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Optimisation of an Advanced Oxidation Protein Products Assay: Its Application to Studies of Oxidative Stress in Diabetes Mellitus.

Taylor EL, Armstrong KR, Perrett D, Hattersley AT, Winyard PG - Oxid Med Cell Longev (2015)

Bottom Line: However, the accurate measurement of AOPP in human plasma is hampered by the formation of a precipitate following the addition of potassium iodide and glacial acetic acid according to the published assay procedure.The improved method revealed a significant association of AOPP levels with age (p < 0.05) and hypertension (p = 0.01) in EDTA-anticoagulated plasma samples from 52 patients with diabetes and 38 nondiabetic control subjects, suggesting a possible link between plasma oxidising capacity and endothelial and/or vascular dysfunction.There was no significant difference between AOPP concentrations in diabetic (74.8 ± 7.2 μM chloramine T equivalents) and nondiabetic (75.5 ± 7.0 μM chloramine T equivalents) individuals.

View Article: PubMed Central - PubMed

Affiliation: University of Exeter Medical School and NIHR Exeter Clinical Research Facility, University of Exeter, Exeter EX1 2LU, UK.

ABSTRACT
Advanced oxidation protein products (AOPP) are reportedly elevated in the plasma of patients with a number of diseases, including diabetes mellitus, that involve oxidative stress. However, the accurate measurement of AOPP in human plasma is hampered by the formation of a precipitate following the addition of potassium iodide and glacial acetic acid according to the published assay procedure. Here we describe a modification of the AOPP assay which eliminates interference by precipitation and provides a robust, reliable, and reproducible protocol for the measurement of iodide oxidising capacity in plasma samples (intra-assay CV 1.7-5.3%, interassay CV 5.3-10.5%). The improved method revealed a significant association of AOPP levels with age (p < 0.05) and hypertension (p = 0.01) in EDTA-anticoagulated plasma samples from 52 patients with diabetes and 38 nondiabetic control subjects, suggesting a possible link between plasma oxidising capacity and endothelial and/or vascular dysfunction. There was no significant difference between AOPP concentrations in diabetic (74.8 ± 7.2 μM chloramine T equivalents) and nondiabetic (75.5 ± 7.0 μM chloramine T equivalents) individuals.

No MeSH data available.


Related in: MedlinePlus

Association of AOPPTIOC with age in nondiabetic and diabetic subjects. AOPPTIOC was measured in 37 subjects without diabetes and 50 patients with Type 2 diabetes and linear regression analyses (Pearson's rank correlation) of AOPPTIOC versus age were performed. Both diabetic (r = 0.485) and nondiabetic (r = 0.388) individuals showed a significant (p < 0.05) increase in AOPPTIOC with age. Open circles represent data from nondiabetic individuals and dashed line shows the linear trendline through the data. Grey squares represent subjects with Type 2 diabetes and the linear trendline is shown by the solid line.
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fig2: Association of AOPPTIOC with age in nondiabetic and diabetic subjects. AOPPTIOC was measured in 37 subjects without diabetes and 50 patients with Type 2 diabetes and linear regression analyses (Pearson's rank correlation) of AOPPTIOC versus age were performed. Both diabetic (r = 0.485) and nondiabetic (r = 0.388) individuals showed a significant (p < 0.05) increase in AOPPTIOC with age. Open circles represent data from nondiabetic individuals and dashed line shows the linear trendline through the data. Grey squares represent subjects with Type 2 diabetes and the linear trendline is shown by the solid line.

Mentions: The modified assay was then applied to 90 plasma samples from individuals with diabetes or control subjects (50 Type 2 diabetics, 3 subjects with unclassified diabetes, and 37 nondiabetic controls). It was found that AOPPTIOC values were not significantly different between Type 2 diabetic and nondiabetic individuals (p = 0.665 by unpaired Student's t-test). Mean (± 1 S.D.) AOPPTIOC in diabetics was 74.8 ± 7.2 μM chloramine T equivalents and in controls was 75.5 ± 7.0 μM chloramine T equivalents. It was found that AOPPTIOC values associated significantly with age in both nondiabetic (r = 0.392, p < 0.05) and Type 2 diabetic (r = 0.489, p < 0.05) subjects, as assessed by Pearson's rank correlation (Figure 2), although AOPPTIOC did not correlate with disease duration in 46 Type 2 diabetes patients for whom this information was available (r = −0.024; p > 0.05). AOPPTIOC also significantly associated with age in the combined dataset of 90 subjects, including the three subjects with Type 1 or unclassified diabetes (r = 0.393, p < 0.05).


Optimisation of an Advanced Oxidation Protein Products Assay: Its Application to Studies of Oxidative Stress in Diabetes Mellitus.

Taylor EL, Armstrong KR, Perrett D, Hattersley AT, Winyard PG - Oxid Med Cell Longev (2015)

Association of AOPPTIOC with age in nondiabetic and diabetic subjects. AOPPTIOC was measured in 37 subjects without diabetes and 50 patients with Type 2 diabetes and linear regression analyses (Pearson's rank correlation) of AOPPTIOC versus age were performed. Both diabetic (r = 0.485) and nondiabetic (r = 0.388) individuals showed a significant (p < 0.05) increase in AOPPTIOC with age. Open circles represent data from nondiabetic individuals and dashed line shows the linear trendline through the data. Grey squares represent subjects with Type 2 diabetes and the linear trendline is shown by the solid line.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4465816&req=5

fig2: Association of AOPPTIOC with age in nondiabetic and diabetic subjects. AOPPTIOC was measured in 37 subjects without diabetes and 50 patients with Type 2 diabetes and linear regression analyses (Pearson's rank correlation) of AOPPTIOC versus age were performed. Both diabetic (r = 0.485) and nondiabetic (r = 0.388) individuals showed a significant (p < 0.05) increase in AOPPTIOC with age. Open circles represent data from nondiabetic individuals and dashed line shows the linear trendline through the data. Grey squares represent subjects with Type 2 diabetes and the linear trendline is shown by the solid line.
Mentions: The modified assay was then applied to 90 plasma samples from individuals with diabetes or control subjects (50 Type 2 diabetics, 3 subjects with unclassified diabetes, and 37 nondiabetic controls). It was found that AOPPTIOC values were not significantly different between Type 2 diabetic and nondiabetic individuals (p = 0.665 by unpaired Student's t-test). Mean (± 1 S.D.) AOPPTIOC in diabetics was 74.8 ± 7.2 μM chloramine T equivalents and in controls was 75.5 ± 7.0 μM chloramine T equivalents. It was found that AOPPTIOC values associated significantly with age in both nondiabetic (r = 0.392, p < 0.05) and Type 2 diabetic (r = 0.489, p < 0.05) subjects, as assessed by Pearson's rank correlation (Figure 2), although AOPPTIOC did not correlate with disease duration in 46 Type 2 diabetes patients for whom this information was available (r = −0.024; p > 0.05). AOPPTIOC also significantly associated with age in the combined dataset of 90 subjects, including the three subjects with Type 1 or unclassified diabetes (r = 0.393, p < 0.05).

Bottom Line: However, the accurate measurement of AOPP in human plasma is hampered by the formation of a precipitate following the addition of potassium iodide and glacial acetic acid according to the published assay procedure.The improved method revealed a significant association of AOPP levels with age (p < 0.05) and hypertension (p = 0.01) in EDTA-anticoagulated plasma samples from 52 patients with diabetes and 38 nondiabetic control subjects, suggesting a possible link between plasma oxidising capacity and endothelial and/or vascular dysfunction.There was no significant difference between AOPP concentrations in diabetic (74.8 ± 7.2 μM chloramine T equivalents) and nondiabetic (75.5 ± 7.0 μM chloramine T equivalents) individuals.

View Article: PubMed Central - PubMed

Affiliation: University of Exeter Medical School and NIHR Exeter Clinical Research Facility, University of Exeter, Exeter EX1 2LU, UK.

ABSTRACT
Advanced oxidation protein products (AOPP) are reportedly elevated in the plasma of patients with a number of diseases, including diabetes mellitus, that involve oxidative stress. However, the accurate measurement of AOPP in human plasma is hampered by the formation of a precipitate following the addition of potassium iodide and glacial acetic acid according to the published assay procedure. Here we describe a modification of the AOPP assay which eliminates interference by precipitation and provides a robust, reliable, and reproducible protocol for the measurement of iodide oxidising capacity in plasma samples (intra-assay CV 1.7-5.3%, interassay CV 5.3-10.5%). The improved method revealed a significant association of AOPP levels with age (p < 0.05) and hypertension (p = 0.01) in EDTA-anticoagulated plasma samples from 52 patients with diabetes and 38 nondiabetic control subjects, suggesting a possible link between plasma oxidising capacity and endothelial and/or vascular dysfunction. There was no significant difference between AOPP concentrations in diabetic (74.8 ± 7.2 μM chloramine T equivalents) and nondiabetic (75.5 ± 7.0 μM chloramine T equivalents) individuals.

No MeSH data available.


Related in: MedlinePlus