High-Fructose Diet-Induced Hyperuricemia Accompanying Metabolic Syndrome-Mechanisms and Dietary Therapy Proposals

Deciphering the complex interplay of obesity, epithelial barrier dysfunction, and tight junction remodeling: Unraveling potential therapeutic avenues

Obesity stands as a formidable global health challenge, predisposing individuals to a plethora of chronic illnesses such as cardiovascular disease, diabetes, and cancer. A confluence of genetic polymorphisms, suboptimal dietary choices, and sedentary lifestyles significantly contribute to the elevated incidence of obesity. This multifaceted health issue profoundly disrupts homeostatic equilibrium at both organismal and cellular levels, with marked alterations in gut permeability as a salient consequence. The intricate mechanisms underlying these alterations have yet to be fully elucidated. Still, evidence suggests that heightened inflammatory cytokine levels and the remodeling of tight junction (TJ) proteins, particularly claudins, play a pivotal role in the manifestation of epithelial barrier dysfunction in obesity. Strategic targeting of proteins implicated in these pathways and metabolites such as short-chain fatty acids presents a promising intervention for restoring barrier functionality among individuals with obesity. Nonetheless, recognizing the heterogeneity among affected individuals is paramount; personalized medical interventions or dietary regimens tailored to specific genetic backgrounds and allergy profiles may prove indispensable. This comprehensive review delves into the nexus of obesity, tight junction remodeling, and barrier dysfunction, offering a critical appraisal of potential therapeutic interventions.

PROTECTIVE ROLE OF CELLS AND SPORES OF SHOUCHELLA CLAUSII SF174 AGAINST FRUCTOSE-INDUCED GUT DYSFUNCTIONS IN SMALL AND LARGE INTESTINE

The oral administration of probiotics is nowadays recognized as a strategy to treat or prevent the consequences of unhealthy dietary habits. Here we analyze and compare the effects of the oral administration of vegetative cells or spores of Shouchella clausii SF174 in counteracting gut dysfunctions induced by 6 weeks of high fructose intake in a rat model. Gut microbiota composition, tight junction proteins, markers of inflammation and redox homeostasis were evaluated in ileum and colon in rats fed fructose rich diet and supplemented with cells or spores of Shouchella clausii SF174. Our results show that both spores and cells of SF174 were effective in preventing the fructose-induced metabolic damage to the gut, namely establishment of "leaky gut", inflammation and oxidative damage, thus preserving gut function. Our results also suggest that vegetative cells and germination-derived cells metabolize part of the ingested fructose at the ileum level.

Uric acid and cardiovascular diseases: a reappraisal

Serum uric acid (SUA) has garnered an increased interest in recent years as an important determinant of cardiovascular disease. Uric acid, a degradation product of purine metabolism, is affected by several inheritable and acquired factors, such as genetic mutation, metabolic syndrome, chronic kidney disease, and medication interactions. Even though elevated SUA have been commonly associated with the development of gout, it has significant impact in the development of hypertension, metabolic syndrome, and cardiovascular disease. Uric acid, in both crystalline and soluble forms, plays a key role in the induction of inflammatory cascade and development of atherosclerotic diseases. This concise reappraisal emphasizes key features about the complex and challenging role of uric acid in the development and progression of atherosclerosis and cardiovascular disease. It explores the pathogenesis and historical significance of uric acid, highlights the complex interplay between uric acid and components of metabolic syndrome, focuses on the pro-inflammatory and pro-atherogenic effects of uric acid, as well as discusses the role of urate lowering therapies in mitigating the risk of cardiovascular disease while providing the latest evidence to the healthcare professionals focusing on the clinical importance of SUA levels with regards to cardiovascular disease.

Exploring Fibrosis Pathophysiology in Lean and Obese Metabolic-Associated Fatty Liver Disease: An In-Depth Comparison

While obesity-related nonalcoholic fatty liver disease (NAFLD) is linked with metabolic dysfunctions such as insulin resistance and adipose tissue inflammation, lean NAFLD more often progresses to liver fibrosis even in the absence of metabolic syndrome. This review aims to summarize the current knowledge regarding the mechanisms of liver fibrosis in lean NAFLD. The most commonly used lean NAFLD models include a methionine/choline-deficient (MCD) diet, a high-fat diet with carbon tetrachloride (CCl4), and a high-fructose and high-cholesterol diet. The major pro-fibrogenic mechanisms in lean NAFLD models include increased activation of the extracellular signal-regulated kinase (ERK) pathway, elevated expression of α-smooth muscle actin (α-SMA), collagen type I, and TGF-β, and modulation of fibrogenic markers such as tenascin-X and metalloproteinase inhibitors. Additionally, activation of macrophage signaling pathways promoting hepatic stellate cell (HSC) activation further contributes to fibrosis development. Animal models cannot cover all clinical features that are evident in patients with lean or obese NAFLD, implicating the need for novel models, as well as for deeper comparisons of clinical and experimental studies. Having in mind the prevalence of fibrosis in lean NAFLD patients, by addressing specific pathways, clinical studies can reveal new targeted therapies along with novel biomarkers for early detection and enhancement of clinical management for lean NAFLD patients.

Assessing the impact of concurrent high-fructose and high-saturated fat diets on pediatric metabolic syndrome: A review

High-saturated fat (HF) or high-fructose (HFr) consumption in children predispose them to metabolic syndrome (MetS). In rodent models of MetS, diets containing individually HF or HFr lead to a variable degree of MetS. Nevertheless, simultaneous intake of HF plus HFr have synergistic effects, worsening MetS outcomes. In children, the effects of HF or HFr intake usually have been addressed individually. Therefore, we have reviewed the outcomes of HF or HFr diets in children, and we compare them with the effects reported in rodents. In humans, HFr intake causes increased lipogenesis, hypertriglyceridemia, obesity and insulin resistance. On the other hand, HF diets promote low grade-inflammation, obesity, insulin resistance. Despite the deleterious effects of simultaneous HF plus HFr intake on MetS development in rodents, there is little information about the combined effects of HF plus HFr intake in children. The aim of this review is to warn about this issue, as individually addressing the effects produced by HF or HFr may underestimate the severity of the outcomes of Western diet intake in the pediatric population. We consider that this is an alarming issue that needs to be assessed, as the simultaneous intake of HF plus HFr is common on fast food menus.

Assessment of the correlation between KAP scores regarding sugar-sweetened beverage consumption and hyperuricemia amongst Chinese young adults

BACKGROUND

The prevalence of hyperuricemia in China has been consistently increasing, particularly among the younger generation. The excessive consumption of sugar-sweetened beverages is associated with hyperuricemia. This study examined the knowledge, attitudes, and practices (KAP) of Chinese young adults regarding sugar-sweetened beverage consumption and the correlation with hyperuricemia.

METHODS

This cross-sectional investigation was conducted from June 28th, 2023, to July 21st, 2023, and enrolled Chinese young adults. Demographics and KAP were evaluated using a questionnaire (Cronbach's α = 0.787). Factors influencing KAP scores were analyzed using multivariable analyses.

RESULTS

A total of 1288 valid questionnaires were analyzed. The median knowledge, attitude, and practice scores were 16 (12,19)/22, 22 (20,24)/30, and 27.5 (23,31.75)/40. The multivariable analysis showed that bachelor's/associate education (OR = 1.912, 95%CI: 1.128-3.239), white collar/employee (OR = 0.147, 95%CI: 0.105-0.206), educator (OR = 0.300, 95%CI: 0.174-0.518), healthcare worker (OR = 0.277, 95%CI: 0.188-0.407), not suffering from hyperuricemia (OR = 0.386, 95%CI: 0.253-0.590), and not having gout (OR = 0.456, 95%CI: 0.282-0.736) were independently associated with knowledge. Age 26-30 (OR = 1.470, 95%CI: 1.052-2.052), age 31-35 (OR = 1.489, 95%CI: 1.097-2.022), age 36-40 (OR = 0.328, 95%CI: 1.010-1.746), age 41-44 (OR = 1.548, 95%CI: 1.091-2.198), and not having hyperuricemia (OR = 0.512, 95%CI: 0.345-0.760) were independently associated with attitude. White collar/employee (OR = 0.386, 95%CI: 0.285-0.521), educator (OR = 0.534, 95%CI: 0.317-0.899), healthcare worker (OR = 0.341, 95%CI: 0.236-0.493), having siblings (OR = 0.725, 95%CI: 0.573-0.917), and not suffering from hyperuricemia (OR = 0.442, 95%CI: 0.296-0.659), were independently associated with practice.

CONCLUSION

Chinese young adults display moderate KAP toward sugar-sweetened beverages. Notably, an association was observed between hyperuricemia and each KAP dimension.

Dissecting the risk factors for hyperuricemia in vegetarians in Taiwan

BACKGROUND

Vegetarian diets have been shown to lower the risks of hyperuricemia and gout. Little is known about the risk factors of hyperuricemia in vegetarians.

METHODS

This community-based retrospective case-control study was conducted to establish prediction models for hyperuricemia. From September 5, 2005, to December 31, 2016, 7331 adult vegetarians were recruited at Taipei Tzu Chi Hospital. Hyperuricemia was defined as a serum uric acid concentration greater than 7 mg/dL.

RESULTS

There were 593 (8.1%) vegetarians with hyperuricemia and 6738 (91.9%) without hyperuricemia. We stepwise built up three models for predicting hyperuricemia in vegetarians. The full model (model 3) has the highest area under the receiver operating characteristic curve (AUROC, 85.52%). Additionally, the AUROC of model 3 is 77.97% and 84.85% in vegetarians with or without prior gout history, respectively. Moreover, male gender, hyperlipidemia, body mass index, and serum albumin are independent risk factors for hyperuricemia in vegetarians. In contrast, estimated glomerular filtration rate and proteinuria are independently associated with lower risks of hyperuricemia in vegetarians.

CONCLUSION

Our study revealed that risk factors for hyperuricemia, which includes clinical characteristics, account for more than 85% of discriminatory performance in Taiwanese vegetarians. This model may be helpful for monitoring and preventing hyperuricemia in the population.

Catalpol ameliorates fructose-induced renal inflammation by inhibiting TLR4/MyD88 signaling and uric acid reabsorption

Accumulating evidence suggests that excess fructose uptake induces metabolic syndrome and kidney injury. Here, we primarily investigated the influence of catalpol on fructose-induced renal inflammation in mice and explored its potential mechanism. Treatment with catalpol improved insulin sensitivity and hyperuricemia in fructose-fed mice. Hyperuricemia induced by high-fructose diet was associated with increases in the expressions of urate reabsorptive transporter URAT1 and GLUT9. Treatment with catalpol decreased the expressions of URAT1 and GLUT9. Futhermore, treatment with catalpol ameliorated renal inflammatory cell infiltration and podocyte injury, and these beneficial effects were associated with inhibiting the production of inflammatory cytokines including IL-1β, IL-18, IL-6 and TNF-α. Moreover, fructose-induced uric acid triggers an inflammatory response by activiting NLRP3 inflammasome, which then processes pro-inflammatory cytokines. Treatment with catalpol could inhibit the activation of NLRP3 inflammasome as well. Additionally, TLR4/MyD88 signaling was activated in fructose-fed mice, while treatment with catalpol inhibited this activation along with promoting NF-κB nuclear translocation in fructose-fed mice. Thus, our study demonstrated that catalpol could ameliorate renal inflammation in fructose-fed mice, attributing its beneficial effects to promoting uric acid excretion and inhibit the activation of TLR4/MyD88 signaling.

The Ketogenic Diet and Cardiovascular Diseases

The most common and increasing causes of death worldwide are cardiovascular diseases (CVD). Taking into account the fact that diet is a key factor, it is worth exploring this aspect of CVD prevention and therapy. The aim of this article is to assess the potential of the ketogenic diet in the prevention and treatment of CVD. The article is a comprehensive, meticulous analysis of the literature in this area, taking into account the most recent studies currently available. The ketogenic diet has been shown to have a multifaceted effect on the prevention and treatment of CVD. Among other aspects, it has a beneficial effect on the blood lipid profile, even compared to other diets. It shows strong anti-inflammatory and cardioprotective potential, which is due, among other factors, to the anti-inflammatory properties of the state of ketosis, the elimination of simple sugars, the restriction of total carbohydrates and the supply of omega-3 fatty acids. In addition, ketone bodies provide "rescue fuel" for the diseased heart by affecting its metabolism. They also have a beneficial effect on the function of the vascular endothelium, including improving its function and inhibiting premature ageing. The ketogenic diet has a beneficial effect on blood pressure and other CVD risk factors through, among other aspects, weight loss. The evidence cited is often superior to that for standard diets, making it likely that the ketogenic diet shows advantages over other dietary models in the prevention and treatment of cardiovascular diseases. There is a legitimate need for further research in this area.

Effect of Alcohol Consumption Habits on Early Arterial Aging in Subjects with Metabolic Syndrome and Elevated Serum Uric Acid

BACKGROUND

Hyperuricemia is perceived as one of the risk factors for developing and progressing cardiovascular disease and metabolic syndrome through various pathological mechanisms. Endogenous synthesis and exogenous factors such as diet and beverages consumed play a major role in determining serum uric acid (sUA) levels. The aim of this study was to evaluate the effect of alcohol consumption on early arterial aging in middle-aged patients with metabolic syndrome (MetS) and hyperuricemia.

MATERIALS AND METHODS

This study included 661 middle-aged subjects (241 men and 420 women) from the Lithuanian High Cardiovascular Risk (LitHiR) primary prevention program. Characteristics of subjects such as blood pressure, laboratory testing, and the specialized nutrition profile questionnaire were evaluated. As an early marker of arterial stiffness, carotid-femoral pulse wave velocity (cfPWV) was assessed using a non-invasive applanation tonometry technique.

RESULTS

Hyperuricemia was present in 29% of men and 34% of women. Hyperuricemic men reported 1.6 times higher rates of alcohol drinking compared to men with normal sUA levels. After analyzing the correlation between alcohol consumption and cfPWV, no statistically significant relationships were found at a significance level of α = 0.05 but lowering the significance level to 0.06 revealed significant associations in men with normal sUA (ε2ordinal = 0.05, p = 0.06) and in women with increased sUA levels (ε2ordinal = 0.05, p = 0.08). Regression analysis showed that hyperuricemic men, consuming more than one unit of alcohol per week, had a significant impact on increasing cfPWV, while men with normal sUA levels, abstaining from alcohol entirely, resulted in a statistically significant decrease in cfPWV. Our results showed statistically significant relationships only among a group of men, although the women in the hyperuricemic group had a statistically higher cfPWV than women with normal sUA levels.

CONCLUSIONS

Drinking alcohol is associated with increased arterial stiffness among hyperuricemic middle-aged men with MetS.