Fig. 1Glucose reabsorption in the renal proximal tubule. Under normal physiological conditions, the kidney reabsorbs all of the filtered glucose. This occurs via the actions of sodium-glucose cotransporter 2 (SGLT2) in the early proximal tubule, which reabsorbs most of the filtered glucose load, and SGLT1 in the more distal regions of the tubule, which absorbs the remaining glucose. These cotransporters are located on the luminal epithelium. Glucose transporter 2 (GLUT2) and GLUT1 facilitate glucose transport across the basolateral membrane in the early and the more distal regions of the proximal tubule, respectively.
Fig. 2Renal glucose handling before and after sodium-glucose cotransporter 2 (SGLT2) inhibition. SGLT2 inhibition reduces the maximum transport rate (Tm) of glucose. This reduced Tm for glucose through SGLT2 inhibition results in a decrease in glucose reabsorption in the renal proximal tubule and lowers the renal threshold so that glucosuria occurs at a lower plasma glucose concentration.
Fig. 3Mean changes in (A) the glycated hemoglobin (HbA1c) level, (B) the fasting plasma glucose (FPG) level, and (C) body weight in clinical trials with dapagliflozin at a dose of 5 or 10 mg/day. Data are adjusted for baseline values. MET, metformin; GLIM, glimepiride; PIO, pioglitazone; INS, insulin; NA, not available. aP<0.05 vs. the placebo.
Fig. 4Mean changes in (A) the glycated hemoglobin (HbA1c) level, (B) the fasting plasma glucose (FPG) level, and (C) body weight in clinical trials with canagliflozin at a dose of 100 or 300 mg/day. Data are adjusted for baseline values. MET, metformin; SU, sulfonylurea; PIO, pioglitazone; GLIM, glimepiride; SIT, sitagliptin. aP<0.05 vs. the placebo or active comparator.
Table 1Comparisons of SGLT1 and SGLT2
Table 2SGLT2 Inhibitors in Clinical Development