Hyperinsulinemia rather than insulin resistance itself induces blood pressure elevation in high fat diet-fed rats

Xiasangju alleviate metabolic syndrome by enhancing noradrenaline biosynthesis and activating brown adipose tissue

Metabolic syndrome (MetS) is a clinical condition associated with multiple metabolic risk factors leading to type 2 diabetes mellitus and other metabolic diseases. Recent evidence suggests that modulating adipose tissue to adaptive thermogenesis may offer therapeutic potential for MetS. Xiasangju (XSJ) is a marketed drug and dietary supplement used for the treatment of metabolic disease with anti-inflammatory activity. This study investigated the therapeutic effects of XSJ and the underlying mechanisms affecting the activation of brown adipose tissue (BAT) in MetS. The results revealed that XSJ ameliorated MetS by enhancing glucose and lipid metabolism, leading to reduced body weight and abdominal circumference, decreased adipose tissue and liver index, and improved blood glucose tolerance. XSJ administration stimulated catecholamine biosynthesis, increasing noradrenaline (NA) levels and activating NA-mediated proteins in BAT. Thus, BAT enhanced thermogenesis and oxidative phosphorylation (OXPHOS). Moreover, XSJ induced changes in gut microbiota composition, with an increase in Oscillibacter abundance and a decrease in Bilophila, Candidatus Stoquefichus, Holdemania, Parasutterella and Rothia. XSJ upregulated the proteins associated with intestinal tight junctions corresponding with lower serum lipopolysaccharide (LPS), tumor necrosis factor α (TNF-α) monocyte chemoattractant protein-1 (MCP-1) and interleukin-6 (IL-6) levels to maintain NA signaling transport. In summary, XSJ may alleviate MetS by promoting thermogenesis in BAT to ultimately boost energy metabolism through increasing NA biosynthesis, strengthening intestinal barrier integrity and reducing low-grade inflammation. These findings suggest XSJ has potential as a natural therapeutic agent for the treatment of MetS.

Antioxidant, enzymes inhibitory, physicochemical and sensory properties of instant bio-yoghurts containing multi-purpose natural additives

This study aimed to assess the antioxidant, enzyme inhibitory, physicochemical and sensory properties of instant bio-yoghurts containing multi-purpose natural additives. Multi-purpose natural additives were formulated with three natural additives (sweet detar seed, ginger rhizome, and hibiscus calyx flours, as a thickener, flavourant and colourant, respectively) blends at proportions derived from the Design Expert. The additives' synthetic counterparts were formulated with sodium carboxymethylcellulose, vanilla flavor, and red colourant at the same proportions. After that, yoghurt was produced and the additives blends were incorporated into it either in aqueous extract or flour form, yielding bio-yoghurts designated multi-purpose natural additive extract-containing yoghurt (MNAE-yoghurt), multi-purpose natural additive flour-added yoghurt (MNAF-yoghurt), and their multi-purpose synthetic additives-containing counterparts (MSAE-yoghurt and MSAF-yoghurt). A commercially-available bio-yoghurt served as a control. All the yoghurts were lyophilized to obtain instant bio-yoghurts. Subsequently, bioactive components (total phenolics, tannins, total flavonoids and saponins), antioxidants and enzymes [alpha-amylase, alpha-glucosidase, pancreatic lipase, and angiotensin 1-converting enzyme (ACE)] inhibitory activities, as well as proximate, physicochemical and sensory qualities of the bio-yoghurts were determined. The MNAE-yoghurt and MNAF-yoghurt had higher bioactive constituents, total titratable acid levels, and more potent antioxidant and enzyme inhibitory properties, but a lower pH than their synthetic counterparts and the control. The total phenolics, tannins, total flavonoids and saponins levels of MNAE-yoghurt and MNAF-yoghurt were 14.40 ± 0.24 and 16.54 ± 0.62 mg/g, 1.65 ± 0.04 and 1.74 ± 0.08 mg/g, 4.25 ± 0.03 and 4.40 ± 0.02 mg/g, 0.64 ± 0.01 and 0.66 ± 0.02 mg/g, respectively. Among the natural multi-purpose additives-containing bio-yoghurts, MNAF-yoghurt had higher bioactive constituents and stronger antioxidant and enzymes inhibitory properties. Its α-amylase, α-glucosidase, ACE, and pancreatic lipase IC50 values were 72.47 ± 0.47, 74.07 ± 0.02, 25.58 ± 2.58, and 33.56 ± 29.66 μg/mL, respectively. In contrast, MNAE-yoghurt had the highest protein (13.70 ± 0.85%) and the lowest fat (2.63 ± 0.71%) contents. The sensory attributes of all the bio-yoghurts fell within an acceptable likeness range. Overall, the inclusion of multi-purpose natural additives blends enhanced the instant bio-yoghurts' nutritional, health-promoting, and sensory qualities.

Relation of dietary insulin index and dietary insulin load to metabolic syndrome depending on the lifestyle factors: Tehran lipid and glucose study

AIM

The hypothesis of the effect of the insulinogenic effects of diet on the development of cardiovascular diseases has been proposed, but the findings of previous studies are very contradictory. We investigated the association between dietary insulin index (DII) and dietary insulin load (DIL), and metabolic syndrome (MetS) risk. Another objective was to examine the extent to which lifestyle (physical activity, smoking status, and weight change) and sex influence the relationship between DII, DIL, and MetS risk.

MATERIALS AND METHODS

We followed 1915 participants in the Tehran Lipid and Glucose Study. DIL and DII were calculated based on a validated food frequency questionnaire. Weight change was measured, and participants were categorized into > 3% weight loss, weight stable (± 3%), and > 3% weight gain. By joint classification, the association between DII and DIL (< median and ≥ median) and risk of MetS was assessed according to weight change, sex, physical activity levels, and smoking status. Cox proportional hazards models were used to estimate the HRs (95% CI), adjusting for potential confounders.

RESULTS

During 8.9 years of follow-up, among 1915 participants, we documented 591 new cases of MetS. DII and DIL were not associated with MetS risk in the crude and adjusted models. However, DIL and DII were associated with weight gain (≥ 3%). In the crude model, DIL and DII were associated with a higher risk of weight gain [HR: 1.74: 95% CI 1.50-2.03, and 1.70 (1.46-1.98), respectively]. These associations remained significant after further adjustment for confounders. The HRs were 1.61 (1.35-1.92) for DIL and 1.64 (1.39-1.93) for DII. Among men, women, participants with low physical activity levels, and smokers, the risk of MetS, independent of DIL and DII, only increased in a participant with weight gain. In women with weight stability, DIL and DII, higher than the median, were positively associated with MetS risk.

CONCLUSION

Our findings suggest that the association between MetS risk and a hyperinsulinemic diet depended on weight change.

Hyperinsulinemia negatively affects the association between insulin resistance and blood pressure

BACKGROUND AND AIMS

Although hyperinsulinemia and insulin resistance (IR) together cause metabolic diseases, the available evidence fails to link hyperinsulinemia with blood pressure (BP) elevation. To further understand the role of hyperinsulinemia in the pathophysiology of hypertension, we conducted this study to investigate the moderating effect of fasting insulin (FINS) on the association between IR and BP.

METHODS AND RESULTS

The health screening data of 72,076 individuals were analyzed for this moderation analysis. IR was indicated by the homeostatic model assessment of insulin resistance (HOMA-IR), triglyceride-glucose index (TyG), and triglyceride to high-density lipoprotein cholesterol ratio (TG/HDLc). In the adjusted model, three IR indicators were considered independent variables; FINS was used as a moderator, and systolic BP (SBP) and diastolic BP (DBP) were used as dependent variables. The regression coefficient of the interaction term between the three IR indicators and FINS was significantly negative in all moderation models. Simple slope tests and the Johnson-Neymann technique also indicated that FINS negatively moderated the association between IR and BP.

CONCLUSIONS

This moderation analysis showed that FINS negatively mediated the association between IR and BP, suggesting that hyperinsulinemia may buffer, not reinforce, the effect of IR on hypertension.

Female Sex and Angiotensin-Converting Enzyme (ACE) Insertion/Deletion Polymorphism Amplify the Effects of Adiposity on Blood Pressure

The pathophysiological link between adiposity and blood pressure is not completely understood, and evidence suggests an influence of sex and genetic determinants. We aimed to identify the relationship between adiposity and blood pressure, independent of a robust set of lifestyle and metabolic factors, and to examine the modulating role of sex and Angiotensin-Converting Enzyme (ACE) insertion/deletion (I/D) polymorphisms. In the Relationship Between Insulin Sensitivity and Cardiovascular Disease (RISC) study cohort, 1211 normotensive individuals, aged 30 to 60 years and followed-up after 3.3 years, were characterized for lifestyle and metabolic factors, body composition, and ACE genotype. Body mass index (BMI) and waist circumference (WC) were independently associated with mean arterial pressure, with a stronger relationship in women than men (BMI: r=0.40 versus 0.30; WC: r=0.40 versus 0.30, both P<0.01) and in individuals with the ID and II ACE genotypes in both sexes (P<0.01). The associations of BMI and WC with mean arterial pressure were independent of age, sex, lifestyle, and metabolic variables (standardized regression coefficient=0.17 and 0.18 for BMI and WC, respectively) and showed a significant interaction with the ACE genotype only in women (P=0.03). A 5 cm larger WC at baseline increased the risk of developing hypertension at follow-up only in women (odds ratio, 1.56 [95% CI, 1.15-2.10], P=0.004) and in II genotype carriers (odds ratio, 1.87 [95% CI, 1.09-3.20], P=0.023). The hypertensive effect of adiposity is more pronounced in women and in people carrying the II variant of the ACE genotype, a marker of salt sensitivity.

The effects of insulin therapy on maternal blood pressure and weight in women with gestational diabetes mellitus

Background

Although insulin therapy achieves effective glycemic control, it may aggravate hyperinsulinemia. Nonetheless the benefits of insulin as first-line treatment for women with GDM are controversial. This work aimed to investigate the effect of insulin on maternal GDM.

Methods

This retrospective cohort study recruited 708 women with GDM of whom 616 underwent lifestyle intervention and 92 were prescribed insulin therapy. Differences in variables between the two groups were analyzed by univariate analysis and multivariate analysis. Propensity score matching was used to control for age, pre-pregnancy BMI, time and BP at GDM diagnosis, and family history of diabetes and hypertension. Paired sample test was applied to evaluate the changes in BP after intervention in the two groups of women.

Results

There was no significant difference in mode of delivery, newborn weight or incidence of macrosomia between women prescribed insulin and those who adopted lifestyle modifications. Insulin therapy was associated with a slight increase in maternal weight compared with the lifestyle intervention group and was attributed to short-term treatment (about 12 weeks). In addition, insulin therapy remarkably increased maternal blood pressure, an effect that persisted after matching age, pre-pregnancy BMI, time and BP at GDM diagnosis, and family history of diabetes and hypertension. Between commencing insulin therapy and delivery, systolic blood pressure significantly increased by 6mmHg (P = 0.015) and diastolic blood pressure by 9 mmHg (P < 0.001). Increase in BP was significantly higher in the insulin group compared with the lifestyle intervention group (P < 0.001). Logistic regression analysis with enter selection confirmed that insulin therapy was closely correlated with development of gestational hypertension (GH).

Conclusions

This work suggested that short-term insulin therapy for GDM was associated with a slight increase in maternal weight but a significant risk of increasing maternal blood pressure.

Galangin Resolves Cardiometabolic Disorders through Modulation of AdipoR1, COX-2, and NF-κB Expression in Rats Fed a High-Fat Diet

Galangin is a natural flavonoid. In this study, we evaluated whether galangin could alleviate signs of metabolic syndrome (MS) and cardiac abnormalities in rats receiving a high-fat (HF) diet. Male Sprague–Dawley rats were given an HF diet plus 15% fructose for four months, and they were fed with galangin (25 or 50 mg/kg), metformin (100 mg/kg), or a vehicle for the last four weeks. The MS rats exhibited signs of MS, hypertrophy of adipocytes, impaired liver function, and cardiac dysfunction and remodeling. These abnormalities were alleviated by galangin (p < 0.05). Interleukin-6 and tumor necrosis factor-α concentrations and expression were high in the plasma and cardiac tissue in the MS rats, and these markers were suppressed by galangin (p < 0.05). These treatments also alleviated the low levels of adiponectin and oxidative stress induced by an HF diet in rats. The downregulation of adiponectin receptor 1 (AdipoR1) and cyclooxygenase-2 (COX-2) and the upregulation of nuclear factor kappa B (NF-κB) expression were recovered in the galangin-treated groups. Metformin produced similar effects to galangin. In conclusion, galangin reduced cardiometabolic disorders in MS rats. These effects might be linked to the suppression of inflammation and oxidative stress and the restoration of AdipoR1, COX-2, and NF-κB expression.