflammation and oxidation markers in T2D subjects. TZD increases FABP4 plasma concentrations, reflecting PPARgamma activation. FABP4 plasma measurements could be useful in the management of T2D subjects.

Localization and postoperative follow-up of a bronchial carcinoid tumor causing Cushing's syndrome by 111In-DTPA labelled octreotide scintigraphy.

Bronchial carcinoid tumor is the most frequent occult source of ectopic ACTH-dependent Cushing's syndrome, but its initial localization may be very difficult, as well as its postoperative follow-up. We here present the case of a 21-year-old man with Cushing's syndrome and biochemical findings suggesting an ectopic source of ACTH (lack of inhibition of cortisol after overnight 8-mg dexamethasone suppression test, and lack of response to h-CRH challenge). Chest CT-scan showed a node adjacent to the left lung hilium whose nature was confirmed by uptake of 111Indium-DTPA labelled octreotide scintigraphy. Surgical resection of the tumor consisted in an upper lobectomy of the left lung. Microscopic examination identified a typical carcinoid tumor. After surgery pituitary-adrenal function normalized and a second scintigraphy offered additional data on the absence of tumor remnants.

[Measurement of vibratory threshold in the diagnosis of diabetic neuropathy]. / Determinación del umbral vibratorio en el diagnóstico de la neuropatía diabética.

The usefulness of the quantitative measurement of vibration perception threshold (VPT) was assessed by a biothesiometer in the diagnosis of peripheral neuropathy in 36 patients with type I diabetes mellitus. The study included: a) clinical assessment (history and neurological examination); b) measurement of VPT at right metatarsus, right pretibial area and right metacarpus; c) electromiographical study (right peroneal, posterior tibial, right sural, right medial plantar); d) assessment of the autonomous nervous system (sympathetic and parasympathetic indexes); e) metabolic assessment (HbA1c at study and mean HbA1c in the previous year). The prevalence of peripheral neuropathy was 38%. VPT at metatarsal region in diabetic patients was higher than in controls (p < 0.05) and a positive correlation with evolution time of disease at metatarsal region (p < 0.05) and tibia (p < 0.05) was observed. Clinical symptoms and changes at examination correlated with VPT at metatarsus (p < 0.05) and tibia (p < 0.05). No relationship was observed between VPT and metabolic control. In conclusion, vibration threshold increases with evolution time in diabetes, but it was not influenced by metabolic control. Its measurement by a simple method, such as biothesiometer, could be useful in diagnosing peripheral neuropathy in clinically asymptomatic patients.