Effects of Uric Acid on Diabetes Mellitus and Its Chronic Complications

Does Serum Uric Acid Mediate Relation between Healthy Lifestyle and Components of Metabolic Syndrome?

A healthy lifestyle is related to metabolic syndrome (MetS), but the mechanism is not fully understood. This study aimed to examine the association of components of MetS with lifestyle in a Chinese population and potential mediation role of serum uric acid (SUA) in the association between lifestyle behaviors and risk of components of MetS. Data were derived from a baseline survey of the Shaanxi urban cohort in the Regional Ethnic Cohort Study in northwest China. The relationship between components of MetS, healthy lifestyle score (HLS), and SUA was investigated by logistic or linear regression. A counterfactual-based mediation analysis was performed to ascertain whether and to what extent SUA mediated the total effect of HLS on components of MetS. Compared to those with 1 or less low-risk lifestyle factors, participants with 4-5 factors had 43.6% lower risk of impaired glucose tolerance (OR = 0.564; 95%CI: 0.408~0.778), 60.8% reduction in risk of high blood pressure (OR = 0.392; 95%CI: 0.321~0.478), 69.4% reduction in risk of hypertriglyceridemia (OR = 0.306; 95%CI: 0.252~0.372), and 47.3% lower risk of low levels of HDL cholesterol (OR = 0.527; 95%CI: 0.434~0.641). SUA mediated 2.95% (95%CI: 1.81~6.16%) of the total effect of HLS on impaired glucose tolerance, 14.68% (95%CI: 12.04~18.85%) on high blood pressure, 17.29% (95%CI: 15.01~20.5%) on hypertriglyceridemia, and 12.83% (95%CI: 10.22~17.48%) on low levels of HDL cholesterol. Increased HLS tends to reduce risk of components of MetS partly by decreasing the SUA level, which could be an important mechanism by which lifestyle influences MetS.

Unveiling overlooked pathways: The uric acid catabolism genes in the human genome

In hominids, including Homo sapiens, uric acid is the end product of purine catabolism. In contrast, other placental mammals further degrade uric acid to (S)-allantoin by enzymes such as urate oxidase (uricase), HIU hydrolase (HIUase), and OHCU decarboxylase. Some organisms, such as frogs and fish, hydrolyze (S)-allantoin to allantoate and eventually to (S)-ureidoglycolate and urea, while marine invertebrates convert urea to ammonium. In H. sapiens, mutations in the uricase gene led to a reduction in the selective pressure for maintaining the integrity of the genes encoding the other enzymes of the purine catabolism pathway, resulting in an accumulation of uric acid. The hyperuricemia resulting from this accumulation is associated with gout, cardiovascular disease, diabetes, and preeclampsia. Many commonly used drugs, such as aspirin, can also increase uric acid levels. Despite the apparent absence of these enzymes in H. sapiens, there appears to be production of transcripts for uricase (UOX), HIUase (URAHP), OHCU decarboxylase (URAD), and allantoicase (ALLC). While some URAHP transcripts are classified as long non-coding RNAs (lncRNAs), URAD and ALLC produce protein-coding transcripts. Given the presence of these transcripts in various tissues, we hypothesized that they may play a role in the regulation of purine catabolism and the pathogenesis of diseases associated with hyperuricemia. Here, we specifically investigate the unique aspects of purine catabolism in H. sapiens, the effects mutations of the uricase gene, and the potential regulatory role of the corresponding transcripts. These findings open new avenues for research and therapeutic approaches for the treatment of hyperuricemia and related diseases.

Vitamin D Reduces the Activity of Adenosine Deaminase and Oxidative Stress in Patients with Type Two Diabetes Mellitus

SCOPE

Patients with Type 2 diabetes mellitus (T2DM) have lower levels of vitamin D. An elevation in uric acid (UA) contributes to T2DM via an increase in oxidative stress. Adenosine deaminase (ADA) is an enzyme of the purine degradation pathway. It is hypothesized that a reduction of ADA activity via vitamin D supplementation reduces UA and oxidative stress.

METHODS AND RESULTS

A total of 162 participants (81 with T2DM and 81 controls) are enrolled in a case-control study. A follow-up interventional study is performed on 30 patients with vitamin D deficiency. These patients receive 50 000 IU (international units) of vitamin D3 on a weekly basis for 12 weeks. This intervention is followed by the measurement of several markers. T2DM patients has higher ADA activity, UA, and lipid peroxidation but lower 25-hydroxy-vitamin D (25 (OH) vitamin D) and GSH/GSSG ratio (p < 0.05). Vitamin D supplementation results in a reduction of ADA activity and UA levels (p < 0.05) along with an increase in GSH/GSSG ratio (p < 0.05).

CONCLUSION

The results highlight the presence of an axis in T2DM patients between ADA, UA, and oxidative stress. Modulation of this axis can be achieved by clinically approved vitamin D supplementation protocols.

Anthropometry and blood biomarkers of diabetes and their possible association with obesity and metabolic syndrome

Background

Diabetes, a rapidly increasing heterogeneous disorder, is closely linked to the epidemic of obesity and metabolic syndrome (MetS). At present, we do not understand completely the blood biomarkers, molecular aetiology, and role of lifestyle modification and interventions to combat diabetes hand in hand with obesity and the MetS epidemic.

Methods

To measure different anthropometric and blood biomarkers in pre-diabetic and diabetic patients, we collected data and blood samples from patients in a hospital OPD. This was a cross-sectional study that included the identification of possible relationships between different parameters to predict early diagnostic markers of diabetes.

Results

We found increased body mass index (BMI), fasting blood glucose, neck, waist, and hip circumference, sagittal abdominal diameter, and skin fold thickness in the diabetic as compared to the pre-diabetic group. Also, serum uric acid and insulin resistance (HOMA-IR) values were significantly increased in diabetic individuals. We found a significant positive correlation between serum uric acid and BMI, fasting blood glucose, serum insulin, and HOMA-IR values.

Conclusions

Here, we found that pre-diabetic and diabetic patients have increased fasting glucose levels while we did not find any difference in insulin levels. Both pre-diabetic and diabetic patients show high serum uric acid, positively associated with a higher prevalence of diabetes and HOMA-IR. Uric acid may hence be an important parameter for early diagnostics. These findings may be used as a basis for future studies that aim to identify the mechanistic details of the association of uric acid with insulin signaling and hence better understanding of the phenomenon associated with diabetes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01276-4.

Association between hyperuricemia and diabetic nephropathy: insights from the national health and nutrition examination survey 2007-2016 and mendelian randomization analysis

BACKGROUND

This study aimed to investigate the role of uric acid (UA) in diabetic nephropathy (DN) from epidemiological and genetic perspectives.

METHODS

We used data from the 2007-2016 National Health and Nutrition Examination Survey to evaluate the relationship between UA and DN risk using weighted multivariate-adjusted logistic regression. Subsequently, a two-sample Mendelian randomization study was conducted using genome-wide association study summary statistics. The main inverse variance weighting (IVW) method and supplementary MR method were used to verify the causal relationship between UA and DN, and sensitivity analysis was conducted to confirm the credibility of the results.

RESULTS

Our observational study enrolled 4363 participants with diabetes mellitus from NHANES, among them, 2682 (61.4%) participants were identified as DN. The multivariate logistic regression model showed that compared with those without hyperuricemia, the DN risk of the hyperuricemia population was significantly increased (P < 0.05). The MR results suggest a direct causal effect of hyperuricemia on DN (IVW odds ratio (OR): 1.37 (95% confidence interval 1.07-1.76); P = 0.01), which is consistent with findings from other MR methods.

CONCLUSION

The evidence from observational studies indicates a positive correlation between HUA and the onset of DN. And the causal effects of HUA on DN were supported by the MR analysis.

Applying GC-MS based serum metabolomic profiling to characterize two traditional Chinese medicine subtypes of diabetic foot gangrene

Traditional Chinese medicine (TCM) has a long history and particular advantages in the diagnosis and treatment of diabetic foot gangrene (DFG). Patients with DFG are mainly divided into two subtypes, tendon lesion with edema (GT) and ischemic lesion without edema (GI), which are suitable for different medical strategies. Metabolomics has special significance in unravelling the complexities of multifactorial and multisystemic disorders. This study acquired the serum metabolomic profiles of two traditional Chinese medicine subtypes of DFG to explore potential molecular evidence for subtype characterization, which may contribute to the personalized treatment of DFG. A total of 70 participants were recruited, including 20 with DM and 50 with DFG (20 with GI and 30 with GT). Conventional gas chromatography-mass spectrometry (GC-MS) followed by orthogonal partial least-squares discriminant analysis (OPLS-DA) were used as untargeted metabolomics approaches to explore the serum metabolomic profiles. Kyoto encyclopedia of genes and genomes (KEGG) and MetaboAnalyst were used to identify the related metabolic pathways. Compared with DM patients, the levels of 14 metabolites were altered in the DFG group, which were also belonged to the differential metabolites of GI (13) and GT (7) subtypes, respectively. Among these, urea, α-D-mannose, cadaverine, glutamine, L-asparagine, D-gluconic acid, and indole could be regarded as specific potential metabolic markers for GI, as well as L-leucine for GT. In the GI subtype, D-gluconic acid and L-asparagine are positively correlated with activated partial thromboplastin time (APTT) and fibrinogen (FIB). In the GT subtype, L-leucine is positively correlated with the inflammatory marker C-reactive protein (CRP). Arginine and proline metabolism, glycine, serine and threonine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis are the most important metabolic pathways associated with GI. The main metabolic pathways related to GT include pyrimidine metabolism, glutathione metabolism, biosynthesis of valine, leucine, and isoleucine, as well as valine, serine, and isoleucine with metabolites. The results of this study indicate that patients with different DFG subtypes have distinct metabolic profiles, which reflect the pathological characteristics of each subtype respectively. These findings will help us explore therapeutic targets for DFG and develop precise treatment strategies.

Relationship Between Asymptomatic Hyperuricemia and the Hypertriglyceridemic-Waist Phenotype in Korean Adults: A Cross-Sectional Study

Purpose

Visceral fat accumulation can negatively affect uric acid metabolism in healthy adults. The hypertriglyceridemic-waist (HTGW) phenotype is a predictor of diabetes and cardiometabolic risk. This study aimed to investigate the association between the HTGW phenotype and asymptomatic hyperuricemia in Korean adults.

Patients and Methods

The study included 23,240 adults, aged 20-80 years who underwent comprehensive health examinations at a general hospital in Gyeonggi Province, Korea, from January 2020 to December 2022. The HTGW phenotype was defined as the simultaneous presence of elevated serum triglyceride (TG) levels and increased waist circumference (WC). The diagnostic capability of the HTGW phenotype for hyperuricemia and its association with the condition were assessed using the receiver operating characteristic (ROC) curve and logistic regression analysis.

Results

The prevalence of hyperuricemia in the HTGW phenotype was 3.44 times higher than that in the normal TG normal waist (NTNW) phenotype. Compared with those in the NTNW group, the hazard ratios for developing hyperuricemia in the HTGW group were 2.887 (2.566-3.249, P <0.001) for men and 7.341 (5.139-10.487, P <0.001) for women, and these values remained significant after adjusting for potential confounders. The stratified analysis revealed that the HTGW phenotype, coupled with diabetes, had the highest probability of developing asymptomatic hyperuricemia (2.55 times). ROC curve analysis revealed that the area under the curve values of the WC*TG index for hyperuricemia diagnosis were 0.702, 0.627, and 0.685 for all participants, men, and women, respectively.

Conclusion

Among Korean adults, the HTGW phenotype was closely related to hyperuricemia in both men and women and showed a particularly strong association in patients with diabetes. It may be used in combination with an indicator that can complement its accuracy for identifying individuals at high risk of hyperuricemia.

Association between Glycosylated Hemoglobin and Serum Uric Acid: A US NHANES 2011-2020

Background

Serum uric acid (SUA) and glycosylated hemoglobin (HbA1c) were closely related to the body's metabolism. This study aimed to investigate the relationship between HbA1c and SUA in adults.

Methods

This study selected 7293 participants aged ≥20 from 2011 to 2020 in the National Health and Nutrition Examination Survey (NHANES). The multivariate linear regression model was used to test the association between HbA1c and SUA. Subgroup analysis was performed according to age, gender, race, and body mass index (BMI). This study solved the relationship between HbA1c and SUA by fitting a smooth curve. Finally, the inflection point in the nonlinear relationship was calculated by the recursive algorithm, and the relationship between HbA1c and SUA on both sides of the inflection point was analyzed by the two-segment piecewise linear regression model.

Results

All 7293 participants found a negative correlation between HbA1c and SUA by completely adjusting the model (β = -7.93 and 95% CI: -9.49--6.37). In addition, when this study was stratified by gender, age, race, and BMI status, this negative correlation was still statistically significant. In the subgroup analysis, we found that the relationship between the two had different results due to gender differences. In men, HbA1c had a significant negative correlation with SUA. However, in women, the HbA1c value was positively correlated with SUA before 6.8%, and the HbA1c value was negatively correlated with SUA after 6.8%, which indicates that the relationship between HbA1c and SUA in women has changed in prediabetes and diabetes.

Conclusion

This study shows that HbA1c is positively correlated with SUA in American adults before 7%. There is a negative correlation after the HbA1c value of 7%.

The Relationship Between UA/HDL and Diabetic Peripheral Neuropathy: A Cross-Sectional Analysis

Purpose

This study was designed to analyze correlations between the uric acid to high-density lipoprotein cholesterol ratio (UHR) and peripheral nerve conduction velocity (NCV) among type 2 diabetes mellitus (T2DM) patients.

Patients and Methods

This was a single-center cross-sectional analysis of 324 T2DM patients. All patients were separated into a group with normal NCV (NCVN) and a group with abnormal NCV (NCVA). Patients were also classified into groups with low and high UHR values based on the median UHR in this study cohort. Neurophysiological data including motor and sensory conduction velocity (MCV and SCV, respectively) were measured for all patients.

Results

Relative to patients with low UHR values, those in the high UHR group presented with greater NCVA prevalence (P = 0.002). UHR remained negatively correlated with bilateral superficial peroneal nerve SCV, bilateral common peroneal nerve MCV, bilateral ulnar nerve SCV, and bilateral right median nerve MCV even after adjustment for confounding factors. UHR was identified as an NCVA-related risk factor, with a 1.370-fold increase in NCVA prevalence for every unit rise in UHR (P < 0.001).

Conclusion

These results identify UHR as a risk factor associated with NCVA that was independently negatively associated with NCV among T2DM patients.

Comparative Assessment of In Vitro Xanthine Oxidase and α-Glucosidase Inhibitory Activities of Cultured Cambial Meristematic Cells, Adventitious Roots, and Field-Cultivated Ginseng

Panax ginseng, a traditional Chinese medicine with a history spanning thousands of years, faces overexploitation and challenges related to extended growth periods. Tissue-cultured adventitious roots and stem cells are alternatives to wild and field-cultivated ginseng. In this study, we assessed the in vitro xanthine oxidase and α-glucosidase inhibitory activities of saponin extracts among cultured cambial meristematic cells (CMC), adventitious ginseng roots (AGR), and field-cultivated ginseng roots (CGR). The xanthine oxidase (XO) and α-glucosidase inhibitory activities were determined by uric acid estimation and the p-NPG method, respectively. Spectrophotometry and the Folin-Ciocalteu, aluminum nitrate, and Bradford methods were employed to ascertain the total saponins and phenolic, flavonoid, and protein contents. The calculated IC50 values for total saponin extracts against XO and α-glucosidase were 0.665, 0.844, and >1.6 mg/mL and 0.332, 0.745, and 0.042 mg/mL for AGR, CMC, CGR, respectively. Comparing the total saponin, crude protein, and total phenolic contents revealed that AGR > CMC > CGR. To the best of our knowledge, this study presents the first report on the in vitro comparison of xanthine oxidase and α-glucosidase inhibitory activities among AGR, CMC, and CGR. The findings offer valuable insights into the development of hypoglycemic and antihyperuricemic medicinal, nutraceutical, and functional products utilizing AGR and CMC.

Genome-wide association study of serum magnesium in type 2 diabetes

People with type 2 diabetes have a tenfold higher prevalence of hypomagnesemia, which is suggested to be caused by low dietary magnesium intake, medication use, and genetics. This study aims to identify the genetic loci that influence serum magnesium concentration in 3466 people with type 2 diabetes. The GWAS models were adjusted for age, sex, eGFR, and HbA1c. Associated traits were identified using publicly available data from GTEx consortium, a human kidney eQTL atlas, and the Open GWAS database. The GWAS identified a genome-wide significant locus in TAF3 (p = 2.9 × 10-9) in people with type 2 diabetes. In skeletal muscle, loci located in TAF3 demonstrate an eQTL link to ATP5F1C, a gene that is involved in the formation of Mg2+-ATP. Serum Mg2+ levels were associated with MUC1/TRIM46 (p = 2.9 × 10-7), SHROOM3 (p = 4.0 × 10-7), and SLC22A7 (p = 1.0 × 10-6) at nominal significance, which is in combination with the eQTL data suggesting that they are possible candidates for renal failure. Several genetic loci were in agreement with previous genomic studies which identified MUC1/TRIM46 (Pmeta = 6.9 × 10-29, PQ = 0.81) and SHROOM3 (Pmeta = 2.9 × 10-27, PQ = 0.04) to be associated with serum Mg2+ in the general population. In conclusion, serum magnesium concentrations are associated with genetic variability around the regions of TAF3, MUC1/TRIM46, SHROOM3, and SLC22A7 in type 2 diabetes.

Prevalence and association of hyperuricemia with liver function in Saudi Arabia: a large cross-sectional study

BACKGROUND

Hyperuricemia is linked to an increased risk of various chronic diseases, but data on the prevalence and association of hyperuricemia with liver function in Saudi Arabia are scarce.

OBJECTIVES

Evaluate the prevalence, association, and risk measures of hyperuricemia and liver function in the Saudi population.

DESIGN

Retrospective, cross-sectional analysis.

SETTING

Database on large portion of Saudi population.

PATIENTS AND METHODS

Laboratory data, age, and gender of the studied subjects were collected from Al Borg Diagnostics. Subjects were stratified, based on their uric acid (UA) levels, into three groups: hypouricemic, normouricemic, and hyperuricemic. The association of UA with liver enzymes was examined in all three groups.

MAIN OUTCOME MEASURES

Association of serum UA levels with alanine transaminase (ALT), aspartate transferase (AST), alkaline phosphatase (ALP), and total bilirubin (TB).

SAMPLE SIZE

13 314 subjects.

RESULTS

Our study showed that the prevalence of hyperuricemia in the Saudi population is 17.3% (20.3% in males and 15.1% in females). We also found a positive correlation between ALT, AST, and TB with UA levels. The risk of being hyperuricemic was significantly increased in individuals with elevated ALT, AST, and TB. Individuals with elevated ALT, AST, and total TB had a higher chance of having hyperuricemia than those with normal activity. Notably, ALT, AST, and TB had good discriminating capacity for hyperuricemia.

CONCLUSIONS

Hyperuricemia is highly prevalent in the Saudi population and is associated with compromised liver function. However, further studies are needed to elucidate the mechanisms underlying these findings in large prospective cohort studies in different populations.

LIMITATIONS

Lack of data on other potential confounding variables.

The Combination of Uric Acid and Hemoglobin Levels Predicts the Incident Risk of Ischemic Heart Disease More Than Uric Acid Alone in Non-Diabetic Koreans: A Longitudinal Study Using National Health Insurance Data

Uric acid has been related to cardiovascular disease (CVD). Recently, slightly elevated hemoglobin (Hb) was also shown to be associated with CVD. We retrospectively investigated the joint effect of uric acid and elevated Hb by comparing normal-range uric acid alone on incident ischemic heart disease (IHD) risk in a large cohort of non-diabetic Korean adults using National Health Insurance data. We assessed 16,786 participants without diabetes (8595 men and 8191 women) using extensive cohort data. High Hb was defined as ≥16.4 g/dL in men and 13.8 g/dL in women (>75th percentile). We analyzed the data using two different methods. First, the participants were divided into quartiles according to uric acid levels. Second, subjects were also divided into quartiles: reference (group 1), high uric acid and normal Hb (group 2), normal uric acid and high Hb (group 3), and normal uric acid and high Hb (group 4). We evaluated hazard ratios (HRs) with 95% confidence intervals (CIs) for IHD using multivariate Cox regression analysis over a 50-month follow-up. During the follow-up, 345 (1.9%) participants developed IHD. In the analysis using both uric acid and Hb, compared with the reference group, the HRs for IHD were 1.37 (95% CI, 1.01-1.86) in the second group, 1.63 (95% CI, 1.21-2.21) in the third group, and 1.86 (95% CI, 1.30-2.67) in the fourth group after adjusting for IHD risk factors. Subsequently, patients with high uric acid are more likely to develop incident IHD than control patients. Moreover, we confirmed the joint effects of high uric acid and high hemoglobin on incident IHD. Awareness of these interactions is essential for clinicians. Risk factor management and screening for IHD are part of the routine management of patients with high uric acid and Hb.

High levels of uric acid inhibit BAT thermogenic capacity through regulation of AMPK

Hyperuricemia (HUA) is strongly associated with the increasing prevalence of obesity, but the underlying mechanism remains elusive. Dysfunction of brown adipose tissue (BAT) could lead to obesity. However, studies on the role of HUA on BAT are lacking. Our retrospective clinical analysis showed that serum uric acid (UA) is significantly associated with BAT in humans. To investigate the role of UA in regulating BAT function, we used UA to treat primary brown adipocytes (BACs) in vitro and established HUA mice. In vitro results showed that HUA suppressed thermogenic gene expression and oxygen consumption rate. Accordingly, HUA mice exhibited lower energy expenditure and body temperature, with larger lipid droplets and lower thermogenic gene expression. These results demonstrate that HUA inhibits BAT thermogenic capacity in vitro and in vivo. To further elucidate the mechanism of UA on adipocytes, mRNA-sequencing analysis was performed and screened for "AMP-activated protein kinase (AMPK) signaling pathway" and "mitochondrial biogenesis." Further tests in vivo and in vitro showed that the phosphorylation of AMPK was suppressed by HUA. Activation of AMPK alleviated the inhibition of AMPK phosphorylation by HUA and increased mitochondrial biogenesis, subsequently restoring the impaired BAT thermogenic capacity in vitro and vivo. Thus, we confirmed that HUA suppresses mitochondrial biogenesis by regulating AMPK, thereby inhibiting BAT thermogenic capacity. Taken together, our study identifies UA as a novel regulator of BAT thermogenic capacity, providing a new strategy to combat obesity.NEW & NOTEWORTHY To investigate the effect and mechanism of UA on BAT thermogenic capacity, we established HUA models in vitro and in vivo, and performed RNA sequencing analysis. Our results revealed that HUA suppresses mitochondrial biogenesis by regulating AMPK, thereby inhibiting BAT thermogenic capacity. Taken together, our study identifies UA as a novel regulator of BAT thermogenic capacity, providing a new strategy to combat obesity.

The Ratio of Serum Uric Acid to Glycosylated Haemoglobin as a Predictor of All-Mortality in Elderly Patients with Diabetic Foot Ulcers: A Longitudinal Cohort Study

Aim

To clarify the relationship between serum uric acid (UA) and glycosylated hemoglobin (UA/HbA1c) ratio and all-cause mortality in patients with diabetic foot ulcers (DFUs).

Methods

A total of 172 inpatients with DFUs (PEDIS grades 2-4) were eligible for inclusion in this study from 2018 to 2023. This was a retrospective, longitudinal cohort study. All subjects were followed up every 6 months for a median of 60 months. According to the cutoff value of the UA/HbA1c ratio of 39.07 obtained from ROC analysis, the participants were divided into two groups: low-level (≤ 39.07, n = 107) and high-level (> 39.07, n = 65) groups. The correlation between UA/HbA1c ratio and all-cause mortality was also evaluated by Cox regression analysis TheKaplan-Meier survival curve analysis and Log rank tests were used to assess the incidence rates of all-cause mortality. The contribution rate of risk factors was estimated by the population-attributable risk percentage (PAR%) analysis.

Results

ROC analysis showed that the optimal cutoff values for UA and the UA/HbA1c ratio were 372 μmol/L and 39.07, respectively. Multivariate Cox regression analysis indicated that a high UA/HbA1c ratio (HR =4.63; 95% CI = 2.004-10.7, P < 0.001) was independently associated with a high risk of all-cause mortality in patients with DFUs. Stratified analysis indicated that subjects aged ≥ 60 years had a greater risk of all-cause mortality associated with a high UA/HbA1c ratio (HR = 4.450; 95% CI = 1.711-11.574, P = 0.002). Kaplan-Meier survival analysis showed that all-cause mortality had a significant positive association with a high UA/HbA1c ratio (log-rank, P < 0.001) and a significant negative correlation with the lowered HbA1c level (< 6.5%) after a follow-up of 32 months (log-rank, P < 0.001). The population attributable risk percentage (PAR%) analysis suggested that the contribution rate of the high-level UA/HbA1c ratio to all-cause mortality was 33.7%, which was much greater than the 19.69% of UA.

Conclusion

In brief, our study showed that for every 1.0% increase in the UA/HbA1c ratio, the all-cause mortality rate in elderly patients with DFUs aged ≥ 60 years increased by 3.45-fold. For elderly patients with DFUs, a safe and effective strategy to reduce all-cause mortality is to strictly control serum UA levels to < 372 μmol/L and appropriately loosen the control goal of HbA1c to ≥ 6.5%.

Elevated Uric Acid Levels with Early Chronic Kidney Disease as an Indicator of New-Onset Ischemic Heart Disease: A Cohort of Koreans without Diabetes

Several studies have showed that hyperuricemia is related to the development of ischemic heart disease (IHD). There is also growing evidence indicating that hyperuricemia may contribute to the progression of IHD as a pathogenic factor. Ironically, uric acid can be an antioxidant agent, as shown in experimental studies. The aim of our study is to analyse the association between uric acid and IHD with early-stage chronic kidney disease (CKD). Data were assessed from 17,492 participants without cardiovascular disease from the Korean Genome and Epidemiology Study (KoGES) and Korea Health Insurance Review and Assessment (HIRA) data. The subjects were categorized as four groups according to CKD and uric acid levels. We retrospectively evaluated hazard ratios (HRs) with 95% confidence intervals (CIs) for IHD by using multivariate Cox regression analysis over a 4-year period from the baseline survey. During the follow-up, 335 individuals (3.4%; 236 men and 99 women) developed IHD. Compared to the participants without elevated uric acid and early CKD HRs for incident IHD according to uric acid levels and early CKD, the uric acid level was 1.13 (95% CI, 0.86-1.48) in participants with elevated uric acid and without early CKD, 0.99 (95% CI, 0.55-1.77) in participants without elevated uric acid and with early CKD, and 1.65 (95% CI, 1.03-2.66) in participants with elevated uric acid and early CKD after adjusting for confounding metabolic factors. Early CKD and high uric acid levels increased the risk of new-onset IHD (HR, 1.65; 95% CI, 1.03-2.66). Elevated uric acid levels were related to an increased risk of incident IHD in early-stage CKD patients. It is expected that uric acid can be a reliable predictor for IHD, even in early-stage CKD patients; thus, in those with CKD, proactively managing uric acid levels can play a significant role in reducing the risk of cardiovascular disease.

Uric acid and glaucoma: a systematic review and meta-analysis

Background

Glaucoma, the leading cause of irreversible blindness, is a common disorder that contributes to gradual optic nerve degeneration. The beneficial impacts of uric acid (UA) have been reported in some neurodegenerative conditions such as Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis. But the results of current studies about the association between serum UA level and glaucoma are conflicting. The present meta-analysis was conducted to provide a better understanding of the association between serum UA level and glaucoma.

Methods

We searched the databases of PubMed, Scopus, Web of Science, and Google Scholar systematically until November 20, 2022 to identify case-control studies, comparing the serum UA concentrations of the patients with glaucoma and controls. The mean ± standard division difference was used to assess the difference in serum UA concentrations between the glaucoma patients and controls.

Results

Six studies involving 1,221 glaucoma patients and 1,342 control group were included in the present meta-analysis. This meta-analysis using a random effect model indicated that the mean UA level in glaucoma patients was 0.13 (I2 = 91.92%, 95% CI = -0.42 to 0.68) higher than the controls; however, it was not statistically significant.

Conclusions

Our findings provide evidence that glaucoma patients have a higher serum UA level compared to the controls, but this difference is not statistically significant. Prospective studies are needed to determine the possible association between increased UA and glaucoma pathogenesis.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022364055, identifier: CRD42022364055.

Prevalence of hyperuricemia among type 2 diabetes mellitus patients in Africa: a systematic review and meta-analysis

BACKGROUND

Hyperuricemia increases morbidity and mortality in type 2 diabetic individuals. It is linked to the expansion of diabetes and cardiovascular diseases indicators, as well as being a significant predictor of coronary artery disease. It also leads to a poor prognosis and increment of diabetic complications including diabetic neuropathy, retinopathy, and nephropathy. Therefore, this systematic review and meta-analysis was aimed to determine the pooled prevalence of hyperuricemia among type 2 diabetes mellitus patients in Africa.

METHODS

We conducted a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. To identify relevant articles, we searched electronic databases such as PubMed, Google Scholar, African Journal Online, Science Direct, Embase, ResearchGate, Scopus, and Web of Sciences. The quality of the included studies was assessed using the Newcastle-Ottawa Quality Assessment Scale. Statistical analysis was performed using Stata 14.0 software. To evaluate heterogeneity, we utilized Cochran's Q test and I² statistics. Publication bias was assessed through the examination of a funnel plot and Egger's test. The pooled prevalence was estimated using a random effect model. Furthermore, sub-group and sensitivity analyses were conducted.

RESULTS

The overall pooled prevalence of hyperuricemia among type 2 diabetic patients in Africa was 27.28% (95% CI: 23.07, 31.49). The prevalence was highest in Central Africa 33.72% (95% CI: 23.49, 43.95), and lowest in North Africa 24.72% (95% CI: 14.38, 35.07). Regarding sex, the pooled prevalence of hyperuricemia among female and male type 2 diabetic patients was 28.02% (95% CI: 22.92, 33.48) and 28.20% (95% CI: 22.92, 33.48), respectively.

CONCLUSION

This systematic review and meta-analysis showed a high prevalence of hyperuricemia among type 2 diabetic patients. So, regular screening and diagnosis of hyperuricemia required for preventing its pathological effects and contribution to chronic complications of diabetes.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (2022: CRD42022331279).

Elevated Serum Uric Acid Is Associated With Gestational Diabetes Mellitus: An Observational Cohort Study

CONTEXT

Elevated serum uric acid may be closely related to the occurrence of gestational diabetes mellitus (GDM).

OBJECTIVE

We aimed to elucidate the relationship between changes in serum uric acid before 24 weeks of gestation and the risk of GDM and associated adverse pregnancy outcomes and provide clinical epidemiological evidence for the involvement of uric acid in the etiology of GDM.

METHODS

We conducted a retrospective cohort study of 23 843 singleton pregnant women between February 2018 and June 2022. The exposure factor was serum uric acid before 24 weeks of gestation, primary outcome was gestational diabetes diagnosed at 24 to 28 weeks of gestation, and secondary outcomes were GDM A2 (GDM requiring pharmacotherapy), GDM combined with pre-eclampsia, preterm delivery, and large for gestational age infants. Adjusted risk ratios (RRs) were calculated using multivariate predictive marginal proportions from logistic regression models.

RESULTS

Among 23 843 singleton pregnant women, 3204 (13.44%) were diagnosed with GDM at 24 to 28 weeks of gestation, and elevated uric acid before 24 weeks of gestation was strongly associated with the risk of GDM. Compared with uric acid <240 µmol/L, the RR for GDM was 1.43 (95% CI 1.29-1.56) when uric acid was between 240 and 300 µmol/L; when uric acid was >300 µmol/L, the RR for GDM was 1.82 (95% CI 1.55-2.15). In secondary outcomes uric acid had a similar relationship with GDM A2, preterm birth, and GDM combined with pre-eclampsia.

CONCLUSION

Elevated uric acid levels before 24 weeks of gestation are associated with subsequent GDM; the best time to test for uric acid is before 18 weeks of gestation. Pregnant women with low and intermediate risk for GDM development may benefit more from serum uric acid measurements before 18 weeks of gestation.

Risk of type 2 diabetes mellitus in catholic priests compared with general public

AIMS

Although Catholic priests have a life of discipline with many responsibilities, there has been little research on the health effects of their lifestyle. Analysis of disease prevalence in priests will help elucidate the influence of religious life and occupational characteristics on the occurrence of diabetes. This retrospective study was performed to examine the differences in the prevalence of diabetes and prediabetes between Catholic priests and the general population.

METHODS

The study population comprised 1845 Catholic priests aged 31-80 years who visited the health promotion centers of three university hospitals in Korea between 2010 and 2019. Controls consisted of 1801 adult non-clerics aged 31-80 years who underwent health checkups at the screening center during the same period. Logistic regression analysis was performed to compare the differences in the rates of diabetes and prediabetes between the priest and control groups.

RESULT

Priests were younger and had lower rates of smoking, drinking alcohol, and hypertension compared with the control group. However, metabolic markers, such as BMI, waist circumference, body fat mass, insulin, HbA1c, and lipid profiles, were significantly higher in the priest group than the control group (all p < 0.05). After adjusting for covariates, the priest group had a significantly higher likelihood of having diabetes (OR = 1.651, 95% CI 1.146-2.379) or prediabetes (OR = 3.270, 95% CI 2.471-4.327) compared with the controls.

CONCLUSIONS

This study showed that Catholic priests have higher risks of diabetes and prediabetes compared with the general population, and these risks increase with age. Further large-scale prospective studies are required to confirm these relationships.

Lower Serum Uric Acid Levels May Lower the Incidence of Diabetic Chronic Complications in U.S. Adults Aged 40 and Over

Previous studies have generally reported the association between serum uric acid (SUA) and diabetic complications, but large-scale research exploring the above association in U.S. adults with diabetes is limited. To explore the association between SUA and chronic complications of diabetes among U.S. patients aged ≥40, we used data from the National Health and Nutrition Examination Survey 1999−2008. SUA was divided into three levels: T1 (SUA ≥ 420 μmol/L), T2 (300 ≤ SUA < 420 μmol/L), and T3 (SUA < 300 μmol/L). Binary logistic regression and restricted cubic spline analysis were applied to evaluate the association between SUA and chronic complications of diabetes. A trend test was performed as the SUA increased substantially. After full-adjusted confounding factors, patients in the T3 group had a lower risk of diabetic kidney disease, cardiovascular disease, and peripheral neuropathy compared with the T1 group, with a OR (95% CIs) of 0.33 (0.21−0.52), 0.56 (0.36−0.87), and 0.49 (0.27−0.89), respectively. The restricted cubic spline showed a significant positive relationship between SUA and cardiovascular disease and diabetic kidney disease in diabetes patients, but not peripheral neuropathy. Maintaining a SUA of less than 300 μmol/L might be protective against the risk of cardiovascular disease, diabetic kidney disease, and peripheral neuropathy other than diabetic retinopathy compared with a SUA of more than 420 μmol/L in U.S. diabetes patients aged 40 and over.

Association between Serum Uric Acid and Liver Enzymes in Adults Aged 20 Years and Older in the United States: NHANES 2005-2012

Although the relationship between serum uric acid (SUA) and nonalcoholic fatty liver disease has been widely reported, the relationship between SUA and liver enzymes has rarely been reported. The purpose of this study was to evaluate the association of SUA levels with alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in populations aged 20 years and older in the United States. We analyzed 7165 individuals aged 20 years and older from the National Health and Nutrition Examination Survey (NHANES) in the United States. Weighted multiple linear regression models were used to analyze the relationship between SUA and ALT and AST. A generalized additive model and a smooth curve fitting were used to observe the linear relationship. SUA was positively correlated with ALT and AST. In addition, the overall increasing trend of ALT and SUA was observed across the SUA quartile groups. In the stratified analysis by sex and race, the SUA levels in male, female, Mexican American, and Non-Hispanic White individuals, and those of another race, were positively correlated with ALT and AST. However, the SUA levels in Non-Hispanic Black individuals had a nonlinear relationship with ALT and AST. In individuals aged 20 years and older in the United States (excluding Non-Hispanic Black individuals), SUA levels were positively associated with ALT and AST. Therefore, with a rise in SUA levels, liver function should be monitored or intervened with in people aged 20 years and older in the United States.

Effects of long-term vitamin D supplementation on metabolic profile in middle-aged and elderly patients with type 2 diabetes

To evaluate the effects of long-term vitamin D supplementation on metabolic profiles in middle-aged to elderly patients with type 2 diabetes (T2D), a randomized controlled trial was conducted among patients with T2D aged 50-70 years. A total of 270 patients underwent randomization with 135 being allocated to the vitamin D group and 135 to the control group, and participants in the vitamin D group received oral vitamin D₃ (800 IU/day) for 30 months. Serum 25(OH)D and metabolic variables were measured at baseline, and after 6, 12, 18, and 30 months of intervention. After 30 months, the vitamin D group showed a greater increase in serum 25(OH)D than the control group (12.39 ± 6.99 vs 5.35 ± 5.29 ng/ml, P < 0.001). Meanwhile, changes in the levels of fasting insulin, HOMA-IR, non-high-density-lipoprotein cholesterol (non-HDL-C), high-sensitivity C-reactive protein (hs-CRP), and uric acid differed significantly between the two groups (all P < 0.05). Stratified analysis indicated that change in uric acid differed significantly between the two groups in subgroup with baseline 25(OH)D ≥ 20 ng/ml (P = 0.042) or subgroup with female patients (P = 0.034). And the change in fasting blood glucose (FBG) differed significantly between the vitamin D group (-0.30 ± 2.52 mmol/L) and the control group (0.49 ± 1.78 mmol/L, P = 0.049) among patients achieving 25(OH)D concentrations of 30 ng/ml at the end of this trial. A significant difference in the change of triglyceride was observed between the two groups among patients with obesity at baseline [0.05(-0.59, 0.23) vs 0.41(-0.01, 0.80) mmol/L, P = 0.023]. These findings suggested that long-term vitamin D supplementation significantly reduced fasting insulin, HOMA-IR, and serum concentrations of non-HDL-C, hs-CRP, and uric acid among middle-aged to elderly patients with T2D. And vitamin D status, gender, and baseline obesity may modify the effects of vitamin D supplementation.

The Mechanism of Sodium-Glucose Cotransporter-2 Inhibitors in Reducing Uric Acid in Type 2 Diabetes Mellitus

Hyperuricemia is a common comorbidity in patients with type 2 diabetes mellitus (T2DM), as insulin resistance (IR) or hyperinsulinemia is associated with higher serum uric acid (SUA) levels due to decreased uric acid (UA) secretion, and SUA vice versa is an important risk factor that promotes the occurrence and progression of T2DM and its complications. Growing evidence suggests that sodium-glucose cotransporter 2 inhibitors (SGLT-2i), a novel anti-diabetic drug initially developed to treat T2DM, may exert favorable effects in reducing SUA. Currently, one of the possible mechanisms is that SGLT2i increases urinary glucose excretion, probably inhibiting glucose transport 9 (GLUT9)-mediated uric acid reabsorption in the collecting duct, resulting in increased uric acid excretion in exchange for glucose reabsorption. Regardless of this possible mechanism, the underlying comprehensive mechanisms remain poorly elucidated. Therefore, in the present review, a variety of other potential mechanisms will be covered to identify the therapeutic role of SGLT-2i in hyperuricemia.

Interaction of sex and diabetes on the association between hemoglobin glycation index, hemoglobin A1c and serum uric acid

BACKGROUND

Hemoglobin glycation index (HGI), which is calculated by blood glucose and hemoglobin A1c(HbA1c), reflects the individual discrepancy in HbA1c. This study aimed to investigate the association between HGI/HbA1c and serum uric acid(SUA) stratified by sex and diabetes.

METHODS

The study recruited 33772 participants who underwent physical examinations between April 2016 and August 2021 in Beijing Chao-Yang Hospital. A random subsample of 3000 subjects was utilized to calculate the formula of HGI and data of the remaining 30772 participants were used for analysis. HGI and HbA1c were categorized according to quartiles (Q1, Q2, Q3, Q4), using Q1 as the reference. We used multiple linear regression and restricted cubic splines for data analysis.

RESULTS

30772 participants with a mean age of 44.4 years old were included in the analysis, 48.6% (N = 14944) of which were female and 7.7% (N = 2363) with diabetes. Associations of HGI, HbA1c and SUA were modified by sex and diabetes. The relationship between SUA levels and HGI was positive in women without diabetes, with one unit increase in HGI associating with an 11.3 μmol/L increase in SUA (P < 0.001) after adjusting for other confounders. On average, each one-unit increase in HbA1c was associated with a 14.3 μmol/L decrease in SUA in women with diabetes, a 14.9 μmol/L decrease in SUA in men with diabetes, and a 16.5 μmol/L increase in SUA in women without diabetes (all P < 0.001). The SUA levels in men without diabetes showed a bell-shaped relation with HbA1c, increasing as the HbA1c rose to around 5.7% and then falling with a further increase of HbA1c (P < 0.001).

CONCLUSIONS

SUA levels were inversely correlated with HbA1c in diabetic patients, also in men with prediabetes (HbA1c ≥ 5.7%), but positively correlated with HbA1c and HGI in women without diabetes. Glycemic control may help to reduce the risk of hyperuricemia in non-diabetes women.

Camel milk ameliorates diabetes in pigs by preventing oxidative stress, inflammation and enhancing beta cell function

Purpose

The purpose of the study was to determine how camel milk affects hyperglycemia, beta-cell function, oxidative stress, and inflammatory markers in type 2 diabetic pigs.

Methods

Twenty-five (25) pigs were separated into five (5) groups of five pigs each, with five (5) non-diabetic and twenty (20) diabetic pigs in each group. Groups 1 and 2 received distilled water as the standard control and diabetic control groups, respectively, while Groups 3 and 4 received camel milk at 250 mL/day and 500 mL/day, respectively, and Group 5 received metformin at 500 mg/day. The experiment lasted ten weeks. At the end of the ten weeks, all the pigs were euthanized.

Results

Treatments with camel milk substantially enhance glucose fasting levels by reducing hyperglycemia in diabetic pigs, significant level at (p < 0.05). When pigs given camel milk were compared with untreated diabetic pigs, there was a substantial rise (p < 0.05) in superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) levels. Also, camel milk substantially lowered the levels of interleukin (IL-1β) and tumour necrosis factor-alpha (TNF-α) in diabetic pig serum. Similarly, immunohistochemical analysis of islet cells revealed an increase in insulin production, implying improved glycemic control and the eventual commitment of glucose to glycolysis.

Conclusion

The bioactive-mediated anti-hyperglycemic and insulin release potential of camel milk treatments contributed to improving type 2 diabetes mellitus. Camel milk improved beta-cell function while reducing oxidative stress and inflammation in type 2 diabetic pigs.

Association between metabolic syndrome and uric acid: a systematic review and meta-analysis

This systematic review and meta-analysis aim to provide the best evidence on the association between metabolic syndrome (MetS) and uric acid (UA) by determining the size of the effect of this biomarker on MetS. The review protocol is registered with PROSPERO (CRD42021231124). The search covered the PubMed and Scopus databases. Methodological quality was assessed with the STROBE tool, overall risk of bias with RevMan (Cochrane Collaboration) and quality of evidence with Grade Pro. Initially, 1582 articles were identified. Then, after excluding duplicates and reviewing titles and abstracts, 1529 articles were excluded from applying the eligibility criteria. We included 43 papers (56 groups) comparing UA concentrations between subjects 91,845 with MetS and 259,931 controls. Subjects with MetS had a higher mean UA of 0.57 mg/dl (95% CI 0.54-0.61) (p < 0.00001). Given the heterogeneity of the included studies, the researchers decided to perform subgroups analysis. Men with MetS have a higher UA concentration mg/dl 0.53 (95% CI 0.45-0.62, p < 0.00001) and women with MetS 0.57 (95% CI 0.48-0.66, p < 0.00001) compared to subjects without MetS. Assessment of UA concentration could provide a new avenue for early diagnosis of MetS, as a new biomarker and the possibility of new therapeutic targets.

Clinical and Metabolic Characteristics of Hyperuricemia with Risk of Liver Fibrosis: A Cross-Sectional Study

The role of serum uric acid (SUA) in the role of advanced fibrosis is not fully explored. The study assesses the risk of advanced fibrosis according to SUA in an Asian population with a total of 3612 subjects enrolled in one health management center between 2006 and 2008. The fibrosis-4 score was used for the prediction of the high risk of advanced fibrosis. SUA scores higher than 7.6 mg/dL in men and 6.6 mg/dL in women were defined as hyperuricemia. A proportional odds model was used to assess cumulative risks of advanced fibrosis. The prevalence of high risk of advanced fibrosis was 2.5% in the hyperuricemia group and 0.6% in the normal SUA group (p < 0.001). After adjustment for confounding factors, the odds ratios (OR) for more severe advanced fibrosis were 1.37 (95% confidence interval [CI]: 1.07−1.78) in the hyperuricemia group. Hyperuricemia only increased the risk of advanced fibrosis in the non-T2DM group (OR, 1.29; 95% CI, 1.04 to 1.74) instead of T2DM group (OR, 1.85; 95% CI, 0.97 to 3.53). SUA is a risk factor for a higher risk of advanced fibrosis, with the disease likely progressing from a steatotic to a fibrotic picture. The focus should be more emphasized in non-T2DM groups.

Lower risk of gout in sodium glucose cotransporter 2 (SGLT2) inhibitors versus dipeptidyl peptidase-4 (DPP4) inhibitors in type-2 diabetes

BACKGROUND

The effects of sodium-glucose cotransporter 2 inhibitors (SGLT2I) vs dipeptidyl peptidase-4 inhibitors (DPP4I) on the risk of new-onset gout remains unknown. This study aims to compare the effects of SGLT2I against DPP4I on gout risks.

METHODS

This was a retrospective population-based cohort study of patients with type-2 diabetes mellitus treated with SGLT2I or DPP4I between January 1st, 2015 and December 31st, 2020 in Hong Kong. The study outcomes are new-onset gout and all-cause mortality. Propensity score matching (1:1 ratio) between SGLT2I and DPP4I was performed. Univariable and multivariable Cox regression analysis models were conducted. Competing risks models and multiple approaches based on the propensity score were applied.

RESULTS

This study included 43201 patients (median age: 63.23 years old [Interquantile range, IQR]: 55.21-71.95, 53.74% males; SGLTI group: n = 16144; DPP4I group: n = 27057) with a median follow-up of 5.59 years (IQR: 5.27-5.81 years) since initial drug exposure. The incidence rate of developing gout (Incidence rate [IR]: 2.5; 95% CI: 2.2-2.9) among SGLT2I users was significantly lower than DPP4I users (IR: 5.2; 95% CI: 4.8-5.8). SGLT2 was associated with 51% lower risks of gout (HR: 0.49; 95% CI: 0.42-0.58; P-value < 0.0001) and 51% lower risks of all-cause mortality (HR: 0.49; 95% CI: 0.42-0.58; P-value < 0.0001) after adjusting for significant demographics, past comorbidities, medications, and laboratory results. The results remained consistent on competing risk and other propensity score approaches.

CONCLUSIONS

SGLT2I use was associated with lower risks of new gout diagnosis compared with DPP4I use.

Uric Acid and Diabetic Retinopathy: A Systematic Review and Meta-Analysis

Background

The relationship between uric acid (UA) and diabetic retinopathy (DR) remains ambiguous, and the results of current studies on the UA levels in patients with DR are conflicting. A meta-analysis was performed to provide a better understanding of the relationship between UA levels and DR.

Methods

PubMed, Web of Science, Embase, and the Cochrane Library databases were searched until December 11, 2021 to identify eligible studies, that compared the UA levels of the case group (patients with DR) and control group (controls with diabetes and healthy participants). The weighted mean difference (WMD) with a 95% confidence interval (CI) was used to evaluate the difference in UA levels between the case and control groups.

Results

Twenty-one studies involving 4,340 patients with DR and 8,595 controls (8,029 controls with diabetes and 566 healthy participants) were included in this meta-analysis. We found that patients with DR had significantly higher UA levels than those in the controls with diabetes (WMD = 36.28; 95% CI: 15.68, 56.89; P < 0.001) and healthy participants (WMD = 70.80; 95% CI: 19.85, 121.75; P = 0.006). There was an obvious heterogeneity among the 21 studies (I² = 97%, P < 0.001). Subgroup analyses of different phases of DR showed that UA levels were significantly increased in participants with proliferative diabetic retinopathy (PDR) (WMD = 46.57; 95% CI: 28.51, 64.63; P < 0.001) than in controls with diabetes; however, the difference is not statistically significant when comparing UA levels in patients with non-proliferative diabetic retinopathy (NPDR) and controls with diabetes (WMD = 22.50; 95% CI: −6.07, 51.08; P = 0.120). In addition, UA levels were higher in participants with a body mass index (BMI) ≥25.0 kg/m² and over 15 years of diabetes. Univariate meta-regression analysis revealed that BMI (P = 0.007, Adj R² = 40.12%) and fasting blood glucose (FBG) (P = 0.040, Adj R² = 29.72%) contributed to between-study heterogeneity.

Conclusions

In conclusion, our study provides evidence that UA levels are higher in patients with DR than those in the controls, but this difference is not statistically significant in the early phases. UA might be a potential biomarker for identifying disease severity in patients with DR, rather than predicting the onset of DR among patients with diabetes. However, more prospective and high-quality clinical evidence is required to confirm these present findings.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=297708.

Stress Hyperglycemia Is Associated With an Increased Risk of Subsequent Development of Diabetes Among Bacteremic and Nonbacteremic Patients

OBJECTIVE

Stress hyperglycemia is associated with an increased risk of diabetes among survivors of critical illness. We investigated whether patients without diabetes hospitalized for bacteremia or nonbacteremic diseases with transient stress hyperglycemia would have a higher risk of subsequent diabetes development compared with those who remained normoglycemic.

RESEARCH DESIGN AND METHODS

This retrospective observational study was conducted on 224,534 in-patients with blood culture records. Stress hyperglycemia was defined based on the highest random glucose level ≥7.8 mmol/L during the index admission period. Diagnosis of diabetes, as the primary end point of interest, was defined based on diagnostic codes, blood test results, or medication records. Differences in cumulative incidence and hazard ratios (HRs) of diabetes between groups were assessed using the Kaplan-Meier estimator and Cox regression.

RESULTS

After exclusion of patients with preexisting or undiagnosed diabetes or indeterminate diabetes status and propensity score matching, bacteremic patients with stress hyperglycemia had a significantly higher cumulative incidence of diabetes (HR 1.7, 95% CI 1.2-2.4) compared with those who remained normoglycemic. Stress hyperglycemia was further confirmed to be a diabetes predictor independent of age, sex, comorbidity, and other serological markers. For the nonbacteremic patients, stress hyperglycemia was similarly associated with a higher cumulative incidence of diabetes (HR 1.4, 95% CI 1.2-1.7).

CONCLUSIONS

Hospitalized patients with transient stress hyperglycemia had a higher risk of subsequent diabetes development compared with their normoglycemic counterparts. Recognition of an increased risk of diabetes in these patients can allow early detection and monitoring in their subsequent follow-ups.

Noninvasive and Individual-Centered Monitoring of Uric Acid for Precaution of Hyperuricemia via Optical Supramolecular Sensing

Characterized by an excessively increased uric acid (UA) level in serum, hyperuricemia induces gout and also poses a great threat to renal and cardiovascular systems. It is urgent and meaningful to perform early warning by noninvasive diagnosis, thus conducing to blockage of disease aggravation. Here, guanidinocalix[5]arene (GC5A) is successfully identified from the self-built macrocyclic library to specifically monitor UA from urine by the indicator displacement assay. UA is strongly bound to GC5A at micromolar-level, while simultaneously excluding fluorescein (Fl) from the GC5A·Fl complex in the "switch-on" mode. This method successfully differentiates patients with hyperuricemia from volunteers except for those with kidney dysfunction and targets a volunteer at high risk of hyperuricemia. In order to meet the trend from hospital-centered to individual-centered testing, visual detection of UA is studied through a smartphone equipped with a color-scanning feature, whose adaptability and feasibility are demonstrated in sensing UA from authentic urine, leading to a promising method in family-centered healthcare style. A high-throughput and visual detection method is provided here for alarming hyperuricemic by noninvasive diagnosis.

ELEVATED LEVEL OF URIC ACID, BUT NOT GLUCOSE, IN AQUEOUS HUMOR AS A RISK FACTOR FOR DIABETIC MACULAR EDEMA IN PATIENTS WITH TYPE 2 DIABETES

PURPOSE

To determine the association of uric acid (UA) and glucose in aqueous humor with diabetic macular edema (DME) in patients with Type 2 diabetes.

METHODS

Patients with DME or diabetes mellitus without retinopathy were enrolled from August 2016 to December 2020. Nondiabetic patients with age-related cataract or age-related macular degeneration were included as controls.

RESULTS

A total of 585 eyes from 585 patients were included for this study. Statistical analysis showed that aqueous UA was associated with central retinal thickness (r = 0.39, P < 0.0001), with higher levels of UA in severe DME and lower levels in mild DME, suggesting an ocular source of UA from the diabetic retina. Aqueous UA {odds ratio (OR), 6.88 (95% confidence interval [CI], 2.61-18.12)}, but not aqueous glucose (0.95 [95% CI, 0.73-1.23]) or serum UA (0.90 [95% CI, 0.66-1.23]), was a stronger predictor for DME than the duration of DM (1.26 [95% CI, 1.12-1.42]) or hemoglobin A1c (1.35 [95% CI, 0.99-1.83]). If aqueous UA (<2.46 mg/dL) and aqueous glucose (<6.43 mmol/L) were used as reference, high UA (≥2.46 mg/dL) alone was associated with 5.83-fold increase in risk of DME, but high glucose (≥6.43 mg/dL) alone was not associated with DME.

CONCLUSION

Increased aqueous UA, but not glucose, is an independent risk factor for DME. These data suggest that an intravitreal UA-lowering therapy could be beneficial for DME.

Arthritis is associated with an increased risk of incident diabetes in Chinese adults: A nationwide cohort study and updated meta-analysis

AIMS

To prospectively examine the association between arthritis and type 2 diabetes (T2D) in the Chinese population and confirm this association through a comprehensive meta-analysis of cohort studies.

METERIALS AND METHODS

Data were from the China Health and Retirement Longitudinal Study which was started in 2011-2013 and followed up in 2013-2014 and 2015-2016. Arthritis was defined as self-reported physician diagnosis at baseline, and incident T2D was determined by self-reported physician diagnosis, fasting blood glucose ≥7.0 mmol/L or glycosylated haemoglobin ≥6.5% during the follow-ups. Cox proportional hazards regression models were used to assess the association between arthritis and risk for T2D. A meta-analysis was conducted to pool our effect estimate and those from other cohort studies using a random-effects model.

RESULTS

Eleven thousand four hundred and eight participants (47.9% men; mean age: 59.3 years) were included in final analyses. During a 4-year follow-up, 981 participants reported incident T2D. Compared with individuals without arthritis, those with arthritis at baseline had an 18% higher risk for incident T2D (multivariable-adjusted hazard ratio: 1.18; 95% confidence interval: 1.04, 1.34). In the meta-analysis of 13 cohort studies including ours, a total of 2,473,514 participants were included with 121,851 incident diabetes. The pooling HR was 1.32 (95% CI: 1.21, 1.44) for the association between arthritis and diabetes.

CONCLUSION

Arthritis was associated with an increased risk of incident diabetes in Chinese adults, and the positive association was confirmed in the meta-analysis of cohort studies. Our work can inform clinical trials to assess the effectiveness of arthritis treatments in reducing risk of diabetes.

The prognostic impact of uric acid in acute heart failure according to coexistence of diabetes mellitus

BACKGROUND AND AIMS

Increased uric acid levels predict higher mortality in heart failure (HF) patients. Patients with diabetes mellitus (DM) appear to have increased xanthine oxidase activity. We aimed to study if the association between uric acid and mortality in acute HF was different according to the coexistence of DM.

METHODS AND RESULTS

We studied a cohort of patients hospitalized due to acute HF in 2009-2010. Patients with no uric acid measurement upon admission were excluded from the analysis.

FOLLOW-UP

2 years; endpoint: all-cause mortality. Patients with elevated uric acid (>80.0 mg/L) were compared with those with lower values. We used a multivariate Cox-regression analysis to assess the prognostic impact of uric acid (both continuous and categorical variable: cut-off 80.0 mg/L). The analysis was stratified according to coexistence of DM. We studied 569 acute HF patients, 44.6%male, mean age 76 years, 290 were diabetic. Median admission uric acid: 81.2 mg/L and 52.2%had uric acid >80.0 mg/L. Elevated uric acid predicted all-cause mortality in acute HF only in patients with DM. The multivariate-adjusted HR of 2-year mortality was 1.68 (95 % CI: 1.15-2.46) for diabetic HF patients with uric acid>80.0 mg/L compared to those with lower levels (p = 0.008) and 1.10 (95 % CI: 1.03-1.18) per each 10 mg/L increase in uric acid (p = 0.007). In non-diabetic HF patients, uric acid was not associated with mortality.

CONCLUSIONS

Increased uric acid predicts ominous outcome in acute HF patients with diabetes, however, it is not prognostic associated in non-diabetics. Uric acid may play a different role in acute HF depending on DM status.

Gender-Specific Association of Serum Uric Acid and Pulmonary Function: Data from the Korea National Health and Nutrition Examination Survey

Background and Objectives: Hyperuricemia is associated with several comorbidities. The association between uric acid (UA) and pulmonary function is still a controversial issue. This study evaluated the gender-specific association of serum UA and pulmonary function. Materials and Methods: A total of 3177 (weighted n = 19,770,902) participants aged 40 years or older were selected from the 2016 Korean National Health and Nutrition Examination Survey and included. Results: Female participants with hyperuricemia were older than participants with normouricemia. Body mass index (BMI), mean arterial pressure (MAP), hemoglobin A1c (HbA1c), and estimated glomerular filtration rate (eGFR) were significantly associated with UA levels in both males and females. Hyperuricemia and increase in UA quartile were significantly associated with decreased forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) in females after adjustment for age, income, region, education, marital status, alcohol consumption, smoking, BMI, MAP, HbA1c, and eGFR. There was no significant association between UA levels and lung function in males. After additional adjustment for respiratory disease including pulmonary tuberculosis, asthma, and lung cancer, the association between hyperuricemia and decreased FEV1 and FVC in females was revealed. Conclusions: Hyperuricemia was associated with decreased FVE1 and FVC in the female general population.

Genistein and Momordica charantia L. prevent oxidative stress and upregulate proglucagon and insulin receptor mRNA in diabetic rats

Type 2 diabetes occurs as a result of insulin resistance and dysfunction in insulin signaling. Controlling hyperglycemia and activation of insulin signaling are important in the management of type 2 diabetes. This study aimed to evaluate the effect of genistein and Momordica charantia L. fruit (MCF) on oxidative stress, markers of inflammation, and their role in proglucagon and insulin receptor messenger RNA (mRNA) expression by real-time PCR in diabetic rats. Thirty-five albino rats were divided into 7 groups (n = 5). Group I (non-diabetic) and group II (diabetic control) were treated with distilled water, and groups III and IV received 250 mg/kg and 500 mg/kg lyophilized MCF, respectively. Groups V and VI received 10 mg/kg and 20 mg/kg genistein, respectively, while group VII received 500 mg/kg metformin. The administration lasted for 28 days. MCF and genistein significantly reduced interleukin (IL)-1β and tumor necrosis factor alpha (TNF-α) levels, which were elevated in the serum of diabetic rats. Treatment with MCF and genistein significantly increased the expression of proglucagon mRNA in the small intestine and insulin receptor mRNA in the liver of diabetic rats. In conclusion, MCF and genistein ameliorate type 2 diabetes complications by preventing the loss of insulin-positive cells, inhibiting IL-1β and TNF-α, and upregulating proglucagon and insulin receptor mRNA expression. Novelty: MCF and genistein have an inhibitory effect on diabetic induced IL-1β and TNF-α production. MCF and genistein upregulate proglucagon and insulin receptor mRNA expression.

Serum Uric Acid and Diabetes: From Pathophysiology to Cardiovascular Disease

Hyperuricemia, has been traditionally related to nephrolithiasis and gout. However, it has also been associated with the development of type 2 diabetes mellitus (T2DM) and cardiometabolic and cardiovascular diseases. Pathophysiologically, elevated serum uric acid (SUA) levels may be associated with abnormal lipid and glucose metabolism. In this narrative review, we consider the associations between hyperuricemia, hyperglycemia, atherosclerosis and thrombosis. Furthermore, we comment on the available evidence linking elevated SUA levels with the incidence and outcomes of coronary heart disease, stroke, peripheral artery disease and non-alcoholic fatty liver in subjects with T2DM. The effects of antidiabetic drugs (e.g. metformin, pioglitazone, sulfonylureas, dipeptidyl peptidase 4 inhibitors, glucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter 2 inhibitors and insulin) on SUA concentrations are also reviewed.

Association between serum uric acid levels and cardiovascular events in hospitalized patients with type 2 diabetes

AIMS

This study aimed to determine the association between serum uric acid (UA) levels and cardiovascular events in hospitalized patients with type 2 diabetes mellitus (T2DM).

METHODS

A retrospective cohort study was conducted in 2227 hospitalized patients with T2DM. Cox proportional hazards regression was used to assess the association between serum UA and cardiovascular events, including cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, heart failure, unstable angina, and arrhythmias requiring hospitalization.

RESULTS

Among 1314 men, 143 (10.9%) experienced cardiovascular events. Serum UA level was not associated with the risk of cardiovascular events (hazard ratio [HR] per 100 μmol/L increase in serum UA: 1.12, 95% confidence interval [CI]: 0.90-1.40). Among 913 women, 96 (10.5%) experienced cardiovascular events. For every 100 μmol/L increase in serum UA level, the risk of experiencing a cardiovascular event increased by 27% (HR: 1.27, 95% CI: 1.02-1.57).

CONCLUSIONS

In hospitalized patients with T2DM, baseline serum UA levels were positively associated with cardiovascular events in women, but not in men. Serum UA levels may be a significant independent risk factor for cardiovascular events in women with T2DM.

Hydralazine as a Versatile and Universal Matrix for High-Molecular Coverage and Dual-Polarity Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging

Few matrices have the potential to be universally applicable for imaging vast endogenous compounds ranging from micro to macromolecules. In this article, we present hydralazine (HZN) as a versatile and universal matrix for matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) of a wide range of endogenous compounds between 50.0 and 20,000.0 Da. HZN was prepared from its hydrochloride by alkalizing HZN·HCl with ammonia to enhance the optical absorptivity at the preferred MALDI UV laser wavelength. To further improve its performance for MALDI MS, HZN was doped with NH₄OH or TFA, resulting in matrix superior performance for imaging biologically relevant compounds in the negative and positive-ion modes, respectively. The analyte-matrix interaction was also enhanced by the optimized matrix solvent and the deposition amount. Compared with conventional matrices such as 2,5-dihydroxybenzoic acid, α-cyano-4-hydroxycinnamic acid, and 9-aminoacridine (9-AA), the HZN matrix provided higher sensitivity, broader molecular coverage, and improved signal intensities. Its broad acquisition range makes it versatile for imaging small molecular metabolites and lipids, as well as proteins. In addition, HZN was applied successfully for the visualization of tissue-specific distributions and changes of small molecules, lipids, and proteins in the kidney and liver sections of obese ob/ob and diabetic db/db mice. The use of the HZN matrix shows great potential application in the field of pathological research.

Serum uric acid is positively associated with the prevalence of nonalcoholic fatty liver in non-obese type 2 diabetes patients in a Chinese population

AIMS

To investigate whether SUA is independently associated with NAFLD in non-obese type 2 diabetic patients in a Chinese population.

METHODS

A cross-sectional study was carried out among 400 non-obese type 2 diabetic inpatients. Patients were stratified according to SUA levels and presence/absence of NAFLD. The clinical and laboratory features were collected retrospectively. Multivariate logistic regression analysis was conducted to estimate odds ratios of SUA for NAFLD.

RESULTS

The levels of SUA were significantly higher in patients with NAFLD than those without NAFLD. SUA was positively associated with the risk factors of NAFLD such as BMI, serum insulin and lipids. The odds of NAFLD were increasingly higher from the second to the fourth quartile of SUA as compared to the lowest quartile. After adjustment for age, gender, BMI and other metabolic components, the odds of NAFLD remained significantly increased for quartile 4.

CONCLUSIONS

SUA levels are strongly and independently associated with the prevalence of NAFLD. SUA may be used as a useful predictor to stratify the higher risks for NAFLD of non-obese type 2 diabetes patients.

Higher Serum Uric Acid Levels Are Associated With an Increased Risk of Vision-Threatening Diabetic Retinopathy in Type 2 Diabetes Patients

Purpose

To investigate the association between serum uric acid (SUA) levels and vision-threatening diabetic retinopathy (VTDR) in patients with type 2 diabetes.

Methods

This cross-sectional study evaluated 3481 patients with type 2 diabetes from four communities in China between 2016 and 2019. VTDR was defined as severe nonproliferative, proliferative diabetic retinopathy, or clinically significant macular edema evaluated by fundus photography and optical coherence tomography. Potential association between SUA and VTDR was examined using multivariable logistic regression. Sub-group analyses based on sex were constructed.

Results

A total of 305 participants had VTDR. Both higher SUA (odds ratio [OR], 1.22 per 100 µmol/L; 95% confidence interval [CI], 1.04–1.44; P = 0.013) and hyperuricemia (OR, 1.47; 95% CI, 1.07–2.04; P = 0.019) were positively associated with VTDR after adjustment for relevant covariates. Compared with those in the lowest SUA quartile, participants in the third (OR, 1.60; 95% CI, 1.07–2.39; P = 0.022) and fourth (OR, 2.05; 95% CI, 1.37–3.08; P = 0.001) sex-specific SUA quartiles showed a significantly increased risk of VTDR after adjustment. No sex-related difference was observed.

Conclusions

Higher SUA levels were associated with an increased risk of VTDR in patients with type 2 diabetes in both sexes, although females seemed to be more sensitive to high SUA than males. Prospective cohort studies are needed to verify SUA as a biomarker for predicting the risk of VTDR. Whether decreased SUA levels could decrease the risk of VTDR also requires further investigation.

Type 2 diabetes is more predictable in women than men by multiple anthropometric and biochemical measures

Men and women are sexually dimorphic but whether common anthropometric and biochemical parameters predict type 2 diabetes (T2D) in different ways has not been well studied. Here we recruit 1579 participants in Hainan Province, China, and group them by sex. We compared the prediction power of common parameters of T2D in two sexes by association, regression, and Receiver Operating Characteristic (ROC) analysis. HbA1c is associated with FPG stronger in women than in men and the regression coefficient is higher, consistent with higher prediction power for T2D. Age, waist circumference, BMI, systolic and diastolic blood pressure, triglyceride levels, total cholesterol, LDL, HDL, fasting insulin, and proinsulin levels all predict T2D better in women. Except for diastolic blood pressure, all parameters associate or tend to associate with FPG stronger in women than in men. Except for diastolic blood pressure and fasting proinsulin, all parameters associate or tend to associate with HbA1c stronger in women than in men. Except for fasting proinsulin and HDL, the regression coefficients of all parameters with FPG and HbA1c were higher in women than in men. Together, by the above anthropometric and biochemical measures, T2D is more readily predicted in women than men, suggesting the importance of sex-based subgroup analysis in T2D research.

Ameliorative potentials of Persea americana leaf extract on toxicants - induced oxidative assault in multiple organs of wistar albino rat

Background

Persea americana (PA) is a popular medicinal plant in folkloric medicines. The present study therefore investigates the ameliorative potentials of its leaves extract on carbon tetrachloride and rifampicin-induced toxicity in the liver, kidney and heart of albino rat. This was aimed at assessing the potentials of the plant in the management of liver, kidney and heart diseases.

Methodology

Forty (40) rats were randomly divided into eight (8) groups of five animals each. Groups I and II were administered with only distilled water and carbon tetrachloride (CCl4) respectively. Groups III and IV animals received 3.0 ml/kg bw of CCl4 and were treated with the extract at 50 mg/kg bw and 100 mg/kg respectively, while group V received 100 mg/kg bw. of silymarin orally for 14 days. Groups VI animals were administered with rifampicin (250 mg/kg bw.) only, while groups VII and VIII animals received rifampicin and were treated with 50 mg and 100 mg/kg bw of the extract respectively. Activities of creatine kinase, aspartate amino transferase, alanine amino transferase, alkaline phosphatase, superoxide dismutase, catalase as well as levels of urea, uric acid, bilirubin and malonidialdehyde (MDA) were assayed. Lipid profiles and histopathological examination of liver and kidney slices were also performed.

Result

Treatment with P. americana significantly (p < 0.05) restored all deranged biochemical parameters (creatine kinase, aspartate amino transferase, alanine amino transferase, alkaline phosphatase, urea, uric acid, bilirubin, MDA, lipid profile as well as superoxide dismutase and catalase) in a dose-dependent manner. Normal hepatic and renal histoarchitecture were also restored following treatment with P. americana.

Conclusion

Amelioration of distorted cardiac, hepatic and renal histoarchitecture as well as restoration of lipid profile, biomarkers of liver and kidney injury and antioxidant enzymes (catalase and superoxide dismutase) affirm the potential usefulness of P. americana in the management of liver, kidney and heart diseases.

Geniposide Improves Diabetic Nephropathy by Enhancing ULK1-Mediated Autophagy and Reducing Oxidative Stress through AMPK Activation

Diabetic nephropathy (DN) is a common pathological feature in patients with diabetes and the leading cause of end-stage renal disease. Although several pharmacological agents have been developed, the management of DN remains challenging. Geniposide, a natural compound has been reported for anti-inflammatory and anti-diabetic effects; however, its role in DN remains poorly understood. This study investigated the protective effects of geniposide on DN and its underlying mechanisms. We used a C57BL/6 mouse model of DN in combination with a high-fat diet and streptozotocin after unilateral nephrectomy and treated with geniposide by oral gavage for 5 weeks. Geniposide effectively improves DN-induced renal structural and functional abnormalities by reducing albuminuria, podocyte loss, glomerular and tubular injury, renal inflammation and interstitial fibrosis. These changes induced by geniposide were associated with an increase of AMPK activity to enhance ULK1-mediated autophagy response and a decrease of AKT activity to block oxidative stress, inflammation and fibrosis in diabetic kidney. In addition, geniposide increased the activities of PKA and GSK3β, possibly modulating AMPK and AKT pathways, efficiently improving renal dysfunction and ameliorating the progression of DN. Conclusively, geniposide enhances ULK1-mediated autophagy and reduces oxidative stress, inflammation and fibrosis, suggesting geniposide as a promising treatment for DN.

The association between serum uric acid and diabetic complications in patients with type 2 diabetes mellitus by gender: a cross-sectional study

BACKGROUND

The relationship between serum uric acid (SUA) and several diabetic complications or co-morbidities remains a matter of debate. The study aims to explore the association between SUA levels and the prevalence of non-alcoholic fatty liver disease (NAFLD), diabetic retinopathy (DR), diabetic nephropathy (DN) and diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 2,809 participants (1,784 males and 1,025 females) were included in this cross-sectional study. Clinical characteristics and the prevalence of each of the four diseases were analyzed based on gender-specific quartiles of SUA levels. The Pearson correlation analysis and linear-regression analysis were used to access the correlation between SUA levels and clinical characteristics. Furthermore, a binary logistic regression analysis was carried out to determine whether SUA was an independent risk factor for each of the four complications.

RESULTS

SUA levels were positively correlated to BMI, BUN, Scr and TG, but negatively associated with eGFR, HDL, FBG, 2h-PG and HbA1c% for the patients with T2DM. The prevalence of NAFLD and DN, but not DR or DPN, were increased with SUA levels from the first to the fourth quartile. Binary logistic regression further disclosed that SUA was an independent risk factor for NAFLD (ORs Male = 1.002, ∗ P = 0.0013; ORs Female = 1.002, ∗ P = 0.015) and DN (ORs Male = 1.006, ∗ P < 0.001; ORs Female = 1.005, ∗ P < 0.001), but not for DR and DPN. After adjustment for the confounders, SUA levels were significantly associated with NAFLD within the 3rd (ORs = 1.829, P = 0.004) and 4th quartile (ORs = 2.064, P = 0.001) for women, but not independently associated with SUA for man. On the other hand, our results revealed increased prevalence of DN for SUA quartile 2 (ORs = 3.643, P = 0.039), quartile 3 (ORs = 3.967, P = 0.024) and quartile 4 (ORs = 9.133, P < 0.001) in men; however, SUA quartiles were significantly associated with DN only for quartile 4 (ORs = 4.083, P = 0.042) in women.

CONCLUSION

For patients with T2DM, elevated SUA concentration is an independent risk factor for the prevalence of NAFLD and DN after adjustment for other indicators, but not DR or DPN.

Distinctive Metabolomics Patterns Associated With Insulin Resistance and Type 2 Diabetes Mellitus

Obesity is associated with an increased risk of insulin resistance (IR) and type 2 diabetes mellitus (T2DM) which is a multi-factorial disease associated with a dysregulated metabolism and can be prevented in pre-diabetic individuals with impaired glucose tolerance. A metabolomic approach emphasizing metabolic pathways is critical to our understanding of this heterogeneous disease. This study aimed to characterize the serum metabolomic fingerprint and multi-metabolite signatures associated with IR and T2DM. Here, we have used untargeted high-performance chemical isotope labeling (CIL) liquid chromatography-mass spectrometry (LC-MS) to identify candidate biomarkers of IR and T2DM in sera from 30 adults of normal weight, 26 obese adults, and 16 adults newly diagnosed with T2DM. Among the 3633 peak pairs detected, 62% were either identified or matched. A group of 78 metabolites were up-regulated and 111 metabolites were down-regulated comparing obese to lean group while 459 metabolites were up-regulated and 166 metabolites were down-regulated comparing T2DM to obese groups. Several metabolites were identified as IR potential biomarkers, including amino acids (Asn, Gln, and His), methionine (Met) sulfoxide, 2-methyl-3-hydroxy-5-formylpyridine-4-carboxylate, serotonin, L-2-amino-3-oxobutanoic acid, and 4,6-dihydroxyquinoline. T2DM was associated with dysregulation of 42 metabolites, including amino acids, amino acids metabolites, and dipeptides. In conclusion, these pilot data have identified IR and T2DM metabolomics panels as potential novel biomarkers of IR and identified metabolites associated with T2DM, with possible diagnostic and therapeutic applications. Further studies to confirm these associations in prospective cohorts are warranted.

Antidiabetic effect of olive leaf extract on streptozotocin-induced diabetes mellitus in experimental animals

Introduction

Background: recently, a relationship between diabetic complications and oxidative stress has been emphasized. There have been some studies showing the effect of olive leaf on hyperglycemia and diabetic complications due to its antioxidant properties. In many studies the effect of olive leaf on plasma total antioxidant level has been measured by different methods. Our study represents the first time it has been measured by a new method of total thiol disulfide homeostasis. Aim: chronic exposure to hyperglycemia and hyperlipidemia contributes to the pathogenesis of diabetic complications through oxidative stress mediators. Thiol is one of the most important antioxidant barriers in humans, and thiol disulfide homeostasis is a new oxidative stress marker. We aimed to investigate the effect of olive leaf extract (OLE) obtained from fresh leaves of Olea europaea, var oleaster on diabetic complications through their hypoglycemic and antioxidant effect in diabetic rats. Methods: twenty-eight Wistar albino rats aged 12-13 weeks were used in the study. The rats were divided into a control group (C), a diabetic control group (DC), a diabetic group treated with 200 mg/kg OLE (D+200), and a diabetic group treated with 400 mg/kg OLE (D+400), having 7 rats in each group. The treatment groups received OLE by the gavage method for 21 days. At the end of the study, all rats were sacrificed by cervical dislocation. Blood samples collected from the heart were centrifuged and glucose, total cholesterol, triglyceride, urea, uric acid, creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST), lipid hydroperoxide (LOOH) level, and thiol-disulfide homeostasis were determined. The hemoglobin A1c (HbA1c) analysis was performed on complete blood. In addition, a tail flick test and hot plate modeling were performed to indicate pain perception loss. Results: it was observed that OLE had no effect on serum glucose and HbA1c levels. On the contrary, OLE reduced the levels of total cholesterol (p < 0.01), urea (p < 0.01) and hot plate latency (p < 0.01) in a significant manner. Also, OLE showed a tendency to reduce LOOH levels and to increase thiol levels in a dose-dependent manner (p > 0.05). Conclusion: OLE supplementation for 21 days, at the amounts used, cannot protect against hyperglycemia but may be protective against hypercholesterolemia and tissue damage as caused by diabetes mellitus in rats.

Integrated omics analysis reveals the alteration of gut microbe-metabolites in obese adults

Obesity, a risk to health, is a global problem in modern society. The prevalence of obesity was approximately 13% among world's adult population. Recently, several reports suggested that the interference of gut microbiota composition and function is associated with metabolic disorders, including obesity. Gut microbiota produce a board range of metabolites involved in energy and glucose homeostasis, leading to the alteration in host metabolism. However, systematic evaluation of the relationship between gut microbiota, gut metabolite and host metabolite profiles in obese adults is still lacking. In this study, we used comparative metagenomics and metabolomics analysis to determine the gut microbiota and gut-host metabolite profiles in six normal and obese adults of Chinese origin, respectively. Following the functional and pathway analysis, we aimed to understand the possible impact of gut microbiota on the host metabolites via the change in gut metabolites. The result showed that the change in gut microbiota may result in the modulation of gut metabolites contributing to glycolysis, tricarboxylic acid cycle and homolactic fermentation. Furthermore, integrated metabolomic analysis demonstrated a possible positive correlation of dysregulated metabolites in the gut and host, including l-phenylalanine, l-tyrosine, uric acid, kynurenic acid, cholesterol sulfate and glucosamine, which were reported to contribute to metabolic disorders such as obesity and diabetes. The findings of this study provide the possible association between gut microbiota-metabolites and host metabolism in obese adults. The identified metabolite changes could serve as biomarkers for the evaluation of obesity and metabolic disorders.