Effects of a 12-Month Treatment with Glucagon-like Peptide-1 Receptor Agonists, Sodium-Glucose Cotransporter-2 Inhibitors, and Their Combination on Oxidant and Antioxidant Biomarkers in Patients with Type 2 Diabetes

Abstract

Imbalance between oxidative stress burden and antioxidant capacity is implicated in the course of atherosclerosis among type 2 diabetic patients. We addressed the effects of insulin, glucagon-like peptide-1 receptor agonists (GLP1-RA), sodium-glucose cotransporter-2 inhibitors (SGLT-2i), and their combination on levels of oxidant and antioxidant biomarkers. We recruited a total of 160 type 2 diabetics, who received insulin (n = 40), liraglutide (n = 40), empagliflozin (n = 40), or their combination (GLP-1RA+SGLT-2i) (n = 40). We measured at baseline, at 4 and at 12 months of treatment: (a) Thiobarbituric Acid Reactive Substances (TBARS), (b) Malondialdehyde (MDA), (c) Reducing Power (RP), (d) 2,2¢-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) radical (ABTS) and (e) Total Antioxidant Capacity TAC). Dual treatment resulted in significant improvement of TBARS, MDA, and ABTS at four months compared with the other groups (p < 0.05 for all comparisons). At twelve months, all participants improved TBARS, MDA, and ABTS (p < 0.05). At 12 months, GLP1-RA and GLP-1RA+SGLT2-i provided a greater reduction of TBARS (-8.76% and -9.83%) compared with insulin or SGLT2i (-0.5% and 3.22%), (p < 0.05). GLP1-RA and GLP-1RA+SGLT-2i showed a greater reduction of MDA (-30.15% and -31.44%) compared with insulin or SGLT2i (4.72% and -3.74%), (p < 0.05). SGLT2i and GLP-1RA+SGLT2-i showed increase of ABTS (12.87% and 14.13%) compared with insulin or GLP1-RA (2.44% and -3.44%), (p < 0.05). Only combined treatment resulted in increase of TAC compared with the other groups after 12 months of treatment (p < 0.05).12-month treatment with GLP1-RA and SGLT2i resulted in reduction of biomarkers responsible for oxidative modifications and increase of antioxidant biomarker, respectively. The combination treatment was superior and additive to each separate agent and also the beneficial effects appeared earlier.

Keywords: 2,2¢-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) radical; Malondialdehyde; Thiobarbituric Acid Reactive Substances; glucagon-like peptide-1 receptor agonists; sodium-glucose cotransporter-2 inhibitors.

Figure 1

Flowchart of study progress. GLP-1RA: glucagon-like peptide-1 receptor agonists; SGLT-2i: sodium-glucose cotransporter-2 inhibitors.

Figure 2

Percentage changes (Δ) from baseline in -(a) Thiobarbituric Acid Reactive Substances (TBARS), -(b) Malondialdehyde (MDA) and -(c) 2,2¢-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) radical (ABTS) at 4 and 12 months in the 4 study groups. Data are presented as means ± SD. * p < 0.05; ** p < 0.01; *** p < 0.001 versus baseline.

Figure 2

Percentage changes (Δ) from baseline in -(a) Thiobarbituric Acid Reactive Substances (TBARS), -(b) Malondialdehyde (MDA) and -(c) 2,2¢-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) radical (ABTS) at 4 and 12 months in the 4 study groups. Data are presented as means ± SD. * p < 0.05; ** p < 0.01; *** p < 0.001 versus baseline.