Objective: To evaluate the influence of combined therapy of sitagliptin and metformin on fat metabolism in patients with type 2 diabetes mellitus.
Methods: The study included 82 patients (age, 55.3±9.1 years) with obesity and lipid metabolism disorders. None of the patients had reached their target glycated haemoglobin levels after metformin and diet therapy. Patients in gr1 (n=42) received 1.5-2-g metformin daily before the study and were switched to a formulation of 100-mg sitagliptin and 2-g metformin once a day. Patients in gr 2 (n=40) were on a diet therapy before inclusion and were started on 2-g metformin/day. The following were evaluated at baseline and after 6 months of therapy: fasting glucose levels, postprandial glucose levels, HbA1c, weight, waist circumference and lipid profile; insulin, proinsulin, leptin and adiponectin levels; HOMA IR and HOMA-β. In addition, magnetic resonance imaging was performed to assess the amount of visceral fat for the total cohort.
Results: After 6 months, HbA1c decreased by 18.52% (p <0.001) in gr 1 and by 8.17% (p <0.001) in gr 2. FPGl and PPG levels in gr 1 were reduced by 21% (p <0.001) and 26.35% (p <0.001), respectively; the corresponding reductions in gr 2 were 1.45% (p >0.05) and 5.31% (p <0.05), respectively. HOMA-β increased by 33% in gr1 (p <0.001) and by 11% in gr 2 (p >0.05). Adiponectin levels increased by 27.06% (p <0.001) in gr 1 and by 7.16% in gr 2 (p <0.001). Leptin levels were reduced by 30.47% (p <0.001) in gr 1 and by 5.41% in gr 2 (p <0.001). MRI showed a 7.52% reduction in visceral fat for gr 1 (p <0.001) and a 1.76% reduction for gr2 (p <0.01). The comparison of subcutaneous fat dynamics did not show statistically significant differences between the groups.
Conclusion: Compared with metformin monotherapy, sitagliptin and metformin combination therapy had a prominent effect on nonglycaemic parameters, with more marked decreases in visceral fat and leptin and increases in adiponectin levels.
A. Ametov: None. D. Gusenbekova: None.