Biomarkers of oxidative stress in diabetic polyneuropathy

Aims/Hypothesis: Oxidative stress has been implicated in the development of diabetic neuropathy. The objective of this study was to establish if type 1 or type 2 diabetes in the presence of polyneuropathy (PNP) and/or cardiovascular autonomic neuropathy (CAN) is associated with alterations in plasma and urinary measures of oxidative stress. Studied population: Diabetic patients (n=185; type1: n=61 and type 2: n=124) were recruited. Of these, 60 patients were without PNP and CAN, 103 patients with PNP but without CAN and 22 patients with PNP and CAN. Non-diabetic subjects (n=70) were employed as controls. Methods: Plasma and urinary 8-epi-PGF2α and its metabolites were measured by gas- chromatography/mass-spectrometry. Plasma total antioxidant capacity (TAC) was assessed by quenching of peroxiynitrite Pholasin® chemiluminescence (peroxynitrite-QPC), quenching of superoxide anion Pholasin® chemiluminescence (superoxide anion-QPC) and quenching of hypochlorous acid Pholasin® chemiluminescence (hypochlorous acid-QPC). Plasma vitamin C was assayed spectrofluorometrically. Plasma vitamin E was determined by HPLC with fluorometric detection. Results: Type 1 diabetic patients (PNP-/CAN-) had lower TAC (peroxynitrite-QPC, superoxide anion-QPC), vitamin C levels, vitamin E cholesterol/ratios, and 8-epi-PGF2α concentrations than in control subjects. Lower TAC (superoxide anion-QPC) and increased 8-epi-PGF2α concentrations were seen in the presence PNP. The additional presence of CAN was associated with further reductions in TAC (peroxynitrite-QPC and superoxide anion-QPC) and vitamin E/cholesterol ratios. Type 2 diabetic patients (PNP-/CAN-) exhibited lower TAC (peroxynitrite-QPC, superoxide anion-QPC), and vitamin E cholesterol/ratios compared to control subjects. Lower TAC (peroxynitrite-QPC and superoxide anion-QPC), vitamin C levels and vitamin E/cholesterol ratios, and increased 8-epi-PGP2α concentrations were observed the presence of PNP. Lower TAC (superoxide anion-QPC) was seen in the presence of additional CAN. Correlations occurred between neurological impairment score of the lower limb (NIS-LL) and peroxynitrite-QPC, superoxide anion-QPC as well as vitamin C levels. Multiple regression analysis revealed that peroxynitrite-QPC was independently associated with the neurological impairment score of the lower limb. Urinary 8-epi-PGF2α and its metabolites levels were lower in diabetic patients than in control subjects. However, no firm conclusion could be drawn concerning urinary 8-epi-PGF2α and its metabolites because the results exhibited substantial variability. Conclusions: This study has revealed that oxidative stress is enhanced in diabetic patients (PNP-/CAN-). Oxidative stress was more pronounced in patients with PNP and that the additional presence of CAN was without influence. Measurement of TAC, as assessed by peroxynitrite-QPC or superoxide anion-QPC, was superior in the terms of simplicity, cost and diagnostic value to nutrient antioxidants and lipid-oxidation products in assessing oxidative stress. These results indicate improved strategies for patient selection for clinical trials involving antioxidants aimed at the prevention or treatment of diabetic neuropathy

Assessing the impact of oral iodine supplementation on whole body iodine store, thyroid autoimmunity and serum biochemistry profile in women of childbearing age

Background and aims: Iodine supplementation is advised for women with compromised iodine intake in the preconception period. The purpose of this study was to evaluate the benefits and harms of a supplementary dose of iodine (150 μg/day) for 90 days in women of childbearing age. Materials and methods: Non-pregnant females (n = 38; mean age: 24.1 ± 2.6 years; Range: 20–30) receiving a hall diet were enrolled. Measurements of urinary iodine excretion (UIC), thyroid autoimmunity biomarkers, serum clinical biochemistry profile and serum thyroglobulin were performed at baseline- and after iodine supplementation at 45- and 90 days, respectively. Results: Median UICs (μg/L) at baseline and after iodine intervention were 110, 304 and 310, respectively. This coincided with reductions in thyroglobulin, triacylglycerol, HDL-C, LDL-C, LDH, ALP and CPK levels as well as the prevalence of participants with UIC <150 μg/L. One new case of Tg-AB (+), a marked increase the titer of Tg-AB in one participant with TPO-AB (+)/Tg-AB (+) and two cases of increased thyroglobulin were observed after the iodine treatment. Conclusions: This investigation indicates that in iodine sufficient regions, it might be difficult to maintain maternal iodine adequacy without iodine supplementation. The iodine supplementation was associated with improvement of atherogenic serum index, diminished levels of markers of cellular injury and a 42.1% drop in the prevalence of participants with maternal iodine deficiency. In instances, which screening of thyroid autoimmunity titers and thyroglobulin are not an option, we recommend the administration of iodine in lower dosages to prevent adverse and exaggerated autoimmune reactions. Keywords: Urinary iodine excretion, Iodine, Thyroid peroxidase antibody, Thyroglobulin antibody, Thyroglobulin, Serum biochemistry profile, Thyroid autoimmunit

Inter-relationship between evolutions of the temporal trend of urinary iodine excretion with iodized salt accessibility and thyroid function in an exclusive cohort of mothers residing in a mild iodine-deficient region

Background and aims: Maternal iodine deficiency (UIC<150 µg/L) is common in regions with borderline iodine sufficiency. Hence, exploring evolution of the temporal trend for UIC during pregnancy as well as impact of possible modifiers aids in defining the timing and the dose of iodide administration supplement during foetal development. The aim of present investigation was to evaluate the inter-relationships between UIC and iodized salt accessibility and thyroid function as assessed by thyroid-stimulating hormone (TSH) in an exclusive cohort of pregnant women depending on household salt as the predominant source of iodine intake. Materials and Methods: Healthy pregnant women (n=95; gestation > 4 and < 8 weeks) and non-pregnant women (n=40) with similar lifestyle and dietary habits were enrolled. UIC, TSH and table-salt iodine content were determined. Results: Median UIC (µg/L) according to trimesters was significantly lower than that of controls (61.6, 130.2 and 90.3 vs 133.8). Accordingly, prevalence of subjects with UIC<150 µg/L were 97.9, 67.4, 77.9 and 60. Median TSH (mIU/L) according to trimesters and control group were 1, 1.6, 1.4 and 1.6. Accordingly, prevalence of subjects with abnormal lower TSH limit was 17.2, 8.5, 3.2 and 2.4. Conclusion: This investigation demonstrates that UIC varies according to the foetal life cycle and that the highest frequencies of severe iodine (UIC <50 μg/L) were identified at the first- and third trimesters. This investigation paves the way for future studies aiming at exploring the therapeutic impact of iodine supplementation on body iodine stores during pregnancy

Inter-relationships between inflammatory biomarkers and severity of angiographically verified coronary artery occlusion

Background and Aim: Growing clinical evidence suggests that inflammation is the hallmark of the initiation, progression and extent of occlusion by atherosclerosis plaques, but biochemical data are still controversial. The aim of the present cross-sectional investigation was to evaluate the relationship between the severity of coronary artery occlusion (CAO), serum amyloid A (SAA), and interleukin -6 (IL-6) Materials and Methods: The subjects assessed were165 having stable coronary artery disease, but without left main artery lesion. Angiographic examination revealed that 37 subjects had minimal CAO (control group), 41 one CAO, 41 two CAO , and 47 three CAO. The Subjects’ SAA and IL-6 were assessed by means of ELISA.The level of fibrinogen was estimated using coaglumetry. The obtained data was analysed by means of SPSS (v: 13). Results: Fibrinogen concentrations were significantly higher in subjects with 1, 2 or 3 CAO compared to the controls. SAA levels in the subjects were higher than those in the controls, but the differences were not statistically significant. On the other hand, IL6- concentrations in patients with a varying degree of CAO were similar but slightly lower than those in the controls. Significant correlations were distinguished between SAA, IL-6, and fibrinogen in the patients as a whole (p=0.05). Fibrinogen levels in the patients were significantly correlated with HDL and LDL. Conclusion: It was found that fibrinogen estimation is .superior to IL-6 and SAA in examining the interrelationship between inflammation and progression of CAO

F4-isoprostanes as specific marker of docosahexaenoic acid peroxidation in Alzheimer's disease

10.1046/j.1471-4159.1999.0720734.xJournal of Neurochemistry722734-740JONR