The Association Between the Dosage of SGLT2 Inhibitor and Weight Reduction in Type 2 Diabetes Patients: A Meta-Analysis

Pharmacotherapy of obesity: Available medications and drugs under investigation

Obesity is a chronic disease with a continuously rising prevalence that currently affects more than half a billion people worldwide. Energy balance and appetite are highly regulated via central and peripheral mechanisms, and weight loss triggers a homeostatic response leading to weight regain. Lifestyle and behavioral modifications are the cornerstones of obesity management; however, they often fail to achieve or sustain long-term weight loss. Pharmacotherapy added onto lifestyle modifications results in an additional, albeit limited, weight reduction. Regardless, this weight reduction of 5-10% conveys multiple cardiovascular and metabolic benefits. In this review, evidence on the food and drug administration (FDA)-approved medications, i.e., orlistat, lorcaserin, phentermine/topiramate, liraglutide and naltrexone/bupropion, is summarized. Furthermore, anti-obesity agents in the pipeline for potential future therapeutic use are presented.

Beneficial effects of SGLT2 inhibitors on fatty liver in type 2 diabetes: A common comorbidity associated with severe complications

Patients with type 2 diabetes mellitus (T2DM) are exposed to non-alcoholic fatty liver disease (NAFLD), a comorbidity associated with cardiovascular disease and chronic kidney disease, and which may progress to non-alcoholic steatohepatitis (NASH), fibrosis and cirrhosis. Sodium-glucose cotransporter type-2 (SGLT2) inhibitors are glucose-lowering agents that improve glucose control while promoting weight loss and lowering serum uric acid levels. These agents may exert cardiovascular and renal protection in T2DM patients with established cardiovascular disease. Recent findings from both randomized controlled trials and open-label studies have also shown that SGLT2 inhibitors are able to reduce fatty liver content, as assessed by different imaging techniques, and improve biological markers of NAFLD, especially serum liver enzymes, in patients with T2DM. In addition, there are emerging data to suggest a mechanism beyond the reduction of hyperglycaemia and body weight, and a potential role for the decrease in low-grade inflammation and oxidative stress associated with SGLT2 inhibitor therapy. This positive effect of SGLT2 inhibitors on NAFLD complements their already well-known effects on cardiovascular and chronic kidney diseases.

Weight loss associated with sodium-glucose cotransporter-2 inhibition: a review of evidence and underlying mechanisms

With their novel, insulin-independent mechanism, sodium-glucose cotransporter-2 (SGLT2) inhibitors are a major turning point in the management of type 2 diabetes mellitus. At present, there are several SGLT2 inhibitors available or in development, and these oral anti-hyperglycaemic agents lower plasma glucose through the inhibition of SGLT2-mediated reuptake of filtered glucose in the kidney. This unique mechanism of action is also expected to result in other beneficial effects, such as weight loss and blood pressure reduction. In various studies, including randomized controlled trials and real-world studies, patients treated with SGLT2 inhibitors have reported weight loss of around 1 to 3 kg. This review describes the characteristics of weight loss associated with SGLT2 inhibitor therapy, the clinical factors affecting SGLT2 inhibitor-associated weight loss and the possible underlying mechanisms of SGLT2 inhibitor-associated weight loss, including changes in metabolism and body composition, and the role of a reduction in insulin dose and compensatory hyperphagia. Understanding the weight loss effect of SGLT2 inhibitors, its related factors and underlying mechanisms can aid clinicians in optimal treatment decision-making, provide valuable insight on both obesity and diabetes management and reveal areas of future research and new therapeutic options.

The actions of SGLT2 inhibitors on metabolism, renal function and blood pressure

Inhibition of the sodium-glucose cotransporter (SGLT) 2 in the proximal tubule of the kidney has a broad range of effects on renal function and plasma volume homeostasis, as well as on adiposity and energy metabolism across the entire body. SGLT2 inhibitors are chiefly used in type 2 diabetes for glucose control, achieving reductions in HbA_1c of 7-10 mmol/mol (0.6-0.9%) when compared with placebo. This glucose-lowering activity is proportional to the ambient glucose concentration and glomerular filtration of this glucose, so may be greater in those with poor glycaemic control and/or hyperfiltration at baseline. Equally, the glucose-lowering effects of SGLT2 inhibitors are attenuated in individuals without diabetes and those with a reduced eGFR. However, unlike the glucose-lowering effects of SGLT2 inhibitors, the spill-over of sodium and glucose beyond the proximal nephron following SGLT2 inhibition triggers dynamic and reversible realignment of energy metabolism, renal filtration and plasma volume without relying on losses into the urine. In addition, these processes are observed in the absence of significant glucosuria or ongoing natriuresis. In the long term, the resetting of energy/salt/water physiology following SGLT2 inhibition has an impact, not only on adiposity, renal function and blood pressure control, but also on the health and survival of patients with type 2 diabetes. A better understanding of the precise biology underlying the acute actions of SGLT2 inhibitors in the kidney and how they are communicated to the rest of the body will likely lead to improved therapeutics that augment similar pathways in individuals with, or even without, diabetes to achieve additional benefits.

Effects of SGLT2 inhibitors on systemic and tissue low-grade inflammation: The potential contribution to diabetes complications and cardiovascular disease

Chronic low-grade inflammation is a recognized key feature associated with type 2 diabetes mellitus (T2DM) and its complications. In prospective randomized trials, sodium-glucose cotransporter type 2 (SGLT2) inhibitors have demonstrated benefits related to several cardiovascular and renal risk factors, including HbA_1c, blood pressure, body weight, renal hyperfiltration, and improvement of cardiorenal outcomes. SGLT2 inhibitors may improve adipose tissue function and induce decreases in serum leptin, TNF-α and IL-6 while increasing adiponectin. While data on high-sensitivity C-reactive protein and other inflammatory markers are relatively scarce in humans, in animals, a number of reports have shown reductions in cytokine and chemokine concentrations in parallel with protective effects against progression of atherosclerotic lesions. Experimental findings also suggest that part of the renoprotective effects of SGLT2 inhibition may be related to anti-inflammatory actions at the kidney level. Underlying mechanisms to explain this anti-inflammatory effect are multiple, but may involve weight loss, and reduction in adipose tissue inflammation, slight increase in ketone bodies and diminution of uric acid levels or attenuation of oxidative stress. However, further studies in diabetes patients with specific assessment of inflammatory markers are still necessary to determine the specific contribution of the anti-inflammatory action of SGLT2 inhibitors to the reduction of cardiovascular and renal complications and mortality observed with this class of antidiabetic drugs.

Understanding the impact of commonly utilized, non-insulin, glucose-lowering drugs on body weight in patients with type 2 diabetes

INTRODUCTION

The majority of patients with type 2 diabetes also have obesity. Obesity increases the risk of developing diabetes and is associated with worsened glycemic control and increased morbidity and mortality in individuals with diabetes. Sustained weight loss is associated with improved glycemic control, potential for diabetes remission, and decreased medical expenditures.

AREAS COVERED

Herein, the impact of commonly utilized, non-insulin, glucose-lowering drugs on body weight in patients with type 2 diabetes is discussed. The weight change magnitudes, mechanisms, and any within-class differences are also explored.

EXPERT OPINION

The weight impact of diabetes medications should be considered when designing treatment regimens, especially in patients who are overweight or have obesity. Lifestyle modification is paramount for optimal diabetes management. Therapeutic regimens should ideally be designed to maximize weight loss and at least minimize or avoid weight gain. Future glucose-lowering medications should continue to offer improvement in cardiovascular risk factors, including weight, in order to be accepted into the armamentarium of diabetes therapy. Therapeutic regimens should be designed to help patients with diabetes and obesity achieve both glycemic and weight goals. Management of these disease states is expected to become increasingly integrated.