C-reactive protein levels, airflow obstruction, and chronic kidney disease

Comorbidities according to airflow limitation severity: data from comprehensive health examination in Japan

OBJECTIVES

The present study aimed to investigate the relationship between airflow limitation (AL) severity and comorbidities in comprehensive health examination.

METHODS

This cross-sectional study included 6661 men and 6044 women aged 40-89 who underwent a lung function test during medical checkups. AL was defined as forced expiratory volume in 1 s/forced vital capacity of < 0.7. Logistic regression analysis was used to assess the association between AL severity and the presence of comorbidities.

RESULTS

When compared with the normal lung function group, subjects with AL had a higher prevalence of lung cancer (odd ratio (OR) 9.88, 95% confidence interval (CI) 3.88-25.14) in men, hypertension (OR 1.63, 95% CI 1.26-2.10) in women, diabetes and hyperglycemia (OR 1.23, 95% CI 1.02-1.49 in men, OR 1.61, 95% CI 1.18-2.20 in women) in men and women after adjusting for potential confounders. In men, lung cancer and MetS (the Joint Interim Statement: JIS) were significantly associated with moderate-to-very severe AL after adjustment. In women, hypertension, diabetes and hyperglycemia, MetS (JIS), and MetS (the Japanese Committee of the Criteria for MetS: JCCMS) were significantly associated with mild AL after adjustment. Hypertension was significantly associated with moderate-to-very severe AL after adjustment in women.

CONCLUSIONS

Significant relationships were found between AL severity and the presence of comorbid lung cancer in men, hypertension in women, diabetes and hyperglycemia, and MetS in men and women. Knowledge of comorbidities associated with AL should be widely publicized to raise the awareness of chronic obstructive pulmonary disease (COPD).

Relationship of airflow limitation severity with work productivity reduction and sick leave in a Japanese working population

BACKGROUND

The aim of this study was to reveal the association between airflow limitation (AL) severity and reduction with work productivity as well as use of sick leave among Japanese workers.

METHODS

This cross-sectional study included 1,378 workers who underwent a lung function test during a health checkup at the Japanese Red Cross Kumamoto Health Care Center. AL was defined as forced expiratory volume in 1 second/forced vital capacity of <0.7. Workers completed a questionnaire on productivity loss at work and sick leave. The quality and quantity of productivity loss at work were measured on a ten-point scale indicating how much work was actually performed on the previous workday. Participants were asked how many days in the past 12 months they were unable to work because of health problems. Logistic regression analysis was used to assess the associations between AL severity and the quality and quantity of productivity loss at work as well as use of sick leave.

RESULTS

Compared with workers without AL, workers with moderate-to-severe AL showed a significant productivity loss (quality: odds ratio [OR] =2.04, 95% confidence interval [CI]: 1.12-3.71, P=0.02 and quantity: OR =2.19, 95% CI: 1.20-4.00, P=0.011) and use of sick leave (OR =2.69, 95% CI: 1.33-5.44, P=0.006) after adjusting for sex, age, body mass index, smoking status, hypertension, hyperglycemia, dyslipidemia, sleep duration, work hours per day, and workplace smoking environment.

CONCLUSION

AL severity was significantly associated with work productivity loss and use of sick leave. Our findings suggested that early intervention in the subjects with AL at the workforce might be beneficial for promoting work ability.

Mortality Outcomes of Patients with Chronic Kidney Disease and Chronic Obstructive Pulmonary Disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with higher mortality in the general population. We studied the associations between COPD and death among chronic kidney disease (CKD) patients along with reporting cause-specific death data.

METHODS

We included 56,960 patients with stages 3 and 4 CKD who were followed in a large health care system. Associations between COPD and all-cause mortality and various causes of death (respiratory deaths, cardiovascular deaths, malignancy-related deaths and deaths due to other reasons) were studied using the Cox proportional hazards and competing risk models.

RESULTS

Out of 56,960 CKD patients, 4.7% (n = 2,667) had underlying COPD. Old age, presence of diabetes, hypertension, coronary artery disease, congestive heart failure, and smoking were associated with higher risk for COPD. During a median follow-up of 3.7 years, 15,969 patients died. After covariate adjustment, COPD was associated with a 41% increased risk (95% CI 1.31-1.52) for all-cause mortality, and fourfold increased risk (sub-hazard ratio 4.36, 95% CI 3.54-5.37) for respiratory-related deaths. In a sensitivity analysis that was performed by defining COPD as the use of relevant International Classification of Diseases-9 codes and medications used to treat COPD, similar results were noted.

CONCLUSIONS

COPD is associated with higher risk for death among those with CKD, and an underlying lung disease accounts for significant proportion of deaths. These data highlight the need for further prospective studies to understand the underlying mechanisms and potential interventions to improve outcomes in this population.