Chronic exercise (SMD = 1.04, 95% CI: 0.09 to 1.98, p= 0.03) and weekly exercise duration exceeding 150 min (SMD = 1.56, 95% CI: 0.35 to 2.77, p= 0.01) significantly increased BDNF levels in middle-aged and older adults with T2DM. Here, BDNF is linked to type 2 diabetes mellitus.