The effect of pioglitazone treatment on 15-epi-lipoxin A4 levels in patients with type 2 diabetes

ObjectivesArachidonic acid-derived eicosanoids (lipoxins and 15-epilipoxins) have a major role in resolution of inflammation. 15-epi-lipoxin A₄ (15-epi-LXA₄) is a lipid mediator with strong anti-inflammatory and inflammation-resolving effects. We examined the effect of pioglitazone therapy on plasma 15-epi-LXA₄ in patients with type 2 diabetes (T2DM).MethodsT2DM patients (Age = 56 ± 2 y, BMI = 33 ± 1.8, HbA1c = 7.8 ± 0.3%) not on thiazolidinedione therapy for at least 12 months were randomized to receive either pioglitazone 15 mg/daily for two months (PIO 15) or pioglitazone 15 mg/day for one month followed by a dose escalation to 30 mg/day for an additional one month (PIO 30).ResultsPIO 15 increased plasma 15-epi-LXA₄ levels (0.63 ± 0.06–1.05 ± 0.08 ng/mL, p < 0.01) and adiponectin levels (6.4 ± 0.3–10.1 ± 0.7 μg/mL, p < 0.001) and decreased fasting plasma glucose (125 ± 8–106 ± 9 mg/dL, p < 0.05), free fatty acids (FFA) (414 ± 46–320 ± 38 μmol/l, p < 0.05) and HOMA-IR (5.3 ± 0.4 to 4.0 ± 0.4, p < 0.05). Body weight (Δ = 0.2 kg) and HbA1c (7.4 ± 0.2–7.1 ± 0.2%) did not change significantly. PIO 30 treated patients had similar increase in plasma 15-epi-LXA₄ (0.64 ± 0.10–1.08 ± 0.09 ng/mL, p < 0.01), and decrease in plasma FFA (423 ± 42–317 ± 40 μmol/l, p < 0.05) despite a greater increase in plasma adiponectin (6.5 ± 0.4–15.5 ± 0.7 ug/mL, p < 0.001) and a greater reduction in HbA1c (8.7 ± 0.5–7.4 ± 0.3%, p < 0.01), FPG (159 ± 16–120 ± 10 mg/dL, p < 0.01), and HOMA-IR (6.6 ± 0.8–4.4 ± 0.4, p < 0.005). Furthermore, PIO 30 treated patients had a significant increase in body weight (Δ = 1.7 kg, p < 0.02).ConclusionIn T2DM, low dose pioglitazone (15 mg/day) increases 15-epi-LXA₄ and adiponectin levels in the absence of significant changes in body weight. Dose escalation of pioglitazone to 30 mg/day is associated with a similar increase in 15-epi-LXA₄ despite a greater increase in plasma adiponectin concentrations.