Elevated glucose level at 30 minutes during an oral glucose tolerance test in obese adolescents: a new disorder of glucose tolerance.

We observed glucose levels >140 mg/dL measured at 30 minutes (min) during an oral glucose tolerance test (OGTT) in some obese patients. We aimed to investigate the significance of this finding by comparing lipid profiles, insulin resistance indices, and systemic inflammatory mediators between obese adolescents with normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and elevated glucose levels at 30 min. The study involved 80 obese (body mass index >95(th) percentile for age and sex) adolescents (48 female, 32 male) between 11 and 16 years of age. Depending on OGTT results, patients were divided into NGT and IGT groups. The third group was recruited from the NGT group as having glucose levels > 140 mg/dL at 30 minutes. Lipid profiles, [interleukin-6 (IL-6)], neopterin, and lipoprotein associated phospholipase A2 (Lp-PLA2)] were assessed. Neopterin and Lp-PLA2 levels were significantly higher in obese adolescents with elevated glucose levels at 30 min. compared with those in both NGT and IGT groups (p=0.013, and 0.004, respectively). In these adolescents, IL-6 levels were significantly higher only than the NGT group (p=0.01). In logistic regression analysis, IL-6, neopterin and Lp-PLA2 levels were detected to be related to high blood glucose levels at 30 min (OR 1.11, p=0.01; OR 9.03, p=0.013; OR 1.01, p=0.004 respectively). Obese adolescents with elevated glucose levels at 30 min. demonstrated higher inflammatory mediators levels, which were atherosclerotic indicators, than obese adolescents with NGT and IGT. These results suggest that glucose levels >140 mg/dL measured at 30 min during an OGTT may be a new disorder of glucose tolerance in obesity.

Do cardiac risk factors affect the homocysteine and asymmetric dimethylarginine relationship in patients with coronary artery diseases?

OBJECTIVES: Elevated homocysteine (Hcy) concentrations have been shown to be a risk factor for atherosclerotic vascular disease and thrombosis. Increased asymmetric dimethylarginine (ADMA) levels have been implicated in the pathogenesis of numerous conditions affecting the cardiovascular system. In this study, the influence of cardiovascular risk factors and other variables on Hcy and ADMA relationship in patients with coronary artery disease (CAD) was investigated. DESIGN AND METHODS: Seventy-five patients with CAD were divided into three tertiles according to their Hcy levels. The effect of age, gender, blood pressure, lipid profile, renal function, and the presence of diabetes, insulin resistance, heart failure, inflammation, overweight, smoking and severity of coronary atherosclerosis on Hcy and ADMA relationship was evaluated. RESULTS: ADMA concentrations of patients in the middle and highest Hcy tertiles were significantly higher than the patients in the lowest tertile. When ADMA concentrations were adjusted for demographic, clinical and laboratory variables, the significant differences in ADMA concentrations between the tertiles were preserved. ADMA levels positively correlated with Hcy. Homocysteine levels positively correlated with serum creatinine and NT-proBNP concentrations and negatively correlated with glomerular filtration rates. Stepwise multiple regression analysis revealed Hcy as the unique predictor of ADMA levels. CONCLUSION: Homocysteine concentration has an effect on ADMA levels. There is a strong correlation between Hcy and ADMA. Cardiovascular risk factors do not have an influence on this relationship.

Relation between NT-proBNP levels, iron overload, and early stage of myocardial dysfunction in ß-thalassemia major patients.

BACKGROUND: Heart failure (HF) secondary to myocardial iron loading remains the leading cause of death in ß-thalassemia major (ß-TM) patients. The early diagnosis and treatment of HF in these patients is related to survival. We aimed to evaluate myocardial performance using conventional and tissue Doppler echocardiography and its relation to plasma NT-proBNP levels and iron overload indices in ß-TM patients with preserved systolic function. METHODS: The study population included 49 ß-TM patients (24.0 ± 4.2 years) and 48 age-matched healthy controls. Doppler-echocardiographic study was performed and blood samples for NT-proBNP measurements were drawn on the third day following blood transfusion. Patients were divided as group-1, without diastolic dysfunction: E/E' ratio < 9 and group-2, with suspected diastolic dysfunction: E/E' ratio ≥ 9. RESULTS: NT-proBNP levels and E/E' ratio were increased in patients compared with controls (P < 0.001 and P < 0.001) but did not correlate with each other. A strong positive correlation was detected between NT-proBNP levels and mean ferritin levels in ß-TM patients (r(s) = 0.939; P < 0.001). Median NT-proBNP levels were significantly higher in group-1 in comparison to controls [51.2 (41.51-113.5) vs 30.1 (17.97-68.16) ng/mL, P < 0.01]. NT-proBNP levels were also increased in group-2 in comparison to group-1 but this increase was not statistically significant. CONCLUSION: NT-proBNP secretion begins in the early phase of the disease before the increase in diastolic pressure becomes overt. While there was a strong correlation between the plasma NT-proBNP levels and iron overload, there was no correlation between NT-proBNP levels and diastolic dysfunction parameters in patients in the third decade of life.

Inflammatory marker levels in obese adolescents with glucose intolerance: increased chitotriosidase activity.

OBJECTIVES: Existence of low grade persistent inflammation in obese children may increase the risk of metabolic and cardiovascular events. The aim was to determine whether glucose intolerance has an influence on inflammatory markers in obese adolescents. DESIGNS AND METHODS: 45 obese adolescents (mean BMI: 30.34±5.42 kg/m²) were grouped as normal or impaired glucose tolerance. IL-6 and CRP levels were analyzed by commercially available kits. Chitotriosidase activity was measured by a fluorescence method and neopterin levels were determined by ELISA. Data were expressed as mean±SD. RESULTS: IL-6 and CRP levels were similar in the two groups. Serum neopterin levels were not different between the groups. The chitotriosidase activity was significantly higher in the IGT group than NGT (124.33±51.97 µmol/L/h vs 84.50±53.99 µmol/L/h, p=0.04). CONCLUSION: Serum chitotriosidase activity is increased in obese adolescents with impaired glucose tolerance.

Fibroblast growth factor-19 levels in type 2 diabetic patients with metabolic syndrome.

This study aimed to examine fibroblast growth factor-19 (FGF-19) in type 2 diabetic (T2DM) patients with metabolic syndrome (MetS) and to evaluate the relationship between FGF-19 and other cardiovascular risk factors, such as atherogenic index of plasma (AIP) and hsCRP. 26 T2DM patients with MetS and 12 healthy controls were enrolled in the study. Serum FGF-19 levels were measured by sandwich ELISA, and compared with other cardiovascular risk factors; lipid profile, AIP, glucose, HbA1c, and hsCRP. AIP was calculated as log (TG/HDL-c). The median (1-3.quartile) FGF-19 levels in T2DM patients with MetS and healthy controls were 122.90 (108.63-237.60) pg/ml and 293.45 (153.64-370.31) pg/ml, respectively (P=0.003). Patients were also grouped by body mass index (BMI) <30 kg/m(2) (n=13) and ≥30 kg/m(2) (n=13) with median (1-3.quartile) FGF-19 values 168.70 (113.54-275.77) pg/mL and 115.89 (97.94-200.40) pg/mL, respectively (P=0.007). Significant negative correlations were found between FGF-19 and BMI, triglyceride, log (TG/HDL-c), hsCRP, and HbA1c (r=-0.526, P=0.001; r=-0.327, P=0.05; r=-0.312, P=0.05; r=-0.435, P=0.006; r=-0.357, P=0.028, respectively). We showed that FGF-19 levels are low in T2DM patients with MetS. The negative relationship between FGF-19 and several known cardiovascular risk factors such as TG, log (TG/HDL-c), hsCRP and HbA1c in diabetic patients with MetS suggests that FGF-19 can be used as a contributing marker.

The detection of left ventricular diastolic dysfunction in hypertensive patients: Performance of N-terminal probrain natriuretic peptide.

AIM: Diastolic dysfunction (DD) results in increased cardiovascular risk in hypertensives. We studied the performance of N-terminal probrain natriuretic peptide (NT-proBNP) in detecting DD. MATERIALS AND METHODS: 241 hypertensive patients admitted to cardiology polyclinics were included in this study. They were grouped according to the presence of DD. Group 1: Essential hypertensive patients without DD (n= 119); group 2: essential hypertensive patients with DD (n= 122). All underwent trans-thoracic echocardiography for the evaluation of transvalvular flow, morphology, left ventricular wall motion abnormalities and ejection fraction. NT-proBNP levels were measured by an electrochemiluminescence immunoassay. RESULTS: The systolic blood pressure (BP) (mean+/-SD) was 140+/-12 mmHg in group 1 and 144+/-16 mmHg in group 2 (p=0.049), the diastolic BP (mean+/-SD) was 88+/-10 mmHg in group 1 and 90+/-14 mmHg in group 2 (p=0.043). The median (1st-3rd quartile) NT-proBNP level in group 2 was significantly higher than group 1 [121.05 (61.03-207.66) and 31.17 (17.07-54.09) pg/ml, respectively (p<0.001)]. In the receiver operating characteristics analysis, the area under the curve was 0.862 (95% CI 0.816-0.908). At the cut-off of 45 pg/ml, sensitivity was 86.9%, specificity was 62.4%, and at the cut-off 65 pg/ml, sensitivity was 74.6%, specificity was 83.8%. CONCLUSION: Plasma NT-proBNP levels may be useful for identifying patients with DD and it is conceivable to use a cut-off level 65 pg/ml as a "rule in" test.

Diagnostic accuracy of N-terminal pro-brain natriuretic peptide in the evaluation of postoperative left ventricular diastolic dysfunction.

We compared the diagnostic accuracy of N-terminal prohormone brain natriuretic peptide (NT-proBNP) with that of echocardiography in the evaluation of left ventricular diastolic dysfunction after coronary artery bypass grafting. Thirty patients were studied prospectively. Patients who had recent myocardial infarction, unstable angina pectoris, or low ejection fraction with systolic dysfunction were excluded. Two blood samples were obtained: before anesthetic induction and on the 7th postoperative day. Levels of NT-proBNP were measured by electrochemiluminescence immunoassay. Comprehensive echocardiographic Doppler examinations were performed on admission and on the 7th postoperative day. Relationships between NT-proBNP levels and echocardiographic indices were evaluated by correlation, multiple linear regression, and receiver-operating characteristic curve analysis. There were significant and correlated worsenings in diastolic stage as determined both by echocardiographic indices and NT-proBNP levels. Early transmitral-to-early diastolic annular velocity ratio (E/Ea) was found to correlate with both NT-proBNP and postoperative diastolic functional stage (r=0.78, P <0.001). Mitral E/Ea was significantly more sensitive than were NT-proBNP levels in predicting diastolic functional stage. The area under the receiver-operating characteristic curve for NT-proBNP was significantly lower than that of mitral E/Ea (mean difference, 0.12; P=0.024). The NT-proBNP had 87.5% sensitivity and 55% specificity, whereas E/Ea had 87.5% sensitivity and 86.4% specificity. Plasma NT-proBNP levels are significantly related to mitral E/Ea ratio, which is a predictor of diastolic stage. Therefore, elevated NT-proBNP levels may indicate the time for a Doppler echocardiographic evaluation and identify a subgroup of patients at high risk who need closer monitoring during the early postoperative period.

Pleural fluid neopterin levels in tuberculous pleurisy.

OBJECTIVES: Neopterin is produced by stimulated macrophages under the influence of gamma interferon of lymphocyte origin. It is regarded as a biochemical marker of cell-mediated immune response. This study was designed to assess the diagnostic value of pleural fluid neopterin levels in tuberculous pleurisy in comparison with adenosine deaminase activity. DESIGN AND METHODS: Pleural fluid adenosine deaminase (ADA) activity and neopterin levels were measured in 16 patients with tuberculous pleurisy (TP) and 19 patients with malignant pleurisy (MP). ADA activity was determined by a colorimetric method, whereas neopterin levels were determined by a reversed-phase liquid chromatography technique. All values were given as median (min-max). RESULTS: The mean age was 45.43+/-20.39 years in the TP group and 60.42+/-11.02 years in the MP group (p=0.026). The median pleural fluid ADA activity was 51.75 U/L (3.50-62.40 U/L) in the TP group and was 2.30 U/L (1-8.20 U/L) in the MP group. The difference was statistically significant (p<0.001). The median pleural fluid neopterin levels were 13.15 nmol/L (1.86-59.50 nmol/L) and 2.44 nmol/L (0.92-27.60 nmol/L) in the TP group and the MP group, respectively (p=0.021). In order to evaluate the diagnostic value of pleural fluid neopterin concentrations, receiver-operating-characteristic curve analysis was performed. CONCLUSION: Pleural fluid neopterin concentration is significantly higher in TP when compared to MP, however when compared, its clinical use as a diagnostic marker is not valuable as ADA.

Serum N-terminal-pro-B-type natriuretic peptide (NT-pro-BNP) levels in hyperthyroidism and hypothyroidism.

E Natriuretic peptides represent a novel diagnostic tool in the assessment of heart failure. N-terminal-pro-B-type natriuretic peptide (NT-proBNP), a member of the natriuretic peptid family, is produced and released from cardiac ventricles. Changes in cardiac functions are observed in thyroid dysfunctions. The aim of this study was to assess the changes in serum NT-proBNP levels and to evaluate impact of thyroid hormones on serum NT-proBNP in patients with hyperthyroidism and hypothyroidism. Serum NT-proBNP levels were measured in 21 patients with hyperthyroidism and in 24 patients with hypothyroidism and compared with 20 healthy control subjects. Patients without cardiac disease were included into the study as well. Serum NT-proBNP levels were measured by electrochemiluminescence immunoassay. Serum NT-proBNP levels were higher in hyperthyroid patients than in hypothyroid patients and in control subjects, with mean values of 239.03 +/- 47.33, 45.97 +/- 13.48, 55.57 +/- 13.01 pg/ml, respectively (p < 0.0001). Serum NT-proBNP and thyroid hormones were correlated in all patients. Moreover, there was a significant positive correlation between serum NT-proBNP and serum free T4 (FT4) levels (r = 0.549, p = 0.012) in hyperthyroidic patients. Multiple regression analyses demonstrated that increasing FT4 was independently associated with a high serum NT-proBNP levels, whereas heart rate was not in hyperthyroid patients. Serum NT-proBNP levels are higher in the hyperthyroid state as compared with the hypothyroid and euthyroid state. Thyroid dysfunction affects serum NT-proBNP levels, possibly influencing the secretion of the peptide. Therefore, thyroid function has to be considered when evaluating high serum NT-proBNP levels in patients without cardiac dysfunction.

Increased serum neopterin levels in women with polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) occurs in 5-10% of premenopausal women. Studies suggest that PCOS is associated with increased risk of coronary heart disease (CHD). To investigate this relationship, 15 PCOS women (group 1) and 10 healthy women (group 2) were studied. Blood leukocyte counts (white blood cells, WBC) and serum levels of total cholesterol, HDL-cholesterol, LDL-cholesterol, sensitive C-reactive protein (sCRP), and neopterin were measured in the 2 groups. There were no significant differences in serum total cholesterol, HDL-cholesterol, or LDL-cholesterol concentrations between groups 1 and 2. Blood WBC counts and serum levels of neopterin and sCRP were significantly higher in group 1 than group 2. The median (min-max) levels were: WBC, group 1: 8.05 (5.10-9.70) cells x 10(9)/L, group 2: 6.25 (4.70-9.70) cells x 10(9)/L (p <0.01); neopterin, group 1: 10.6 (7.5-49.5) nmol/L, group 2: 9.6 (6.5-12.9) nmol/L (p < 0.05); and sCRP, group 1: 7.0 (1.2-12.0) mg/L, group 2: 2.0 (0.1-12.0) mg/L (p <0.01). This study shows that blood WBC counts and serum sCRP and neopterin levels are significantly elevated in women with PCOS. These findings support an increased risk for early-onset cardiovascular disease in women with PCOS. This is the first report that women with PCOS have higher serum neopterin levels than healthy women with regular menstrual cycles.

C-reactive protein and neopterin levels in healthy non-obese adults.

BACKGROUND: Obesity and increased waist-to-hip ratio, emphasizing the importance of truncal obesity, have been found to correlate positively with increased cardiovascular disease risk and mortality. Owing to the inflammatory nature of atherosclerosis, the aim of our study was to find possible correlations between body mass index and waist-to-hip ratio, and the inflammatory markers C-reactive protein (CRP) and neopterin in healthy lean and overweight adults. METHODS: A total of 49 healthy adults (mean age 42.4 +/- 1.8 years, 32 females and 17 males) were classified according to their body mass index (BMI) and waist-to-hip ratio values. CRP and neopterin levels were measured. RESULTS: CRP levels were found to be significantly higher in the group with BMI > or = 25 kg/m2 compared to the group with BMI < 25 kg/m2 (p = 0.014). Subjects with increased waist-to-hip ratio displayed significantly higher serum CRP and neopterin levels (p = 0.014 and p = 0.033, respectively) compared with the group in which the waist-to-hip ratio was < 0.9. A strong positive correlation was found between CRP and BMI in the whole group (r = 0.658, p = 0.0001). CONCLUSIONS: Grouping overweight subjects according to their waist-to-hip ratio, which is an indicator of truncal obesity, seems to be convenient in studying the inflammatory process in relation to the elevation of adipose tissue. Elevated CRP and neopterin levels may be useful in the assessment of cardiovascular risk in overweight as well as obese subjects.

Impact of renal function or folate status on altered plasma homocysteine levels in hypothyroidism.

Hyperhomocysteinemia is an independent risk factor for coronary, peripheral and cerebrovascular diseases. Moderately elevated total homocysteine (tHcy) levels have been reported in patients with overt hypothyroidism. Plasma tHcy concentration is affected by several physiological factors and is elevated under conditions of impaired folate and cobalamin status and in renal failure. The aim of this study was to assess plasma tHcy concentrations and to evaluate the role of potential determinants of plasma tHcy levels in hypothyroid patients. Fasting plasma tHcy, serum homocysteine-related vitamins folate and vitamin B(12), serum cystatin C (CysC) and creatinine, were determined in 22 hypothyroid patients and compared with 25 healthy control subjects. Creatinine clearance (CCr) was calculated using the Cockroft-Gault formula. Plasma tHcy levels were determined by HPLC with fluorescence detection and serum CysC by automated particle enhanced immunoturbidimetry. Plasma tHcy, creatinine levels were significantly higher, and serum CysC levels, and creatinine clearance values were lower in hypothyroid patients than in control subjects. Folate levels were lower in hypothyroidic group compared to the control group. There were no differences in vitamin B(12) levels between hypothyroid and control groups. Positive correlation was noted between tHcy and creatinine levels in hypothyroid patients (r = 0.596); however, an inverse correlation was found between tHcy and folate levels (r = -0.705) in hypothyroid patients. In conclusion, tHcy was increased in hypothyroidism, and this increase was more strongly associated with changes in serum folate than in serum creatinine and CysC, suggesting an altered folate status.

Effects of L-arginine and L-carnitine in hypoxia/reoxygenation-induced intestinal injury.

BACKGROUND: This study was designed to show the role of oxidative stress, nitric oxide and glutathione-related antioxidant enzymes in hypoxia/reoxygenation (H/R)-induced intestinal injury model in mice and to evaluate the potential benefits of arginine and carnitine supplementation. METHODS: A total of 28 young Balb/c mice were divided into four groups: Group 1 (untreated) was given physiological saline before the experiment; group 2 H/R mice were supplemented with L-arginine; group 3 H/R mice were given L-carnitine for 7 days; and group 4 mice served as controls. At the end of day 7, H/R injury was induced and intestinal tissue malondialdehyde (MDA), nitrate levels and glutathione peroxidase (GSH-Px), glutathione reductase (GR) and glutathione-S-transferase (GST) activities were measured. RESULTS: MDA levels were higher in the untreated animals than in the other three groups. MDA levels were higher in the L-arginine-treated animals than in the L-carnitine-treated animals. Nitrate levels were found to be increased in the L-arginine-treated group when compared to the controls. GSH-Px and GR activities were increased in the untreated, the L-arginine and the L-carnitine-treated H/R groups when compared to the control group. GST activities were indifferent between the groups. CONCLUSIONS: Oxidative stress contributes to the pathogenesis of H/R-induced intestinal injury. The glutathione redox cycle may have a crucial role in the H/R-induced intestinal injury. L-arginine and L-carnitine supplementations ameliorate the histological evidence of H/R-induced intestinal injury and decrease lipid peroxidation but do not alter the glutathione-related antioxidant enzyme activities.

Amlodipine and glutathione cycle in hypercholesterolaemia.

OBJECTIVE: Effects of amlodipine on lipid peroxidation and alterations in glutathione and related enzymes in blood and aortic tissue were investigated in a cholesterol-induced atherosclerotic rabbit model. METHODS AND RESULTS: New Zealand white male rabbits were fed with regular chow (group I), chow supplemented with I% cholesterol (group II), regular chow plus amlodipine 5 mg/kg/day p.o. (group III) and I% cholesterol diet supplemented with amlodipine (group IV) for 8 weeks. Cholesterol, malondialdehyde (MDA), reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione peroxidase (GSH-PX) and glutathione reductase (GSH-Rd) were determined in blood samples drawn before and after the experimental period. Aortic tissue was examined morphologically for atherosclerotic changes and tissue cholesterol, MDA, GSSG, GSH-PX, GSH-Rd and glutathione-S-transferase (GST) were measured. After 8 weeks, blood cholesterol, MDA, GSSG and GSH-PX were elevated in groups II and IV; GSH was reduced in group IV; MDA levels were higher in group II than in group IV. Aortic tissue investigations revealed higher cholesterol and MDA concentrations in group II than in group IV. Morphological examination of aortic tissues exhibited endothelial disarrangement and lipid deposition in group II. Histopathological alterations related to atherogenesis were less in group IV than in group II. CONCLUSIONS: Amlodipine reduced the increase in oxidative stress by inhibiting excessive MDA production. Accelerated glutathione redox cycle activity of erythrocytes from animals supplemented with amlodipine suggests that this drug may reduce oxidative stress by enhancing the glutathione system. However, this drug does not seem to affect the glutathione redox cycle in the aortic tissue.

Pentoxifylline does not prevent hypoxia/reoxygenation-induced necrotizing enterocolitis. An experimental study.

Hypoxia/reoxygenation (H/R)-induced intestinal injury plays a significant role in the development of necrotizing enterocolitis (NEC). We experimentally explored the effect of pentoxifylline (PTX) on an NEC model. Twenty-one newborn rabbits were divided into three groups: group 1 (control), group 2 (H/R) and group 3 (H/R + PTX). Five minutes of reoxygenation following 5 min of hypoxia was performed three times a day during 3 days. Before each H/R procedure in the H/R + PTX group, the rabbits were treated with PTX 25 mg/kg intraperitoneally. Animals were sacrificed on the third day and ileum samples were taken for histopathological examination and biochemical enzyme studies [superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione S-transferase (GST)]. There was a significant difference in the grade and number of the intestinal lesions between controls and the H/R and H/R + PTX groups (p < 0.001), but no significant difference was found between the H/R and the H/R + PTX groups (p > 0.05). Intestinal SOD, GR and GST activities in the H/R and H/R + PTX groups were significantly higher than in the control group (p < 0.05); however, there was no significant difference between the H/R and H/R + PTX groups (p > 0.05). Significantly reduced GPx activity was found in the H/R and H/R + PTX groups compared with the controls (p < 0.05). No significant difference in GPx activity existed between the H/R group and the H/R + PTX group (p > 0.05). Ischemia/reperfusion injury was responsible for mediating hypoxia-induced intestinal necrosis in NEC and PTX pretreatment did not have a protective effect on NEC.

Association between serum paraoxonase activity and oxidative stress in acute coronary syndromes.

OBJECTIVE: The oxidation of low-density lipoprotein (LDL) is believed to have a central role in atherogenesis. Under oxidative stress not only LDL, but all other serum lipids are exposed to oxidation. High-density lipoprotein (HDL)-associated paraoxonase (PON1) was shown to inhibit LDL and HDL oxidation. We investigated the relationship between PON1 and oxidative stress in acute myocardial infarction and unstable angina in a comparative fashion. METHODS AND RESULTS: Activities of PON1, concentrations of malondialdehyde (MDA), lipids and lipoproteins were measured in patients (38 subjects with acute myocardial infarction and 33 subjects with unstable angina pectoris) and in age- and sex-matched controls (32 subjects). Serum PONI activity was significantly lower in patients than in controls (p < 0.001). Patients had significantly increased serum MDA concentrations (p < 0.001) and there were strong negative correlations (p < 0.001) between serum PON1 and MDA levels in the acute myocardial infarction group (r = -0.673), in the unstable angina pectoris group (r = -0.868) and in healthy controls (r = -0.778). Serum HDL-cholesterol (HDL-C) concentrations were lower in patients than controls (p < 0.05). No correlation was observed between PON1 and HDL-C levels in patients or controls. Apo A I concentrations were significantly lower in the patient groups (p < 0.01), but were insignificant between patients with AMI and UAP. Apo A-I and PON1 levels did not show any correlation. Apo B concentrations were lowest in the healthy controls, higher in the UAPgroup and highest in the AMI group (p < 0.001). In the acute myocardial infarction group LDL/apo B ratio was lower than in healthy controls and in the UAP group, suggesting smaller LDL particle size. CONCLUSIONS: Results of this study indicate that lower serum PON1 activity is associated with oxidative stress and the activity of PON1 is not related to HDL-cholesterol.

Serum and urinary nitric oxide in Type 2 diabetes with or without microalbuminuria: relation to glomerular hyperfiltration.

BACKGROUND: Glomerular hyperfiltration is considered as one of the pathophysiological mechanisms for the development of diabetic nephropathy. Oxidative stress is enhanced in patients with diabetes mellitus. Reportedly, nitric oxide (NO) might be involved in the pathogenesis of hyperfiltration. We investigated the relationship between hyperfiltration and NO system, and malondialdehyde (MDA) levels in Type 2 diabetics with/without microalbuminuria. METHODS: In 39 microalbuminuric, 29 normoalbuminuric Type 2 diabetic patients and 32 healthy controls, serum creatinine, nitrite, nitrate, urinary microalbumin, nitrite, nitrate, plasma MDA and estimated glomerular filtration rate (EGFR) values, calculated according to the Cockcroft and Gault formula, were recorded. RESULTS: Serum and urine NO levels were higher in both microalbuminurics and normoalbuminurics than controls. There were no significant differences in EGFR between groups. However, hyperfiltration was determined in 31% of normoalbuminurics and 20% of microalbuminurics. Serum and urine NO levels were higher in patients with hyperfiltration. Plasma MDA levels were significantly elevated in both microalbuminurics and normoalbuminurics when compared with controls. Serum glucose and microalbuminuria were positively correlated in microalbuminuric diabetics. Serum NO levels were also positively correlated with EGFR in both normoalbuminurics and microalbuminurics. HbA1c levels were positively correlated with both urinary albumin excretion and plasma MDA levels in normoalbuminuric diabetics. CONCLUSIONS: Hyperglycemia is associated with an increased NO biosynthesis and lipid peroxidation. Increased oxidative stress may contribute to the high NO levels in Type 2 diabetes. Furthermore, the high NO levels may lead to hyperfiltration and hyperperfusion, which in turn leads to an increase in urinary albumin excretion and thus causes progression of nephropathy in early Type 2 diabetes.