The Neuronal and Non-Neuronal Pathways of Sodium-Glucose Cotransporter-2 Inhibitor on Body Weight-Loss and Insulin Resistance

A multicentre, double-blind, placebo-controlled, randomized, parallel comparison, phase 3 trial to evaluate the efficacy and safety of pioglitazone add-on therapy in type 2 diabetic patients treated with metformin and dapagliflozin

AIM

To investigate the efficacy and safety of pioglitazone compared to placebo when added to metformin plus dapagliflozin, a sodium-glucose cotransporter-2 (SGLT2) inhibitor, for patients with type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

In a multicentre study, with a randomized, double-blind, placebo-controlled design, 249 Korean patients with T2DM suboptimally managed on metformin and dapagliflozin were assigned to receive either pioglitazone (15 mg daily) or placebo for 24 weeks, followed by a 24-week pioglitazone extension. Primary outcomes included changes in glycated haemoglobin (HbA1c), with secondary outcomes assessing insulin resistance, adiponectin levels, lipid profiles, liver enzymes, body weight and waist circumference.

RESULTS

Pioglitazone administration resulted in a significant reduction in HbA1c levels (from 7.80% ± 0.72% to 7.27% ± 0.82%) compared with placebo (from 7.79% ± 0.76% to 7.69% ± 0.86%, corrected mean difference: -0.42% ± 0.08%; p < 0.01) at 24 weeks. Additional benefits from pioglitazone treatment included enhanced insulin sensitivity, increased adiponectin levels, raised high-density lipoprotein cholesterol levels and reduced liver enzyme levels, resulting in improvement in nonalcoholic fatty liver disease liver fat score. Despite no serious adverse events in either group, pioglitazone therapy was modestly but significantly associated with weight gain and increased waist circumference.

CONCLUSIONS

Adjunctive pioglitazone treatment in T2DM inadequately controlled with metformin and dapagliflozin demonstrates considerable glycaemic improvement, metabolic benefits, and a low risk of hypoglycaemia. These advantages must be weighed against the potential for weight gain and increased waist circumference.

The Effect of Canagliflozin on High-Density Lipoprotein Cholesterol and Angiopoietin-Like Protein 3 in Type 2 Diabetes Mellitus

Background

Diabetes mellitus is often accompanied by dyslipidemia. Sodium-glucose cotransporter-2 (SGLT2) inhibitors, as a novel therapeutic agent for the treatment of type 2 diabetes mellitus (T2DM), have been reported to exert effects on lipid, while the results remain controversial. This study is aimed at exploring the effect of SGLT2 inhibitor canagliflozin on lipid profile.

Methods

This study was a single-center, open-label, nonrandomized, prospective study. Metformin (500 mg three times per day) or canagliflozin (100 mg, once daily) was administered for 12 weeks. Fasting blood samples were collected before and 12 weeks after treatment. Serum lipid profile levels and angiopoietin-like protein 3 (ANGPTL3) were determined. In animal experiment, C57BL/6 J mice were divided into three groups including control, STZ + HFD, and STZ + HFD + canagliflozin. Lipid profile and plasma ANGPTL3 level were measured after 12 week's treatment. Moreover, the expression of ANGPTL3 was detected in the liver tissues.

Results

There was a decreased trend in low-density lipoprotein cholesterol (LDL-c) and triglycerides (TG) after canagliflozin treatment, while canagliflozin significantly increased high-density lipoprotein cholesterol (HDL-c) level and decreased plasma ANGPTL3 level. In addition, the expression of ANGPTL3 in liver tissues decreased obviously in diabetic mice with canagliflozin treatment.

Conclusions

Canagliflozin increases HDL-c level and suppresses ANGPTL3 expression in patients with T2DM and diabetic mice. The reduction of ANGPTL3 may contribute to the increase of HDL-c. However, the specific mechanism needs further research. This trial is registered with ChiCTR1900021231.

The changes of cardiac energy metabolism with sodium-glucose transporter 2 inhibitor therapy

Background/aims

To investigate the specific effects of s odium-glucose transporter 2 inhibitor (SGLT2i) on cardiac energy metabolism.

Methods

A systematic literature search was conducted in eight databases. The retrieved studies were screened according to the inclusion and exclusion criteria, and relevant information was extracted according to the purpose of the study. Two researchers independently screened the studies, extracted information, and assessed article quality.

Results

The results of the 34 included studies (including 10 clinical and 24 animal studies) showed that SGLT2i inhibited cardiac glucose uptake and glycolysis, but promoted fatty acid (FA) metabolism in most disease states. SGLT2i upregulated ketone metabolism, improved the structure and functions of myocardial mitochondria, alleviated oxidative stress of cardiomyocytes in all literatures. SGLT2i increased cardiac glucose oxidation in diabetes mellitus (DM) and cardiac FA metabolism in heart failure (HF). However, the regulatory effects of SGLT2i on cardiac FA metabolism in DM and cardiac glucose oxidation in HF varied with disease types, stages, and intervention duration of SGLT2i.

Conclusion

SGLT2i improved the efficiency of cardiac energy production by regulating FA, glucose and ketone metabolism, improving mitochondria structure and functions, and decreasing oxidative stress of cardiomyocytes under pathological conditions. Thus, SGLT2i is deemed to exert a benign regulatory effect on cardiac metabolic disorders in various diseases.

Systematic review registration

https://www.crd.york.ac.uk/, PROSPERO (CRD42023484295).