Correlation of body muscle/fat ratio with insulin sensitivity using hyperinsulinemic-euglycemic clamp in treatment-naïve type 2 diabetes mellitus.

AIMS: Fat deposition and obesity are crucial pathological components of diabetes mellitus (DM). In clinical practice, assessment of insulin resistance is important. We hypothesized that body muscle and fat composition might be a key factor for insulin resistance in patients with type 2 DM.

METHODS: Subjects included 61 untreated DM patients. Hyperinsulinemic-euglycemic clamp examination was performed to calculate the M/I value as the insulin resistance reference indicator. Elementary body composition was measured by impedance analysis using InBody770.

RESULTS: Simple regression analysis showed that total muscle quantity/total fat quantity ratio (muscle/fat) was significantly correlated with M/I value (B=0.806, P<0.001). The regression equation was M/I value=3.6934×(muscle/fat ratio)+0.0347 (R(2)=0.6503, P<0.001). Multivariate logistic regression analysis showed that muscle/fat ratio was independently and significantly associated with insulin resistance, defined by M/I value <9 (odds ratio, 0.89; 95% confidence interval, 0.80-0.99, P=0.04). With receiver operating curve analysis, the cutoff value of muscle/fat ratio for insulin resistance was 2.40 and area under the curve was 0.87 (sensitivity 91% and specificity 76%, P<0.001), indicating that muscle/fat ratio was significantly effective for predicting insulin resistance in treatment-naïve DM. The result could provide a possible estimation of the M/I value using the regression equation M/I value=2.5438×(muscle/fat ratio)+48.6194×QUICKI-13.6522 (R(2)=0.7012).

CONCLUSION: In treatment-naïve DM, the muscle/fat ratio, assessed by InBody770 is clinically useful for evaluating the presence of insulin resistance in daily clinical practice.