Table 1 Inclusion and exclusion criteria for patient recruitment

Inclusion criteria

Age 30–70 years

Diagnosis of type 2 diabetes mellitus ≥ 12 months

Glycosylated hemoglobin (HbA1c) level 6.5–10%

Receiving oral anti-diabetic medication

Able to walk continuously for at least 20 min and climb one flight of stairs unaided without stopping

Sedentary: do not engage in exercising more than 20 min on 3 or more days a week

Exclusion criteria

Body mass index > 40 kg/m²

Exogenous insulin

Autoimmune diseases

Retinopathy, nephropathy, peripheral neuropathy

Inflammatory and other conditions potentially associated with altered cytokine regulation

Liver impairment

Renal insufficiency (creatinine levels > 2.0 mg/dl)

Diagnosed cardiovascular disease; recent onset of cardiac-origin symptoms

Prescription of a very low caloric diet (fewer than 1000 kcal/day) or drugs for the treatment of obesity

Orthopedic problems limiting physical activity

Already engaging in intensive physical activity for > 2 h/week