Serum klotho protein levels and their correlations with the progression of type 2 diabetes mellitus.

ABSTRACT

AIM: To investigate the associations of serum α-Klotho and ß-Klotho levels with type 2 diabetes mellitus (T2DM) progression. METHODS: We evaluated 106 healthy controls and 261 cases of T2DM with or without diabetic complications (range 45-84years). Serum α-Klotho and ß-Klotho levels were analyzed using enzyme-linked immunosorbent assays. RESULTS: Compared to the healthy controls, α-Klotho and ß-Klotho levels were significantly lower among patients with T2DM and with or without diabetic complications (P<0.05). Furthermore, α-Klotho levels were lower in the microalbuminuric and macroalbuminuric groups, compared to the normoalbuminuric group. However, ß-Klotho levels were only lower in the macroalbuminuric group (P<0.05). Multiple linear regression analyses revealed that α-Klotho and ß-Klotho levels were positively correlated with the creatinine clearance rate, and negatively correlated with the urinary albumin to creatinine ratio and randomly sampled serum levels of creatinine, blood urea nitrogen, and blood glucose. Moreover, α-Klotho and ß-Klotho levels were positively correlated among patients with T2DM (r=0.693, P<0.001). CONCLUSIONS: Serum levels of α-Klotho and ß-Klotho are down-regulated in patients with T2DM. Thus, these proteins may participate in the pathological mechanism of diabetes, and the positive correlation of α-Klotho and ß-Klotho levels indicates that they might have similar mechanisms in T2DM.