The association between risk of airflow limitation and serum uric acid measured at medical health check-ups

[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.

A study on the correlation between hyperuricemia and TG/HDL-c ratio in the Naxi ethnic group at high-altitude regions of Yunnan

Objective

The study aimed to explore the risk factors for hyperuricemia (HUA) in the Naxi ethnic population residing in high-altitude areas of Yunnan, China, and assess the clinical value of the triglyceride/high-density lipoprotein cholesterol (TG/HDL-c) ratio as a diagnostic marker.

Methods

In this cross-sectional study, clinical data were collected from the health checkup population in the People's Hospital of Yulong Naxi Autonomous County, Yunnan Province, from January 2021 to January 2023. Participants were divided into quartiles based on the TG/HDL-c ratio (Q1, Q2, Q3, and Q4) for group analysis using chi-square tests, t-tests, and rank sum tests. Logistic regression analysis and linear regression models were employed to further investigate the correlation between the prevalence of hyperuricemia and TG/HDL-c ratio in this high-altitude Naxi population.

Results

A total of 714 participants from the health checkup population were included in the study, of whom 61.5% were male participants and 38.5% were female participants, and the average age was 41.21 ± 11.69 years. The mean uric acid level was 388.51 ± 99.24. After correcting for confounding factors, TG/HDL-c, serum creatinine (Scr), blood urea nitrogen (BUN), triglyceride (TG), high-density lipoprotein cholesterol (HDL-c), red blood cells (RBCs), and hemoglobin (Hb) showed a positive correlation with blood uric acid. Further analysis involved categorizing the TG/HDL-c ratio from a continuous variable to a categorical variable using quartiles. The fully adjusted model showed results that were consistent with the trend observed in the continuous variable analysis when considering the TG/HDL-c ratio as a categorical variable. In addition, in all unadjusted and adjusted models, the serum uric acid (SUA) levels in the high TG/HDL-c ratio group were significantly higher than those in the low TG/HDL-c ratio group (trend p < 0.001). Further linear relationship analysis indicated that after adjusting for covariates, there was an approximate linear relationship between the TG/HDL-c and SUA levels, with a coefficient (β) of 5.421.

Conclusion

The prevalence of hyperuricemia is greater in high-altitude areas of Yunnan, showing a nearly linear positive correlation with the TG/HDL-c ratio. Monitoring TG/HDL-c levels may benefit patients with hyperuricemia.

Risk factors analysis of noninvasive positive pressure ventilation in inpatients with overlapping syndrome of chronic obstructive pulmonary disease combined with obstructive sleep apnea

OBJECTIVE

The aim of the study was to analyze the clinical data of patients with chronic obstructive pulmonary disease and obstructive sleep apnea overlap syndrome (OS) during hospitalization and to evaluate the risk factors of patients treated with Non-Invasive Ventilation (NIV).

METHODS

Demographic and clinical data of patients with confirmed OS during hospitalization were retrospectively collected. The patients were divided into two groups according to whether noninvasive ventilator was used during hospitalization, including OS treated with NIV (244 cases) and OS without NIV (239 cases). The t-test, χ 2 test, and Kaplan-Meier curve were used to compare the two groups, and multiple logistic regression was used to analyze the risk factors of NIV in patients with OS.

RESULTS

Compared with the OS group without NIV, the pulmonary hypertension, lymphocyte count, and left ventricular ejection fraction% of OS patients with NIV were lower, whereas PCO2, uric acid, C-reactive protein, procalcitonin, and N-terminal pro-B-type natriuretic peptide were higher, with statistical differences (P < 0.05). During hospitalization and follow-up, OS patients with NIV had a longer hospital stay (P < 0.001), and there was no significant difference in the rate of readmission within 28 days. The logistic regression analysis showed that the history of diuretic use, previous history of noninvasive ventilator use, and ischemic heart disease were independent risk factors for NIV treatment in OS patients during hospitalization.

CONCLUSION

Patients with OS undergoing NIV during hospitalization exhibited more severe overall illness and had prolonged hospital stays compared to OS patients not receiving NIV. History of diuretic use, history of NIV use, and ischemic heart disease are independent risk factors for NIV treatment in OS patients during hospitalization.

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.

Association between smoking behavior and serum uric acid among the adults: Findings from a national cross-sectional study

BACKGROUND

Gout incidence is increasing worldwide; appropriate management of serum uric acid levels and a healthy lifestyle may help its prevention. The popularity of electronic cigarettes and the resultant emergence of dual smokers is increasing. Despite many studies on the effects of various health behaviors on serum uric acid levels, the association between smoking and serum uric acid levels remains controversial. This study aimed to investigate the association between smoking and serum uric acid levels.

METHODS

In this study, total sample of 27,013 participants (11,924 men and 15,089 women) were analyzed. This study used data from the Korea National Health and Nutrition Examination Survey (2016-2020) and grouped adults into dual smokers, single smokers, ex-smokers, and non-smokers. Multiple logistic regression analyses were performed to investigate the association between smoking behavior and serum uric acid levels.

RESULTS

Compared to male non-smokers, male dual smokers had significantly higher serum uric acid level (odds ratio [OR], 1.43; 95% confidence interval [CI], 1.08-1.88). In female, serum uric acid level was higher among single smokers than non-smokers (OR, 1.68; 95% CI, 1.25-2.25). Higher serum uric acid levels were more likely to be present in male dual smokers with a > 20 pack-year smoking habit (OR, 1.84; 95% CI, 1.06-3.18).

CONCLUSION

Dual smoking may contribute to high serum uric acid levels in adults. Thus, serum uric acid levels should be properly managed through smoking cessation.

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.

Monocyte to high-density lipoprotein cholesterol ratio and serum uric acid in Chinese adults: a cross-sectional study

BACKGROUND

Previous studies have shown that the monocyte to high-density lipoprotein cholesterol (HDL-C) ratio (MHR) is a predictor of various diseases such as coronary heart disease, diabetic microangiopathy, and metabolic syndrome. However, there are few scientific reports on the correlation between MHR and serum uric acid. The objective of this report is to explore the relationship between MHR and serum uric acid in Chinese adults.

METHODS

This cross-sectional study included 646 participants from southwest China who underwent a health examination at the Health Management Center of Deyang People's Hospital. The examination included blood pressure readings, routine blood tests (lipid, fasting glucose, serum transaminase, and serum uric acid levels), and various standardized questionnaires. We employed a generalized additive model and smoothed curve fitting to explore the relationship between MHR and serum uric acid levels. We then performed subgroup analyses to investigate the robustness of this relationship.

RESULTS

After adjusting for confounders (age, sex, body mass index, systolic blood pressure, diastolic blood pressure, aspartate transaminase, alanine aminotransferase, fasting glucose, total cholesterol, low-density lipoprotein, smoking, drinking, and exercise status), MHR was found to be positively correlated with serum uric acid levels (P < 0.001). The smoothing curve showed an approximately linear correlation between MHR and serum uric acid levels, and the linear correlation coefficient was 146.74 (95% CI 96.16-197.33, P < 0.0001). The subgroup analyses showed that the effect of MHR on serum uric acid levels was smaller in occasional smokers and smokers than in nonsmokers (P = 0.0194).

CONCLUSION

MHR was significantly and positively correlated with serum uric acid levels. Additionally, the effect of MHR on serum uric acid levels was lower in the individuals who smoked more.

Mortality Beyond the First Year After Spinal Cord Injury: Does Body Mass Index Matter?

OBJECTIVE

To examine the association between body mass index (BMI [calculated as weight in kilograms divided by height in meters squared]) and mortality after the first year post spinal cord injury (SCI) overall and across demographic and injury characteristics.

DESIGN

Cohort study.

SETTING

Sixteen Spinal Cord Injury Model Systems (SCIMS) centers.

PARTICIPANTS

SCIMS Database participants age 20 years or older and having a BMI assessment during the 2007-2011 wave of data collection.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

All-cause mortality rate. Life table method and log-rank test were used to estimate and compare mortality rates across BMI groups and other factors. Cox proportional hazard regression model was conducted to estimate hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

A total of 2346 participants (N=2346) with SCI were classified into 1 of the 8 BMI groups: <18.5 (6.9%), 18.5-19.9 (7.3%), 20.0-22.49 (15.0%), 22.5-24.9 (18.8%), 25.0-27.49 (17.5%), 27.5-29.9 (13.2%), 30.0-34.9 (13.5%), and ≥35.0 (7.8%). Compared with people with BMI of 22.5-29.9, a higher mortality risk was observed among people with BMI<18.5 (HR, 1.76; 95% CI, 1.25-2.49), 18.5-19.9 (HR, 1.51; 95% CI, 1.06-2.15), and ≥35.0 (HR, 1.51; 95% CI, 1.11-2.07) after adjusting for confounding factors (sex, age at the time of BMI assessment, marital status, neurologic status). The U-shape BMI-mortality relationship varied by age, sex, neurologic status, and years since injury.

CONCLUSIONS

To improve life expectancy after SCI, health care professionals could focus on weight management among patients with relatively low and extremely high BMI, defined by demographic and injury-related characteristics. Future studies should explore factors that contribute to such a higher mortality after SCI, including pre-existing conditions, poor diet and/or nutrition, and cardiorespiratory fitness.

Serum uric acid level as a biomarker for chronic obstructive pulmonary disease: a meta-analysis

OBJECTIVE

To determine if there is a relationship between the levels of serum uric acid and the different Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages (1-4) classified by the severity of the airflow limitation in patients with stable chronic obstructive pulmonary disease (COPD).

METHODS

Electronic databases, including PubMed®, Embase®, Web of Science™ and China National Knowledge Infrastructure (CNKI), were searched from inception to December 2018. Observational studies that reported serum uric acid levels in stable COPD patients were included. Two investigators independently extracted data and RevMan version 5.3 was used to carry out the statistical analyses.

RESULTS

Seven studies with 932 stable COPD patients and 401 healthy control subjects were included in this meta-analysis. Serum uric acid levels were significantly higher in stable COPD patients compared with healthy control subjects (mean difference [MD] 1.91, 95% confidence interval [CI] 1.55, 2.28). Serum uric acid levels were significantly lower in the GOLD 1+2 subgroup compared with the GOLD 3+4 subgroup (MD -1.39, 95% CI -1.63, -1.15).

CONCLUSION

Serum uric acid might be a useful biomarker for identifying disease severity in stable COPD patients, but further studies are needed to confirm this finding.

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.

Association of urinary cotinine-verified smoking status with hyperuricemia: Analysis of population-based nationally representative data

INTRODUCTION

Smoking status based solely on self-reporting is unreliable and might be inaccurate, particularly among women. This study investigated the association between urinary cotinine-verified smoking status and hyperuricemia in a nationwide Korean population.

METHODS

This study included 5329 participants aged ≥19 years with information on smoking status, urine cotinine levels and serum uric acid. We determined smoking status according to self-reports and urinary cotinine levels. Multivariate linear regression analysis was used to measure the association between smoking exposure and serum uric acid levels. The effects of smoking on hyperuricemia were evaluated by multivariate logistic regression analysis.

RESULTS

Biochemically verified active and passive smokers comprised 22% (38.7% of men and 8.8% of women) and 12.3% (11.9% of men and 12.6% of women) of the study population, respectively. While reclassification rate of active smokers was 1.4% in men, 31.8% of cotinine-verified female active smokers were self-reported never smokers. Higher uric acid levels were observed with increased tobacco exposure among women (p-trend=0.007) but not among men. After adjusting for confounders, the risk of hyperuricemia increased with tobacco exposure only in women (p-trend=0.016).

CONCLUSIONS

Cotinine-verified smoking status was associated with increased serum uric acid and hyperuricemia in a dose-response manner only in women. This study might provide evidence to support the importance of smoking cessation in women with gout and further studies are necessary to elucidate the underlying mechanism of the observed association.

Uric acid and uric acid to creatinine ratio in the assessment of chronic obstructive pulmonary disease: Potential biomarkers in multicomponent models comprising IL-1beta

Chronic obstructive pulmonary disease (COPD) is a complex and heterogeneous disease, with oxidative stress and inflammation implicated in its development. Uric acid (UA) could exert anti-oxidative, pro-oxidative or pro-inflammatory effects, depending on the specific context. It was recently shown that soluble UA, and not just its crystals, could activate the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, leading to interleukin (IL)-1β secretion. We aimed to assess the differences in blood levels of UA and its ratio with creatinine (UCR) between COPD patients and healthy subjects, as well as their association with disease severity, smoking status, common COPD comorbidities and therapy regimes. The diagnostic characteristics of UA and UCR were also explored. This study included 109 stable COPD patients and 95 controls and measured white blood cells (WBC), C-reactive protein (CRP), fibrinogen (Fbg), IL-1β, creatinine (CREAT) and UA. All of the parameters were increased in COPD patients, except for CREAT. UA and UCR were positively associated with WBC, CRP and IL-1β. COPD smokers had lower UA and UCR values. Common COPD therapy did not affect UA or UCR, while patients with cardiovascular diseases (CVD) had higher UA, but not UCR, levels. Patients with higher UCR values showed worse disease-related outcomes (lung function, symptoms, quality of life, history of exacerbations, BODCAT and BODEx). Also, UCR differentiated patients with different severity of airflow limitation as well as symptoms and exacerbations. The great individual predictive potential of UCR and IL-1β was observed with their odds ratios (OR) being 2.09 and 5.53, respectively. Multiparameter models of UA and UCR that included IL-1β were able to correctly classify 86% and 90% of cases, respectively. We suggest that UA might be a useful biomarker when combined with IL-1β, while UCR might be even more informative and useful in overall COPD assessments.

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.

Association between underweight and pulmonary function in 282,135 healthy adults: A cross-sectional study in Korean population

In contrast to obesity, studies on the relationship between underweight and pulmonary function are still sparse. Thus, the objective of this study was to investigate the effect of being underweight on pulmonary function in a general population without apparent lung disease. A total of 282,135 retrospective cohort subjects between January 2012 and December 2014 in Korea were included. Using multivariate-adjusted analysis, the relationship between body mass index (BMI) and pulmonary function were assessed. Underweight individuals represented 5.5% of the total study population (n = 282,135), with most (87.9%) of them being females. Compare to normal weight and obese, underweight was associated with decreased pulmonary function. Forced expiratory volume in first second (FEV1), predicted FEV1 (%), forced vital capacity (FVC), predicted FVC (%), and peak expiratory flow (PEF) were lower in the underweight group than those in other groups after adjusting for age, sex, height, status of smoking, frequency of vigorous exercise, diabetes, and high-sensitivity C-reactive protein (hsCRP) (P < 0.001). Lower BMI tended to decrease pulmonary function parameters such as FEV1 (L), predicted FEV1 (%), FVC (L), predicted FVC (%), and PEF (L/sec) (P for trend <0.001). After adjusting for possible confounders, odds ratios (ORs; 95% confidence interval) for subjects with predicted FEV1% < 80% in underweight and normal weight groups compared to obese group (reference) were 2.10 (1.98–2.21), and 0.93 (0.90–0.97), respectively. ORs for subjects with predicted FVC% < 80% in underweight and normal weight groups compared to obese group (reference) were 4.90 (4.62–5.18) and 1.32 (1.27–1.38), respectively. This study demonstrated a proportional relationship between pulmonary function and the degree of BMI. We found that underweight status was independently associated with decreased pulmonary function in Korean population.

Impact of reduced pulmonary function in the Japanese general population: Lessons from the Yamagata-Takahata study

Regional epidemiological studies for respiratory diseases have been rarely performed in Japan, because spirometry is not regularly conducted in the standard annual health checks. The Yamagata-Takahata Study is an epidemiological study utilizing regional characteristics based on the 21st Century Centers of Excellence (COE) Program and the Global COE Program. Spirometric examination and other specific measurements via blood sampling were performed for the study participants in annual health check-ups held in Takahata, a town in Yamagata Prefecture. The Yamagata-Takahata Study revealed the impact of cigarette smoking habit on pulmonary function, the impact of reduced pulmonary function on mortality, and the situation regarding COPD comorbidities in Japan. Additionally, the study identified biomarkers of decline in pulmonary function among active smokers, and the risk factors for respiratory mortality in Japan. In this review, we summarize the findings of the Yamagata-Takahata study regarding the association between lower pulmonary function and the clinical characteristics of a Japanese general population.

Association between smoking and serum uric acid in Korean population: Data from the seventh Korea national health and nutrition examination survey 2016

The aim of this study was to identify any association between serum uric acid and smoking status using data from the Seventh Korea National Health and Nutrition Examination Survey (KNHANES VII-1) 2016 of the Korean population.This study used a cross-sectional design and analyzed 5609 subjects aged ≥ 19 years among 8150 participants enrolled in the KNHANES VII-1 2016. Smoking status was classified into current smokers, never smokers, and ex-smokers. Hyperuricemia was defined as > 7.0 mg/dL for men and > 6.0 mg/dL of serum uric acid for women. Association between smoking and serum uric acid/hyperuricemia was assessed by Pearson's or Spearman's correlation analyses and multivariate logistic regression analysis showing odds ratio (OR) and 95% confidence interval (CI).A significant difference in serum uric acid according to smoking status was identified in female (P < .001) but not in male subjects (P = .069). In female subjects, current smokers and ex-smokers showed higher serum uric acid than never smokers (P < 0.001 of both). Serum uric acid was associated with smoking status in female but not male subjects (r = 0.057, P = .001 and r = 0.025, P = .220, respectively). There was significant difference of smoking status between female subjects with and without hyperuricemia (P < .001). Current smokers had 2.7 times higher likely to have hyperuricemia in female, compared to never smokers (OR 2.674, 95% CI 1.578 - 4.531, P < .001).This study revealed that smoking was closely associated with serum uric acid in female but not in male subjects in Korean population.

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.