Dipeptidyl peptidase-4 inhibitor and sodium-glucose cotransporter 2 inhibitor additively ameliorate hepatic steatosis through different mechanisms of action in high-fat diet-fed mice

AIM

Dipeptidyl peptidase-4 (DPP-4) inhibitors suppress the inactivation of incretin hormones and lower blood glucose levels by inhibiting DPP-4 function. Sodium-glucose cotransporter 2 (SGLT2) inhibitors lower blood glucose levels in an insulin-independent manner by inhibiting renal reabsorption of glucose. DPP-4 and SGLT2 inhibitors each have the potential to improve hepatic steatosis; however, their combined effects remain unclear. In this study, we examined the effects of the combination of these drugs on hepatic steatosis using high-fat diet-fed mice.

METHOD

C57BL/6J male mice were fed a 60% high-fat diet for 2 months to induce hepatic steatosis. Mice were divided into four groups (control; DPP-4 inhibitor anagliptin; SGLT2 inhibitor luseogliflozin; anagliptin and luseogliflozin combination), and the effects of each drug and their combination on hepatic steatosis after a 4-week intervention were evaluated.

RESULTS

There were no differences in blood glucose levels among the four groups. Anagliptin suppresses inflammation- and chemokine-related gene expression. It also improved macrophage fractionation in the liver. Luseogliflozin reduced body weight, hepatic gluconeogenesis and blood glucose levels in the oral glucose tolerance test. The combination treatment improved hepatic steatosis without interfering with the effects of anagliptin and luseogliflozin, respectively, and fat content and inflammatory gene expression in the liver were significantly improved in the combination group compared with the other groups.

CONCLUSION

The combination therapy with the DPP-4 inhibitor anagliptin and the SGLT2 inhibitor luseogliflozin inhibits fat deposition in the liver via anti-inflammatory effects during the early phase of diet-induced liver steatosis.

Cardiovascular Outcomes and Risks After Initiation of a Sodium Glucose Cotransporter 2 Inhibitor: Results From the EASEL Population-Based Cohort Study (Evidence for Cardiovascular Outcomes With Sodium Glucose Cotransporter 2 Inhibitors in the Real World)

Supplemental Digital Content is available in the text.

Background:

Clinical trials have shown cardiovascular benefits and potential risks from sodium glucose cotransporter 2 inhibitors (SGLT2i). Trials may have limited ability to address individual end points or safety concerns.

Methods:

We performed a population-based cohort study among patients with type 2 diabetes mellitus with established cardiovascular disease newly initiated on antihyperglycemic agents within the US Department of Defense Military Health System between April 1, 2013, and December 31, 2016. Incidence rates, hazard ratios (HRs), and 95% confidence intervals (CIs) for time to first composite end point of all-cause mortality and hospitalization for heart failure event, major adverse cardiovascular events (defined as all-cause mortality, nonfatal myocardial infarction, and nonfatal stroke), and individual end points were evaluated using conditional Cox models comparing new SGLT2i users with other antihyperglycemic agents. The exploratory safety end point was below-knee lower extremity amputation. Intent-to-treat and on-treatment analyses were performed.

Results:

After propensity matching, 25 258 patients were followed for a median of 1.6 years. Compared with non-SGLT2i, initiation of SGLT2i was associated with a lower rate of all-cause mortality and hospitalization for heart failure (1.73 versus 3.01 events per 100 person-years; HR, 0.57; 95% CI, 0.50–0.65) and major adverse cardiovascular events (2.31 versus 3.45 events per 100 person-years; HR, 0.67; 95% CI, 0.60–0.75). SGLT2i initiation was also associated with an ≈2-fold higher risk of below-knee lower extremity amputation (0.17 versus 0.09 events per 100 person-years; HR, 1.99; 95% CI, 1.12–3.51). Because of the disproportionate canagliflozin exposure in the database, the majority of amputations were observed on canagliflozin. Results were consistent in the on-treatment analysis.

Conclusions:

In this high-risk cohort, initiation of SGLT2i was associated with lower risk of all-cause mortality, hospitalization for heart failure, and major adverse cardiovascular events and higher risk of below-knee lower extremity amputation. Findings underscore the potential benefit and risks to be aware of when initiating SGLT2i. It remains unclear whether the below-knee lower extremity amputation risk extends across the class of medication, because the study was not powered to make comparisons among individual treatments.

Formulation of two-layer dissolving polymeric microneedle patches for insulin transdermal delivery in diabetic mice

Dissolving microneedles (MNs) display high efficiency in delivering poorly permeable drugs and vaccines. Here, two-layer dissolving polymeric MN patches composed of gelatin and sodium carboxymethyl cellulose (CMC) were fabricated with a two-step casting and centrifuging process to localize the insulin in the needle and achieve efficient transdermal delivery of insulin. In vitro skin insertion capability was determined by staining with tissue-marking dye after insertion, and the real-time penetration depth was monitored using optical coherence tomography. Confocal microscopy images revealed that the rhodamine 6G and fluorescein isothiocyanate-labeled insulin (insulin-FITC) can gradually diffuse from the puncture sites to deeper tissue. Ex vivo drug-release profiles showed that 50% of the insulin was released and penetrated across the skin after 1 h, and the cumulative permeation reached 80% after 5 h. In vivo and pharmacodynamic studies were then conducted to estimate the feasibility of the administration of insulin-loaded dissolving MN patches on diabetic mice for glucose regulation. The total area above the glucose level versus time curve as an index of hypoglycemic effect was 128.4 ± 28.3 (% h) at 0.25 IU/kg. The relative pharmacologic availability and relative bioavailability (RBA) of insulin from MN patches were 95.6 and 85.7%, respectively. This study verified that the use of gelatin/CMC MN patches for insulin delivery achieved a satisfactory RBA compared to traditional hypodermic injection and presented a promising device to deliver poorly permeable protein drugs for diabetic therapy. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 84-93, 2017.