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

Abstract

The prevalence of COPD and asthma is increasing all over the world; however, their morbidities are thought to be greatly underestimated because of unawareness of patients’ conditions and respiratory symptoms. Spirometry is useful for the early detection of COPD and asthma with airflow limitation (AL), although it is not yet widely used for screening in epidemiological and primary care settings. A simple predictive marker used in combination with spirometry for AL is expected to be established. In medical health check-ups, serum uric acid (s-UA) is measured when screening for gout and has recently been suggested to have an association with several respiratory disorders, including asthma and COPD. However, whether s-UA influences the development of AL remains unclear. Therefore, the aims of this study were to examine the relationship between AL and s-UA and to investigate s-UA as a potential auxiliary marker for predicting AL risk in medical health check-ups. A total of 8,662 subjects aged >40 years were included. They were administered a simple questionnaire and assessed using pulmonary function tests, blood pressure (BP) measurements, and blood samplings. One hundred and fifty-six subjects (1.8%) had AL, just 29% of whom had experienced respiratory symptoms. The subjects with AL had significantly higher s-UA levels compared with never-smoking subjects without AL. Forced expiratory volume in 1 second (FEV1) %predicted showed significant correlations with age, smoking index, body mass index (BMI), mean BP, white blood cells, hemoglobin A1c, s-UA, and high-density lipoprotein cholesterol. In multiple logistic regression analysis, s-UA, in addition to age, smoking index, respiratory symptoms, and BMI, was independently associated with AL. In conclusion, elevated s-UA levels, together with respiratory symptoms, high smoking index, and weight loss, may epidemiologically predict the development of AL risk.

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

“…Another report from the Coronary Artery Risk Development in Young Adults (CARDIA) study showed that women who were smoking at baseline had a significantly higher risk for increased uric acid levels over 10 years than women who were non-smokers; however, this finding was not observed among men 13 . Comparable findings were also reported in a study conducted in Japan showing increased serum uric acid among the smoking population 14 . Although the reason for the positive association between smoking exposure and hyperuricemia only in women is unclear, prominent renal function declining in women with IgA nephritis might, at least partly, be related to this finding 21 .…”

“…The Coronary Artery Risk Development in Young Adults (CARDIA) study showed higher serum uric acid levels in female smokers than in female non-smokers 13 . Another study conducted in Japan showed that smoking was associated with increased serum uric acid levels regardless of sex 14 . However, a study using Framingham Heart Study cohort data reported that cigarette smoking had protective effects against elevated uric acid levels 15 and a longitudinal study from Japan observed a decreased risk of hyperuricemia among smokers 16 .…”

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

“…Fukuhara et al . have found that predicted FEV1 is negatively correlated with BMI in 8,662 subjects aged over 40 years 13 . Another study on 370 university students has found that the underweight group has significantly lower FVC than the normal weight group 14 .…”

Association between smoking and serum uric acid in Korean population

“…An increasing effect of smoking on serum uric acid was also consistently observed in other Asian study populations including Japan and Nepal. [16,17]…”