Cardiopulmonary and endothelial effects of metformin treatment in an insulin resistant population

Exercise Pills: At the Starting Line

“…Of interest, treating healthy individuals with metformin for 7-9 days slightly but significantly reduced key outcomes related to maximal exercise capacity, such as peak oxygen uptake (VO 2max ), heart rate (HR), peak ventilation (VE), peak respiratory exchange ratio (RER), and exercise duration [32]. Such findings have since been confirmed in patients with heart failure and lower degrees of insulin resistance [33][34][35]. The effects of metformin on exercise capacity are complicated by findings that metformin blunts the full effects of exercise training in prediabetic individuals [36], and other findings retort that it modestly reduces the benefits of exercise on glycemic control (by measuring hemoglobin A1c or HbA1c levels) or fitness (aerobic and/or resistance exercise) in an exercise intervention trial.…”

“…Decreased ACC induces fatty acid oxidation and suppresses expression of lipogenic enzymes [31]. Metformin also inhibits complex 1 of the mitochondrial respiratory chain [37][38][39][40], but unfortunately inhibition of complex 1 reduces the mitochondrial reserve induced by exercise training and decreases exercise performance [35]. Thus, metformin may not be rightly considered a candidate exercise pill.…”

Effects of metformin and exercise training, alone or in association, on cardio-pulmonary performance and quality of life in insulin resistance patients

“…Also, MET reduces average oxygen consumption to a modest but significant extent in IR subjects. Indeed, this effect is not manifested by all subjects, being present only in patients featuring a lower degree of IR, while in patients with very high IR, CP performance is significantly improved [9,10]. In an heart failure setting, Wong et al showed how metformin did not increase peak VO2 but reduced the sub-maximal measure of VE/VCO2 slope in patients affected by heart failure and IR [11].…”

In which HOMA-IR value acceptable for sampling the patients with insulin resistance?

“…With great interest, we read the recent manuscript by Cadeddu et al [1] regarding the beneficial effects of metformin treatment on cardiopulmonary performance and vascular endothelial functions in patients with insulin resistance (IR). The authors have selected 20 IR patients without cardiovascular disease, and aimed to examine the possible effects of early metformin treatment for 3 months on exercise oxygen consumption and vasodilatory function, measured as endothelial flow reserve.…”