Calculated estimation of the metabolic clearance rate of insulin measured by glucose clamp examination in out-patient clinical practice.

Purpose: A subpopulation of Japanese patients with type 2 diabetes mellitus (T2DM) who have elevated insulin clearance (IC) exists. We tested our hypothesis that it is possible to estimate IC using common and simple test results collected in routine clinical practice.

Methods: We recruited patients with newly diagnosed, treatment-naïve T2DM and measured the metabolic clearance rate of insulin (MCRI) determined by a hyperinsulinemic-euglycemic clamp examination. Multivariable regression analysis was performed with body mass index (BMI), serum uric acid (UA), and fasting plasma insulin (F-IRI) which were independently associated with IC increase in our previous reports as explanatory variables to calculate a prediction equation for MCRI.

Results: We enrolled 101 patients in this study. Because MCRI is not normally distributed, we calculated the logarithmically transformed estimated Log₁₀MCRI as a prediction formula for IC. Multivariable regression analysis showed that Log₁₀BMI (β =  - 0.3257, P < 0.001), UA (β =  - 0.1834, P = 0.0081), and Log₁₀F-IRI (β =  - 0.4367, P < 0.001) were significant independent factors for Log₁₀MCRI. The regression equation was as follows: estimated Log₁₀MCRI =  - 0.5421 × Log₁₀BMI - 0.0167 × UA - 0.1792 × Log₁₀F-IRI + 3.8251 (r = 0.7677, R ² = 0.5894, P < 0.001).

Conclusion: IC can easily be predicted using BMI, UA, and F-IRI which are common and simple test results collected in routine clinical practice.