Effect of parthenolide, an NLRP3 inflammasome inhibitor, on insulin resistance in high-fat diet-obese mice

The activation of Nod-like receptor proteins (NLRP3) containing the pyrin domain inflammasome is a hallmark of the pathogenesis of metabolic disorders. Inhibition of the NLRP3 inflammasome by phytoconstituents has been attempted as a strategy to mitigate these disorders. Therefore, the present study aimed to evaluate the efficacy of an NLRP3 inflammasome inhibitor, parthenolide (PN; 5 mg/kg i.p.) against inflammation and insulin resistance in high-fat diet (HFD) - obese mice. Treatment with PN and pioglitazone (PIO; 30 mg/kg p.o.) attenuated lipopolysaccharide (LPS; 1 ng/ml) - induced elevation of tumor necrosis factor-α and interleukin-1β in mouse peritoneal macrophages in a dose-dependent manner. Sixty days of PN and PIO treatment marginally reduced obesity-induced insulin resistance in HFD-obese mice. PN treatment also decreased blood glucose from 14th to 60th day, supporting the hypothesis of simultaneous attenuation of inflammation and insulin resistance in obese mice. Thus, PN treatment was also evident with significant improvement in glucose tolerance and peripheral insulin resistance validated through the respective tolerance tests. Therefore, the present study suggests that PN, an NLRP3 inflammasome inhibitor, could be a possible therapeutic agent for attenuating obesity-induced insulin resistance.

Incidence and Outcomes of Gestational Diabetes Mellitus Using the New International Association of Diabetes in Pregnancy Study Group Criteria in Hôpital Maisonneuve-Rosemont

OBJECTIVES

At 1 Canadian university hospital, pregnant women were routinely screened for gestational diabetes mellitus (GDM) with a 75-g oral glucose tolerance test (OGTT). Diagnostic plasma glucose thresholds were as follows: fasting: ≥5.3 mmol/L, 1 h: ≥10.6 mmol/L and 2 h: ≥9.0 mmol/L. In 2015, diagnostic thresholds were reduced to those recommended by the International Association of Diabetes in Pregnancy Study Group (IADPSG) as follows: fasting: ≥5.1 mmol/L, 1 h: ≥10.0 mmol/L and 2 h: ≥8.5 mmol/L. However, subsequent Diabetes Canada guidelines state that further evidence is required before recommending those thresholds. Our objectives were to compare pregnancy outcomes of all pregnant women who underwent a 75-g OGTT before and after the adoption of the IADPSG criteria.

METHODS

Pregnancy outcomes of all women (N=2,830) that had a pregnancy OGTT at the Hôpital Maisonneuve-Rosemont between July 1, 2014 and March 1, 2015 (pre-IADPSG group) were compared with women who were screened between March 1, 2015 and January 1, 2016 (post-IADPSG group). Medical files were reviewed to compare outcomes.

RESULTS

Women in the post-IADPSG group had a higher early body mass index (26.3 vs 25.5 kg/m², p=0.01) and more chronic hypertension (3.7% vs 1.2%, p<0.0001), respectively. OGTT results were similar, but rates of GDM were 10.8% (141 of 1,295) in the pre-IADPSG group and 17.6% (271 of 1,535) in the post-IADPSG group. In the post-IADPSG group, pre-eclampsia rates were lower (1.0% vs 2.2%, p=0.021), as was labour induction (25.6% vs 32.8%, p<0.0001) and neonatal intensive care unit admission (4.8% vs 8.5%, p<0.001), respectively.

CONCLUSIONS

Adopting IADPSG criteria for GDM improved pregnancy outcomes in our obstetric population.

[Prediabetes, definition and treatment]

Prediabetes corresponds to high levels of glycaemia on an empty stomach and/or lower tolerance to glucose. It is necessary to detect and treat it in order to prevent type 2 diabetes and its long-term morbidity-mortality. Several clinical trials, based notably on modifying the patient's lifestyle, have shown that prevention is possible. Bariatric surgery could constitute a favoured treatment option in prediabetic obese patients.

Serum Galanin Concentration is Increased in Subjects with Impaired Glucose Tolerance

OBJECTIVES

Although extensive data have shown that galanin can regulate the food intake and glucose metabolism of animals, little is known regarding the galanin concentration in patients with impaired glucose tolerance (IGT). Therefore, the aims of this study were to investigate whether serum galanin levels and other metabolic parameters are changed in patients with IGT compared with controls with normal glucose tolerance (NGT).

METHODS

Data regarding serum galanin levels and relative metabolic parameters were collected in 12 patients with IGT and 12 healthy patients with NGT.

RESULTS

At 1 hour and 2 hours after dinner, serum galanin, insulin and glucose levels were significantly higher in patients with IGT than in controls with NGT. Additionally, the body weights of patients with IGT was higher than those of the controls. Furthermore, a negative correlation was found between galanin levels and 1-hour glucose concentrations (r=-0.580; p=0.048) in patients with IGT.

CONCLUSIONS

The higher serum galanin levels as well as the negative correlation between galanin levels and 1-hour glucose content in patients with IGT may result from the interaction between insulin and galanin in differing conditions, suggesting that the galanin level may be used as a potential biomarker for the prediction of IGT in clinical settings.