Context: Dapagliflozin, a selective sodium-glucose cotransporter 2 (SGLT2) inhibitor, reduces hyperglycemia in patients with type 2 diabetes mellitus (T2DM) by increasing urinary glucose excretion, and weight loss is a consistent associated finding.
Objectives: Our objectives were to confirm weight loss with dapagliflozin and establish through body composition measurements whether weight loss is accounted for by changes in fat or fluid components.
Design and setting: This was a 24-wk, international, multicenter, randomized, parallel-group, double-blind, placebo-controlled study with ongoing 78-wk site- and patient-blinded extension period at 40 sites in five countries.
Patients: Included were 182 patients with T2DM (mean values: women 63.3 and men 58.6 yr of age; hemoglobin A1c 7.17%, body mass index 31.9 kg/m2, and body weight 91.5 kg) inadequately controlled on metformin.
Intervention: Dapagliflozin 10 mg/d or placebo was added to open-label metformin for 24 wk.
Main outcome measures: Primary endpoint was total body weight (TBW) change from baseline at wk 24. Key secondary endpoints were waist circumference and dual-energy x-ray absorptiometry total-body fat mass (FM) changes from baseline at wk 24, and patient proportion achieving body weight reduction of at least 5% at wk 24. In a subset of patients, magnetic resonance assessment of visceral adipose tissue (VAT) and sc adipose tissue (SAT) volume and hepatic lipid content were also evaluated.
Results: At wk 24, placebo-corrected changes with dapagliflozin were as follows: TBW, -2.08 kg [95% confidence interval (CI)=-2.84 to -1.31; P<0.0001]; waist circumference, -1.52 cm (95% CI=-2.74 to -0.31; P=0.0143); FM, -1.48 kg (95% CI=-2.22 to -0.74; P=0.0001); proportion of patients achieving weight reduction of at least 5%, +26.2% (95% CI=15.5 to 36.7; P<0.0001); VAT, -258.4 cm3 (95% CI=-448.1 to -68.6; nominal P=0.0084); SAT, -184.9 cm3 (95% CI=-359.7 to -10.1; nominal P=0.0385). In the dapagliflozin vs. placebo groups, respectively, serious adverse events were reported in 6.6 vs. 1.1%; events suggestive of vulvovaginitis, balanitis, and related genital infection in 3.3 vs. 0%; and lower urinary tract infections in 6.6 vs. 2.2%.
Conclusions: Dapagliflozin reduces TBW, predominantly by reducing FM, VAT and SAT in T2DM inadequately controlled with metformin.