Novel Insights on SGLT-2 Inhibitors Rajeev Chawla, Shalini Jaggi
INDEX
Page numbers followed by ‘f’ indicate figures respectively.
A
Acetyl-CoA derived 41
Adenosine triphosphatase 9
Adipokine 42
kinetics besides effects 40
levels of anti-inflammatory 42
paracrine regulation of 42
reducing proinflammatory 42
Adipose tissue 31
Albuminuria, effects on 91f
Alpha-glucosidase inhibitors 73
American College of Endocrinology, guidelines 66
American Diabetes Association 64
Antianaphylactic 4
Antiasthmatic 4
Antiatherogenic properties 59
Antidiabetic agents 4
doses, adjusting of 76f
drugs 72, 73, 77
Antihypertensive
agents doses, adjusting of 76f
therapy 75
Anti-inflammatory, antitumor 4
Antimicrobial and immunoregulatory 4
Atherosclerotic cardiovascular disease 22, 35, 63, 69
Atherosclerotic events 87
B
Bacteria, increased adherence of 50
Basolateral membrane 9, 15
Beta-carboxy-telopeptide 57
Beta-cell function 63
Beta-hydroxybutyrate 38
Biguanides 73
Blood pressure 35, 76
changes 54
diastolic 54
lowering 38
reduction 48, 73, 40
systolic 54
Body mass index 32
Bone effects and fractures 56
Bowman's capsule 17
Breast cancer, rates of 61
C
Canagliflozin 3, 25, 26-28, 32, 35-37, 48-50, 57-59, 57, 64, 74, 83, 88
bladder cancer, trial with 61
breast cancer, trial with 61
Cardiovascular Assessment Study 22, 23, 24f, 28f, 34
metabolism of 60
Cancer risk 60
Candida glabrata 49
Cardiac
fibroblasts results 41
metabolism and bioenergetics, improvement in 41
structural remodeling 41
Cardioprotection 60
Cardioprotective action 40
Cardiorenal
benefits 66
pleiotropic benefits 68
Cardiovascular
benefits: implications of 35
death 93
composite of 89
disease 25
prevalence of 35
event 22
primarily 40
thrombolysis 37
thrombolysis in myocardial infarction 58 trial with dapagliflozin 26
Outcome Trials 23, 29, 87
with SGLT-2 inhibitors 21, 27
protective effects 4
Catabolic state 75
Coronary artery disease 23, 25, 36
Credence trial
exploratory outcomes 92
interpretation 93
limitations 94
methodology 88
outcomes 89
primary outcomes 89
safety evaluations 89
secondary outcomes 89, 92
Cytokine 42
Cytokine interleukin-6 42
D
Dapagliflozin 3, 22, 25-28, 34, 35, 37, 40, 49, 50, 57, 59, 64, 80, 81, 85
antifibrotic effects of 41
cardiovascular safety of 26
effect on cardiovascular events-thrombolysis 23, 28f
reported for 60
versus placebo 61
Dehydration 73
Dehydration-related dyshidrotic eczema 60
Diabetes mellitus
and cardiovascular disease 21
management of 63
treatment of type 2 diabetes 7
type 1 diabetes 75, 78
controlled 81
need for adjuvant therapies in 79
type 2 diabetes 4, 11, 14, 52, 63, 75, 78, 87
management of 21
patients trial with empagliflozin 23
Diabetic foot ulcers 74
Diabetic ketoacidosis 53
associated increased risk of 84
essential pathophysiology of 53f
euglycemic 34, 48, 52, 53, 75
incidence of 34
increased risk for 34
Diabetic kidney 7, 8
Diabetic nephropathy 14
development of 18
Diabetic tubulointerstitial fibrosis 15
Diabetologia 40
Dihydrochalcone compound isolated 2
Dipeptidyl peptidase 4 inhibitors 69, 73, 76
Distal tubular sodium delivery 45
Diuresis leads 73
Dizziness 66
Drug interactions 60
Dyselectrolytemia 56
Dysentery 4
Dyslipidemia 21
E
Empagliflozin 21, 22, 25, 26, 28, 32, 35, 36, 40-41, 49-51, 56, 58, 59, 64, 80, 83
cardiovascular outcome event trial 23
in type 2 diabetes mellitus 24, 28, 34
causes inhibition 41
dose of 56
reported for 60
treatment blocks proximal tubule glucose 45
Endogenous 65
glucose production 33, 53
Epicardial adipose tissue mass 42
Epidermal growth factor receptor 46
Ertugliflozin 4
Euglycemic insulin clamp 53
European Medicines Agency's CHMP regulatory committee 85
Exogenous 65
Eythropoietin levels leading 56
F
Fabaceae 4
Familial renal glucosuria 12, 18
Fasting blood glucose 19, 81
Fatty acid 39
FDA Advisory Committee 60
Fever 4
treatment option for 2
Flavescens 4
Formononetin 4
Free fatty acid 84
G
Gastrointestinal 76
epithelial cells 18
Genital infections 49, 64
Genital mycotic infections 77
Gliflozin 3, 4, 49
Glimepiride 32
Glimpse 1
Glitazones 79
Glomerular filtration rate 17, 26, 37, 45, 54, 74, 87, 91
baseline estimated 28
estimated 69, 73
spectrum of estimated 42
Glomerular hyperfiltration 14, 39, 45, 46, 55
Glucagon
levels
increased 55
stimulating neoglucogenesis 84
like peptide-1 receptor agonist 69, 76, 79
production 52
secretion 33
improements in 32
Glucose
conservation 8, 17
deficiency 31
diffuses 16
excretion 10
galactose malabsorption 18
homeostasis, regulation of 12
levels, postprandial 31
lowering medication in type 2 diabetes 69f
lowering therapies 49
oxidation 33
reabsorption 17, 18
inhibition of 31
mechanics of 10
physiology of 17
threshold for 17
toxicity, improvements in 32
transport in tubular epithelial cells 9f
transporter 2, 9, 15
Glucoside analogs 2
Glucosuria 49
condition of natural 12
in uncontrolled T2DM 50
Glucotoxicity 31, 46, 65
reduction in 53
Glycated hemoglobin 73, 76
Glycemic control 79
Glycosuria 14
H
Hazard ratio 24
Heart failure 65, 69
development of 41
hospitalization for 22
prevention of 40
Hemoconcentration 56
manifested 40
Hemodynamic 44
effects 38-39
Hemoglobin A1c 3, 19, 23, 39, 66, 69
Hepatic
gluconeogenesis 8
neoglucogenesis 53
Heterozygous FRG in benign condition 18
Hydroxyl functional group 4
Hyperglycemia
chronic 1
management of 13
mild 35
worsening 7
Hyperkalemia 73
Hypertension 21
management, case for aggressive 35
Hypoglycemia 49
risk of 72, 79
agents 49
I
Immunoreactive insulin 39
Incretin axis 1
Infectious diseases, treatment option for 2
Inhibiting histone deacetylase 41
Inhibitory constant values 2
Insulin 4
add-on to 66
doses, careful titration of 79
resistance 65
secretion, improvements in 32
sensitivity 32
using triple combination therapy of 80
Insulinopenia 83
degree of 53
Interstitial fibrosis 18
Intracellular sodium concentration 16
Intraglomerular hypertension in patients 46
Ipragliflozin 4, 26
efficacy 60
Isoflavanoid
glycosides 4
based structures 4
J
Jaundice 4
K
Ketogenesis 46
Ketone 38
body production, clinical significance of increased 34
oxidation 41
Kidney disease 88
chronic 65, 69, 87
epidemiology collaboration equation 88
failure, risk of 88
progression 42
Kidney interstitium 16
Kidneys filter 17
Kurarinone 4
L
Lavandulyl functional 4
Leukorrhea 4
Lifestyle, management of 63
Lipids effects on 59
Lipoprotein cholesterol
high-density 38, 39
low-density 59
Liraglutide 80
Luseogliflozin 4, 26
M
Maackiain 4
Malaria, treatment option for 2
Malignancy risk 61
Meglitinides 73
Metabolic syndrome 79
Metformin 49, 53, 65, 66, 67, 72, 79
Mitochondrial
biogenesis 40
enzymes, hyperacetylation of 41
Monotherapy, agent of choice for 67
Multifactorial metabolic 39
Mycotic infections 73
Myocardial
glucose metabolism 41
infarction 23, 28f, 37, 58, 89, 93
metabolism 40
Myocardium, direct effects on 40
N
Natriuresis diuresis 40
Necrosis, reduction of 41
Nephroprotection 44
Neurohormonal derangement 1
Nonesterified fatty acids 38
North American inTandem1 Study 82
O
Obesity epidemic 78
Obesity-related comorbid issues 65
Orthostatic hypotension 73
Osmotic diuresis 40, 73
Osteocalcin 57
P
Pain 4
Pancreatic beta-cells 49
Paracrine insulin inhibition 53
Parathyroid hormone increases bone resorption 57
Peripheral artery disease 25, 27
Peripheral vascular disease 59, 74, 83
Phenobarbital 60
Phenytoin 60
Phlorizin 2, 3
Phosphate 56
Pioglitazone 79
Placebo 36, 82
Plasma glucose 17
Pramlintide 79
Prohypertrophic transcription pathways 41
Proximal
convoluted tubule 74
straight tubule 15
tubular cells, basolateral membrane of 16
tubular sodium reabsorption 45
tubules 49
Pyogenic skin infections 4
R
Real-World
data with canagliflozin 25
practice 25
Remogliflozin 3, 80
Renal
death 42
components, effect on primary outcome 90
disease 38
end stage 42, 87
progression of 27, 29, 42 65
effects
acute kidney injury 54
with blood pressure 35
function 19
gluconeogenesis in postabsorptive state 7
glucose
reabsorption in diabetes, alterations of 17
release in the postprandial state 8
transport genetic defects in 11, 18
transport upregulation of 8
glycogenesis 8
glycosuria 18, 75
drugs water 73
hemodynamic effects associated with SGLT-2 inhibition 45f
impairment 65
insufficiency 73
plasma flow 45
threshold for glucose excretion 10
tubular factors, overactivation of 14
tubules 7, 9
Renin–angiotensin–aldosterone system 14, 18, 55
Rifampicin 60
Ritonavir 60
S
Scabies 4
Sedentarism 78
Sergliflozin 3
Serum calcium 56
SGLT-2 inhibitors 1, 9, 11, 21, 31, 39, 45, 56, 66, 69, 73
advantages and disadvantages in use of 28f
adverse effects and safety of 48
current evidences 80
dosage adjustments based on renal function 74
effect of 54
glycemic efficacy of 31
in diabetes 63
intrarenal effect of 14
in therapy, positioning of 64
in type 1 diabetes: emerging evidences 78
induced hematocrit 56
mechanism of action of 15
mediated glucose transportation 15
metabolic
and hemodynamic effects of 31
effects of 32
offer renoprotection 18
on fracture risk 58
physiology of 7
potential mechanism for 84
role of kidneys in glucose homeostasis 7
safety concerns 83
treatment with 31, 33
type 2 diabetes mellitus 7
use of 65
caution in 72, 73
clinical beneficial effects 72
clinical pearls 72, 74
contraindications 72
of indications 72
Skin disorders 60
SLC5A2 gene 12, 18
Small intestine 64
Sodium
electrochemical potential gradient 9
glucose cotransporters 15, 64
glucose linked transporter T2DM (SGLT-2) inhibitors, effect of 51
glucose cotransporter-2 87
potassium adenosine triphosphatase 9, 90, 16
reabsorption 45
Sophora flavescens 4
Sotagliflozin 4, 81, 82, 83
Stroke 56, 93
Sulfonylureas 49, 66, 73, 76
dose of 49
Swelling 4
T
Target glycemic range 82
Thiazolidinediones 66, 69, 73
Thiophene derivative of C-glucoside 3
Tissue glucose disposal 53
Tofogliflozin 4, 26
Total daily insulin, dose of 82
Tubular
cells 16
glucose reabsorption, mechanism of 16
intracellular space 16
lumen 16
Tubuloglomerular, restoration of impaired 55
Tubulointerstitial fibrosis 18
U
United States Food and Drug Administration 3
Urinary albumin-to-creatinine ratio 88
Urinary glucose
clearance rate 53
excretion 17, 64
Urinary tract infections 19, 48, 50, 51, 77
Urothelium 50
USA Food and Drug Administration 22
V
Variabilin 4
Vasodilatation, potential induction of 41
Voltage-gated potassium, activation of 41
Vulvovaginal candidiasis 73
W
Weight gain 79
insulin-induced 66
Weight loss 48, 68
significant 73
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Chapter Notes

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The Evolution of SGLT-2 InhibitorsCHAPTER 1

 
INTRODUCTION
Diabetes mellitus is a state of chronic hyperglycemia secondary to multiple pathophysiological defects that include not only a dysfunction of the β-cells and α-cells resulting in impaired insulin and glucagon actions but also defective incretin axis, neurohormonal derangement in the brain as well as an increase in the glucose reabsorption in the kidneys. An understanding of these multiple etiological defects has stimulated researchers to search for novel agents targeting each of these mechanisms to optimize and individualize treatment of diabetes in current times. The latest agents to be added to our armamentarium are the sodium-glucose cotransporter-2 inhibitors (SGLT-2 inhibitors), commonly known as the gliflozins that primarily work by reducing the excessive renal glucose reabsorption that occurs in patients with diabetes. Following the discovery of phlorizin, the first natural SGLT-2 inhibitor, a number of synthetic glucoside analogs have been developed and are being used today while the search for newer agents is still ongoing. This chapter will introduce readers to the history and evolution of early-generation SGLT-2 inhibitors derived from natural plants leading to the development of the currently used prototypes of this class of agents and will give a glimpse into the recent advancement on the futuristic molecules in the pipeline.2
 
THE FIRST NATURAL SGLT-2 INHIBITOR—PHLORIZIN AND ITS GLUCOSIDE ANALOGS
The first recognized natural substance with SGLT-2 inhibitory action was phlorizin, a dihydrochalcone compound isolated from barks of apple trees way back in 1835. Initially regarded as a treatment option for fevers, malaria and infectious diseases owing to its similarity with cinchona and willow tree extracts, the evolution of phlorizin as an inhibitor of renal glucose reabsorption that caused increase in urinary glucose excretion was reported almost five decades later by Chasis et al. The relationship between the glucose transport system of the proximal tubular brush border epithelium and phlorizin came to be established in 1970s. Several in vivo studies on diabetic animal models showed reduced fasting and/or postprandial blood glucose levels and increased insulin sensitivity following phlorizin administration. Katsuno et al. reported inhibition of both human SGLT-1 and SGLT-2 with phlorizin, with the inhibitory constant (Ki) values of 151 nM and 18.6 nM, respectively. In spite of its sufficient SGLT inhibitory actions, certain critical drawbacks disqualified phlorizin from further use as an antihyperglycemic agent. Most prominent of these was the low therapeutic selectivity of phlorizin for both SGLT-1 and SGLT-2. By inhibiting SGLT-1 primarily localized in the small intestine, phlorizin was shown to cause several gastrointestinal side effects, such as diarrhea, dehydration and malabsorption. Also, its absorption from small intestine was quite poor owing to its low oral bioavailability. Besides, phloretin, α-glycosidase catalyzed hydrolytic metabolite of phlorizin, strongly inhibits the ubiquitous glucose transporter 1 (GLUT1), which then may obstruct glucose uptake in various tissues.
These drawbacks lead to a quest for developing novel analogs of phlorizin that would have better stability, bioavailability, and higher selectivity for SGLT-2 receptors. Researchers then focused on the O-glucoside analogs of phlorizin eventually developing T-1095, an oral selective inhibitor of SGLT-2 that undergoes extensive hepatic metabolism into its active metabolite T-1095A. This metabolite demonstrated dose-dependent reduction in urinary glucose reabsorption with consequent reduction in blood glucose, 3triggering development of numerous other similar O-glucoside derivatives such as sergliflozin, remogliflozin and AVE2268 over the next few years. Though these agents minimized glucosidase-mediated degradation and increased systemic exposure, they were pharmacokinetically unstable and had incomplete pharmacological selectivity for SGLT-2. This eventually led to phasing out of these agents and shifted research toward other derivatives of phlorizin.
The first C-glucoside analogs of phlorizin were developed in 2000 which further lead to development of the currently used molecules—the first one being dapagliflozin, developed in 2008 by Meng et al. with lipophilic ethoxy substituents at position 4 on the B-ring of phlorizin as shown here in Figure 1. Dapagliflozin showed a dose-dependent glucosuric response and significantly reduced fasting and postprandial blood glucose levels as well as hemoglobin A1c (HbA1c) with significant weight loss and a 1,200-fold higher selectivity for human SGLT-2 versus SGLT-1 (IC50: 1.12 nM vs. 1,391 nM). Dapagliflozin was introduced and became commercially available first in Europe in 2012 followed by the United States Food and Drug Administration (USFDA) approval in January 2014 paving its way for use in US and eventually globally thereafter.
Canagliflozin, a thiophene derivative of C-glucoside was approved by the USFDA in 2013 with similar antihyperglycemic properties and an over 400-fold difference in selectivity for SGLT-2 versus SGLT-1 (IC50: 2.2 nM vs. 910 nM).
zoom view
FIG. 1: Phlorizin and its major O- and C-glucoside analogs.
4
The third gliflozin to hit the global markets was empagliflozin characterized by the highest, i.e. 2,700-fold selectivity for SGLT-2 versus SGLT-1. Various other gliflozins such as ipragliflozin, tofogliflozin and luseogliflozin have since been developed, mainly by the Japanese, while others such as ertugliflozin and LX-4211 (sotagliflozin—a dual SGLT-2/SGLT-1 inhibitor) are also now the latest entrants into this arena.
 
SOPHORA FLAVESCENS (FABACEAE)
Sophora flavescens (S. flavescens) or the shrubby sophora is a popular Chinese shrub belonging to the pea family Fabacea. Its root, known as “Kushen”, being rich in alkaloids and flavonoids, has traditionally been used for treating numerous diseases including dysentery, fever, jaundice, leukorrhea, scabies, pyogenic skin infections, swelling and also pain. Studies have also proven additional anti-inflammatory, antitumor, antianaphylactic, antiasthmatic, antimicrobial and immunoregulatory as well as cardiovascular protective effects. Research has further demonstrated that the methanol extract of this plant has a potent SGLT inhibitory activity. Three of these extracts, namely—(1) maackiain; (2) variabilin; and (3) formononetin, with isoflavonoid-based structures having a hydroxyl functional group, demonstrated exclusive SGLT-2 inhibitory activity. Also, flavanone compounds, the most potent being kurarinone and sophoraflavanone G, demonstrated extensive inhibition of both SGLT-2 and SGLT-1, with increased selectivity for SGLT-2 attributable to the common lavandulyl functional group at the C-8 position. Currently, SGLT-2 inhibitory effects of all nine isolated compounds of isoflavanoid glycosides from roots of S. flavescens have been demonstrated.
 
CONCLUSION
The identification of renal glucose reabsorption as an important pathophysiological contributor to hyperglycemia paved the way for SGLT-2 inhibition as a promising therapeutic strategy for treatment of type 2 diabetes mellitus. The last few years have shown the introduction of various SGLT-2 inhibitors derived from the natural active compound phlorizin, approved for use in type 2 diabetes both as monotherapy and as combination therapy with other antidiabetic 5agents including insulin. A number of these agents are now available globally while newer ones are being constantly developed and studied.
SUGGESTED READING
  1. Abdul-Ghani MA, DeFronzo RA. Inhibition of renal glucose absorption: A novel strategy for achieving glucose control in type 2 diabetes mellitus. Endocr Pract. 2008;14(6):782–90.
  1. Baynes JW. Role of oxidative stress in development of complications in diabetes. Diabetes. 1991;40(4):405–12.
  1. Bays H. Sodium glucose co-transporter type 2 (SGLT2) inhibitors: Targeting the kidney to improve glycemic control in diabetes mellitus. Diabetes Ther. 2013;4(2):195–220.
  1. Bickel M, Brummerhop H, Frick W, et al. Effects of AVE2268, a substituted glycopyranoside, on urinary glucose excretion and blood glucose in mice and rats. Arzneimittelforschung. 2008;58(11):574–80.
  1. Chasis H, Jolliffe N, Smith HW. The action of phlorizin on the excretion of glucose, xylose, sucrose, creatinine and urea by man. J Clin Invest. 1933;12(6):1083–90.
  1. Derdau V, Fey T, Atzrodt J. Synthesis of isotopically labelled SGLT inhibitors and their metabolites. Tetrahedron. 2010;66(7):1472–82.
  1. Ehrenkranz JR, Lewis NG, Kahn CR, et al. Phlorizin: A review. Diabetes Metab Res Rev. 2005;21(1):31–8.
  1. Gorboulev V, Schürmann A, Vallon V, et al. Na+-D-glucose cotransporter SGLT1 is pivotal for intestinal glucose absorption and glucose-dependent incretin secretion. Diabetes. 2012;61(1):187–96.
  1. Grempler R, Thomas L, Eckhardt M, et al. Empagliflozin, a novel selective sodium glucose cotransporter-2 (SGLT-2) inhibitor: Characterisation and comparison with other SGLT-2 inhibitors. Diabetes Obes Metab. 2012;14(1):83–90.
  1. Han S, Hagan DL, Taylor JR, et al. Dapagliflozin, a selective SGLT2 inhibitor, improves glucose homeostasis in normal and diabetic rats. Diabetes. 2008;57(6):1723–9.
  1. Hung HY, Qian K, Morris-Natschke SL, et al. Recent discovery of plant-derived anti-diabetic natural products. Nat Prod Rep. 2012;29(5):580–606.
  1. Meng W, Ellsworth BA, Nirschl AA, et al. Discovery of dapagliflozin: A potent, selective renal sodium-dependent glucose cotransporter 2 (SGLT2) inhibitor for the treatment of type 2 diabetes. J Med Chem. 2008;51(5):1145–9.
  1. Mudaliar S, Polidori D, Zambrowicz B, et al. Sodium-glucose cotransporter inhibitors: Effects on renal and intestinal glucose transport: From bench to bedside. Diabetes Care. 2015;38(12):2344–53.
  1. Nomura S, Sakamaki S, Hongu M, et al. Discovery of canagliflozin, a novel C-glucoside with thiophene ring, as sodium-dependent glucose cotransporter 2 inhibitor for the treatment of type 2 diabetes mellitus. J Med Chem. 2010;53(17): 6355–60.

  1. 6 Oku A, Ueta K, Arakawa K, et al. T-1095, an inhibitor of renal Na+-glucose cotransporters, may provide a novel approach to treating diabetes. Diabetes. 1999;48(9):1794–800.
  1. Rahmoune H, Thompson PW, Ward JM, et al. Glucose transporters in human renal proximal tubular cells isolated from the urine of patients with non-insulin-dependent diabetes. Diabetes. 2005;54(12):3427–34.
  1. Rieg T, Masuda T, Gerasimova M, et al. Increase in SGLT1-mediated transport explains renal glucose reabsorption during genetic and pharmacological SGLT2 inhibition in euglycemia. Am J Physiol Renal Physiol. 2014;306(2):F188–93.
  1. Rosenstock J, Aggarwal N, Polidori D, et al. Dose-ranging effects of canagliflozin, a sodium-glucose cotransporter 2 inhibitor, as add-on to metformin in subjects with type 2 diabetes. Diabetes Care. 2012;35(6):1232–8.
  1. Rossetti L, Lauglin MR. Correction of hyperglycemia with phlorizin normalizes tissue sensitivity to insulin in diabetic rats. J Clin Invest. 1989;84(3):892–9.
  1. Sato S1, Takeo J, Aoyama C, et al. Na+-glucose cotransporter (SGLT) inhibitory flavonoids from the roots of Sophoraflavescens. Bioorg Med Chem. 2007;15(10):3445–9.
  1. Vallon V, Platt KA, Cunard R. SGLT2 mediates glucose reabsorption in the early proximal tubule. J Am Soc Nephrol. 2011;22(1):104–12.
  1. Vallon V. The mechanisms and therapeutic potential of SGLT2 inhibitors in diabetes mellitus. Annu Rev Med. 2015;66:255–70.
  1. Vestri S, Okamoto MM, de Freitas HS, et al. Changes in sodium or glucose filtration rate modulate expression of glucose transporters in renal proximal tubular cells of rat. J Membr Biol. 2001;182(2):105–12.
  1. Vick H, Diedrich DF, Baumann K. Reevaluation of renal tubular glucose transport inhibition by phlorizinanalogs. Am J Physiol. 1973;224(3):552–7.
  1. White JR. Apple trees to sodium glucose co-transporter inhibitors: a review of SGLT2 inhibition. Clin Diabetes. 2010;28(1):5–10.
  1. Wright EM, Loo DD, Hirayama BA. Biology of human sodium glucose transporters. Physiol Rev. 2011;91(2):733–94.