Remodelamento de partículas lipoprotéicas de alta densidade (HDL) e atividade antioxidante entre pacientes diabéticos e não diabéticos com doença aterosclerótica coronária / Remodeling of high-density lipoprotein particles (HDL) and antioxidant activity between diabetic and non-diabetic patients with coronary artery disease

sendo a doença aterosclerótica a de maior morbimortalidade. Além disso, a aterosclerose pode manifestar-se precocemente dada a presença de dislipidemias, processos inflamatórios e alterações metabólicas como a diabetes. OBJETIVO: avaliar se existem diferenças no remodelamento da HDL e atividade antioxidante entre pacientes diabéticos e não diabéticos com doença aterosclerótica. Ainda, identificar, quantificar e estimar biomarcadores relacionados ao remodelamento de partículas lipoprotéicas e ao risco cardiovascular em função da concentração de colesterol na HDL, colesterol livre total,LDL-C, apoB, apoA-I, atividade da paraoxonase 1 (PON1), razões de risco como TG/HDL-C, LDL-C/ApoB, HDL-C/apoA-I, PON1/apoA-I, apoA-I/ApoB e tamanho estimado de partículas de HDL, LDL, glicemia, insulina e HbA1c. MÉTODOS: foram selecionados por conveniência 69 pacientes do sexo masculino, entre 18 e 75 anos,oriundos da enfermaria de cardiologia do Hospital Ana Neri, subdivididos em dois subgrupos: diabéticos e não diabéticos, ambos, com doença aterosclerótica coronária.Foram utilizadas metodologias enzimáticas, imunoturbidimétricas e nefelometricas nesse estudo. RESULTADOS: dos achados da comparação direta entre os grupos apenas a glicemia de jejum foi significativamente diferente (Teste t; p<0,05). Embora não significante o valor do colesterol não esterificado (CL) foi, em média, quatro vezes maior nos diabéticos quando comparado aos não diabéticos. A análise de correlação linear mostrou achados importantes do ponto de vista fisiológico, como correlação positiva entre CL e HDL-C (r=0,617; p<0,01083) e razão apoA-I/apoB e insulina (r=0,489; p<0,02095) nos diabéticos, e correlação negativa entre PON1/apoA-I com CL (r=-0,499; p<0,0065) e HDL-C com HbA1c (r=-0,444; p<0,0324) nos pacientes não diabéticos. CONCLUSÃO: Os achados desse estudo mostram que o cálculo das razões utilizadas para a análise de risco cardiovascular foram importantes indicadores quando correlacionados com marcadores séricos sugestivos de risco cardiovascular na população masculina diabética deste estudo.

Introduction: cardiovascular diseases affect thousands of people around the world, and atherosclerotic disease is the one with the greatest morbidity and mortality. Furthermore, atherosclerosis may manifest early by the presence of dyslipidemia, inflammatory processes and metabolic disorders such as diabetes. Objective: to assess whether there are differences between HDL remodeling and antioxidant activity from diabetic and nondiabetic patients with coronary artery disease. Also, identify, quantify and evaluate biomarkers related to lipoprotein particles remodeling and cardiovascular risk depending on HDL cholesterol concentration, total free cholesterol, LDL-C, apoB, apoA-I, paraoxonase activity 1 (PON1), and risk ratios like TG/HDL-C, LDL-C/ApoB, HDLC/apoA-I, PON1/apoA-I, apoA-I/ApoB, HDL and LDL estimated particles size, glucose, insulin and HbA1c. Methods: we selected by convenience 69 male patients between 18 and 75 years, from the Cardiology Unit of Hospital Ana Neri, they were subdivided into two groups: diabetic and non-diabetic patients, both with coronary atherosclerosis. In these study were used enzymatic, immunoturbidimetric and nephelometric methodologies. Results: From the findings of the direct comparison between groups only fasting glucose was significantly different (t test; p <0.05). Although not significant, the value of non-esterified cholesterol (CL) was on average, four times higher in diabetics when compared to non-diabetics. Linear correlation analysis showed significant findings, from a physiological point of view, as positive correlation between CL and HDL-C (r = 0.617, p <0.01083) and apoA-I ratio/apoB and insulin (r = 0.489, p <0.02095) in diabetics, and negative correlation between PON1/apoA-I with CL (r = -0.499; p <0.0065) and HDL-C with HbA1c (r = -0.444; p <0.0324) in patients non-diabetic. Conclusion: the findings shows that the calculated ratio´s used for cardiovascular risk analysis were important indicators when correlated to serum markers suggestive of cardiovascular risk in the study diabetic male population.

[Clinical and laboratory parameters in patients with urolithiasis in the presence and absence of primary hyperparathyroidism].

The clinical and laboratory findings in 78 patients with various forms of urolithiasis depending on the presence of primary hyperparathyroidism (PHPT) were analyzed. PHPT was diagnosed in 17 patients. Group "without PHPT" and group "with PHPT" differed significantly in terms of parathyroid hormone (PTH) level, serum calcium, phosphorus, chloride, alkaline phosphatase, calciuria and kaliuria. In patients with staghorn calculi, PHPT was diagnosed in 12.5%, and staghorn calculi in the presence of PHPT were identified in 17.7% of cases. Hypercalciuria in the group "with PHPT" was detected in 82.4% of patients (all 3 patients with staghorn calculi), and in the group "without PHPT"--in 18% of patients (2 of 21 patients with staghorn calculi). Hyperoxaluria was observed in 42.3% of patients "without PHPT" and in 35.3% of patients "with PHPT", in 36.8% of patients with simple stones and in 57.2%--with staghorn calculi. In 39% of patients "without PHPT", secondary hyperparathyroidism (SHPT) was diagnosed. SHPT prevalence was 28% in patients with staghorn calculi, and 45% in patients with simple stones. In 87.5% of patients with hypomagnesemia, staghorn calculi were observed. Significant relationship between magnesium and triglycerides (r(s) = -0.296; P = 0.041), and magnesium and high-density lipoproteins (r(s) = 0.339; P = 0.032) in all patients with urolithiasis were revealed. Thus, the study found no association between staghorn nephrolithiasis and PHPT. Elevated PTH levels usually indicate SHPT rather than PHPT. In hypocalcemia, there was more strong association between PTH and calcium, in normocalcaemia--between PTH and magnesium.

Urinary high density lipoprotein--a possible marker for glomerular proteinuria.

High--resolution two--dimension electrophoresis technique for protein with silver staining was used to characterise urinary high density lipoprotein (HDL)--apolipoproteins. Sequential ultracentrufugation method was used to isolate urinary lipoprotein particles of the same density as serum HDL. Immunostaining of electroblotted proteins further confirmed the presence of HDL--Apos in urine. HDL--Apolipoprotein A--1, A--11 and C were identified in urine of normal subjects, diabetic patients and patients with biopsy proven glomerular proteinuria. An in-house ELISA method was used to quantify urinary HDL--Apo A--1. Selectivity indices were also determined. A high degree of association was found between selectivity index and urinary HDL--Apo A--1 (r = 0.87) and also between HFL--APO A--1 loss/24 h and total protein loss/24 h (r = 0.91). This appear to indicate that HDL loss in urine was a function of glomerular selectivity. Urinary HDL--Apo A--1 levels were significantly raised in the patients with glomerular proteinuria (p less than 0.01). HDL--Apo A--1 levels appear to be a marker for glomerular proteinuria. Consistent with glomerular proteinuria serum lipids and protein loss were significantly higher in patients with glomerular proteinuria (p less than 0.001) but HDL--Cholesterol was lower (p less than 0.001).

High-density lipoprotein apolipoproteins in urine: I. Characterization in normal subjects and in patients with proteinuria.

A high-resolution two-dimensional electrophoretic method for protein, with silver staining, has been used to characterize and identify urinary high-density-lipoprotein apolipoproteins (HDL-Apos) and their isoforms in healthy subjects and in patients with kidney disease. Analytical techniques based on both molecular mass and ultracentrifugal flotation properties were used to isolate urinary lipoprotein particles with characteristics identical to those of HDL in plasma. HDL-Apos identified in urine of normal subjects and patients with glomerular proteinuria were Apos A-I, A-II, and C. Five isoforms of Apo A-I were present. Immunostaining of electroblotted proteins further confirmed the presence of HDL-Apos in urine. Creatinine clearance rate was decreased in the patients with proteinuria, and ranged from 32.5 to 40 mL/min. Concentrations of cholesterol and triglycerides in serum were greater in the patients' group, whereas mean HDL-cholesterol (0.68, SD 0.10 mmol/L) and Apo A-I (0.953, SD 0.095 g/L) were significantly (each P less than 0.01) lower. Results of this study suggest that measurement of urinary Apo A-I will reflect excretion of HDL in urine.

High-density lipoprotein apolipoproteins in urine: II. Enzyme-linked immunoassay of apolipoprotein A-I.

We have developed a capture antibody, noncompetitive, enzyme-linked immunoassay for urinary apolipoprotein A-I (Apo A-I) in urine, with use of affinity-purified polyclonal antisera against Apo A-I. A 96-well microtiter plate format is used, with unconcentrated urine as sample and dilutions of serum or high-density lipoprotein (HDL) as standards. The intra- and interassay variation (CV) averaged 7.4% and 9.4%, respectively. The limit of detection is low (1.25 ng/L), and no cross-reactivity with Apo B, C, E, or A-II was detected. The mean (+/- SD) concentrations of Apo A-I in urine of patients with glomerular proteinuria were a thousandfold greater (38.4 +/- 23.1 mg/L) than in normal subjects (16.3 +/- 11.3 micrograms/L in men, 17.97 +/- 7.7 micrograms/L in women, a significant difference, P less than 0.001). Apo A-I measurements correlated very well (r = 0.92) with selectivity index assessment. The diurnal variation of the concentration of Apo A-I in urine appears to result from dilution related to fluid intake. This enzymatic method is easy to perform, can be used with large numbers of samples, and is adaptable for use in the routine clinical laboratory. The method holds promise for discriminating between normal and subclinical kidney disease populations by measuring the concentrations of urinary Apo A-I excreted on HDL particles.

Relation of hyperlipidemia in serum and loss of high density lipoproteins in urine in the nephrotic syndrome.

The mechanism leading to hyperlipidemia in the nephrotic syndrome is not fully understood but may be related in part to loss of high density lipoproteins in the urine of patients with nephrosis. To prove this hypothesis, we compared serum lipoprotein profiles with the excretion of high density lipoproteins in urine in 19 nephrotic patients. Serum cholesterol ranged from 19-152 (median value 45) mg/dl in very low density lipoproteins (VLDL), from 130-443 (median 186) mg/dl in low density lipoproteins (LDL) and from 19-64 (median 33) mg/dl in high density lipoproteins (HDL). Hyperlipoproteinemia was found in 17 patients, which was classified as phenotype IIa (Fredrickson) in 2, as phenotype IIb in 9 and as phenotype IV in 6 subjects. Two patients showed normal lipoprotein patterns. VLDL- and LDL-cholesterol were not found in detectable amounts in urine, whereas HDL-cholesterol was measured in low concentrations from 0.1-8.3 mg/24 h in all samples. There was no correlation between serum HDL-cholesterol and urinary HDL-cholesterol, but a positive correlation between serum LDL-cholesterol and urinary HDL-cholesterol (r = +0.54, p less than 0.05). However, the total amount of the daily urinary loss of HDL (less than 1% of total plasma HDL) seems not to be sufficient to explain hyperlipoproteinemia in the nephrotic syndrome.

Nontropical chyluria secondary to massive mesenteric adenitis. Case report with metabolic and immunologic studies.

This report describes metabolic and immunologic studies in a 17-year-old white man with nontropical chyluria secondary to massive mesenteric adenitis. Numerous red cells and mature lymphocytes were observed in the urine, and cystoscopic examination demonstrated chyle emanating from both ureteral orifices. Retrograde studies demonstrated pyelolymphatic backflow, and lymphangiography revealed prominent lymphaticocaliceal communications. Twenty-four-hour urinary studies showed proteinuria and lipiduria, which decreased after lymphangiography and a low-fat diet. Skin tests for delayed hypersensitivity were nonreactive, the lymphocyte count was decreased, and lymphocyte responses to phytohemagglutinin and pokeweed mitogen were normal. Chyluria ceased after interruption and ligation of the renal and mesenteric lymphatics.

A case of nephrotic syndrome with urinary excretion of lipoproteins.

A 47-year-old woman with nephrotic syndrome (membranous glomerulonephropathy) who excreted high, low density lipoproteins (HDL, LDL) which are almost similar to serum HDL and LDL, and small amount of slightly deformed very low density lipoprotein (VLDL) in the urine has been presented.

Apoproteins of high density lipoproteins in the urine of normal subjects.

Apoproteins of high density lipoproteins were detected in the urine of normal subjects after the urinary proteins were highly concentrated. By immunoelectrophoresis, all of the urinary apoproteins gave precipitin lines with similar electrophoretic mobility. This suggests that the various apoproteins are present in the same particle. The apoproteins were present only in the ultracentrifugal fraction of density greater than 1.24 g/ml. Neither apoprotein B nor apoprotein E were detected in the urine, suggesting that very low density and low density lipoproteins are not excreted in the urine of normal subjects.

Human intestinal lipoproteins. Studies in chyluric subjects.

To explore the role of the human intestine as a source of apolipoproteins, we have studied intestinal lipoproteins and apoprotein secretion in two subjects with chyluria (mesenteric lymphatic-urinary fistulae). After oral corn oil, apolipoprotein A-I (apoA-I) and apolipoprotein A-II (apoA-II) output in urine increased in parallel to urinary triglyceride. One subject, on two occasions, after 40 g of corn oil, excreted 8.4 and 8.6 g of triglyceride together with 196 and 199 mg apoA-I and on one occasion, 56 mg apoA-II. The other subject, after 40 g corn oil, excreted 0.3 g triglyceride and 17.5 mg apoA-I, and, after 100 g of corn oil, excreted 44.8 mg apoA-I and 5.8 mg apoA-II. 14.5+/-2.1% of apoA-I and 17.7+/-4.3% of apoA-II in chylous urine was in the d < 1.006 fraction (chylomicrons and very low density lipoprotein). Calculations based on the amount of apoA-I and apoA-II excreted on triglyceride-rich lipoproteins revealed that for these lipid loads, intestinal secretion could account for 50 and 33% of the calculated daily synthetic rate of apoA-I and apoA-II, respectively. Similarly, subject 2 excreted 48-70% and 14% of the calculated daily synthetic rate of apoA-I and apoA-II, respectively. Chylous urine contained chylomicrons, very low density lipoproteins and high density lipoproteins, all of which contained apoA-I. Chylomicrons and very low density lipoproteins contained a previously unreported human apoprotein of 46,000 mol wt. We have called this apoprotein apoA-IV because of the similarity of its molecular weight and amino acid composition to rat apoA-IV. In sodium dodecyl sulfate gels, chylomicron apoproteins consisted of apoB 3.4+/-0.7%, apoA-IV 10.0+/-3.3%, apoE 4.4+/-0.3%, apoA-I 15.0+/-1.8%, and apoC and apoA-II 43.3+/-11.3%. Very low density lipoprotein contained more apoB and apoA-IV and less apoC than chylomicrons. Ouchterlony immunodiffusion of chylomicron apoproteins revealed the presence of apoC-I, apoC-II, and apoC-III. In contrast, plasma chylomicrons isolated during a nonchyluric phase revealed a markedly altered chylomicron apoprotein pattern when compared with urinary chylomicrons. The major apoproteins in plasma chylomicrons were apoB, apoE, and the C peptides: no apoA-I or apoA-IV were present in sodium dodecyl sulfate gels indicating that major changes in chylomicron apoproteins occur during chylomicron metabolism. When incubated in vitro with plasma, urinary chylomicrons lost apoA-I and apoA-IV and gained apoE and apoC. Loss of apoA-I and apoA-IV was dependent upon the concentration of high density lipoproteins in the incubation mixture. These studies demonstrate that the human intestine secretes significant amounts of apoA-I and apoA-II during lipid absorption. Subsequent transfer of apoproteins from triglyceride-rich lipoproteins to other plasma lipoproteins may represent a mechanism whereby the intestine contributes to plasma apoprotein levels.

Urinary high density lipoprotein in minimal change glomerular disease and chronic glomerulopathies.

Serum lipids and lipoproteins and urinary apolipoprotein A (Apo A) were determined in two groups of patients. One group consisted of 11 children (ages ranging from 4 to 14 years) with minimal change glomerular disease. The other group consisted of 13 patients, eight less than 19 years old five adults, with different types of chronic glomerulopathy. Elimination of urinary lysozyme was a feature of chronic glomerulopathies, and creatinine clearances were also significantly lower in this group. Patients with chronic glomerulopathies had significantly lower HDL cholesterol and Apo A concentrations in their sera. In contrast, urinary Apo A concentrations were significantly higher in patients with chronic glomerulopathies, who also showed significantly lower urinary protein selectivities. Lipoprotein electrophoresis of urines containing Apo A showed distinct high-density lipoprotein (HDL) fractions, suggesting that HDL is eliminated in the urine as a result of increased glomerular permeability. This is also supported by a correlation coefficient of 0.77 between the selectivity indices and the ratio of urinary Apo A to total proteinuria. The determination of urinary Apo A appears to give valuable diagnostic information in patients with glomerular disease. According to our results the absence of urinary Apo A is very suggestive of minimal change glomerular disease.

High density lipoprotein metabolism in man.

The turnover of (125)I-high density lipoprotein (HDL) was examined in a total of 14 studies in eight normal volunteers in an attempt to determine the metabolic relationship between apolipoproteins A-I (apoA-I) and A-II (apoA-II) of HDL and to define further some of the determinants of HDL metabolism. All subjects were first studied under conditions of an isocaloric balanced diet (40% fat, 40% carbohydrate). Four were then studied with an 80% carbohydrate diet, and two were studied while receiving nicotinic acid (1 g three times daily) and ingesting the same isocaloric balanced diet. The decay of autologous (125)I-HDL and the appearance of urinary radioactivity were followed for at least 2 wk in each study. ApoA-I and apoA-II were isolated by Sephadex G-200 chromatography from serial plasma samples in each study. The specific activities of these peptides were then measured directly. It was found that the decay of specific activity of apoA-I and apoA-II were parallel to one another in all studies. The mean half-life of the terminal portion of decay was 5.8 days during the studies with a balanced diet.Mathematical modeling of the decay of plasma radioactivity and appearance of urinary radioactivity was most consistent with a two-compartment model. One compartment is within the plasma and exchanges with a nonplasma component. Catabolism occurs from both of these compartments. With a balanced isocaloric diet, the mean synthetic rate for HDL protein was 8.51 mg/kg per day. HDL synthesis was not altered by the high carbohydrate diet and was only slightly decreased by nicotinic acid treatment. These perturbations had effects on HDL catabolic pathways that were reciprocal in many respects. With an 80% carbohydrate diet, the rate of catabolism from the plasma compartment rose by a mean of 39.1%; with nicotinic acid treatment, it fell by 42.2%. Changes in the rate of catabolism from the second compartment were generally opposite those in the rate of catabolism from the plasma compartment, suggesting that these two catabolic pathways may be reciprocally regulated.