Dear Editor,
I read the article by Wang et al., who conducted a meta-analysis to investigate the
association between serum irisin levels and diabetic nephropathy (DN) in patients
with type 2 diabetes mellitus (T2DM) [1]. The mean serum irisin level in T2DM patients with microalbuminuria was significantly
lower than that in T2DM patients with normoalbuminuria. In addition, the mean serum
irisin level in T2DM patients with macroalbuminuria was significantly lower than that
in T2DM patients with microalbuminuria. Furthermore, the mean serum irisin level in
T2DM patients with estimated glomerular infiltration rate (eGFR)<60 ml/min 1.73 m2 was significantly lower than that in T2DM patients with eGFR≥60 ml/min 1.73 m2. The authors concluded that decreased serum irisin level was associated with albuminuria
and reduced eGFR in T2DM patients. DN was significantly related to decreased serum
irisin level in T2DM patients with dose-response manner. Progression of DN may be
considered as advanced DM status, and serum irisin level would reflect glucose intolerance
via insulin resistance. I have a comment about their study with special reference
to the fundamental relationship between the types of DM and serum irisin levels.