AKT1 and chronic obstructive pulmonary disease: The obtained results of single locus and polygenic analysis indicatethe contribution of SIRT3 (rs3782116, rs536715), SIRT6(rs107251) and PIK3R1 (rs10515070, rs831125, rs3730089)polymorphisms to COPD and interaction of genes enco-ding the key components of the PI3K/AKT/mTOR signallingpathway and sirtuins, and confirm the involvement of cellularsenescence mechanisms with COPD development