Relationship between insulin resistance, metabolic syndrome components and serum uric acid

Uric acid and metabolic syndrome: Importance of hyperuricemia cut-off

BACKGROUND

The relationship between HyperUricemia (HU) and Metabolic Sindrome (MS) and if Uric Acid (UA) should be inserted into MS definitions is a matter of debate. Aim of our study was to evaluate the correlation between UA and HU with Insulin Resistance (IR) and MS in a population of hypertensive patients. HU was defined with two cut-offs (the classic one of ≥6 mg/dL for women and ≥ 7 for men; the newly proposed URRAH one with ≥5.6 mg/dL for both sexes).

METHODS

We enrolled 473 Hypertensive patients followed by the Hypertension Unit of San Gerardo Hospital (Monza, Italy). IR was defined through TG/HDL ratio and NCEP-ATP-III criteria were used for MS diagnosis.

RESULTS

MS was found in 33.6 % while HU affected 14.8 % of subjects according to the traditional cut-off and 35.9 % with the URRAH cut-off. 9.7 % (traditional cut-off) and 17.3 % (URRAH's threshold) of the subjects had both HU and MS. UA level was significantly higher in MS group (5.7 vs 4.9 mg/dL, p < 0.0001) as well as for HU (29.0 vs 7.6 % and 51.6 vs 28.0 %, for classic and URRAH cut-off respectively, p < 0.0001 for both comparison). Logistic multivariable regression models showed that UA is related to MS diagnosis (OR = 1.608 for each 1 mg/dL), as well as HU with both cut-off (OR = 5.532 and OR = 3.379, p < 0.0001 for all comparison, for the classic cut-off and the URRAH one respectively).

CONCLUSIONS

The main finding of our study is that UA and HU significantly relate to IR and MS. The higher the values of UA and the higher the cut-off used, the higher the strength of the relationship.

Insulin Resistance Surrogates May Predict HTN-HUA in Young, Non-Obese Individuals

Objective

To compare the associations of three surrogate markers of insulin resistance (IR) [glucose and triglycerides (TyG index), TyG index with BMI (TyG-BMI), and the ratio of triglycerides divided by HDL-C (TG/HDL-C)] with hypertensive patients (HTN) plus hyperuricemia (HUA) (HTN-HUA) in young, non-obese individuals.

Methods

Data from a cross-sectional epidemiological study of an annual health check-up population aged younger than 66 years were used to calculate the three IR surrogate indexes. The association with HTN-HUA and insulin resistance surrogates was examined with multinomial logistic regression and a receiver operating characteristic (ROC) curve.

Results

A total of 6952 participants were included, including 671 (9.65%) participants with HTN alone, 272 (3.91%) participants with HUA alone, and 62 (0.90%) participants with HTN and HUA. Binary multiple-logistic regression results showed that TG/HDL-C was significantly correlated with HTN, HUA, and HTN-HUA. Compared with the lowest quartile, the odds ratios (95% CI) of the highest quartile of TG/HDL-C for HTN-HUA were 3.462 (1.138~10.530). TG/HDL-C and TyG-BMI had moderate discriminative abilities for HTN-HUA, and the area under the curve was 0.748 (0.682~0.815), 0.746 (0.694~0.798).

Conclusion

Our study suggests that TG/HDL-C had a significant correlation with HTN-HUA and that TG/HDL-C had moderate discriminative abilities for HTN-HUA.

Association between Visceral Adiposity Index and Hyperuricemia among Steelworkers: The Moderating Effects of Drinking Tea

BACKGROUND/OBJECTIVES

Steelworkers are more likely to have a higher prevalence of hyperuricemia due to their exposure to special occupational factors and dietary habits. The interrelationships of visceral adiposity index (VAI), hyperuricemia, and drinking tea remain uncertain. This study aimed to assess the association between VAI and hyperuricemia among steelworkers, and if drinking tea modified this association.

METHODS

A total of 9928 steelworkers from Hunan Hualing Xiangtan Iron and Steel Company participated in this cross-sectional study. All participants completed a questionnaire, received anthropometric measurements, and provided blood samples for biochemical testing. Three logistic regression models were used to analyze the association between VAI and hyperuricemia.

RESULTS

In this study, the prevalence of hyperuricemia was approximately 23.74% (males: 24.41%; females: 20.63%), and a positive correlation between VAI and hyperuricemia risk was observed. In multivariate logistic regression analysis, the risk of hyperuricemia increased 1.76 times (95% CI: 1.64-1.89) and 2.13 times (95% CI: 1.76-2.57) with the increase of ln VAI in males and females, respectively. For males, compared to quartile 1, the risk of hyperuricemia in the second, third, and fourth quartile of VAI were 1.75 (95% CI: 1.11-2.71), 2.56 (95% CI: 1.67-3.93) and 4.89 (95% CI: 3.22-7.43). For females, compared to quartile 1, the risk of hyperuricemia in the second, third, and fourth quartile of VAI were 1.99 (95% CI: 1.40-2.82), 2.92 (95% CI: 1.96-4.34) and 4.51 (95% CI: 2.89-7.02). Additionally, our study found that, compared with not consuming tea, drinking tea could reduce uric acid levels by 0.014 in male steelworkers (t = -2.051, p = 0.040), 0.020 in workers consuming smoked food (t = -2.569, p = 0.010), and 0.022 in workers consuming pickled food (t = -2.764, p = 0.006).

CONCLUSIONS

In conclusion, VAI is positively correlated with hyperuricemia in steelworkers. Drinking tea may lower uric acid levels in male steelworkers and steelworkers who prefer smoked and pickled foods.

Associations of total protein, albumin, and globulin with insulin resistance: an NHANES study

Objective

Insulin resistance (IR) is a well-established major risk factor for type 2 diabetes mellitus, nonalcoholic fatty liver disease, and atherosclerotic cardiovascular disease. Previous studies have shown an association between increased serum albumin (ALB) levels and the risk of IR. However, there is a lack of studies simultaneously evaluating the association of total protein (TP), ALB, and globulin (GLB) with IR.

Methods

A total of 14,828 individuals (average age 49 ± 18 years) with complete data from the National Health and Nutrition Examination Survey (NHANES) were enrolled and divided into two groups (non-IR group, n = 8,653 and IR group, n = 6,175). Spearman's correlation analysis, multivariable logistic regression models, restricted cubic spline curves, and subgroup analysis were performed to explore those associations.

Results

After adjustment for potential confounders, multivariable logistic regression analysis revealed that scaled per 10g/L increment, the fully adjusted odds ratios (ORs) (95% confidence interval (CI)) for IR prevalence were 1.54 (95% CI 1.41-1.69, P < 0.0001), 1.09 (95% CI 0.95-1.25), P = 0.1995), and 1.62 (95% CI 1.47-1.79, P < 0.0001) for TP, ALB, and GLB respectively. Compared to those in the lowest quantiles, the prevalence of IR in subjects in the highest TP and GLB quantiles was 2.06 and 1.91 times, respectively. Furthermore, restrictive cubic curves confirmed that the relationship of TP, ALB, and GLB with IR prevalence was a linear relationship.

Conclusions

The present cross-sectional study, for the first time, provided supportive evidence of positive associations of TP and GLB with IR, but not ALB, and demonstrated that TP and GLB might be useful markers for IR prevalence.

Dietary polyunsaturated fatty acids intake is negatively associated with hyperuricemia: The National Health and Nutrition Examination Survey 2003-2015

BACKGROUND AND AIMS

The objective of this research was to explore the associations between dietary PUFAs intake and hyperuricemia risk.

METHODS AND RESULTS

Based on the National Health and Nutrition Examination Survey (NHANES) 2003-2015, all eligible individuals were divided into hyperuricemia and non-hyperuricemia groups based on diagnostic criteria for hyperuricemia (serum uric acid >420 μmol/L for men and >360 μmol/L for women). Multivariate-adjusted logistic regression was employed to explore the relationship between dietary PUFAs intake and hyperuricemia risk. Total PUFAs and their subtypes were modeled to isocalorically replace saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs). Higher intake of n-3 PUFAs, n-6 PUFAs, linoleic acid (LA), alpha-linoleic acid (ALA), and non-marine PUFAs intake correlated with decreased hyperuricemia risk, with adjusted odds ratio (OR) and 95% confidence interval (95%CIs) were 0.77 (0.63, 0.93), 0.75 (0.61, 0.92), 0.75 (0.61, 0.91), 0.69 (0.55, 0.87), and 0.73 (0.59, 0.91), respectively. Replacing 5% of total energy intake from SFAs with isocaloric PUFAs was associated with decreased odds of hyperuricemia in men (0.69 (0.57, 0.84)) and in individuals (0.81 (0.71, 0.92)). Similar trends were observed in the substitution of SFAs with non-marine PUFAs in men (0.87 (0.80, 0.94)) and in all individuals (0.92 (0.88, 0.98)). Sensitivity analyses exhibited consistent results with primary analyses.

CONCLUSION

Higher dietary intake of n-3 PUFAs, n-6 PUFAs, LA, ALA, and non-marine PUFAs was associated with decreased hyperuricemia risk. These results support the recommendation to substitute SFAs with PUFAs in diet.

Uncovering the Potential Mechanisms and Effects of Hyperuricemia and its Associated Diseases on Male Reproduction

Male fertility and metabolic disorders, including obesity and diabetes, are closely connected. Since hyperuricemia and metabolic syndrome are strongly related, male fertility and hyperuricemia may, to some degree, be associated. According to recent studies, hyperuricemia imposes various effects on sex hormones, semen quality, and male erectile dysfunction. Some researchers claim that uric acid worsens male semen and raises the risk of erectile dysfunction (ED), while others state that it safeguards both penile erection and male semen. Additionally, it has been shown that gout and metabolic syndrome also raise the risk of ED. To clarify this controversy, the influence and potential mechanisms of hyperuricemia on ED, semen quality, sex hormone levels, and the effects of hyperuricemia-related disorders on ED will be comprehensively summarized.

Insulin resistance-related circulating predictive markers in the metabolic syndrome: a systematic review in the Iranian population

Background

Specific biomarkers for metabolic syndrome (MetS) may improve diagnostic specificity for clinical information. One of the main pathophysiological mechanisms of MetS is insulin resistance (IR). This systematic review aimed to summarize IR-related biomarkers that predict MetS and have been investigated in Iranian populations.

Methods

An electronic literature search was done using the PubMed and Scopus databases up to June 2022. The risk of bias was assessed for the selected articles using the instrument suggested by the Joanna Briggs Institute (JBI). This systematic review protocol was registered with PROSPERO (registration number CRD42022372415).

Results

Among the reviewed articles, 46 studies investigated the association between IR biomarkers and MetS in the Iranian population. The selected studies were published between 2009 and 2022, with the majority being conducted on adults and seven on children and adolescents. The adult treatment panel III (ATP III) was the most commonly used criteria to define MetS. At least four studies were conducted for each IR biomarker, with LDL-C being the most frequently evaluated biomarker. Some studies have assessed the diagnostic potency of markers using the area under the curve (AUC) with sensitivity, specificity, and an optimal cut-off value. Among the reported values, lipid ratios and the difference between non-HDL-C and LDL-C levels showed the highest AUCs (≥ 0.80) for predicting MetS.

Conclusions

Considering the findings of the reviewed studies, fasting insulin, HOMA-IR, leptin, HbA1c, and visfatin levels were positively associated with MetS, whereas adiponectin and ghrelin levels were negatively correlated with this syndrome. Among the investigated IR biomarkers, the association between adiponectin levels and components of MetS was well established.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01347-6.

Comparison of atherogenic indices for predicting the risk of metabolic syndrome in Southwest Iran: results from the Hoveyzeh Cohort Study (HCS)

BACKGROUND

Metabolic syndrome (MetS) is a cluster of risk factors related to diabetes and cardiovascular disease (CVD). Given that early identification of MetS might decrease CVD risk, it is imperative to establish a simple and cost-effective method to identify individuals at risk of MetS. The purpose of this study was to explore the relationships between several atherogenic indices (including AIP, TyG index, non-HDL-C, LDL-c/HDL-c, and TC/HDL-c) and MetS, and to assess the ability of these indices to predict MetS.

METHODS

The present cross-sectional study was conducted using baseline data from 9809 participants of the Hoveyzeh Cohort Study (HCS). MetS was defined based on the International Diabetes Federation (IDF). To examine the discriminatory abilities of each atherogenic indices in the identification of MetS, a receiver-operating characteristic curve was conducted. Logistic regression analysis was also performed to evaluate the relationship between atherogenic indices and MetS.

RESULTS

All of the atherogenic indices including the TyG index, AIP, non-HDL-C, TC/HDL-c, and LDL-c/HDL-c were significantly higher in participants with MetS than in those without MetS. According to the ROC curve analysis, the TyG index revealed the highest area under the curve (0.79 and 0.85 in men and women, respectively), followed by the AIP (0.76 and 0.83 in men and women, respectively). The best cutoff values for the TyG index and AIP were 8.96 and 0.16 for men and 8.84 and 0.05 for women, respectively. The TyG index and AIP were also strongly associated with MetS.

CONCLUSION

Among the 5 atherogenic indices evaluated, the TyG index and AIP were strongly related to MetS. The TyG index also demonstrated superior discriminative ability compared to other atherogenic indices in predicting MetS.

Effect of short-term moderate intake of ice wine on hepatic glycolipid metabolism in C57BL/6J mice

As the correlation between high fructose intake and metabolism-related diseases (e.g., obesity, fatty liver, and type 2 diabetes) has been increasingly reported, the health benefits of consuming ice wine high in fructose have been called into question. In this study, 6-week-old male C57BL/6J mice were divided into control (pure water), fructose (130 g L-1 fructose solution), alcohol (11% alcohol solution), low-dose (50% diluted ice wine) and high-dose ice wine (100% ice wine) groups to investigate the effects and mechanisms of short-term (4 weeks) ice wine intake on hepatic glycolipid metabolism in mice. The results showed that short-term consumption of ice wine suppressed the elevation of low-density lipoprotein cholesterol content and did not cause hepatic lipid accumulation compared with those of the fructose group. Meanwhile, ice wine had no significant effect on lipogenesis although it inhibited fatty acid oxidation via the PPARα/CPT-1α pathway. Compared with the control group, ice wine interfered with the elevation of fasting glucose and the insulin resistance index in a dose-dependent manner, and led to an increase in plasma uric acid levels, which may further contribute to the disruption of glucolipid metabolism. Overall, short-term moderate intake of ice wine over a 4-week period may not significantly affect hepatic glycolipid metabolism in C57BL/6J mice for the time being.

Serum uric acid levels and prognosis of patients with non-alcoholic fatty liver disease

Uric acid (UA) is associated with non-alcoholic fatty liver disease (NAFLD). However, it is unclear whether UA plays a predictive role in NAFLD prognosis. This study aimed to explore the relationship between UA levels and mortality in NAFLD patients without severe renal disease. Data were obtained from the Third National Health and Nutrition Examination Survey (NHANES). Time-dependent Cox regression was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for mortality. Overall, 2493 individuals with NAFLD and estimated glomerular filtration rate (eGFR) > 60 mL/min/1.73 m2 were included in this study. The median follow-up period was 26.58 years. Patients were divided into high and low-UA groups according to UA levels. Time-independent Cox regression showed that UA level was not an independent risk factor for mortality in NAFLD patients without decreased eGFR (P > 0.05). After matching for age and sex using the propensity score matching method, UA remained not independently associated with death in NAFLD patients (P > 0.05). Similar results were found for cardiovascular-related and cancer-related deaths. Although UA is closely related to NAFLD, UA levels are not independently associated with the long-term survival of patients with NAFLD without decreased eGFR.

Sex-specific differences in the associations between adiposity indices and incident hyperuricemia among middle-aged and older adults: a nationwide longitudinal study

Objective

Although obesity is a known risk for hyperuricemia (HUA), the associations between adiposity indices and incident HUA and whether sex-specific differences exist is still unknown. We aimed to investigate the associations between adiposity indices and incident HUA in a longitudinal study.

Methods

Data from the China Health and Retirement Longitudinal Study (CHARLS) in 2011-2012 and 2015-2016 were used to conduct a cohort study. Participants aged ≥45 years without HUA at baseline were included in this study. Adiposity indices, including body mass index (BMI), waist circumference (WC), waist-to-height ratio body roundness index (BRI), conicity index (CI), lipid accumulation product (LAP) index, waist-to-height ratio (WHtR), visceral adiposity index (VAI), and Chinese visceral adiposity index (CVAI), were calculated. Logistic analysis was used to analyze the association between adiposity indices and incident HUA risk stratified by gender. Receiver operating characteristic curve analysis was performed to evaluate the power of predictions for incident HUA.

Results

Of 5,873 participants aged 59.0 ± 8.7 years enrolled in this study, 578 (9.8%) participants developed HUA during the 4-year follow-up period. After adjusting for confounding variables, LAP, VAI, and CVAI showed significant association with incident HUA. BMI, WC, WHtR, BRI, and CI were significantly associated with incident HUA in women but not in men. LAP had the highest area under the curve (AUC) (0.612) followed by CVAI (0.596) in men, while CVAI had the highest AUC (0.707) followed by LAP (0.691) in women. All indices showed better predictive ability in women than in men.

Conclusion

Our findings indicated that adiposity indices were effective predictors of incident HUA and showed better predictive power in women than men. In clinical practice, adiposity indices could be used to assess and prevent incident HUA among Chinese middle-aged and older adults.

Pathomechanisms of Disturbances Underlying Chronic Disorders

Chronic disorders' complexity poses enormous challenges to our understanding of such disorders [...].

Correlation Between Abdominal Fat Distribution and Serum Uric Acid in Patients Recently Diagnosed with Type 2 Diabetes

Objective

To investigated the link between the distribution of abdominal fat and the concentration of serum uric acid (SUA) in individuals recently diagnosed with type 2 diabetes.

Methods

Studied 364 individuals had been diagnosed with type 2 diabetes within one month, and evaluated factors such as the distribution of fat in the abdomen, indicators related to glucose and lipid metabolism. The participants' SUA concentrations were divided into a normal control group (CG) and a hyperuricemia group (HG).

Results

The HG group had elevated abdominal subcutaneous fat area (SFA), visceral fat content (VFA), body mass index (BMI), fasting blood glucose (FBG), 2-hour postprandial blood glucose (PBG), glycosylated albumin (GA), serum creatinine (SCr), triacylglycerol (TG), and lower values in glomerular filtration rate (eGFR), high-density lipoprotein cholesterol (HDL-C) when compared to the CG group (P < 0.05). Among the obese individuals, the hyperuricemia subgroup exhibited higher measurements in waistline, hipline, VFA, SFA, BMI, PBG, SCr, TG, and lower HDL-C (P < 0.05) compared to the subgroup with normal uric acid levels. In the non-obese group, the hyperuricemia subgroup showed higher VFA, SCr, and FBG levels, and lower HDL-C (P < 0.05). There was a positive correlation between VFA and serum uric acid (SUA) levels (r = 0.329, P < 0.0001). Logistic regression analysis indicated a 24% increased risk of hyperuricemia with every 10cm2 increase in abdominal VFA. Generate the Receiver Operating Characteristic (ROC) curve analysis revealed that VFA was the most effective predictor of hyperuricemia and insulin resistance (P < 0.05).

Conclusion

Newly diagnosed type 2 diabetes patients exhibit a strong correlation between abdominal visceral fat and SUA concentration, the former is identified as an autonomous risk factor for hyperuricemia and an effective indicator for assessing the presence of hyperuricemia and predicting insulin resistance.

Association between the Weight-Adjusted Waist Index and Serum Uric Acid: A Cross-Sectional Study

Background

Serum uric acid (SUA) was closely related to body metabolism. This study aimed to investigate the relationship between the adult weight-adjusted waist index (WWI) and SUA.

Methods

In the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2020, 6494 eligible participants aged ≥20  were included. The multivariate logistic regression model was used to test the correlation between WWI and SUA. At the same time, subgroup analysis was carried out by using multivariate logistic regression according to age, sex, and race. Then, the fitting smooth curve was applied to solve the association between WWI and SUA. Finally, the recursive algorithm was used to calculate the inflection point in the nonlinear relationship, and the two-stage piecewise linear regression model was used to analyze the relationship between WWI and SUA on both sides of the inflection point.

Results

In all the 6494 participants, through the fully adjusted model, this study found that there was a positive correlation between WWI and SUA (β = 5.64; 95% CI: 2.62 and 8.66). In addition, this positive correlation still had certain statistical significance in the subgroup analysis stratified by sex, age, and race. Our research team found a significant positive correlation between the WWI and SUA in females, but the correlation was not significant in males. We also found a small inverted U-shaped curve between the WWI and SUA in men when we stratified the sex subgroups. The small inflection point was determined to be 11.5 cm/√ kg. In racial subgroup analysis, we also found a U-shaped relationship between the WWI and SUA in non-Hispanic White and other race/ethnicity (the inflection point was 11.08 cm/√ kg and 12.14 cm/√ kg, respectively).

Conclusion

This study showed that the WWI was a newly developed and new predictor of centripetal obesity independent of body weight and there was a positive correlation between the WWI and SUA.

Diacylated anthocyanins from purple sweet potato (Ipomoeabatatas L.) attenuate hyperglycemia and hyperuricemia in mice induced by a high-fructose/high-fat diet

Studies have shown that targeting xanthine oxidase (XO) can be a feasible treatment for fructose-induced hyperuricemia and hyperglycemia. This study aimed to evaluate the dual regulatory effects and molecular mechanisms of diacylated anthocyanins from purple sweet potato (diacylated AF-PSPs) on hyperglycemia and hyperuricemia induced by a high-fructose/high-fat diet. The body weight, organ index, serum biochemical indexes, and liver antioxidant indexes of mice were measured, and the kidneys were observed in pathological sections. The relative expression levels of messenger RNAs (mRNAs) of fructose metabolism pathway enzymes in kidney were detected by fluorescent real-time quantitative polymerase chain (qPCR) reaction technique, and the expression of renal transporter protein and inflammatory factor pathway protein was determined by immunohistochemistry (IHC) technique. Results showed that diacylated AF-PSPs alleviated hyperuricemia in mice, and that this effect might be related to the regulation of liver XO activity, lipid accumulation, and relevant renal transporters. Diacylated AF-PSPs reduced body weight and relieved lipid metabolism disorder, liver lipid accumulation, and liver oxidative stress, thereby enhancing insulin utilization and sensitivity, lowering blood sugar, and reducing hyperglycemia in mice. Also, diacylated AF-PSPs restored mRNA levels related to renal fructose metabolism, and reduced kidney injury and inflammation. This study provided experimental evidence for the mechanisms of dual regulation of blood glucose and uric acid (UA) by diacylated AF-PSPs and their utilization as functional foods in the management of metabolic syndrome.

Antiretrovirals Promote Metabolic Syndrome through Mitochondrial Stress and Dysfunction: An In Vitro Study

The prevalence of metabolic syndrome MetS in HIV-infected patients on chronic antiretroviral (ARV) therapy continues to rise rapidly, with an estimated 21% experiencing insulin resistance. The progression of insulin resistance is strongly related to mitochondrial stress and dysfunction. This study aimed to draw links between the singular and combinational use of Tenofovir disoproxil fumarate (TDF), Lamivudine (3TC), and Dolutegravir (DTG) on mitochondrial stress and dysfunction as an underlying mechanism for insulin resistance following a 120 h treatment period using an in vitro system of human liver cells (HepG2). The relative protein expressions of pNrf2, SOD2, CAT, PINK1, p62, SIRT3, and UCP2, were determined using Western blot. Transcript levels of PINK1 and p62 were assessed using quantitative PCR (qPCR). ATP concentrations were quantified using luminometry, and oxidative damage (malondialdehyde (MDA) concentration) was measured using spectrophotometry. The findings suggest that despite the activation of antioxidant responses (pNrf2, SOD2, CAT) and mitochondrial maintenance systems (PINK1 and p62) in selected singular and combinational treatments with ARVs, oxidative damage and reduced ATP production persisted. This was attributed to a significant suppression in mitochondrial stress responses SIRT3 and UCP2 for all treatments. Notable results were observed for combinational treatments with significant increases in pNrf2 (p = 0.0090), SOD2 (p = 0.0005), CAT (p = 0.0002), PINK1 (p = 0.0064), and p62 (p = 0.0228); followed by significant decreases in SIRT3 (p = 0.0003) and UCP2 (p = 0.0119) protein expression. Overall there were elevated levels of MDA (p = 0.0066) and decreased ATP production (p = 0.0017). In conclusion, ARVs induce mitochondrial stress and dysfunction, which may be closely associated with the progression of insulin resistance.

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

Fructose is often used as a food ingredient due to its low production costs and sweetening power. In recent years, it has been noticed that people on a Western diet high in fructose have high levels of uric acid in their blood. It was recognized that the specific metabolism of fructose in the body might cause increased production of uric acid, which then may affect the intensification of lipogenesis and the development of metabolic syndrome (MetS), insulin resistance, gout, cardiovascular diseases, leptin resistance, or non-alcoholic fatty liver disease. So far, to treat hyperuricemia, it has been recommended to use a low-purine diet characterized by limiting protein-containing products. However, this recommendation often leads to an increased intake of carbohydrate-rich foods that may contain fructose. Increased fructose consumption may enhance the secretion of uric acid again and, consequently, does not have therapeutic effects. Therefore, instead of a low-purine diet, using healthy diets, such as DASH or the Mediterranean diet, which can benefit metabolic parameters, could be a better proposal. This article provides an overview of this approach, focusing on MetS and hyperuricemia among high-fructose dieters.

Ghrelin and Leptin among Patients with Urolithiasis with Concomitant Hyperuricemia and Metabolic Syndrome

Introduction: The study evaluated the selected appetite hormones (ghrelin, leptin) and inflammatory parameters (tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6)) in patients with urolithiasis, metabolic syndrome (MetS), and hyperuricemia. Materials: 57 patients with urolithiasis, MetS and hyperuricemia (UP group) and 29 healthy people as the control group (CG group) were recruited to the study. All persons were 22-60 age. Methods: After preliminary testing, the qualified participants were evaluated for fasting serum levels of ghrelin, leptin, IL-6, and TNF-α. Results: Our results revealed differences between average values of leptin (p = 0.045), ghrelin (p < 0.001), IL-6 (p < 0.001), and TNF-α (p < 0.001) in the studied groups. Moreover, in the UP group, significant correlations were found between ghrelin and leptin; between these hormones and IL-6, and between leptin and uric acid (UA). Besides, leptin concentration increased significantly along with the changes in the body mass index (BMI) categories in the UP group. Conclusions: This study showed that patients with urolithiasis, concomitant MetS, and high UA levels may have problems managing appetite hormones.

Correlation Analysis between Uric Acid and Metabolic Syndrome in the Chinese Elderly Population: A Cross-Sectional Study

Background

Currently, both metabolic syndrome and hyperuricaemia have attracted extensive attention in public health. The correlation between uric acid and metabolic syndrome is controversial. Research on the relationship between uric acid and metabolic syndrome in community-dwelling elderly people is relatively lacking. The purpose of this study is to explore the relationship between uric acid and metabolic syndrome in the community-dwelling elderly people.

Design

Cross-sectional study.

Methods

We collected the physical examination data of 1,267 elderly people in Gutian community in Wuhan and used SPSS IBM 25.0 for data analysis. Correlation and logistic regression analyses were performed, and ROC curves were drawn.

Results

The uric acid level of the nonmetabolic syndrome group was lower than that of the metabolic syndrome group (337.31 vs. 381.91 µmol/L; P < 0.05). Uric acid was positively correlated with systolic blood pressure (r = 0.177, P < 0.001), diastolic blood pressure (r = 0.135, P < 0.001), body mass index (r = 0.234, P < 0.001), waist circumference (r = 0.283, P < 0.001), and triglycerides (r = 0.217, P < 0.05). High-density lipoprotein cholesterol (r = -0.268, P < 0.001) showed the opposite trend. Logistic regression analysis results suggested that uric acid is a risk factor for metabolic syndrome. The result is described as exp (B) and 95% CI (1.003 [1.001, 1.005]). Based on the receiver operating characteristic curve, we found that the area under the curve of uric acid to diagnose metabolic syndrome was 0.64 (sensitivity: 79.3%, specificity: 45.1%).

Conclusion

We observed an association between uric acid levels and metabolic syndrome in the elderly Chinese population. The best threshold value for uric acid in predicting metabolic syndrome diagnosis was 314.5 μmol/l.

Lifestyle, Insulin Resistance and Semen Quality as Co-Dependent Factors of Male Infertility

Infertility is a problem that affects millions of couples around the world. It is known as a disease of couples, not individuals, which makes diagnosis difficult and treatment unclear. Male infertility can have many causes, from mechanical ones to abnormal spermatogenesis or spermiogenesis. Semen quality is determined by a number of factors, including those dependent on men themselves, with the number of infertile men growing every year. These include, e.g., diet, physical activity, sleep quality, stress, among many others. As these factors co-exist with insulin resistance, which is a disease closely related to lifestyle, it has been singled out in the study due to its role in affecting semen quality. In order to examine connections between lifestyle, insulin resistance, and semen quality, a review of literature published from 1989 to 2020 in the following databases PubMed/Medline, EMBASE (Elsevier), Scopus, Web of Science, and Google Scholar was performed. Hence, semen quality, environment, and insulin resistance are interrelated, thus it is difficult to indicate which aspect is the cause and which is the effect in a particular relationship and the nature of possible correlations. Since the influence of lifestyle on semen quality has been extensively studied, it is recommended that more thorough research be done on the relationship between insulin resistance and semen quality, comparing the semen quality of men with and without insulin resistance.

The elevated visceral adiposity index increases the risk of hyperuricemia in Chinese hypertensive patients: A cross-sectional study

Background

Uncertainty still remained about the relationship between visceral adiposity index (VAI) and hyperuricemia. The aim of this study was to investigate whether VAI was an independent risk factor for hyperuricemia in hypertensive Chinese patients.

Methods

A cross-sectional study including 13176 hypertensive participants (6478 males) recruited from Wuyuan County, Jiangxi province, was conducted. All patients received anthropometric measurements, completed questionnaires and provided blood samples for biochemical testing. VAI was calculated by waist circumference, BMI, triglyceride and high-density lipoprotein cholesterol. Hyperuricemia was defined as serum uric acid ≥ 7 mg/dL in men and ≥ 6 mg/dL in women.

Results

Overall, the average level of uric acid was 7.8 ± 2.0 mg/dL in males and 6.34 ± 1.78 in females and prevalence of hyperuricemia was 61.4% and 51.30%, respectively. In multivariate logistic regression analysis, the risk of hyperuricemia increased 1.77 times and 1.88 times with the increase of ln VAI in males (OR:1.77, 95% CI: 1.62, 1.94) and females (OR:1.88, 95% CI: 1.73, 2.04). For males, compared to quartile 1, the risk of hyperuricemia in the second, third and the forth quartile of visceral adiposity index were 1.34 (95% CI: 1.14, 1.57),1.82(95% CI: 1.54, 2.14) and 2.97 (95% CI: 2.48, 3.57). For females, compared to quartile 1, the risk of hyperuricemia in the second, third and the forth quartile of visceral adiposity index were 1.48 (95% CI: 1.28, 1.72), 1.99 (95% CI: 1.71, 2.32) and 2.92 (95% CI: 2.50, 3.42).

Conclusions

This study found that VAI was an independent risk factor for hyperuricemia among hypertensive patients, which may provide some strategies for reducing the level of uric acid.

Uric acid and metabolic syndrome: Findings from national health and nutrition examination survey

Introduction

Hyperuricemia commonly associated with Gout has been proposed as an independent risk factor for Metabolic Syndrome (MetS).

Objective

The purpose of the study was to determine if there is a relationship between hyperuricemia and MetS.

Methods

An analysis of cross-sectional data was conducted using the 2013-2018 National Health and Nutrition Examination Survey (NHANES) datasets. Sample weights were assigned by NHANES researchers to each participant allowing researchers to generalize results to all non-institutionalized United States (US) civilians. The analysis included 6,432 individuals, which were representative of 94,729,059 US citizens.

Results

Pearson's correlations, chi-square tests, and logistic regression equations were calculated to determine the association between hyperuricemia and MetS. In an unadjusted regression analysis, individuals with hyperuricemia (above 7.0 mg/dL in males and 6.0 mg/dL in females) were 3.19 times more likely to have MetS compared to those with normal uric acid (UA) levels. When controlling for various confounding variables those with hyperuricemia were 1.89 and 1.34 times more likely to have MetS than those with normal UA levels in two additional logistic regression models.

Conclusion

In this large cross-sectional study, hyperuricemia was found to be associated with MetS. Additional analyses that controlled for various risk factors previously identified as predictive of MetS still demonstrated hyperuricemia independently associated with MetS. The results of this study suggest a need to understand the metabolic pathways of UA more clearly to further explain the contribution to MetS. Additional research should include prospective clinical trials assessing the effects of UA and the control of UA on MetS and concomitant medical outcomes.

Usefulness of four surrogate indexes of insulin resistance in middle-aged population in Hefei, China

OBJECTIVE

Previous study have shown that lipid accumulation product (LAP), visceral adiposity index (VAI), triglyceride/high-density lipoprotein cholesterol ratio (TG/HDL-C) and triglycerides/glucose index (TyG index) could be simple clinical indicators of insulin resistance (IR) based on anthropometric and/or biochemical parameters. However, the rational and preferred surrogate marker of IR in different population has yet to be validated. The aim of this study was evaluating the practicability of the LAP, VAI, TG/HDL-C, and TyG in predicting IR in middle-aged Chinese population.

METHODS

A cross-sectional study was conducted in 569 Chinese participants (mean age was 48.5; man 67.7%), and each participant completed a questionnaire survey, anthropometric measurement, and biochemical testing. One-way ANOVAs, Chi-squared test, Pearson's correlation, and multiple logistic regression were used to evaluate the association between VAI, LAP, TG/HDL-C, and TyG with IR. To correctly discriminate individuals with insulin resistance, a receiver operating characteristic (ROC) analysis was conducted for each evaluated variable and the overall diagnostic accuracy was quantified using the area under the ROC curve (AUC). The AUC of evaluated variables were compared using a nonparametric approach. The optimal cut-off points were determined by the Youden's index, and the corresponding sensitivity and specificity were provided.

RESULTS

Significant positive correlation was identified between HOMA-IR with TG/HDL-C (r = 0.306), VAI (r = 0.217), LAP (r = 0.381), and TyG (r = 0.371), respectively (all p < .001). After adjustment for potential confounders of IR, compared with the lowest tertiles, odds ratio (95% CI) having IR in the highest tertiles of TG/HDL-C, VAI, LAP and TyG were 6.07 (2.89-12.71), 10.89 (4.37-27.13), 4.68 (2.00-10.92), and 12.20 (5.04-29.56). The area under ROC curves to predict HOMA-diagnosed IR was 0.773 for TG/HDL-C, 0.767 for VAI, 0.806 for LAP, and 0.800 for TyG, respectively. Among those, LAP showed the greatest value of AUC [0.806 (0.763-0.850)] and highest specificity (0.804).

CONCLUSION

Compared with other indicators, the LAP and TyG are simple, relatively accurate, clinically available surrogate markers of insulin resistance in middle-aged population in Hefei, China. Among 4 evaluated parameters, the LAP have the highest specificity and the TyG have the highest sensitivity.Key MessagesLAP and TyG could be used as simple and alternative methods to identify the individuals at risk for insulin resistance.LAP and TyG have relatively high predictive ability in diagnosis of IR compared with VAI and TG/HDL-C.No significant difference is observed between LAP and TyG in the ability of predicting insulin resistance.

Insulin resistance in children

PURPOSE OF REVIEW

Insulin resistance (IR) is a clinical condition due to the decline in the efficiency of insulin promoting glucose uptake and utilization. The aim of this review is to provide an overview of the current knowledge on IR in children, focusing on its physiopathology, the most appropriate methods of measurement of IR, the assessment of risk factors, the effects of IR in children, and finally giving indications on screening and treatment.

RECENT FINDINGS

IR has evolved more and more to be a global public health problem associated with several chronic metabolic diseases.

SUMMARY

Detecting a correct measurement method and specific risk predictors, in order to reduce the incidence of IR, represents a challenging goal.

Correlation between serum C-peptide-releasing effects and the risk of elevated uric acid in type 2 diabetes mellitus

Our study aimed to investigate the C-peptide-releasing effect associated with the risk of elevated serum uric acid (SUA) levels in patients with type 2 diabetes mellitus (T2DM). In the cross-sectional study, 345 patients with T2DM hospitalized at the First Affiliated Hospital of Harbin Medical University were consecutively enrolled, and their baseline data were collected. The study design used two parameters for C-peptide releasing effects: the multiplication effect of 1 h postprandial C-peptide to fasting C-peptide ratio (1hCp/FCp) and 2hCp/FCp; the incremental effect of 1hCp minus FCp (1hΔCp) and 2hΔCp. The patients with T2DM in the upper quartiles of SUA had higher FCp, 1hCp, 1hΔCp, 2hCp, and 2hΔCp. Multiple linear regression analysis revealed that after adjusting all the confounding factors, the serum C-peptide including 1hCp (β = 5.14, p = 0.036), 1hΔCp (β = 7.80, p = 0.010), 2hCp (β = 4.27, p = 0.009) and 2hΔCp (β = 5.20, p = 0.005) were still positively correlated with SUA levels in patients with T2DM. In female patients, only the 2hCp (β = 4.78, p = 0.017) and 2hΔCp (β = 5.28, p = 0.019) were associated with SUA level; however, in male patients, no C-peptide parameter was associated with SUA levels in T2DM (all p > 0.05). Within a certain range, the elevated SUA levels might be associated with the better C-peptide incremental effect of islet β cell function in T2DM, especially in female patients.

The Prevalence of Insulin Resistance in Malaysia and Indonesia: An Updated Systematic Review and Meta-Analysis

Background and Objectives: Noncommunicable diseases such as diabetes are strongly associated with the insulin resistance (IR) status of an individual. However, the prevalence of insulin resistance in Southeast Asia is poorly reported. Hence, this study investigated the prevalence of IR in Southeast Asia from the year 2016 to 2021. Materials and Methods: This study was carried out according to PRISMA guidelines. The literature search was conducted utilizing the PubMed and SCOPUS databases from the year 2016 to 2021 using the keywords ‘(insulin AND resistance) OR (insulin AND sensitivity) OR (prevalence OR incidence) AND (Malaysia OR Thailand OR Singapore OR Brunei OR Cambodia OR Indonesia OR Laos OR Myanmar OR Philippines OR Timor leste OR Vietnam)’. Funnel plot and publication bias were assessed using Egger’s tests. Data were expressed as the prevalence rate. Results: A total of 12 studies with 2198 subjects were considered in the meta-analysis. Significant heterogeneity (I2 > 94% and p-value < 0.001) was observed in the meta-analysis. The overall prevalence of IR in Southeast Asia was 44.3%, with Malaysia having the highest prevalence rate at 50.4%, followed by Indonesia at 44.2%. Bias was detected in the meta-analysis. It may be that reports published before the year 2016 met the study selection criteria, but were excluded from the meta-analysis. Conclusions: The results from the meta-analysis indicate that the prevalence of IR in Southeast Asia is very high. This provided insights for healthcare policy makers and public health officials in designing IR screening programs.

The Association Between Total Percent Fat and Serum Uric Acid in Adults

Background

Serum uric acid (SUA) has been proven to be closely associated with metabolic abnormalities, including obesity. This study aimed to investigate the detailed relationship between total percent fat (TPF) and SUA among adults.

Methods

Briefly, 23,715 adults aged 18–59 years in the National Health and Nutrition Examination Survey (NHANES) 1999–2018 were included in this study. Multivariable linear regression models were used to examine the association between TPF and SUA. Subgroup analyses stratified by sex and obesity status were also performed by multivariable linear regression. Then, fitted smoothing curves and generalized additive models were also applied to address the non-linear relationship between TPF and SUA. Finally, a recursive algorithm was used to calculate the inflection point in the non-linear relationship and a two-segment piecewise linear regression model was used to analyze the relationship between TPF and SUA on both sides of the inflection point.

Results

There were 15,808 (66.7%) obese individuals in all 23,715 participants. In the fully adjusted model, there was a positive association between TPF and SUA (β = 0.99, 95% CI: 0.73–1.26). Besides, this positive association remained statistically significant in subgroup analyses stratified by sex and obesity status. Interestingly, in males, the association of TPF and SUA was an inverted U-shaped curve (inflection point: 34.3%).

Conclusion

Our study revealed a significant positive relationship between TPF and SUA among adults and this association remained statistically significant when stratified by sex and obesity status, but the shape of the smoothing curve in males differed from that in females.

Elevated serum uric acid is a facilitating mechanism for insulin resistance mediated accumulation of visceral adipose tissue

OBJECTIVE

Serum uric acid (SUA) has been associated with cardiometabolic conditions such as insulin resistance (IR) and visceral adipose tissue (VAT) accumulation. Here, we aimed to clarify a unifying mechanism linking elevated SUA to IR and VAT.

METHODS

We conducted analyses in 226 subjects from the UIEM cohort with both euglycemic hyperinsulinemic clamp (EHC) and dual X-ray absorptiometry (DXA) measurements for IR and VAT accumulation and explored the role of SUA and adiponectin by developing a network of causal mediation analyses to assess their impact on IR and VAT. These models were then translated to two population-based cohorts comprising 6337 subjects from NHANES 2003-2004 and 2011-2012 cycles in the US and ENSANUT Medio Camino 2016 in Mexico, using HOMA2IR and adipoIR as indicators of peripheral and adipose tissue IR, and METS-VF as a surrogate for VAT accumulation.

RESULTS

SUA has a mediating role inside a bidirectional relationship between IR and visceral obesity, which was similar using either gold standard measurements or surrogate measures for IR and VAT. Furthermore, adiponectin acts as a linking mediator between elevated SUA and both peripheral IR and VAT accumulation. The proportion of the mechanism for IR-mediated (in either peripheral or adipose tissue) VAT accumulation was greater, compared to VAT-mediated IR accumulation (10.53% [9.23%-12.00%] to 5.44% [3.78%-7.00%]). Normal-range SUA levels can be used to rule-out underlying cardio-metabolic abnormalities in both men and women.

CONCLUSIONS

Elevated SUA acts as a mediator inside the bidirectional relationship between IR and VAT accumulation and these observations could be applicable at a phenotype scale.

The correlation of uric acid levels with biochemical parameters and dietary factors in individuals with asymptomatic hyperuricemia and gouty arthritis

Diet may play an important role in the development of asymptomatic hyperuricemia (ASH) and gouty arthritis (GOUT). However, the association between dietary factors and hyperuricemia remains unclear. Serum uric acid levels are affected by dietary factors. This study aimed to evaluate the correlation of uric acid levels with biochemical parameters and dietary factors in individuals with ASH and GOUT. This study was conducted in 145 individuals with ASH and GOUT. General characteristics of individuals were collected via face-to-face interviews. Food frequency questionnaire was used to obtain energy, macro- and micronutrients intakes. Biochemical parameters were obtained from patient files. The incidence of gout was higher in men comparing to women. Individuals in the GOUT group consumed more alcohol and higher serum levels of vitamin B₁₂, C-reactive protein (CRP), triglyceride, and uric acid. Individuals in the GOUT group had higher intakes of energy, protein, carbohydrate, fat, fructose, vitamin C, and vitamin B₁₂. Triglyceride, uric acid, CRP, vitamin B₁₂, and homeostatic model assessment of insulin resistance were found to be affected by high uric acid levels. Dietary factors can pose a risk for health problems in addition to GOUT and ASH, such as cardiovascular disease, diabetes, and obesity.

Triglyceride-Glucose Index for the Diagnosis of Metabolic Syndrome: A Cross-Sectional Study of 298,652 Individuals Receiving a Health Check-Up in China

OBJECTIVE

We herein aim to explore the relationship between the triglyceride-glucose (TyG) index and metabolic syndrome (MS).

METHODS

We enrolled 298,652 individuals with an average age of 47.08 ± 12.94 years and who underwent health check-ups at the First Affiliated Hospital of Wuhu Wannan Medical College in this cross-sectional study from 2014 to 2016. We enlisted 125,025 women (41.86%) and 173,627 men (58.14%). The survey information included a questionnaire survey, a physical examination, and a laboratory examination.

RESULTS

The prevalence of MS increased gradually in the TyG-index subgroups (Q1, TyG <8.30; Q2, 8.30≤ TyG <8.83; and Q3, TyG ≥8.83). We noted significant differences in hypertension, hyperlipidemia, hyperglycemia, sex, age, body mass index (BMI), smoking and drinking habits, and estimated glomerular filtration rate between the TyG-index subgroups. Multiclass logistic regression analysis showed that the group with TyG <8.30 was the reference group, and the 8.30≤ TyG <8.83 and the TyG ≥8.83 groups exhibited a higher TyG index with MS, and a lower TyG index without MS disease. In the linear curve analysis of the TyG index and MS components, BMI, systolic blood pressure, and diastolic blood pressure showed upward trends, while high-density lipoprotein cholesterol showed no obvious trend in the TyG index at a range of 7.8-11.0. Receiver operating characteristic analysis was used to evaluate the predictive value of the TyG index, triglycerides, and fasting blood glucose for MS, and we found that the area under the TyG index curve was the largest (AUC = 0.89).

CONCLUSION

There were associations between the TyG index and MS and its components, and the TyG index is therefore of great value in the early diagnosis of MS.

Mediation effect of obesity on the association between triglyceride-glucose index and hyperuricemia in Chinese hypertension adults

The triglyceride glucose (TyG) index was regarded as a simple surrogate marker of insulin resistance (IR). It is confirmed that IR was significantly associated with hyperuricemia, and obesity was the risk factor for IR and hyperuricemia. However, the relationship between the TyG index and hyperuricemia and the potential role of obesity in Han Chinese hypertension are not entirely elucidated. A community‐based cross‐sectional study was conducted in 4551 hypertension patients aged 40–75 years with clinical and biochemical data. The TyG index was calculated as ln [fasting triglyceride (mg/dl) × fasting plasma glucose (mg/dl)/2]. Hyperuricemia was determined as serum uric acid ≥357μmol/L (6 mg/dl) for females and ≥417μmol/L (7 mg/dl) for males. Our study suggested that the TyG index was higher in patients with hyperuricemia than in those without (8.99±0.61, 8.70±0.59, p < .001). The prevalence of hyperuricemia in patients with the lowest (≤8.32), second (8.33–8.66), third (8.67–9.07) and the highest quartile (≥9.08) of the TyG index was 6.0%, 10.4%, 15.4%, 21.4%, respectively. Logistic regression analysis suggested that the higher quartile of TyG index was associated with increased hyperuricemia risk whether in crude or adjusted models (p < .05). Mediation analysis showed that all of our obesity indexes partially mediated the association between the TyG index and hyperuricemia to some extent. In Conclusions, the TyG index is significantly associated with hyperuricemia in hypertension patients among Han Chinese, obesity plays a partial mediation role in this relationship.

[Triglyceride-glucose product is an independent risk factor for predicting chronic kidney disease in middle-aged and elderly population: a prospective cohort study]

OBJECTIVE

To explore the correlation of triglyceride-glucose product (TyG) index with chronic kidney disease (CKD) in elderly population in Lanzhou (Gansu Province, China).

METHODS

From May to September, 2011, a total of 3868 middleaged and elderly individuals without CKD from 3 communities in Lanzhou were selected as the cohort study population and were followed for an average of 3.1 years (from June, 2014 to August, 2015). After excluding those with missing follow-up data, a total of 3439 individuals were included for analysis, who were divided according to the quartile of TyG index into Q1 group (TyG≤8.47), Q2 group (TyG 8.48-8.84), Q3 group (TyG 8.85-9.20) and Q4 group (TyG>9.20). The estimated glomerular filtration rate (eGFR) and urinary albumin/creatinine ratio (UACR) were used to evaluate the renal function of the participants.

RESULTS

In this cohort, a high TyG index was found to correlate with a high risk of CKD (P < 0.05). Analysis of the follow-up data showed that the TyG index was significantly higher in patients who developed CKD during the follow-up than in those without CKD (P < 0.05). Logistic regression analysis showed that TyG index was an independent risk factor for abnormal eGFR and CKD (P < 0.05).

CONCLUSION

A high TyG index is an independent risk factor for CKD in middle-aged and elderly population.

Serum Uric Acid Is Associated with Metabolic Syndrome and Insulin Resistance among Health Personnel from Peru

We explored the association between serum uric acid (SUA) and metabolic syndrome (MetS) and insulin resistance (IR) among health personnel from a public hospital in Peru in a cross-sectional study with data from the Plan for the Prevention and Surveillance of Communicable and Noncommunicable Diseases of Huaycán Hospital. MetS was defined according to Latin American Diabetes Association (ALAD) criteria and IR with surrogate IR markers, triglyceride-to-HDL-C ratio (TG/HDL-C), and triglyceride-to-glucose index (TyG). The association between SUA and MetS and IR was determined using Poisson regression models in a sample of 292 participants with an average age of 46.2 ± 10.6 years. The total prevalence of MetS was 38%, and the individuals with MetS presented mainly alterations in anthropometric parameters (obesity and body fat). Finally, the adjusted regression models showed that women with SUA in the highest tertile increased the prevalence of MetS (PR: 1.71, 95% CI: 1.07-2.74) compared to the lowest tertile of SUA in women, while SUA increased hypertriglyceridemia and IR (TG/HDL-C and TyG) in both sexes. We concluded that SUA is strongly associated with MetS in women, and SUA increases hypertriglyceridemia and IR in both sexes. On the contrary, more research is required regarding the female population.

Kun-Dan Decoction Ameliorates Insulin Resistance by Activating AMPK/mTOR-Mediated Autophagy in High-Fat Diet-Fed Rats

Background: Metabolic syndrome is characterized by central obesity, hyperglycemia and hyperlipidemia. Insulin resistance is the leading risk factor for metabolic syndrome. Kun-Dan decoction (KD), a traditional Chinese medicine, has been applied to treat patients with metabolic syndrome for over ten years. It is increasingly recognized that autophagy deficiency is the key cause of metabolic syndrome. Therefore, we aimed to explore whether KD can activate autophagy to improve metabolic syndrome.

Methods: Network pharmacology was used to explore the underlying mechanism of KD in the treatment of metabolic syndrome. The high-fat diet-fed rats and oleic acid-induced LO2 cells were employed in our study. Oral glucose tolerance test and insulin tolerance test, obesity and histological examination, serum cholesterol, triglyceride, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), homeostasis model assessment of insulin resistance (HOMA-IR) and insulin sensitivity in high-fat diet-fed rats were analyzed. Furthermore, the protein expressions of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK), phospho-AMPK, mammalian target of rapamycin (mTOR), phospho-mTOR, p62, autophagy related protein (Atg) 5, Atg7, Atg12, Atg13, Atg16L1 and microtubule-associated protein 1A/1B-light chain 3 (LC3)-Ⅱ/Ⅰ were examined in rats and LO2 cells. Moreover, autophagy activator rapamycin and inhibitor 3-methyladenine, and small interfering RNA against Atg7 were utilized to verify the role of autophagy in the treatment of metabolic syndrome by KD in oleic acid-induced LO2 cells.

Results: Results from network pharmacology indicated that targeted insulin resistance might be the critical mechanism of KD in the treatment of metabolic syndrome. We found that KD significantly suppressed obesity, serum cholesterol, triglyceride and LDL-C levels and increased serum HDL-C level in high-fat diet-fed rats. Furthermore, KD enhanced insulin sensitivity and attenuated HOMA-IR in high-fat diet-fed rats. Western blot showed that KD could enhance autophagy to increase the insulin sensitivity of high-fat diet-fed rats and oleic acid-induced LO2 cells. Furthermore, 3-methyladenine and small interfering RNA against Atg7 could reverse the protective effect of KD on LO2 cells. However, rapamycin could cooperate with KD to enhance autophagic activation to increase insulin sensitivity in LO2 cells.

Conclusion: The induction of autophagy may be the major mechanism for KD to improve insulin resistance and metabolic syndrome.

Uric acid lowering improves insulin sensitivity and lowers blood pressure: a meta-analysis of randomized parallel-controlled clinical trials

Objectives

This meta-analysis aimed to investigate whether uric acid lowering treatment can improve β-cell function and insulin sensitivity.

Methods

PubMed, Cochrane Library, EMBASE and China Biology Medicine were searched up to March 1, 2020. Randomized controlled clinical trials of urate lowering therapy in hyperuricemia patients were included in meta-analysis. Effect size was estimated as mean difference with 95% confidence interval (CI).

Results

Our search yielded 7 eligible trials with 503 participants. This meta-analysis showed that uric acid-lowering therapy decreased fasting insulin -1.43 µIU/ml (weighted mean differences (WMD, 95% CI -2.78 to -0.09), homeostasis model assessment of insulin resistance -0.65 (WMD, 95% CI -1.05 to -0.24), systolic blood pressure -2.45 mm Hg (WMD, 95%CI -4.57 to -0.33) and diastolic blood pressure -3.41 mm Hg (WMD, 95%CI -3.87 to -2.95). However, the treatment had no significant effect on fasting plasma glucose (WMD -0.19 mmol/L, 95%CI -0.42 to 0.05), homeostasis model assessment of β-cell function index (WMD -0.02, 95%CI -0.28 to 0.24), total cholesterol (WMD 0.18 mg/dl; 95%CI, -1.39 to 1.75) and triglyceride (WMD 3.15 mg/dl, 95% CI -9.83 to 16.14).

Conclusion

Uric acid-lowering therapies might improve insulin sensitivity and lower blood pressure, but had no significant effect on HOMA-β and serum lipids.

Targets and mechanisms of dietary anthocyanins to combat hyperglycemia and hyperuricemia: a comprehensive review

Hyperglycemia and hyperuricemia are both metabolic disorders related to excessive amount of metabolites in blood, which are considered as high risk factors for the development of many chronic diseases. Enzymes, cells, tissues and organs, which are relevant to metabolism and excretion of glucose and UA, are usually regarded to be the targets in treatment of hyperglycemia and hyperuricemia. Several drugs have been commonly applied to combat hyperglycemia and hyperuricemia through various targets but with unignorable side effects. Anthocyanins have become promising alternatives against hyperglycemia and hyperuricemia because of their bio-activities with little side effects. Structurally different anthocyanins from berry fruits, cherries and purple sweet potato lead to the diverse functional activity and property. This review is aimed to illustrate the specific targets that are available for anthocyanins from berry fruits, cherries and purple sweet potato in hyperglycemia and hyperuricemia management, as well as discuss the structure-activity relationship, and the underlying mechanisms associated with intracellular signaling pathway, anti-oxidative stress and anti-inflammation. In addition, the relationship of hyperglycemia and hyperuricemia, and the possibly regulative role of anthocyanins against them, along with the effects of anthocyanins in clinical trial are mentioned.