Table 1.
Selected clinical retrospective studies on circulating oxidative stress markers in T2DM and prediabetes. All the studies included in this table were categorized under the class of evidence C, retrospective studies.
| Disease and population | Sample | Markers | Observation | Information on medication or supplements | Reference |
|---|---|---|---|---|---|
| Prediabetics (N = 47) T2DM (N = 43) Controls (N = 37) |
Urine | 8-OHdG 8-iso-PGF2α |
↑ 8-iso-PGF2α and 8-OHdG in prediabetes compared to controls ↑ 8-OHdG in T2DM patients compared to controls |
No medication No special diet No supplements |
[57] |
| Prediabetics (N = 176) Controls (N = 252) |
Urine Erythrocytes |
8-iso-PGF2α 8-OHdG GSH/GSSG |
No differences in 8-iso-PGF2α ↑ 8-OHdG in prediabetes group compared to control ↓ GSH/GSSG in prediabetes compared to control |
Antihypertensive drugs: Prediabetes (35.8%) Controls (5.2%) Statins and anticoagulants: Controls (<4%) Prediabetes (<16%) |
[59] |
| Prediabetics (N = 49) T2DM (N = 30) Controls (N = 30) |
Plasma | 8-iso-PGF2α MDA TAOC SOD |
↑ 8-iso-PGF2α and MDA in prediabetes and T2DM compared to controls ↑ 8-iso-PGF2α in T2DM compared to prediabetes ↓ TAOC in T2DM compared to controls and prediabetes ↓ SOD in prediabetes compared to controls No differences in TAOC between prediabetes and controls ↓ SOD in T2DM compared to controls and prediabetes |
No use of medication that affects glucose metabolism within 6 months | [58] |
| Prediabetics (N = 111) T2DM (N = 186) Controls (N = 259) |
Plasma and erythrocyte | Nrf2 MDA TAS GPx SOD GSH |
↓ TAS and GSH in controlled and uncontrolled T2DM compared to controls and prediabetes ↓ Nrf2 in prediabetes and in uncontrolled T2DM compared to controls ↑ MDA in uncontrolled T2DM compared to controls and prediabetes and in controlled T2DM compared to controls ↑ GPx in uncontrolled T2DM compared to prediabetes ↑ SOD in controlled and uncontrolled T2DM compared to prediabetes and controls |
Not provided | [67] |
| Prediabetics (N = 9) T2DM (N = 55) Controls (N = 29) Ethnicity: whites, blacks, Brazilians |
Plasma and erythrocyte | SOD CAT GPx TBARS |
No differences in TBARS, SOD, GPx, and CAT between prediabetes and controls ↑ SOD and TBARS in T2DM compared to controls and prediabetes |
Antihypertensive drugs: 76.4% of T2DM, 66.7% of the pre-DM, and 37.9% of the controls Among T2DM: 92.7% sulphonylurea and/or biguanide |
[60] |
| T2DM (N = 215) Controls (N = 37) |
Serum | SOD TBARS GSH |
↓ SOD and GSH in T2DM compared with controls ↑ TBARS in T2DM compared with controls |
Not provided | [61] |
| T2DM (N = 39) Controls (N = 18) |
Plasma | FRAP | ↓ FRAP lower in T2DM with poor glycaemic control than controls | T2DM treated with metformin and glibenclamide in combination with other | [99] |
| T2DM (N = 31) Controls (N = 31) |
Plasma | Protein carbonyl AOPP Radical scavenging capacity of plasma |
↑ protein carbonyl content and AOPPs in T2DM in comparison to healthy volunteers ↓ Radical scavenging capacity of plasma in T2DM than controls |
Not provided | [84] |
| T2DM (N = 80) Controls (N = 79) |
Plasma | FRAP GSH GR GPx |
↑ FRAP and GR in T2DM compared to controls ↓ GPx activity in T2DM compared to controls |
Not provided | [98] |
| T2DM (N = 115) Controls (N = 32) |
Plasma | GSH GPx TAS |
↓ GSH, GPx in T2DM compared to controls No differences in TAS |
No use of vitamins, minerals, or other supplements | [100] |
| T2DM (N = 420) Controls (N = 429) |
Plasma | HO1 | ↑ HO1 in T2DM compared to controls | Not provided | [110] |
| T2DM (N = 30) Controls (N = 20) Ethnicity: Indian |
Serum | PON1 | ↑ PON1 in controls compared to T2DM | Not provided | [102] |
| T2DM (N = 90) Controls (N = 90) |
Serum | PON1 | ↑ PON1 in controls compared to T2DM | Not provided | [103] |
| T2DM (N = 145) Controls (N = 574) |
Serum | PON1 | ↑ PON1 in controls compared to T2DM | 10 controls and 15% of T2DM were on active lipid-lowering treatment | [104] |
8-iso-PGF2α: 8-iso- prostaglandin F2α; 8-OHdG: 8-hydroxy-2′-deoxyguanosine; AGEs: advanced glycation end products; AOPP: advanced oxidation protein products; CAT: catalase; FRAP: ferric reducing ability of plasma; GSH: reduced glutathione; GSSG: oxidized glutathione; GPx: glutathione peroxidase; GR: glutathione reductase; HNE: 4- hydroxy-2-nonenal; HO1: heme oxygenase; MDA: malondialdehyde; Nrf2: nuclear factor erythroid 2; PON1: paraoxonase 1; SOD: superoxide dismutase; TBARS: thiobarbituric acid reactive substances; TAS: total antioxidant status.