Plasma (A,B) and urine (C,D) levels of soluble α-klotho in normal participants (n = 25) and patients with type 2 diabetes (n = 147).

Plasma and urine α-klotho levels were higher in diabetes patients with relatively preserved renal function than the non-diabetic controls (A,C). The diabetes patients were categorized into 3 groups according to urine ACR: ACR <30 mg/g creatinine (normoalbuminuria group, n = 75), ACR 30–299 mg/g creatinine (microalbuminuria group, n = 42), and ACR ≥300 mg/g creatinine (macroalbuminuria group, n = 30). Plasma α-klotho levels decreased in proportion to urinary albumin excretion, although urinary α-klotho levels were stable with increasing urinary albumin excretion (B,D). Data of non-diabetic control are expressed as a shaded area for the reference (B, D). Data are presented as geometric means and 95% CIs as an error bar plot. P-values calculated using the log-transformed values are shown in the graph. normo; normoalbuminuria, micro; microalbuminuria, macro; macroalbuminuria.