Serum uric acid is positively associated with pulmonary function in Korean health screening examinees

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.

Serum uric acid is inversely associated with lung function in US adults

The relationship between serum uric acid and lung function has been controversial. This study aims to determine whether there is an independent relationship between serum uric acid and lung function in the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2012. Serum uric acid was considered the exposure variable, and lung function (FEV1 and FVC) was the outcome variable. Multivariable linear regression was conducted with adjustments for potential confounders. The total number of participants from NHANES (2007-2012) was 30,442, of which 7514 were included in our analysis after applying exclusion criteria. We observed that serum uric acid was negatively associated with FEV1 and FVC after adjusting for confounders (β for FEV1 [- 24.77 (- 36.11, - 13.43)] and FVC [- 32.93 (- 47.42, - 18.45)]). Similarly, serum uric acid showed a negative correlation with FEV1 and FVC after adjusting for confounding variables both in male and female populations. The relationship between serum uric acid and FEV1 and FVC remained consistent and robust in various subgroups within both male and female populations, including age, race, BMI, alcohol consumption, smoking status, and income-poverty ratio. Serum uric acid is negatively associated with FEV1 and FVC in the US general healthy population. This negative relationship is significant in both the male and female populations.

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.

Association of serum uric acid levels with benign prostatic hyperplasia in US men: results from NHANES 2005-2008

BACKGROUND

The relationship between uric acid (UA) and benign prostatic hyperplasia (BPH) is controversial and has rarely been studied in American populations.

METHODS

Data from two cycles of the National Health and Nutrition Examination Surveys, comprising data from 2005 to 2008, were used. The majority of BPH were identified by self-report. We investigated the relationship between UA and BPH using univariate and multivariate logistic regression analyses.

RESULTS

2,845 participants were enrolled in the study, including 531 participants with BPH and 2,314 controls. After fully adjusting for all confounders, the risk of developing BPH was reduced by 18% for every 100 μmol/L increase in UA (OR = 0.82, 95% CI: 0.69-0.97, p = 0.023). Participants in the highest quartile of UA were found to have a reduced likelihood of developing BPH (ORQ4vs1 = 0.61, 95% CI: 0.41-0.91) in comparison to those in the lowest quartile of UA. Subgroup analyses found that among those younger than 60 years, non-Hispanic whites, former smokers, heavy drinkers, those without diabetes, or those with hypertension, high UA remained negatively associated with BPH.

CONCLUSIONS

The above results suggest that UA may be a potential protective factor for BPH, but the mechanism needs to be further explored.

Epidemiology and treatment-related concerns of gout and hyperuricemia in Korean

Gout is the most common form of inflammatory arthritis that affects mainly middle-aged men, and there is clear evidence of an association between hyperuricemia and the risk for gout. Increasing prevalence of gout and hyperuricemia has been reported in many countries. The prevalence of gout and hyperuricemia are constantly increasing in Korea with the patients at risk for developing a variety of comorbidities. Although there have been studies on the association between gout or serum uric acid level and several neurodegenerative diseases, cancer, and cardiovascular mortality, the causal relationship between gout and these comorbidities are still unclear. The associations of substantial economic burden with hyperuricemia, gout attack, and suboptimal treatment are well known. Gout is a disease that requires lifelong management including lifestyle modification. However, gout is poorly managed worldwide although effective urate-lowering drugs exist. In this review, we addressed epidemiological studies and treatment-related problems in the Korean population with gout or hyperuricemia to obtain the best clinical outcomes and reduce their medical burden.

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 serum uric acid levels of patients with gout and their complications and examination fees: A cross-sectional analysis

OBJECTIVE

Correlation influence factor analysis of gout patients' serum uric acid (SUA) levels, their examination fees, and various complications were explored.

METHODS

From January 2017 to December 2021, 17 666 patients with gout were obtained. Conduct quartile grouping according to gout patients' SUA levels was used to compare the differences between groups in terms of examination fees and complications. Kernel density estimation method was adopted to analyze the data distribution, Spearman and Mantel-Haenszel χ² tests were used to analyze the correlation between SUA levels and examination fees and complications. Binary logistic regression analysis was used to analyze the correlation influence factor between SUA levels and complications.

RESULTS

Of the 17 666 gout cases, 85.46% were male. Among them, 7637 (43.23%) were inpatients and 10 029 (56.77%) were outpatients. Compared with outpatients, age, SUA levels, and examination fees were significantly higher, and there were more complications among inpatients (P < 0.05). Correlation analysis revealed that outpatients and SUA levels of patients with gout were positively correlated with examination fees, cardiovascular diseases, pulmonary diseases, liver diseases, and kidney diseases (P < 0.01). Binary logistic regression analysis showed that SUA level is an independent influence factor for cardiovascular diseases, pulmonary diseases, liver diseases, and kidney diseases (odds ratio [95% confidence interval]: 1.002 [1.002-1.002], 1.001 [1.000-1.001], 1.003 [1.002-1.003], and 1.001 [1.001-1.002], respectively).

CONCLUSIONS

As SUA levels increased, examination fees, cardiovascular disease, pulmonary disease, liver disease, and kidney disease complications increased. SUA level is an independent influence factor for the combination of gout with cardiovascular diseases, pulmonary diseases, liver diseases, and kidney diseases.

Higher Levels of Serum Uric Acid Have a Significant Association with Lower Incidence of Lower Urinary Tract Symptoms in Healthy Korean Men

Gout has been correlated with the risk of incident benign prostatic hyperplasia. In line with increasing prevalence of hyperuricemia, the aim of this study was to investigate the relationship between serum uric acid (SUA) level and the incidence of lower urinary tract symptoms (LUTS) among clinically healthy middle-aged men. We performed a cohort study in 101,091 Korean men without LUTS at baseline who completed health checkups between 2011 and 2016. LUTS were evaluated using the International Prostate Symptom Score, where a score ≥ 8 was defined as significant LUTS. Men were divided into six groups according to their SUA levels in mg/dL (<5.5, 5.5−6.4, 6.5−7.4, 7.5−8.4, 8.5−9.4, and ≥9.5). Throughout the follow-up—encompassing a total of 358,982.6 person years—13,424 people had significant LUTS (37.3 per 1000 person years for incidence rate). The multivariable models demonstrated that the highest level of SUA (≥9.5 mg/dL) was related to the lowest risk of significant LUTS compared with the reference category (<5.5 mg/dL) (0.77 (95% CI 0.59−0.99) for adjusted HR). In this large cohort composed of middle-aged men, higher SUA levels were related to a reduced risk of LUTS. This result suggests another potential role of SUA in restraining LUTS. Additional studies are needed to explain the underlying biological mechanisms of this phenomenological relationship.

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.

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.

How much does fat mass change affect serum uric acid levels among apparently clinically healthy Korean men?

Objective:

The aim of this study was to examine the impact of fat mass alteration on serum uric acid (SUA) levels in apparently clinically healthy men.

Methods:

We evaluated 27,387 men who consecutively underwent health check ups between 2015 and 2017. We assessed the likelihood of achieving a SUA level of <0.41 mmol/L and compared the SUA levels according to fat mass changes.

Results:

Compared with those without fat mass change (the reference group), the odds ratios (95% confidence interval) of achieving a SUA level of <0.41 mmol/L for fat mass decreases of ⩾2.5, 1.5–2.5, and 0.5–1.5 kg were 1.63 (1.45–1.82), 1.19 (1.06–1.34), and 1.07 (0.97–1.18), respectively, while those for a fat mass increase of ⩾2.5, 1.5–2.5, and 0.5–1.5 kg were 0.71 (0.64–0.78), 0.87 (0.79–0.97), and 0.95 (0.86–1.04), respectively. The corresponding beta-coefficients of SUA levels (mmol/L) were –0.26 [–0.29–(–0.23)], –0.12 [–0.16–(–0.09)], and –0.09 [–0.12–(–0.06)] for fat mass decreases of ⩾2.5, 1.5–2.5, and 0.5–1.5 kg, respectively. Every 1-kg fat mass reduction was associated with 9% increased odds of achieving the target SUA level. The multivariate SUA level difference per 1-kg fat mass gain was 2.97 µmol/L. Similar levels of association persisted among the prespecified subgroups.

Conclusion:

We quantitatively demonstrated that fat mass reduction contributes to a clinically relevant decrease in SUA levels and a significant increase in the likelihood of achieving target SUA levels. Our findings may help to provide clear clinical guidance on fat mass alteration to reduce SUA levels in patients with hyperuricemia.

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.

Association between serum uric acid and spirometric pulmonary function in Korean adults: The 2016 Korea National Health and Nutrition Examination Survey

BACKGROUND

A limited number of epidemiological studies have investigated the association between serum uric acid and pulmonary function in the general population. However, the results have been inconclusive.

OBJECTIVES

This study was performed to investigate the association between serum uric acid and spirometric pulmonary function in general population.

METHODS

Among the 8,150 participants who participated in the 2016 Korea National Health and Nutrition Examination Survey, 2,901 participants were analyzed in this study. Subjects were divided into four groups according to forced vital capacity (FVC)% predicted or forced expiratory volume in 1 second (FEV1) % predicted quartiles. Participants in the lowest quartile of FVC % predicted and FEV1% predicted were compared to those in the remaining quartiles according to age, education level, household income, smoking status, alcohol consumption, aerobic exercise, obesity, hypertension, diabetes, renal impairment, serum uric acid, and hyperuricemia. Multivariable logistic regression analyses were used to calculate the odds ratio (OR) of hyperuricemia for participants in the lowest quartile of FVC% and FEV1 predicted, with above covariates.

RESULTS

In women, hyperuricemia was associated with lowest quartile of FVC% predicted (OR 1.71, 95% CI 1.06-2.75, p = 0.027) and FEV1 predicted (OR 1.70, 95% CI 1.06-2.74, p = 0.028) respectively, serving as above confounding variables. In men, hyperuricemia (OR 1.54, 95% CI 1.07-2.22, p = 0.021) was associated with the lowest quartile of FEV1% predicted, not FVC% predicted. According to median age, in women, age ≥ 56 years old with hyperuricemia was associated with lowest quartile of FVC% predicted (OR 1.85, 95% CI 1.04-3.28, p = 0.037) and FEV1% predicted (OR 1.99, 95% CI 1.11-3.75, p = 0.021), respectively. In men, age ≥ 56 years old with hyperuricemia was associated with lowest quartile of FEV1% predicted (OR 1.75, 95% CI 1.05-2.94, p = 0.033), not FCV% predicted.

CONCLUSIONS

Hyperuricemia was associated with lowest quartile of FEV1% or FVC% predicted in Korean general population. This correlation between hyperuricemia and low pulmonary function was more pronounced in women and older age.

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.

Decreased lung function is associated with elevated ferritin but not iron or transferrin saturation in 42,927 healthy Korean men: A cross-sectional study

Objectives

Though elevated ferritin level and decreased lung function both predispose people to cardio-metabolic disease, few reports have investigated the association between them. Furthermore, it remains unclear whether the association reflects a change in iron stores or an epiphenomenon reflecting metabolic stress. Therefore, we looked for possible associations between ferritin, iron, and transferrin saturation (TSAT) and lung function to clarify the role of iron-related parameters in healthy men.

Methods

We conducted a cohort study of 42,927 healthy Korean men (mean age: 38.6 years). Percent predicted forced expiratory volume in one second (FEV1%) and forced vital capacity (FVC%) were categorized into quartiles. Adjusted odds ratios (aORs) and 95% confidence intervals (using the highest quartile as reference) were calculated for hyperferritinemia, high iron, and high TSAT after controlling for potential confounders.

Results

The median ferritin level was 199.8 (141.5–275.6) ng/mL. The prevalence of hyperferritinemia (defined as >300 ng/mL) was 19.3%. Subjects with hyperferritinemia had lower FEV1% and FVC% than those with normal ferritin level with a slight difference, but those were statistically significant (99.22% vs.99.61% for FEV1%, p = 0.015 and 98.43% vs. 98.87% for FVC, p = 0.001). However, FEV1/FVC ratio was not significantly different between groups (P = 0.797). Compared with the highest quartile, the aORs for hyperferritinemia across decreasing quartiles were 1.081 (1.005–1.163), 1.100 (1.007–1.200), and 1.140 (1.053–1.233) for FEV1% (p for trend = 0.007) and 1.094 (1.018–1.176), 1.101 (1.021–1.188), and 1.150 (1.056–1.252) for FVC% (p for trend = 0.001). However, neither FEV1% nor FVC% was associated with iron or TSAT.

Conclusions

Hyperferritinemia was associated with decreased lung function in healthy Korean men, but iron and TSAT were not. Longitudinal follow-up studies are required to validate our findings.

The Multi-Institutional Health Screening Records Database of South Korea: Description and Evaluation of Its Characteristics

This study sought to describe and to evaluate the characteristics of the Health Screening Records Database (HSRD) of the Korea Association of Health Promotion as a data source for epidemiologic studies. The HSRD was compared to a National Health Insurance Service-Health Screening Cohort (NHIS-HEALS) database for 2015. Common variables between the databases were selected, and sex-based analyses were conducted. The HSRD showed statistical concordance when NHIS-HEALS estimates fell within the HSRD estimate's 95% confidence interval. The HSRD and NHIS-HEALS included 946461 and 111690 participants in health screening programs, respectively. Compared to the NHIS-HEALS, the HSRD had more female (55.2% vs. 42.6%) but fewer older adult participants (34.4% vs. 51.2%). Virtually all variables had clinical concordance, with some having statistical concordance as well, among both general and life-transition program participants. The HSRD comprised more clinical information over a wider age range in contrast to the NHIS-HEALS, while showing clinical concordance. Providing more comprehensive clinical data, the HSRD may serve as an alternative resource for epidemiologic studies.

Decline in lung function is associated with elevated lipoprotein (a) in individuals without clinically apparent disease: A cross-sectional study

BACKGROUND AND OBJECTIVE

Reduced lung function and high lipoprotein (a) (Lp(a)) levels are both recognized risk factors for cardiovascular disease. Few studies have investigated the association between serum Lp(a) and lung function in the general population. We evaluated the association between reduced lung function and high Lp(a) levels in healthy individuals without known medical disease diagnoses.

METHODS

We performed a cross-sectional study on 64 082 Korean health screening examinees (33 049 males, 38 ± 7 years) who underwent a health examination in 2015.

RESULTS

The median Lp(a) level was 12 (6-25)mg/dL. The prevalence of high Lp(a) (defined as >30 mg/dL) was 19.5%. Subjects with a high Lp(a) had both lower values of measured forced expiratory volume in 1 s (FEV₁ ) and forced vital capacity (FVC; L) than those with a low Lp(a) (P < 0.001). However, FEV₁ /FVC ratio was not significantly different between groups (P = 0.112). Comparison of the second, third and fourth measured FVC (L) quartiles with that of the lowest quartile (1Q) group (reference) on regression analysis revealed adjusted odd ratios (OR) for a high Lp(a) of 0.928 (95% CI: 0.876-0.982), 0.860 (0.808-0.916) and 0.895 (0.839-0.954), respectively (P for trend < 0.001). In addition, adjusted OR for high Lp(a) compared with reference was 0.894 (0.844-0.947), 0.857 (0.806-0.912) and 0.882 (0.8727-0.940) across the measured FEV₁ (L) quartiles in increasing order (P for trend < 0.001).

CONCLUSION

High Lp(a) levels were associated with reduced lung function in this cross-sectional population study. Longitudinal follow-up studies will be required to validate our findings.

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.