Serum uric acid and the risk of respiratory disease: a population-based cohort study

Investigating the causal association between serum uric acid levels and gastric cancer risk: a Mendelian randomization study

The causal link between serum uric acid (SUA) levels and gastric cancer susceptibility remains inadequately elucidated. This investigation employed a two-sample Mendelian randomization (MR) framework to assess the potential causative link between SUA concentrations and the propensity for developing gastric cancer. To further explore potential racial differences, this MR analysis was conducted on cohorts of both European and East Asian descent. Data from a large-scale GWAS in 343,836 Europeans and 92,615 East Asians were screened for 206 and 45 SNPs significantly linked to SUA levels, respectively, as genetic variants. Subsequently, four distinct MR methodologies were deployed to determine how SUA levels affected gastric cancer risk. Using the fixed-effects IVW approach, our analysis revealed no significant association between SUA levels and gastric cancer risk, with P-values exceeding the threshold of significance in both populations (European P = 0.778; East Asian P = 0.245). The findings were supported by three additional MR methods. The reliability of these results was substantiated by comprehensive sensitivity analyses. In summary, our data do not support a significant causal linkage between SUA levels and gastric cancer risk.

Luteolin ameliorates hyperuricemic nephropathy by activating urate excretion and Nrf2/HO-1/NQO1 antioxidant pathways in mice

Luteolin is a natural flavonoid, which exists in many plants, including onions, broccoli, carrots, peppers, celery, olive oil, and mint. Luteolin is a dietary flavonoid with potent uric acid-lowering and antioxidant bioactivities. To date, the mechanism by which luteolin alleviates hyperuricemia nephropathy (HN) still needs to be better defined. This study aims to evaluate the therapeutic efficacy of luteolin in a preclinical mouse model and in vitro. Luteolin was administered in the HN mice induced by the combination of potassium oxonate and hypoxanthine to evaluate the potential renoprotective effects in vivo. The NRK-52E cells were stimulated with adenosine for in vitro evaluation. Hematoxylin and eosin staining, biochemical analysis, immunoblotting, immunofluorescence, and immunohistochemistry were performed for the histopathologic and mechanistic investigations. The results suggest that luteolin attenuated tubular dilation and epithelial atrophy in the renal tissue of HN mice. Further, luteolin improved biochemical indicators concerning renal functions and oxidative stress in vivo. Mechanistically, luteolin reduced the renal expressions of KIM-1 and caspase-3. Luteolin activated renal SIRT1/6 cascade and its downstream Nrf2-mediated antioxidant pathway. Furthermore, luteolin elevated the renal expressions of ATP-binding cassette subfamily G isoform 2 protein (ABCG2) and organic anion/cation transporters. In addition, livers of luteolin-treated HN mice exhibited robust inhibition of xanthine oxidase. Together, our study shows that luteolin alleviates renal injury in the HN mice by activating urate excretion and Nrf2/HO-1/NQO1 antioxidant pathways and inhibiting liver xanthine oxidase activity. Thus, luteolin may be a potential agent for the treatment of HN.

UA influences the progression of breast cancer via the AhR/p27Kip1/cyclin E pathway

Uric acid (UA) is the end product of purine metabolism. In recent years, UA has been found to be associated with the prognosis of clinical cancer patients. However, the intricate mechanisms by which UA affects the development and prognosis of tumor patients has not been well elucidated. In this study, we explored the role of UA in breast cancer, scrutinizing its impact on breast cancer cell function by treating two types of breast cancer cell lines with UA. The role of UA in the cell cycle and proliferation of tumors and the underlying mechanisms were further investigated. We found that the antioxidant effect of UA facilitated the scavenging of reactive oxygen species (ROS) in breast cancer, thereby reducing aryl hydrocarbon receptor (AhR) expression and affecting the breast cancer cell cycle, driving the proliferation of breast cancer cells through the AhR/p27Kip1/cyclin E1 pathway. Moreover, in breast cancer patients, the expression of AhR and its downstream genes may be closely associated with cancer progression in patients. Therefore, an increase in UA could promote the proliferation of breast cancer cells through the AhR/p27Kip1/cyclin E1 pathway axis.

[Association between serum uric acid and airflow obstruction based on the health-checkup population]

OBJECTIVE

To investigate the association between serum uric acid, pulmonary function and airflow obstruction in Chinese Taiwan healthy subjects.

METHODS

All the cross-sectional analysis was performed in the population over 40 years old using the physical examination data of Chinese Taiwan MJ Health Resource Center between 1996 and 2016 stratification by gender. The correlation analyses between serum uric acid were done and multivariate Logistic regression analysis was used to explore the effect of serum uric acid on airflow obstruction.

RESULTS

A total of 35 465 people were included in the study, including 16 411 men and 19 054 women. Among them, the serum uric acid concentration of men was higher than that of women, and the serum uric acid concentration of the people with airflow obstruction was higher than that of the people without airflow obstruction. There was a negative correlation between serum uric acid level and the forced expiratory volume in one second (FEV1) and the force vital capacity (FVC) in women (P < 0.05), but in men the correlation didn' t exist (P>0.05). After adjusting for age, education, smoking status, drinking status, work strength, body mass index, history of cough, history of hypertension, history of diabetes, history of dyslipidemia, white blood cells and blood albumin, the airflow obstruction in women was more likely to exist with the serum uric acid elevated (OR=1. 12, 95%CI: 1.02-1.22, P < 0.05). The results showed that women with hyperuricemia were more likely to have airflow obstruction than those without hyperuricemia (OR=1.36, 95%CI: 1.06-1.75, P < 0.05). There was no correlation between serum uric acid concentration and airflow obstruction in men (OR=1.04, 95%CI: 0.96-1.13, P>0.05), also the hyperuricemia and airflow obstruction (OR=1.12, 95%CI: 0.89-1.39, P>0.05).

CONCLUSION

There is a negative correlation between serum uric acid and FEV1 and FVC in relatively healthy women, and there is an association between elevated serum uric acid and airflow obstruction in women, but not in men. Further prospective studies are needed to explore whether high serum uric acid level can increase the risk of airflow obstruction.

Associations between serum uric acid and breast cancer incidence: A systematic review and meta-analysis

BACKGROUND

Serum uric acid (SUA) may be involved in the development of cancer by inhibiting oxidative stress, but its relationship with breast cancer remains unclear.

MATERIALS AND METHODS

The PubMed, Embase, and Web of Science databases were searched systematically for studies on SUA levels in women with breast cancer and the effect of SUA levels on the risk of breast cancer. The Newcastle‒Ottawa Quality Assessment Scale (NOS) was used to assess the quality of all relevant studies included.

RESULTS

A total of 19 studies were included, including 75,827 women with breast cancer and 508,528 healthy controls. A meta-analysis found that SUA levels were negatively correlated with breast cancer risk in women (HR = 0.94, 95% CI: 0.89 - 0.99, p = 0.003). SUA levels in female breast cancer patients were not significantly different from those in healthy controls (SMD = 0.49, 95% CI = -0.09 - 1.08, p = 0.10), while SUA levels were increased in female breast cancer patients in articles published after 2010, SUA concentration detected by spectrophotometry, and non-Asian populations, regardless of menopausal state and treatment state.

CONCLUSION

High levels of SUA may reduce the risk of breast cancer in women, suggesting that SUA was a protective factor in women.

Exploring the causal association between uric acid and lung cancer in east Asian and European populations: a mendelian randomization study

BACKGROUND

Lung cancer still ranks first in the mortality rate of cancer. Uric acid is a product of purine metabolism in humans. Its presence in the serum is controversial; some say that its high levels have a protective effect against tumors, others say the opposite, that is, high levels increase the risk of cancer. Therefore, the aim of this study was to investigate the potential causal association between serum uric acid levels and lung cancer.

METHODS

Mendelian randomization was used to achieve our aim. Sensitivity analyses was performed to validate the reliability of the results, followed by reverse Mendelian analyses to determine a potential reverse causal association.

RESULTS

A significant causal association was found between serum uric acid levels and lung cancer in East Asian and European populations. Further sublayer analysis revealed a significant causal association between uric acid and small cell lung cancer, while no potential association was observed between uric acid and non-small cell lung cancer, squamous lung cancer, and lung adenocarcinoma. The sensitivity analyses confirmed the reliability of the results. Reverse Mendelian analysis showed no reverse causal association between uric acid and lung cancer.

CONCLUSIONS

The results of this study suggested that serum uric acid levels were negatively associated with lung cancer, with uric acid being a potential protective factor for lung cancer. In addition, uric acid level monitoring was simple and inexpensive. Therefore, it might be used as a biomarker for lung cancer, promoting its wide use clinical practice.

Large-scale cross-ancestry genome-wide meta-analysis of serum urate

Hyperuricemia is an essential causal risk factor for gout and is associated with cardiometabolic diseases. Given the limited contribution of East Asian ancestry to genome-wide association studies of serum urate, the genetic architecture of serum urate requires exploration. A large-scale cross-ancestry genome-wide association meta-analysis of 1,029,323 individuals and ancestry-specific meta-analysis identifies a total of 351 loci, including 17 previously unreported loci. The genetic architecture of serum urate control is similar between European and East Asian populations. A transcriptome-wide association study, enrichment analysis, and colocalization analysis in relevant tissues identify candidate serum urate-associated genes, including CTBP1, SKIV2L, and WWP2. A phenome-wide association study using polygenic risk scores identifies serum urate-correlated diseases including heart failure and hypertension. Mendelian randomization and mediation analyses show that serum urate-associated genes might have a causal relationship with serum urate-correlated diseases via mediation effects. This study elucidates our understanding of the genetic architecture of serum urate control.

Joint association of serum urate and healthy diet with chronic obstructive pulmonary disease incidence: results from the UK Biobank study

Background: The role of serum urate (SU) levels in the development of chronic obstructive pulmonary disease (COPD) remains a topic of debate, and it is unclear whether a healthy diet can mitigate the impact of SU on COPD risk. The objective of this study is to examine whether and to what extent a healthy diet can reduce the risk of COPD in relation to SU levels. Methods: The cohort analysis included 155 403 participants from the UK Biobank. SU levels were measured at the time of recruitment. A healthy diet score was calculated based on the consumption of vegetables, fruits, fish, processed meats, unprocessed red meat, whole grains, and refined grains. The Cox proportional hazards model was used to analyze the associations between SU levels, a healthy diet score, and the risk of COPD. Results: During a follow-up period of 1 409 969 person-years, 2918 incident cases of COPD were identified. Compared with the lowest SU level group, the hazard ratio (HR) and 95% confidence interval (CI) for COPD were 1.17 (1.03, 1.34) for participants with the highest SU level (hyperuricemia), indicating a positive association. Additionally, a dose-response relationship was observed between SU levels and the incidence of COPD (P-value for overall <0.0001). In the combined effect analysis, compared to individuals with high SU (hyperuricemia) + a low diet score (diet score <4), those with normal SU + a high diet score (diet score ≥4) had a HR (95% CI) of 0.75 (0.65, 0.87) for COPD. Conclusions: In summary, there is a positive association between SU levels and the risk of COPD. Furthermore, a healthier diet can mitigate the risk of COPD associated with high SU levels.

Robust positive association between serum urate and the risk of chronic obstructive pulmonary disease: hospital-based cohort and Mendelian randomisation study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) and hyperuricaemia are both characterised by systemic inflammation. Preventing chronic diseases among the population with common metabolic abnormality is an effective strategy. However, the association of hyperuricaemia with the higher incidence and risk of COPD remains controversial. Therefore, replicated researches in populations with distinct characteristics or demographics are compellingly warranted.

METHODS

This cohort study adopted a design of ambispective hospital-based cohort. We used propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) to minimise the effects of potential confounding factors. A Cox regression model and restricted cubic spline (RCS) model were applied further to assess the effect of serum urate on the risk of developing COPD. Finally, we conducted a two-sample Mendelian randomisation (MR) analysis to explore evidence of causal association.

RESULTS

There is a higher incidence in the population with hyperuricaemia compared with the population with normal serum urate (22.29/1000 person-years vs 8.89/1000 person-years, p=0.009). This result is robust after performing PSM (p=0.013) and IPTW (p<0.001). The Cox model confirms that hyperuricaemia is associated with higher risk of developing COPD (adjusted HR=3.35 and 95% CI=1.61 to 6.96). Moreover, RCS shows that the risk of developing COPD rapidly increases with the concentration of serum urate when it is higher than the reference (420 µmol/L). Finally, in MR analysis, the inverse variance weighted method evidences that a significant causal effect of serum urate on COPD (OR=1.153, 95% CI=1.034 to 1.289) is likely to be true. The finding of MR is robust in the repeated analysis using different methods and sensitivity analysis.

CONCLUSIONS

Our study provides convincing evidence suggesting a robust positive association between serum urate and the risk of developing COPD, and indicates that the population with hyperuricaemia is at high risk of COPD in the Chinese population who seek medical advice or treatment in the hospital.

Analysis of the prognostic value of uric acid on the efficacy of immunotherapy in patients with primary liver cancer

PURPOSE

Uric acid (UA) plays a dual role as an antioxidant and a prooxidant in patients with malignant tumors; however, the relationship between serum UA and malignancy is currently unclear. This study aims to investigate the prognostic value of serum uric acid level before immunotherapy on the efficacy of primary liver cancer (PLC) immunotherapy, which might provide a basis for optimizing the comprehensive treatment scheme.

METHODS

Patients with PLC who were admitted to the First Affiliated Hospital of Gannan Medical College from January 2019 to June 2022 and underwent immunotherapy were collected retrospectively. The difference between serum UA levels in patients with PLC, the correlation between serum UA levels, and the clinical characteristics of patients with PLC were analyzed using the chi-square test, and the survival was estimated using the Kaplan-Meier analysis. To further assess the prognostic significance of UA concentrations, univariate and multivariate Cox regression analyses were performed.

RESULTS

Ninety-nine patients were included in this study cohort. The median follow-up was 7 months (range: 1-29 months), and 76 (76.8%) of the 99 patients with PLC died as of December 31, 2022. Serum UA concentrations ranged from 105 to 670 μmol/l, with a median of 269 μmol/l. The results showed that the serum UA level of patients with PLC was higher than that of healthy subjects (P < 0.001). After subgroup analyses, only male patients with liver cancer had higher serum UA levels than healthy men (P = 0.001). The results of the Kaplan-Meier analysis showed that higher UA levels were associated with poor overall survival (OS) (P = 0.005). In univariate analysis, the OS rate of patients with elevated serum UA levels was significantly lower than the cut-off value (hazard ratio [HR]: 3.191, 95% confidence interval [CI]: 1.456-6.993, P = 0.004), with a median survival time of 151 and 312 days in the high and low serum UA groups, respectively. The results of multivariate analysis showed that the UA level was an independent prognostic factor for immunotherapy in patients with PLC (HR: 3.131, 95% CI: 1.766-5.553, P < 0.001).

CONCLUSIONS

The serum UA level is a reliable biomarker for predicting the prognosis of patients undergoing immunotherapy for PLC, and might provide a basis for the individualized treatment of these patients. Dynamic monitoring of the serum UA level may compensate for the deficiency of the current liver cancer staging system.

The potential of aryl hydrocarbon receptor as receptors for metabolic changes in tumors

Cancer cells can alter their metabolism to meet energy and molecular requirements due to unfavorable environments with oxygen and nutritional deficiencies. Therefore, metabolic reprogramming is common in a tumor microenvironment (TME). Aryl hydrocarbon receptor (AhR) is a ligand-activated nuclear transcription factor, which can be activated by many exogenous and endogenous ligands. Multiple AhR ligands can be produced by both TME and tumor cells. By attaching to various ligands, AhR regulates cancer metabolic reprogramming by dysregulating various metabolic pathways, including glycolysis, lipid metabolism, and nucleotide metabolism. These regulated pathways greatly contribute to cancer cell growth, metastasis, and evading cancer therapies; however, the underlying mechanisms remain unclear. Herein, we review the relationship between TME and metabolism and describe the important role of AhR in cancer regulation. We also focus on recent findings to discuss the idea that AhR acts as a receptor for metabolic changes in tumors, which may provide new perspectives on the direction of AhR research in tumor metabolic reprogramming and future therapeutic interventions.

Association between serum uric acid levels and lung function in the NHANES cohort (2007-2012): A cross-sectional analysis of a diverse American population

BACKGROUND

Hyperuricemia has been linked to various health conditions. However, the relationship between uric acid (UA) levels and lung function remains debated.

METHODS

In a cross-sectional study of 6750 participants aged 20-69 from NHANES, we assessed UA levels and lung function (FVC and FEV1). We conducted regression analyses while adjusting for potential confounders.

RESULTS

After accounting for factors like age, sex, BMI, smoking, and more, we found a negative association between UA FVC and FEV1. Specifically, for every 0.1 mg/dL increase in UA, FEV1 decreased by 15.265 mL, and FVC decreased by 24.46 mL. No association was observed with FEV1/FVC. Subgroup analyses revealed similar negative correlations among various groups, particularly in non-Hispanic Black females under 60.

CONCLUSION

Serum UA levels are inversely associated with FEV1 and FVC in the American population, with a notable impact on non-Hispanic Black females under 60.

Analyses of Factors Associated with Acute Exacerbations of Chronic Obstructive Pulmonary Disease: A Review

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is the exacerbation of a range of respiratory symptoms during the stable phase of chronic obstructive pulmonary disease (COPD). AECOPD is thus a dangerous stage and key event in the course of COPD, as its deterioration and frequency seriously affects the quality of life of patients and shortens their survival. Acute exacerbations occur and develop due to many factors such as infection, tobacco smoke inhalation, air pollution, comorbidities, airflow limitation, various biomarkers, history of previous deterioration, natural killer cell abnormalities, immunoglobulin G deficiency, genetics, abnormal muscle and nutritional status, negative psychology, and seasonal temperature changes. There is relatively limited research on the impact of the role of standardized management on the alleviation of AECOPD. However, with the establishment of relevant prevention and management systems and the promotion of artificial intelligence technology and Internet medical approaches, long-term effective and standardized management of COPD patients may help to achieve the quality of life and disease prognosis in COPD patients and reduce the risk of AE.

J-shaped association between uric acid and breast cancer risk: a prospective case-control study

BACKGROUND/AIM

In terms of breast cancer risk, there is no consensus on the effect of uric acid (UA) levels. The aim of our study was to clarify the link between UA and breast cancer risk in a prospective case-control study and to find the UA threshold point.

METHODS

We designed a case-control study with 1050 females (525 newly diagnosed breast cancer patients and 525 controls). We measured the UA levels at baseline and confirmed the incidence of breast cancer through postoperative pathology. We used binary logistic regression to study the association between breast cancer and UA. In addition, we performed restricted cubic splines to evaluate the potential nonlinear links between UA and breast cancer risk. We used threshold effect analysis to identify the UA cut-off point.

RESULTS

After adjusting for multiple confounding factors, we found that compared with the referential level (3.5-4.4 mg/dl), the odds ratio (OR) of breast cancer was 1.946 (95% CI 1.140-3.321) (P < 0.05) in the lowest UA level and 2.245 (95% CI 0.946-5.326) (P > 0.05) in the highest level. Using the restricted cubic bar diagram, we disclosed a J-shaped association between UA and breast cancer risk (P-nonlinear < 0.05) after adjusting for all confounders. In our study, 3.6 mg/dl was found to be the UA threshold which acted as the optimal turning point of the curve. The OR for breast cancer was 0.170 (95% CI 0.056-0.512) to the left and 1.283 (95% CI 1.074-1.532) to the right of 3.6 mg/dl UA (P for log likelihood ratio test < 0.05).

CONCLUSION

We found a J-shaped association between UA and breast cancer risk. Controlling the UA level around the threshold point of 3.6 mg/dl provides a novel insight into breast cancer prevention.

Evidence relating cigarette, cigar and pipe smoking to lung cancer and chronic obstructive pulmonary disease: Meta-analysis of recent data from three regions

BACKGROUND

There is a need to have up-to-date information for various diseases on the risk related to the use of different smoked products and the use of other nicotine-containing products. Here, we contribute to the information pool by presenting up-to-date quantitative evidence for North America, Europe and Japan and for both lung cancer and chronic obstructive pulmonary disease (COPD) on the relative risk (RR) relating to current vs never product use for each of the three smoked tobacco products, cigarettes, cigars and pipes.

AIM

To estimate lung cancer and COPD current smoking RRs for the three products using recent data for the three regions.

METHODS

Publications in English from 2010 to 2020 were considered that, based on epidemiological studies in the three regions, estimated the current smoking RR of lung cancer and/or COPD for one or more of the three products. The studies should involve at least 100 cases of the disease considered, not be restricted to specific lung cancer types or populations with specific medical conditions, and should be of cohort or nested case-control study design or randomized controlled trials. Literature searches were conducted on MEDLINE separately for lung cancer and for COPD, examining titles and abstracts initially, and then full texts. Additional papers were sought from reference lists of selected papers, reviews and meta-analyses. For each study identified, the most recent available data on each product were entered on current smoking, as well as on characteristics of the study and the RR estimates. Combined RR estimates were derived using random-effects meta-analysis. For cigarette smoking, where far more data were available, heterogeneity was studied by a wide range of factors. For cigar and pipe smoking, a more limited heterogeneity analysis was carried out. Results were compared with those from previous meta-analyses published since 2000.

RESULTS

Current cigarette smoking: For lung cancer, 44 studies (26 North American, 14 European, three Japanese, and one in multiple continents), gave an overall estimate of 12.14 [95% confidence interval (CI) 10.30-14.30]. The estimates were higher (heterogeneity P < 0.001) for North American (15.15, CI 12.77-17.96) and European studies (12.30, CI 9.77-15.49) than for Japanese studies (3.61, CI 2.87-4.55), consistent with previous evidence of lower RRs for Asia. RRs were higher (P < 0.05) for death (14.85, CI 11.99-18.38) than diagnosis (10.82, CI 8.61-13.60). There was some variation (P < 0.05) by study population, with higher RRs for international and regional studies than for national studies and studies of specific populations. RRs were higher in males, as previously reported, the within-study male/female ratio of RRs being 1.52 (CI 1.20-1.92). RRs did not vary significantly (P ≥ 0.05) by other factors. For COPD, RR estimates were provided by 18 studies (10 North American, seven European, and one Japanese). The overall estimate of 9.19 (CI 6.97-12.13), was based on heterogeneous data (P < 0.001), and higher than reported earlier. There was no (P > 0.1) variation by sex, region or exclusive use, but limited evidence (0.05 < P < 0.1) that RR estimates were greater where cases occurring shortly after baseline were ignored; where bronchiectasis was excluded from the COPD definition; and with greater confounder adjustment. Within-study comparisons showed adjusted RRs exceeded unadjusted RRs. Current cigar smoking: Three studies gave an overall lung cancer RR of 2.73 (CI 2.36-3.15), with no heterogeneity, lower than the 4.67 (CI 3.49-6.25) reported in an earlier review. Only one study gave COPD results, the RR (2.44, CI 0.98-6.05) being imprecise. Current pipe smoking: Four studies gave an overall lung cancer RR of 4.93 (CI 1.97-12.32), close to the 5.20 (CI 3.50-7.73) given earlier. However, the estimates were heterogeneous, with two above 10, and two below 3. Only one study gave COPD results, the RR (1.12, CI 0.29-4.40), being imprecise. For both diseases, the lower RR estimates for cigars and for pipes than for current smoking of cigarettes aligns with earlier published evidence.

CONCLUSION

Current cigarette smoking substantially increases lung cancer and COPD risk, more so in North America and Europe than Japan. Limited evidence confirms lower risks for cigars and pipes than cigarettes.

The value of blood-based measures of liver function and urate in lung cancer risk prediction: A cohort study and health economic analysis

BACKGROUND

Several studies have reported associations between low-cost blood-based measurements and lung cancer but their role in risk prediction is unclear. We examined the value of expanding lung cancer risk models for targeting low-dose computed tomography (LDCT), including blood measurements of liver function and urate.

METHODS

We analysed a cohort of 388,199 UK Biobank participants with 1873 events and calculated the c-index and fraction of new information (FNI) for models expanded to include combinations of blood measurements, lung function (forced expiratory volume in 1 s - FEV1), alcohol status and waist circumference. We calculated the hypothetical cost per lung cancer case detected by LDCT for different scenarios using a threshold of ≥ 1.51 % risk at 6 years.

RESULTS

The c-index was 0.805 (95 %CI:0.794-0.816) for the model containing conventional predictors. Expanding to include blood measurements increased the c-index to 0.815 (95 %CI: 0.804-0.826;p < 0.0001;FNI:0.06). Expanding to include FEV1, alcohol status, and waist circumference increased the c-index to 0.811 (95 %CI: 0.800-0.822;p < 0.0001;FNI: 0.04). The c-index for the fully expanded model containing all variables was 0.819 (95 %CI:0.808-0.830;p < 0.0001;FNI:0.09). Model expansion had a greater impact on the c-index and FNI for people with a history of smoking cigarettes relative to the full cohort. Compared with the conventional risk model, the expanded models reduced the number of participants meeting the criteria for LDCT screening by 15-21 %, and lung cancer cases detected by 7-8 %. The additional cost per lung cancer case detected relative to the conventional model was £ 1018 for adding blood tests and £ 9775 for the fully expanded model.

CONCLUSION

Blood measurements of liver function and urate made a modest improvement to lung cancer risk prediction compared with a model containing conventional risk factors. There was no evidence that model expansion would improve the cost per lung cancer case detected in UK healthcare settings.

Association between serum uric acid/serum creatinine ratios and lung function in the general American population: National Health and Nutrition Examination Survey (NHANES), 2007-2012

BACKGROUND

Assessment of lung function is essential for the early screening chronic airway diseases (CADs). Nevertheless, it is still not widely used for early diagnosing CADs in epidemiological or primary care settings. Thus, we used data from the US National Health and Nutrition Examination Survey (NHANES) to discuss the relationship between the serum uric acid/serum creatinine (SUA/SCr) ratio and lung function in general adults to gain the role of SUA/SCr in early assessment of lung function abnormalities.

METHODS

From 2007 to 2012 NHANES, a total of 9569 people were included in our study. Using the regression model, XGBoost algorithm model, generalised linear model and two-piecewise linear regression model, the link between the SUA/SCr ratio and lung function was investigated.

RESULTS

After correcting for confounding variables, the data revealed that forced vital capacity (FVC) declined by 47.630 and forced expiratory volume in one second (FEV1) decreased by 36.956 for each additional unit of SUA/SCr ratio. However, there was no association between SUA/SCr and FEV1/FVC. In the XGBoost model of FVC, the top five most important were glycohaemoglobin, total bilirubin, SUA/SCr, total cholesterol and aspartate aminotransferase, whereas in FEV1, were glycohaemoglobin, total bilirubin, total cholesterol, SUA/SCr and serum calcium. In addition, we determined the linear and inverse association between SUA/SCr ratio and FVC or FEV1 by constructing a smooth curve.

CONCLUSIONS

In the general American population, the SUA/SCr ratio is inversely linked with FVC and FEV1, but not with FEV1/FVC, according to our research. Future studies should investigate the impact of SUA/SCr on lung function and identify possible mechanisms of action.

Baseline serum uric acid level is associated with progression-free survival, disease control rate, and safety in postoperative patients with colorectal cancer treated by FOLFOX, FOLFIRI, or XELOX

Background

High serum uric acid (SUA) levels increase the risk of overall cancer morbidity and mortality, particularly for digestive malignancies. Nevertheless, the correlation between SUA level and clinical outcomes of the postoperative patients with colorectal cancer (CRC) treated by chemotherapy is unclear. This study aimed at exploring the relationship between baseline SUA level and progression-free survival (PFS), disease control rate (DCR), and safety in postoperative CRC patients receiving chemotherapy.

Patients and Methods

We conducted a retrospective study to evaluate the relationship between baseline SUA level and PFS, DCR, and incidence of serious adverse events of 736 postoperative CRC patients treated with FOLFOX, FOLFIRI or XELOX at our center.

Results

Data from our center suggested that high baseline SUA level is linked to poor PFS in non-metastatic CRC patients using FOLFOX (HR=2.59, 95%CI: 1.29-11.31, p=0.018) and in male patients using FOLFIRI (HR=3.77, 95%CI: 1.57-39.49, p=0.012). In patients treated by FOLFIRI, a high SUA is also linked to a low DCR (p=0.035). In patients using FOLFOX, high baseline SUA level is also linked to a high incidence of neutropenia (p=0.0037). For patients using XELOX, there is no significant correlation between SUA level and PFS, effectiveness, or safety.

Conclusions

These findings imply that a high SUA level is a promising biomarker associated with poor PFS, DCR and safety of postoperative CRC patients when treated with FOLFOX or FOLFIRI.

Development of a new method based on gold nanoparticles for determination of uric acid in urine samples

In the current work, we have reported a fast and easy method based on gold nanoparticles for the determination of uric acid in urine samples. In the first stage, gold nanoparticles were synthesized using the chemical reduction method and then applied as a sensor to measure uric acid concentration based on its strong reducing property. The main parameters affecting response signals such as pH, reagent concentration, and time are optimized using the multivariate method. Under the optimum conditions, the calibration graphs were linear in the range of 0.5 - 10.0 mg.L^-1 with limits of detection of 0.2 mg.L^-1 and RSD% of 1.2% These results show that this nano-based method is a very sensitive and simple method for the determination of uric acid in urine samples.

U-shaped association of uric acid to overall-cause mortality and its impact on clinical management of hyperuricemia

Serum uric acid (SUA) is significantly elevated in obesity, gout, type 2 diabetes mellitus, and the metabolic syndrome and appears to contribute to the renal, cardiovascular and pulmonary comorbidities that are associated with these disorders. Most previous studies have focused on the pathophysiologic effects of high levels of uric acid (hyperuricemia). More recently, research has also shifted to the impact of hypouricemia, with multiple studies showing the potentially damaging effects that can be caused by abnormally low levels of SUA. Along with these observations, recent inconclusive data from human studies evaluating the treatment of hyperuricemia with xanthine oxidoreductase (XOR) inhibitors have added to the debate about the causal role of UA in human disease processes. SUA, which is largely derived from hepatic degradation of purines, appears to exert both systemic pro-inflammatory effects that contribute to disease and protective antioxidant properties. XOR, which catalyzes the terminal two steps of purine degradation, is the major source of both reactive oxygen species (O2.-, H2O2) and UA. This review will summarize the evidence that both elevated and low SUA may be risk factors for renal, cardiovascular and pulmonary comorbidities. It will also discuss the mechanisms through which modulation of either XOR activity or SUA may contribute to vascular redox hemostasis. We will address future research studies to better account for the differential effects of high versus low SUA in the hope that this will identify new evidence-based approaches for the management of hyperuricemia.

Association Between Serum Uric Acid and Lung Function in People with and without Chronic Obstructive Pulmonary Disease

Background

The effect of serum uric acid (SUA) levels on lung function in chronic obstructive pulmonary disease (COPD) people remained unclear. We aimed to investigate the association between SUA and lung function.

Methods

A cross-sectional study was performed to measure the SUA levels and lung function in 2797 consecutive eligible individuals. Of these, individuals in our study were divided into two groups, the COPD group (n=1387) and the non-COPD group (n=1410). The diagnosis of COPD is defined as post-bronchodilator first second of forced expiratory volume (FEV₁)/forced vital capacity (FVC) ratio of less than 0.70. Multivariable adjustment linear models were applied to estimate the effect of SUA levels on FEV₁% predicted, FVC% predicted, and FEV₁/FVC stratified by COPD status.

Results

After multivariable adjustment, each 1 mg/dL increase of SUA was significantly associated with a decrease in FEV₁% predicted (−1.63%, 95% confidence interval [CI] −2.37 to −0.90), FVC % predicted (−0.89%, 95% CI −1.55 to −0.24), and FEV₁/FVC (−0.70%, 95% CI −1.10 to −0.30). In the COPD group, each 1 mg/dL increase of SUA was significantly associated with decreases in FEV₁% predicted (−1.87%, 95% CI −2.91 to −0.84), FVC% predicted (−1.35%, 95% CI −2.35 to −0.34), and FEV₁/FVC (−0.63%, 95% CI −1.18 to −0.08). However, no significant association between lung function and SUA was found among people without COPD.

Conclusion

High SUA levels were associated with lower lung function, especially in COPD patients. However, no statistically significant effect of SUA on lung function was found in people without COPD.

Concomitant genetic alterations are associated with plasma D-dimer level in patients with non-small cell lung cancer

Objective: D-dimer is correlated to the poor prognosis of non-small cell lung cancer. The study aimed to investigate the association between plasma D-dimer and concomitant mutations in non-small cell lung cancer. Methods: A total of 517 non-small cell lung cancer patients were recruited and tested for ALK, BRAF, EGFR, HER2/ERBB2, KRAS, MET, PIK3CA, RET and ROS1 mutation by next-generation sequencing. Multiple gene mutation information, clinical baseline data and laboratory test data were analyzed statistically. Results: All patients were divided into three groups: wild-type group, single-gene mutation group and concomitant mutation group. The analysis of D-dimer, uric acid, gender, family history, smoking history, histology and distant metastasis all showed significant differences in the three groups (p < 0.05). D-dimer was considered as a risk factor for concomitant mutations according to the unordered multiple logistic regression analysis. The receiver operating characteristic curve analysis indicated that D-dimer had an important predictive value for the occurrence of concomitant mutations (AUC: 0.94; sensitivity: 88.71%; specificity: 86.46). There was significantly shorter median progression-free survival in the concomitant mutation group compared with the single mutation group (7.70 months vs 14.00 months; p = 0.0133). Conclusion: Plasma D-dimer is significantly associated with concomitant mutations and may be regarded as a potent predictor of concomitant mutations for non-small cell lung cancer patients.

High serum uric acid may associate with the increased risk of colorectal cancer in females: A prospective cohort study

Elevated serum uric acid (SUA) levels have been previously reported to play a role in multiple types of cancers. However, epidemiological studies evaluating SUA levels and colorectal cancer risk remain sparse. This cohort study included 444 462 participants between the ages of 40 and 69 years from the UK Biobank, followed up from 2006 to 2010. Multivariable adjusted Cox regression models were used to estimate hazard ratios (HRs). During a mean follow-up of 6.6 years, 2033 and 855 cases of colon and rectal cancers, respectively, were diagnosed. The multivariable-adjusted HRs for risks of colon cancer in the lowest uric acid categories (≤3.5 mg/dL) compared with the reference groups were 1.31 (95% confidence interval [CI] = 0.75-2.29) in males and 1.26 (95% CI = 1.03-1.55) in females. The HRs in the highest uric acid groups (>8.4 mg/dL) were 1.16 (95% CI = 0.83-1.63) in males and 2.00 (95% CI = 1.02-3.92) in females. The corresponding HRs of rectal cancer in the lowest uric acid groups compared with the reference group were 2.21 (95% CI = 1.15-4.23) in males and 0.98 (95% CI = 0.66-1.45) in females. The HRs in the highest uric acid groups were 1.35 (95% CI = 0.82-2.23) in males and 3.81 (95% CI = 1.38-10.56) in females. In conclusion, SUA showed a U-shaped association with colon cancer risk in both male and female populations. The same pattern was observed in male patients with rectal cancer. However, SUA levels were positively associated with occurrence of rectal cancer in female subjects.

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.

Hyperuricemia is a Adverse Prognostic Factor for Colon Cancer Patients

Objective

Hyperuricemia is linked to the prognosis of a number of cancers; however, its association with colon cancer survival has not been fully elucidated. To investigate whether hyperuricemia affects the prognosis of colon cancer, we conducted a retrospective study.

Methods

The study included age- and sex-matched colon cancer patients, of whom 60 patients were diagnosed with hyperuricemia, and 120 patients did not have hyperuricemia. The overall survival (OS) and disease-free survival (DFS) of these patients were evaluated by Kaplan–Meier (K-M) analysis. The association between the survival of colon cancer patients and hyperuricemia was analyzed using the Cox regression method after adjusting for tumor stage and grade and vascular infiltration.

Results

The K-M survival analysis supported that patients with hyperuricemia had poor OS (P for the Log rank test = 0.0008) and DFS. As demonstrated by the univariate analysis, the presence of hyperuricemia was correlated with decreased OS (HR_OS = 2.09, P = 0.002). Tumor grade and tumor stage were also found to be independent predictors for the prognosis of colon cancer patients. In addition, poor OS among patients with hyperuricemia was also confirmed in the adjusted analysis (HR_OS = 1.94, P = 0.005).

Conclusion

Hyperuricemia has an adverse effect on the prognosis and survival of patients with colon cancer. Further studies evaluating the cellular and molecular mechanisms are needed to validate the prognostic value of hyperuricemia in colon cancer.

Serum urate and lung cancer: a cohort study and Mendelian randomization using UK Biobank

BACKGROUND

Serum urate is the most abundant small molecule with antioxidant properties found in blood and the epithelial lining fluid of the respiratory system. Moderately raised serum urate is associated with lower rates of lung cancer and COPD in smokers but whether these relationships reflect antioxidant properties or residual confounding is unknown.

METHODS

We investigated the observational and potentially causal associations of serum urate with lung cancer incidence and FEV1 using one-sample Mendelian randomization (MR) and the UK Biobank resource. Incident lung cancer events were identified from national cancer registries as FEV1 was measured at baseline. Observational and genetically instrumented incidence rate ratios (IRRs) and risk differences per 10,000 person-years (PYs) by smoking status were estimated.

RESULTS

The analysis included 359,192 participants and 1,924 lung cancer events. The associations between measured urate levels and lung cancer were broadly U-shaped but varied by sex at birth with the strongest associations in current smoking men. After adjustment for confounding variables, current smoking men with low serum urate (100 µmol/L) had the highest predicted lung cancer incidence at 125/10,000 PY (95%CI 56-170/10,000 PY) compared with 45/10,000 PY (95%CI 38-47/10,000 PY) for those with the median level (300 µmol/L). Raised measured urate was associated with a lower baseline FEV1. The MR results did not support a causal relationship between serum urate and lung cancer or FEV1.

CONCLUSIONS

We found no evidence that serum urate is a modifiable risk factor for respiratory health or lung cancer.

Lung function decline is associated with serum uric acid in Korean health screening individuals

We performed a retrospective cohort study of 19,237 individuals who underwent at least three health screenings with follow-up periods of over 5 years to find a routinely checked serum marker that predicts lung function decline. Using linear regression models to analyze associations between the rate of decline in the forced expiratory volume in 1 s (FEV1) and the level of 10 serum markers (calcium, phosphorus, uric acid, total cholesterol, total protein, total bilirubin, alkaline phosphatase, aspartate aminotransferase, creatinine, and C-reactive protein) measured at two different times (at the first and third health screenings), we found that an increased uric acid level was significantly associated with an accelerated FEV1 decline (P = 0.0014 and P = 0.037, respectively) and reduced FEV1 predicted % (P = 0.0074 and P = 8.64 × 10^–7, respectively) at both visits only in non-smoking individuals. In addition, we confirmed that accelerated forced vital capacity (FVC) and FEV1/FVC ratio declines were observed in non-smoking individuals with increased serum uric acid levels using linear mixed models. The serum uric acid level thus potentially predicts an acceleration in lung function decline in a non-smoking general population.

Differential relationship of uric acid to mortality and clinical biomarkers of aging according to grip strength in older adults: a cohort study

Uric acid is both a pro-oxidant and antioxidant. We investigated serum uric acid's association with mortality and aging biomarkers in older adults with varying levels of grip strength. A total of 5329 community-dwelling adults aged ≥55 years underwent assessments of serum uric acid levels, grip strength, and biomarkers of diverse physiological systems. The primary outcome was all-cause mortality. We observed a significant (P < .001) interaction between uric acid levels and grip strength on all-cause mortality risk. Among participants with low grip strength, a nonlinear association (P for nonlinearity = .006) was observed between serum uric acid levels and mortality risk after multivariate adjustment. Compared with participants with neither extreme uric acid levels nor low grip strength, those with a combination of high serum uric acid and low grip strength exhibited greater risks of mortality (adjusted hazard ratio [aHR], 1.52; 95% confidence interval [CI], 1.15–2.02) and deviations in biomarkers of specific systems, so did those with a combination of low serum uric acid and low grip strength (aHR, 1.52; 95% CI, 1.13–2.05). In conclusion, there was a J-shaped association between serum uric acid and the risk of all-cause mortality in older adults. This was primarily true for those with low grip strength.

Serum Uric Acid Levels and Risk of Eight Site-Specific Cancers: A Mendelian Randomization Study

The relationship between serum uric acid (UA) levels and cancer risk remains controversial. Here, a two-sample Mendelian randomization analysis was performed to identify a causal effect of serum UA levels on cancer risk. Twenty-six single nucleotide polymorphisms strongly associated with serum UA levels were screened as genetic variants from large-scale meta-analysis data of a genome-wide association study of 110,347 European individuals. Genetic associations with eight common site-specific cancers were subsequently explored. A total of six Mendelian randomization methods were used to estimate the potential effect of serum UA levels on cancer risk, including random effects inverse variance weighting, fix effects inverse variance weighting, MR-Egger, median weighting, mode weighting, and simple mode analysis. Our primary random effects inverse variance weighted analysis revealed that no significant associations with cancers was found (all p > 0.05). Sensitivity analyses and additional analyses also showed similar pooled results. In conclusion, no significant causality between serum UA levels and cancer risk was evidenced.

Correlation between smokeless tobacco (Gutkha) and biomarkers of oxidative stress in plasma with cardiovascular effects

Tobacco products are widely consumed around the world in smoking and smokeless tobacco (SLT) forms. Analysis of smokeless tobacco consumption suggested that the effects of nicotine and tobacco-specific N-nitrosamines, the main ingredients of smokeless tobacco are attractive to study because its consumption often results in biochemical changes of plasma parameters and markers of oxidative stress development. Smokeless tobacco users generally consume the most commonly available SLT products like khaleja brand of gutkha and mahak chaini brand of khaini 3–5 times per day. We found a significant increase in plasma glucose levels, total cholesterol, triglycerides, and a significant decrease in high-density lipoprotein (HDL) cholesterol indicative of atherosclerosis risk. We also found that the plasma peroxynitrites (ONOO⁻), nitric oxide (NO), lipid peroxidation (LPO), and protein carbonyls (PCO) levels were significantly elevated. Plasma nicotine and cotinine levels were significantly elevated in study subjects, suggesting that nicotine could be responsible for the oxidative and nitrosative stress indirectly inducing cardiovascular risk. There was a strong correlation of nicotine with reactive oxygen species (ROS), reactive nitrogen species (RNS), cholesterol, and creatinine in exposed smokeless tobacco (gutkha) consumers. These data demonstrate SLT users are at high cardiovascular risk due to nicotine-induced free radicals and oxidative damage.

Associations between serum uric acid and hepatobiliary-pancreatic cancer: A cohort study

BACKGROUND

Uric acid is the end product of purine metabolism. Previous studies have found that serum uric acid (SUA) levels are associated with the total cancer risk. However, due to the dual effect of uric acid on cancer, the relationship between the SUA levels and most specific-site cancer remains unclear.

AIM

To investigate the associations between the SUA levels and incidence of hepatobiliary-pancreatic cancer.

METHODS

In this prospective cohort study, 444462 participants free of cancer from the UK Biobank were included. The SUA levels were measured at baseline, and the incidence of hepatobiliary-pancreatic cancer was determined by contacting the cancer registry. The hazard ratios (HRs) and 95% confidence intervals (CIs) between the SUA levels and hepatobiliary-pancreatic cancer were investigated using multiple adjusted Cox regression models adjusted for potential confounders.

RESULTS

In total, 920 participants developed liver, gallbladder, biliary tract or pancreatic cancer during a median of 6.6 yrs of follow-up. We found that the HR of pancreatic cancer in the highest SUA group was 1.77 (95%CI: 1.29-2.42) compared with that in the lowest group. After stratifying by gender, we further found that SUA was associated with an increased risk of pancreatic cancer only among the females (highest quartile vs lowest quartile HR 2.04, 95%CI: 1.35-3.08). Among the males, the SUA levels were positively associated with the gallbladder cancer risk (highest quartile vs lowest quartile HR 3.09, 95%CI: 1.28-7.46), but a U-shaped association with the liver cancer risk was observed (P-nonlinear = 0.03).

CONCLUSION

SUA is likely to have gender-specific effects on hepatobiliary-pancreatic cancer. High SUA levels are a risk factor for pancreatic cancer in females and gallbladder cancer in males. A U-shaped association with the liver cancer risk was identified.

High Serum Uric Acid Was a Risk Factor for Incident Asthma: An Open Cohort Study

Background

Several cross-sectional studies have suggested an association between SUA and asthma. However, few studies have investigated this relationship longitudinally. Although SUA is an independent risk factor for chronic kidney disease and cardiovascular diseases, its contribution to incident asthma remains uncertain.

Objective

To determine whether a high SUA was a risk factor for adult incident asthma.

Methods

By using health care data from the Shandong multicenter health check-up, 76,369 participants, aged 20 to 79 years, were identified who had an SUA determination with a mean follow-up period of 3.73±2.21 years. Multivariate modeling employed Cox proportional hazards models to verify the association between SUA and incident asthma by adjusting age, BMI, smoking habits, drinking habits, and asthma-like diseases.

Results

A total of 51,389 individuals were included in the analysis. Cut-off values of SUA able to discriminate asthma status were identified by means of maximally selected rank statistics in the whole participants (≥376.80umol/L), women (≥314.45umol/L), and men (≥376.80umol/L). Multivariate Cox regression analyses adjusted for covariates (age, body mass index (BMI), smoking habit, drinking habit, and asthma-like disease) identified an independent association between SUA and incident asthma in the whole participants (hazard ratio (HR) 2.92, 95% confidence intervals (CI), 1.76–4.48, P=0.00) and men (HR 3.02, 95% CI 1.70–5.39, P=0.00), but not in women.

Conclusion

The results of the current study confirmed that high SUA was an independent risk factor for incident asthma after adjustment of potential covariates and suggested that a cut-off value related to incident asthma could be identified only in men.

Metabolomic analysis of lung cancer patients with chronic obstructive pulmonary disease using gas chromatography-mass spectrometry

Chronic obstructive pulmonary disease (COPD), characterized by intermittent exacerbations and clinical subphenotypes like emphysema and chronic bronchitis, poses a significant risk of lung cancer (LC) development. Metabolomic studies of COPD are scarce, and those of LC patients with COPD subphenotypes have not been investigated. To study metabolite profile alteration in LC patients with different COPD subphenotypes, lung paracancer tissue from 10 LC (CON) patients, 10 LC patients with emphysema (E), and 9 LC patients with chronic bronchitis (CB) were analyzed using gas chromatography-mass spectrometry. Multivariate analysis indicated a distinct separation between LC patients with COPD subphenotypes and LC patients. Overall, 60, 55, 33 and 63 differential metabolites (DM) were identified in comparisons between CB vs CON, E vs CON, CB vs E, and CB + E vs CON, respectively, and of these, 8 DM were shared in all comparisons. Among the high altered metabolites, E samples showed higher 'acetol' than CON samples, and lower 'azelaic acid', '3-methylglutaric acid' and 'allose'. CB samples showed higher 'turanose' and 'o-phosphoserine' and lower 'anandamide' than CON and E samples. In CB and E samples, 'galactonic acid', '2-mercaptoethanesulfonic acid', 'D-alanyl-D-alanine' '3-methylglutaric acid', 'glycine', 'L-4-Hydroxyphenylglycine' and 'O-phosphonothreonine' had common alteration trends compared with those of CON samples. 'Glycine', 'L-4-Hydroxyphenylglycine' and 'O-phosphonothreonine' were significantly enriched in glycine, serine and threonine metabolism pathways. The total differential metabolites detected were remarkably altered in pyrimidine, beta-alanine and purine metabolism. Our study provided altered DM patterns of lung paracancer tissue, the key metabolites and their enriched metabolic pathways in LC patients with different COPD subphenotypes.

Serum level of Xanthine oxidase, Uric Acid, and NADPH oxidase1 in Stage I of Multiple Myeloma

OBJECTIVE

The etiology of multiple myeloma (MM) is not known. Enzymes such as xanthine oxidase (XO) and NADPH oxidase 1 (NOX1) as relevant sources of reactive oxygen species (ROS) production may play a crucial role in the incidence and progress of MM. Uric acid generated by XO has a controversial dual role in both the prevention and promotion of cancer. We conducted a case-control study and selected patients with stage I MM to investigate the status of XO, NOX1, and uric acid in the patients and controls.

METHODS

We used a sample of 33 patients with stage I MM and 30 healthy controls. The enzyme-linked immunosorbent assay (ELISA) measured the enzyme concentration of XO and NOX1, and the colorimetric method measured the serum level of uric acid.

RESULTS

Mean serum levels for XO in patients and controls were 6.17±0.83 ng/ml and 4.12±0.57 ng/ml (P<0.001). serum levels of NOX1 were 4.35±1.03 ng/ml in patients and 3.54±0.91 ng/ml in controls (P<0.001). Evaluating the levels of XO and NOX1 in male and female populations showed a significant difference in the male population (NOX1 P=0.002; XO P<0.001) and female population (NOX1 P=0.002; XO P<0.001). Also, a significant correlation was observed between the two enzymes only in the female population (Pearson correlation=0.5; P=0.006). A significant inverse correlation found between albumin and XO (Pearson correlation=-0.7, P<0.001) and NOX1 (Pearson correlation=-0.5, P<0.001). XO was correlated with B2-m (Pearson correlation=0.37, P=0.003). There was no significant difference in uric acid between patients (6.2±1.2 mg/dl) and controls (5.7±1 mg/dl) (P=0.2), and no correlation was found with XO.

CONCLUSION

The present study indicates the possible role of XO and NOX 1 in the etiology of MM. Although we found no correlation between uric acid and XO, further studies will help clarify the function of uric acid in the pathogenesis of MM.
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Higher Blood Uric Acid in Female Humans and Mice as a Protective Factor against Pathophysiological Decline of Lung Function

The oxidant/antioxidant imbalance plays a pivotal role in the lung. Uric acid (UA), an endogenous antioxidant, is highly present in lung tissue, however, its impact on lung function under pathophysiological conditions remains unknown. In this work, pharmacological and genetic inhibition of UA metabolism in experimental mouse models of acute and chronic obstructive pulmonary disease (COPD) revealed that increased plasma UA levels improved emphysematous phenotype and lung dysfunction in accordance with reduced oxidative stress specifically in female but not in male mice, despite no impact of plasma UA induction on the pulmonary phenotypes in nondiseased mice. In vitro experiments determined that UA significantly suppressed hydrogen peroxide (H₂O₂)-induced oxidative stress in female donor-derived primary human bronchial epithelial (NHBE) cells in the absence of estrogen, implying that the benefit of UA is limited to the female airway in postmenopausal conditions. Consistently, our clinical observational analyses confirmed that higher blood UA levels, as well as the SLC2A9/GLUT9 rs11722228 T/T genotype, were associated with higher lung function in elderly human females. Together, our findings provide the first unique evidence that higher blood UA is a protective factor against the pathological decline of lung function in female mice, and possibly against aging-associated physiological decline in human females.

Hyperuricemia and Hypertension: Links and Risks

Hyperuricemia has long been recognized to be associated with increased cardiovascular risk, including risk of developing hypertension. Epidemiological findings suggest that the link with hypertension is stronger in children and adolescents. Uric acid acts as a strong antioxidant compound in the extracellular environment but has pro-inflammatory effects within the intracellular setting. A chronic phase of microvascular injury is known to occur after prolonged periods of hyperuricemia. This is proposed to contribute to afferent arteriolopathy and elevation of blood pressure that may become unresponsive to uric acid-lowering therapies over time. Studies have struggled to infer direct causality of hyperuricemia due to a vast number of confounders including body mass index. The aim of this review is to present the available data and highlight the need for large scale prospective randomized controlled trials in this area. At present, there is limited evidence to support a role for uric acid-lowering therapies in helping mitigate the risk of hypertension.

Oxidative Stress Mechanisms in the Pathogenesis of Environmental Lung Diseases

Globally, respiratory diseases are major cause of disability and mortality, and more alarmingly, it disproportionately affects developing countries, which is largely attributed to poor quality of air. Tobacco smoke and emissions from combustion of fossil fuel and biomass fuel are the major airborne pollutants affecting human lung health. Oxidative stress is the dominant driving force by which the airborne pollutants exert their toxicity in lungs and cause respiratory diseases. Most airborne pollutants are associated with intrinsic oxidative potential and, additionally, stimulate endogenous production of reactive oxygen species (ROS) and reactive nitrogen species (RNS). Elevated ROS and RNS in lungs modulate redox signals and cause irreversible damage to critical biomolecules (lipids, proteins and DNA) and initiate various pathogenic cellular process. This chapter provides an insight into oxidative stress-linked pathogenic cellular process such as lipid peroxidation, inflammation, cell death, mitochondrial dysfunction, endoplasmic reticulum stress, epigenetic changes, profibrotic signals and mucus hypersecretion, which drive the development and progression of lung diseases. Lungs are associated with robust enzymatic and non-enzymatic (GSH, ascorbic acid, uric acid, vitamin E) antioxidant defences. However, sustained production of free radicals due to continuous exposures to airborne pollutants overwhelms lung antioxidant defences and causes oxidative injury. Preclinical studies have demonstrated the critical roles and therapeutic potential of upregulating lung antioxidants for intervention of respiratory diseases; however, so far clinical benefits in antioxidant supplementation trials have been minimal and conflicting. Antioxidants alone may not be effective in treatment of respiratory diseases; however it could be a promising adjunctive therapy.

Decreased uric acid levels in the acute phase of Plasmodium vivax malaria

INTRODUCTION

Uric acid is one of the compounds associated with the inflammatory process in malaria. It acts as an indicator of cellular damage by activating the immune response and inflammatory process.

METHODS

We measured serum concentrations of uric acid in 60 symptomatic patients before and after treatment for malarial infections caused by Plasmodium vivax.

RESULTS

Lower serum concentrations of uric acid were found during the acute phase of P. vivax malaria compared to those in its convalescent phase (p < 0.0001).

CONCLUSIONS

Patients in the acute phase of malaria had lower uric acid levels than those in its convalescent phase.

Hyperuricemia and gout are associated with cancer incidence and mortality: A meta-analysis based on cohort studies

The association between hyperuricemia or gout and cancer risk has been investigated in various published studies, but their results are conflicting. We conducted a meta-analysis to investigate whether hyperuricemia or gout was associated with the cancer incidence and mortality. Linear and nonlinear trend analyses were conducted to explore the dose-response association between them. The pooled relative risk (RR) and 95% confidence interval (CI) were used to evaluate cancer risk. A total of 24 articles (33 independent studies) were eligible for inclusion. When compared participants with the highest SUA (hyperuricemia) levels and those with the lowest SUA levels, the pooled RR was 1.08 (95% CI, 1.04-1.12), it was significantly associated among males but not among females (males, RR = 1.07; 95% CI, 1.03-1.11; females, RR = 1.06; 95% CI, 0.96-1.17). Hyperuricemia increased total cancer mortality (RR = 1.15; 95% CI, 1.05-1.26), but a significant association was observed in females rather than in males (females: RR = 1.26; 95% CI, 1.09-1.45; males, RR = 1.02; 95% CI, 0.80-1.30). Linear relationships of SUA levels with overall cancer incidence (p for nonlinearity = 0.238) and overall cancer mortality (p for nonlinearity = 0.263) were identified. However, 1 mg/dL increment in SUA levels was weakly significant in overall cancer incidence (RR = 1.01; 95% CI, 1.01-1.01) but not associated with overall cancer mortality (RR = 1.01; 95% CI, 0.99-1.03). Gout was significantly associated with increased cancer incidence (RR = 1.19; 95% CI, 1.12-1.25). In conclusion, Hyperuricemia or gout was associated with higher cancer incidence and mortality. Though a potential linear relationship between them was found, we'd better treat this result with caution.

Urinary 8-isoprostane levels and occurrence of lung, colorectal, prostate, breast and overall cancer: Results from a large, population-based cohort study with 14 years of follow-up

BACKGROUND

Urinary 8-isoprostane is an established biomarker for lipid peroxidation. However, the association between its pre-diagnostic levels and cancer incidence has rarely been evaluated.

METHODS

8793 older adults from the German ESTHER cohort were followed up for cancer incidence by cancer registry data. A directed acyclic graph was utilized to identify potential confounders. Multivariate Cox regression models were applied to estimate hazard ratios (HRs) and 95% confidence intervals (95% CI).

RESULTS

During 14-year follow-up, 1540 incident cancer cases, including 207 lung, 196 colorectal, 218 breast and 245 prostate cancer cases were detected. 8-isoprostane concentrations were positively associated with lung cancer, but not with cancer at the other sites. The HR (95% CI) for the association with lung cancer was 1.61 (1.10, 2.34) for comparison of the top with bottom tertile in total population. The association of 8-isoprostane levels with lung cancer persisted after the adjustment for smoking and other potential confounders and was multiplicative to the effect of smoking. However, 8-isoprostane levels did not improve lung cancer prediction when added to a model containing age, sex and smoking. A protective association of increasing 8-isoprostane levels was observed for prostate cancer incidence but this association was only statistically significant among current smokers.

DISCUSSION

Our findings suggest that lipid peroxidation is involved in the development of lung cancer. However, high oxidative stress may be a protective factor for prostate cancer, especially among current smokers.

Uric acid, lung function, physical capacity and exacerbation frequency in patients with COPD: a multi-dimensional approach

Background

Recent investigations showed single associations between uric acid levels, functional parameters, exacerbations and mortality in COPD patients. The aim of this study was to describe the role of uric acid within the network of multiple relationships between function, exacerbation and comorbidities.

Methods

We used baseline data from the German COPD cohort COSYCONET which were evaluated by standard multiple regression analyses as well as path analysis to quantify the network of relations between parameters, particularly uric acid.

Results

Data from 1966 patients were analyzed. Uric acid was significantly associated with reduced FEV₁, reduced 6-MWD, higher burden of exacerbations (GOLD criteria) and cardiovascular comorbidities, in addition to risk factors such as BMI and packyears. These associations remained significant after taking into account their multiple interdependences. Compared to uric acid levels the diagnosis of hyperuricemia and its medication played a minor role.

Conclusion

Within the limits of a cross-sectional approach, our results strongly suggest that uric acid is a biomarker of high impact in COPD and plays a genuine role for relevant outcomes such as physical capacity and exacerbations. These findings suggest that more attention should be paid to uric acid in the evaluation of COPD disease status.

Circulating uric acid levels and subsequent development of cancer in 493,281 individuals: findings from the AMORIS Study

Objectives

Serum uric acid has been suggested to be associated with cancer risk. We aimed to study the association between serum uric acid and cancer incidence in a large Swedish cohort.

Results

A positive association was found between uric acid levels and overall cancer risk, and results were similar with adjustment for glucose, triglycerides and BMI. Hazard ratio (HR) for overall cancer for the 4^th quartile of uric acid compared to the 1^st was 1.08 (95% CI: 1.05–1.11) in men and 1.12 (1.09 – 1.16) in women. Site-specific analysis showed a positive association between uric acid and risk of colorectal, hepatobiliary, kidney, non-melanoma skin, and other cancers in men and of head and neck and other cancers in women. An inverse association was observed for pulmonary and central nervous system (CNS) cancers in men and breast, lymphatic and haematological, and CNS malignancies in women.

Materials and Methods

We included 493,281 persons aged 20 years and older who had a measurement of serum uric acid and were cancer-free at baseline in the AMORIS study. Multivariable Cox proportional hazards regression was used to investigate sex-specific quartiles of serum uric acid in relation to cancer risk in men and women. Analysis was further adjusted for serum glucose, triglycerides and, where available, BMI. Site-specific analysis was performed for major cancers.

Conclusions

Altered uric acid levels were associated with risk of overall and some specific cancers, further indicating the potential role of uric acid metabolism in carcinogenesis.

MR-PheWAS: exploring the causal effect of SUA level on multiple disease outcomes by using genetic instruments in UK Biobank

Objectives

We aimed to investigate the role of serum uric acid (SUA) level in a broad spectrum of disease outcomes using data for 120 091 individuals from UK Biobank.

Methods

We performed a phenome-wide association study (PheWAS) to identify disease outcomes associated with SUA genetic risk loci. We then implemented conventional Mendelianrandomisation (MR) analysis to investigate the causal relevance between SUA level and disease outcomes identified from PheWAS. We next applied MR Egger analysis to detect and account for potential pleiotropy, which conventional MR analysis might mistake for causality, and used the HEIDI (heterogeneity in dependent instruments) test to remove cross-phenotype associations that were likely due to genetic linkage.

Results

Our PheWAS identified 25 disease groups/outcomes associated with SUA genetic risk loci after multiple testing correction (P<8.57e-05). Our conventional MR analysis implicated a causal role of SUA level in three disease groups: inflammatory polyarthropathies (OR=1.22, 95% CI 1.11 to 1.34), hypertensive disease (OR=1.08, 95% CI 1.03 to 1.14) and disorders of metabolism (OR=1.07, 95% CI 1.01 to 1.14); and four disease outcomes: gout (OR=4.88, 95% CI 3.91 to 6.09), essential hypertension (OR=1.08, 95% CI 1.03 to 1.14), myocardial infarction (OR=1.16, 95% CI 1.03 to 1.30) and coeliac disease (OR=1.41, 95% CI 1.05 to 1.89). After balancing pleiotropic effects in MR Egger analysis, only gout and its encompassing disease group of inflammatory polyarthropathies were considered to be causally associated with SUA level. Our analysis highlighted a locus (ATXN2/S2HB3) that may influence SUA level and multiple cardiovascular and autoimmune diseases via pleiotropy.

Conclusions

Elevated SUA level is convincing to cause gout and inflammatory polyarthropathies, and might act as a marker for the wider range of diseases with which it associates. Our findings support further investigation on the clinical relevance of SUA level with cardiovascular, metabolic, autoimmune and respiratory diseases.

Alcohol abuse is associated with enhanced pulmonary and systemic xanthine oxidoreductase activity

Acute respiratory distress syndrome (ARDS) is a common and devastating disorder. Alcohol use disorders (AUDs) increase ARDS risk and worsen outcomes through mechanisms that may include enhancement of pulmonary oxidative stress. Alcohol consumption increases activity of the enzyme xanthine oxidoreductase (XOR) that contributes to production of both reactive oxygen species (ROS) and uric acid, a damage-associated molecular pattern. These by-products have the potential to modulate proinflammatory pathways, such as those involving cyclooxygenase (COX)-2, and to activate the nucleotide-binding domain, leucine-rich-containing family, pyrin-domain containing-3 (NLRP3) inflammasome. We sought to determine if pulmonary and systemic XOR activity was altered by AUDs. Bronchoscopy with bronchoalveolar lavage (BAL) and blood sampling was performed in otherwise healthy human subjects with AUDs and controls. Uric acid in epithelial-lining fluid, derived from BAL, was substantially higher among individuals with AUDs and did not normalize after 7 days of abstinence; serum uric acid did not differ across groups. XOR enzyme activity in fresh BAL cells and serum was significantly increased in subjects with AUDs. XOR protein in BAL cells from AUD subjects was increased in parallel with COX-2 expression, and furthermore, mRNA expression of NLRP3 inflammasome components was sustained in LPS-stimulated BAL cells from AUD subjects in conjunction with increased IL-1β. Our data suggest that AUDs augment pulmonary and systemic XOR activity that may contribute to ROS and uric acid generation, promoting inflammation. Further investigations will be necessary to determine if XOR inhibition can mitigate alcohol-associated pulmonary oxidative stress, diminish inflammation, and improve ARDS outcomes.

Plasma urate, lung function and chronic obstructive pulmonary disease: a Mendelian randomisation study in 114 979 individuals from the general population

BACKGROUND

Urate is a strong antioxidant in plasma and may protect against lung function impairment. We tested the hypothesis that high plasma urate is causally associated with better lung function and low risk of respiratory symptoms and COPD.

METHODS

We measured lung function and plasma urate in 114 979 individuals from the Copenhagen City Heart Study and the Copenhagen General Population Study and genotyped for SLC2A9 rs7442295 and ABCG2 rs2231142 variants, previously associated with high plasma urate, in 110 152 individuals.

RESULTS

In the two studies combined, multivariable-adjusted 100 µmol/L higher plasma urate was associated with -1.54% (95% CI -1.67 to -1.40) lower FEV₁ % predicted and -1.57% (95% CI -1.69 to -1.44) lower FVC % predicted observationally; the corresponding estimates for genetically determined 100 µmol/L higher plasma urate were -0.46% (95% CI -1.17 to 0.25) and -0.40% (95% CI -1.03 to 0.23). High plasma urate was also associated with higher risk of respiratory symptoms; however, genetically determined high plasma urate was not associated with respiratory symptoms. Finally, we identified 14 151 individuals with COPD and found ORs of 1.08 (95% CI 1.06 to 1.11) for COPD observationally and 1.01 (95% CI 0.88 to 1.15) genetically per 100 µmol/L higher plasma urate.

CONCLUSION

High plasma urate was associated with worse lung function and higher risk of respiratory symptoms and COPD in observational analyses; however, genetically high plasma urate was not associated with any of these outcomes. Thus, our data do not support a direct causal relationship.

An association of smoking with serum urate and gout: A health paradox

BACKGROUND

The potential effect of cigarette smoking on levels of serum urate and risk of gout has been considered by a large number of studies, either as the primary variable of interest or as a covariate.

METHODS

Here we systematically review the published evidence relating to the relationship of smoking with serum urate, hyperuricaemia, and gout.

RESULTS

Many studies have reported that smoking reduces serum urate, however, the evidence has not been conclusive with other studies pointing to the opposite or no effect. It has also been suggested that smoking reduces the risk of gout, although there is some evidence to contradict this finding.

CONCLUSION

A consensus has yet to be reached as to the effect of smoking on serum urate levels and the risk of gout.

Inflammatory biomarkers and radiologic measurements in never-smokers with COPD: A cross-sectional study from the CODA cohort

Various biomarkers have emerged as potential surrogates to represent various subgroups of chronic obstructive pulmonary disease (COPD), which manifest with different phenotypes. However, the biomarkers representing never-smokers with COPD have not yet been well elucidated. The aim of this study was to evaluate the associations of certain serum and radiological biomarkers with the presence of COPD in never-smokers. To explore the associations of serum and radiological biomarkers with the presence of COPD in never-smokers, we conducted a cross-sectional patient cohort study composed of never-smokers from the COPD in Dusty Areas (CODA) cohort, consisting of subjects living in dusty areas near cement plants in South Korea. Of the 131 never-smokers in the cohort, 77 (58.8%) had COPD. There were no significant differences in the number of subjects with high levels of inflammatory biomarkers (>90th percentile of never-smokers without COPD), including white blood cell count, total bilirubin, interleukin (IL)-6, IL-8, and C-reactive protein, or radiologic measurements (including emphysema index and mean wall area percentage) between never-smokers with COPD and those without COPD. However, the number of subjects with high uric acid was significantly higher in never-smokers with COPD than never-smokers without COPD (31.2% (24/77) vs. 11.1% (6/54); p = 0.013). In addition, multivariate analysis revealed that high uric acid was significantly associated with the presence of COPD in never-smokers (adjusted relative risk: 1.63; 95% confidence interval: 1.21, 2.18; p = 0.001). Our study suggests that high serum levels of uric acid might be a potential biomarker for assessing the presence of COPD in never-smokers.

Albumin, bilirubin, uric acid and cancer risk: results from a prospective population-based study

BACKGROUND

It has long been proposed that albumin, bilirubin and uric acid may inhibit cancer development due to their anti-oxidative properties. However, there is a lack of population-based studies on blood levels of these molecules and cancer risk.

METHODS

Associations between pre-diagnostic serum albumin, bilirubin and uric acid and the risks of common cancers as well as cancer death in the EPIC-Heidelberg cohort were evaluated by multivariable Cox regression analyses. A case-cohort sample including a random subcohort (n=2739) and all incident cases of breast (n=627), prostate (n=554), colorectal (n=256), and lung cancer (n=195) as well as cancer death (n=761) that occurred between baseline (1994-1998) and 2009 was used.

RESULTS

Albumin levels were inversely associated with breast cancer risk (hazard ratioQuartile 4 vs Quartile 1 (95% CI): 0.71 (0.51, 0.99), Plinear trend=0.004) and overall cancer mortality (HRQ4 vs Q1 (95% CI): 0.64 (0.48, 0.86), Plinear trend<0.001) after multivariable adjustment. Uric acid levels were also inversely associated with breast cancer risk (HRQ4 vs Q1 (95% CI): 0.72 (0.53, 0.99), Plinear trend=0.043) and cancer mortality (HRQ4 vs Q1 (95% CI): 0.75 (0.58, 0.98), Plinear trend=0.09). There were no significant associations between albumin or uric acid and prostate, lung and colorectal cancer. Serum bilirubin was not associated with any cancer end point.

CONCLUSIONS

The present findings indicate that higher levels of albumin and uric acid are related to lower risks of breast cancer and cancer mortality. Further studies are needed to assess whether the observed associations are causal.

Serum Uric Acid in Chronic Obstructive Pulmonary Disease: A Hospital Based Case Control Study

Introduction

Airway inflammation and imbalance between oxidant/anti-oxidant mechanisms are postulated to play a major role in the pathogenesis and exacerbation of Chronic Obstructive Pulmonary Disease (COPD). Previous studies on the role of serum Uric Acid (UA) in COPD subjects have been both confounding and inconclusive.

Aim

To measure the serum UA levels among COPD subjects and to correlate with different stages of the disease.

Materials and Methods

The study included 39 stable COPD subjects (21 males, 18 females; 13 smokers, 26 nonsmokers; age group; 40 to 60 years) and compared with 46 control subjects from the general population. Serum UA levels were measured by enzymatic colorimetric assay in fully automated analyser (Cobas Integra 400+, Roche, Germany) using commercially available kits from Roche. This was further correlated with duration and severity of COPD {determined as per Global Initiative for Obstructive Lung Disease (GOLD) criteria}.

Results

The mean age of COPD and control subjects was 62.97±11.30 and 48.76±12.71 years, respectively (p<0.001). COPD cases had significantly higher level of UA compared to control subjects (4.85±1.67 vs. 2.32±0.93 mg/dl, respectively, p<0.001). Female subjects with COPD had higher levels of UA compared to their male counterparts (5.15±1.89 vs. 4.59±1.45 mg/dl, respectively, p=0.3). Similar insignificant (p=0.56) trend was also observed among control subjects. Hyperuricaemia correlated significantly (p< 0.05) with advance duration (≥ 10 years) of COPD; whereas, statistically insignificant trend was observed for GOLD stage 3/4 versus stage 1/2 disease. Nonsmokers were having higher uric acid level than smokers. Alcohol intake did not affect the level of uric acid in COPD cases (p=0.79).

Conclusion

Serum uric acid is a simple, cost effective biochemical test which may be useful in risk stratification of subjects with newly diagnosed chronic obstructive pulmonary disease. Hyperuricaemia is associated with advance duration and stage of COPD.