Increased peroxiredoxin 4 levels in patients with prediabetes compared to normal glucose tolerance subjects.
BACKGROUND
Peroxiredoxin 4 is a part of endogen antioxidant system and its levels are elevated in oxidative stress conditions. Its levels are positively associated with cardiovascular risk. The aim of this study was to compare serum peroxiredoxin 4 levels between obese subjects with prediabetes and with normal glucose tolerance.


METHODS
In this study, we included 80 patients with mean age 50·4 ± 10·6 years and divided them into two age and BMI-matched groups - group 1 with obesity without glycaemic disturbances (n = 41) and group 2 with obesity and prediabetes (n = 39). Oral glucose tolerance test with measurement of immunoreactive insulin was performed in all participants, and the levels of peroxiredoxin 4 were measured using ELISA method.


RESULTS
We found significantly higher levels of peroxiredoxin 4 in patients with prediabetes compared to controls (2851·2 ± 4576·6 pg/ml vs 1088·0 ± 753·3 pg/ml; P = 0·022). There was a mild but statistically significant correlation between peroxiredoxin 4 and weight (r = 0·232; P = 0·038), waist circumference (r = 0·239; P = 0·044), creatinine (r = 0·264; P = 0·019), liver enzymes (ASAT - r = 0·289; P = 0·019 and ALAT - r = 0·305; P = 0·07) and white blood cells count (r = 0·317; P = 0·005). There was no difference in peroxiredoxin 4 levels in patients with and without insulin resistance, as well as with and without metabolic syndrome (MetS), although the levels of peroxiredoxin 4 increased with the number of components of MetS.


CONCLUSIONS
The levels of peroxiredoxin 4 are higher in patients with prediabetes, but are similar in subjects with and without insulin resistance, which suggests that the main factor for its increased levels is hyperglycaemia and not insulin sensitivity state.
Clinic of Endocrinology, Department of Internal Medicine, University Hospital "Alexandrovska", Medical University, Sofia, Bulgaria. tony_gateva@yahoo.com.
Antoaneta
A
Gateva
Clinic of Endocrinology, Department of Internal Medicine, University Hospital "Alexandrovska", Medical University, Sofia, Bulgaria.
Yavor
Y
Assyov
Laboratory of Clinical Immunology, Department of Clinical Laboratory and Clinical Immunology, University Hospital "St. Ivan Rilski", Medical University, Sofia, Bulgaria.
Tsvetelina
T
Velikova
Clinic of Endocrinology, Department of Internal Medicine, University Hospital "Alexandrovska", Medical University, Sofia, Bulgaria.
Zdravko
Z
Kamenov
D000328:Adult; D049628:Body Size; D016022:Case-Control Studies; D005951:Glucose Tolerance Test; D006801:Humans; D007333:Insulin Resistance; D024821:Metabolic Syndrome; D008875:Middle Aged; D009765:Obesity / Q000097:blood*; D054464:Peroxiredoxins / Q000097:blood*; D011236:Prediabetic State / Q000097:blood*
C515980:PRDX4 protein, human; D054464:Peroxiredoxins