Aerobic exercise training improves the role of high-density lipoprotein antioxidant and reduces plasma lipid peroxidation in type 2 diabetes mellitus.

In this study, we analyzed the effect of aerobic exercise training (AET) and of a single bout of exercise on plasma oxidative stress and on antioxidant defenses in type 2 diabetes mellitus (DM) and in healthy control subjects (C). DM and C did not differ regarding triglycerides, high-density lipoprotein cholesterol (HDL-c), insulin, and HOMA index at baseline and after AET. To measure the lag time for low-density lipoprotein (LDL) oxidation (LAG) and the maximal rate of conjugated diene formation (MCD), participants' plasma HDL(2) and HDL(3) were incubated with LDL from pooled healthy donors' plasma. In the presence of HDL(3), both LAG and MCD were similar in C and DM, but only in DM did AET improve LAG and reduce MCD. In the presence of HDL(2), the lower baseline LAG in DM equaled C after AET. MCD was unchanged in DM after AET, but was lower than C only after AET. Furthermore, after AET plasma thiobarbituric acid-reactive substances were reduced only in DM subjects. Despite not modifying the total plasma antioxidant status and serum paraoxonase-1 activity in both groups, AET lowered the plasma lipid peroxides, corrected the HDL(2), and improved the HDL(3) antioxidant efficiency in DM independent of the changes in blood glucose, insulin, and plasma HDL concentration and composition.

Effect of fat distribution on the pharmacokinetics of cortisol in obesity.

OBJECTIVE: Patients with predominantly upper body obesity are at greater risk for developing diabetes mellitus, hyperlipidemia, hypertension, and cardiovascular disease. Little is known about the mechanisms involved in the regulation of regional body distribution. It has been accepted that the accumulation of fat into adipose tissue depends on regional metabolic regulation of adipocytes and that glucocorticoids play a role in this mechanism. The aim of the present study is to investigate how the pharmacokinetics of cortisol correlate to intraabdominal and subcutaneous fat distribution in obese patients. METHODS: A group of 24 obese patients (13 males and 11 females) were submitted to a CT scan for intraabdominal and subcutaneous fat area evaluation. A 30-min cortisol infusion (0.25 mg/kg) was administered and plasma cortisol was measured over 6 hours. RESULTS: Patients with larger intraabdominal fat areas were found to have a higher cortisol clearance than those with lower intraabdominal fat areas. Cortisol clearance (both, absolute and body-weight corrected) showed a statistically significant correlation with intraabdominal fat area, either expressed by waist-hip ratio or obtained by computerized tomography. CONCLUSIONS: These findings indicate a more effective clearance capability for cortisol in patients with central obesity resulting in lowered cortisol plasma levels despite an increased cortisol secretion observed in this patient group.

Plasma cholesteryl ester transfer protein concentration, high-density lipoprotein cholesterol esterification and transfer rates to lighter density lipoproteins in the fasting state and after a test meal are similar in Type II diabetics and normal controls.

Rates of ester formation from [3H]cholesterol and of [3H]cholesteryl ester transfer from the HDL-containing plasma fraction to lipoproteins of lighter densities (apo B-containing LP) and plasma cholesteryl ester transfer protein concentration (CETP) were measured in normotriglyceridemic Type II diabetics (n = 11) and normal controls (n = 10) both in the fasting state and 4 h after a standard milk-shake test meal (50g of fat/m of body surface). The percent of [3H]cholesteryl ester synthesis was measured in a plasma [3H]cholesterol-HDL containing preparation incubated for 30 min and the [3H]cholesteryl ester transfer was measured upon precipitation of apo B-containing lipoproteins with dextran sulphate/MgCl2 following a 2 h period of plasma incubation with [3H]cholesteryl ester-HDL. The test meal significantly increased the plasma triglyceride concentration and to a similar extent in diabetics and in normal controls. Both a HDL-[3H]cholesteryl ester synthesis and transfer rates were equally stimulated in diabetics and in controls. When data were expressed by the concentration of plasma triglycerides, cholesteryl ester formation and transfer rates were similar in the alimentary and fasting periods, and when expressed per apo B concentration, cholesteryl ester transfer rates rose during the alimentary period in both diabetics and controls indicating that there was a net gain of cholesteryl ester per apo B lipoprotein. Plasma CETP mass, and neutral lipid transfer activity were similar in diabetics and normal controls demonstrating that the reverse transport of cholesterol through the apo B lipoprotein pathway is not altered in normotriglyceridemic Type II diabetics.

Plasma cholesteryl ester synthesis, cholesteryl ester transfer protein concentration and activity in hypercholesterolemic women: effects of the degree of saturation of dietary fatty acids in the fasting and postprandial states.

Hypercholesterolemic women (n = 19) sequentially maintained on a long-term saturated (SAT) or a polyunsaturated (PUFA) fatty acid-rich diet, respectively, were studied in the fasting state and after a meal rich in SAT or PUFA. When apo B-containing lipoprotein was excluded from plasma the in vitro HDL-14C-cholesterol esterification rate was identical for the saturated (SAT) and polyunsaturated (PUFA) fatty acid diets, and did not increase during the postprandial period. Rates of transfer of 14C-cholesteryl ester to apo B-containing lipoproteins from HDL were also similar for both diets in the fasting state and increased to the same extent in the postprandial period in parallel with the rise in plasma triglycerides. When transfer data were related to the plasma concentration of apo B, the gain of cholesteryl ester by the triglyceride-containing particles (VLDL + LDL) also increased in the postprandial period to a similar extent for both diets. Cholesteryl ester transfer protein (CETP) concentration measured by radioimmunoassay was similar during both experimental diets, although greater in the postprandial period for the PUFA diet. The rate limiting factor for CETP-mediated transfer of HDL-derived cholesteryl ester (CE) was the plasma triglyceride concentration, that is, the content of triglycerides per lipoprotein particle and the quantity of TG-containing particles (VLDL + LDL). In contrast, the fatty acid composition of these particles had less effect on CETP-mediated CE transfer.

Simultaneous measurements of chylomicron lipolysis and remnant removal using a doubly labeled artificial lipid emulsion: studies in normolipidemic and hyperlipidemic subjects.

An artificial chylomicron-like lipid emulsion doubly labeled with tri[(N)3H]oleoylglycerol ([3H]TO) and cholesteryl [1-14C]oleate ([14C]CO) was infused intravenously into human subjects with the purpose of simultaneously measuring the plasma disappearance rates (residence time, RT) of [14C]CO, which represents solely the splanchnic organ uptake of the remnant chylomicron core, and of [3H]TO, which combines the remnant disappearance with the shedding off of chylomicron triglycerides by the action of lipoprotein lipase. Thus, the fraction of the particle triglyceride content that is removed before the remnant is taken up is expressed as a delipidation index (DI = 1 - RT of [3H]TO/RT of [14C]CO. The present procedure has an advantage over the use of chylomicrons labeled with retinyl ester or radioactive triglycerides alone that represent, respectively, the chylomicron remnant or the whole particle metabolism only. When normal subjects as well as primary hyperlipidemic subjects were studied, the plasma triglyceride concentration was directly related to [14C]CO RT and [3H]TO RT, but inversely related to the delipidation index. There may be different patterns of relations between these parameters of chylomicron metabolism in primary and in secondary hyperlipidemias, as well as under the action of drugs that influence the metabolism of lipoproteins.

Alteraçöes organicas no diabetes / Organic alterations in diabetes

Os autores fazem uma revisao e analise critica dos diversos tipos de lesoes organicas que aparecem durante a evolucao do diabetes, discutindo alguns aspectos fisiologicos e clinicos

Sindrome de Cushing induzida pelo uso de dexametasona por via nasal sob a forma de spray. Relato de tres casos. / Cushing's syndrome induced by the use of dexamethasone by nasal route under spray form. Report of 3 cases

Sao apresentados tres casos de pacientes com Sindrome de Cushing induzidos pela administracao de Dexametasona sob a forma de spray nasal. Em todos esses casos ha evidencias de inibicao do eixo hipotalamo-pituitaria-adrenal. Em nenhum deles a funcao adrenal foi restaurada ate o momento, pois os pacientes ainda requerem o emprego de administracao oral de corticoide para sua manutencao