David Sprunger

Rheumatoid Arthritis–Interstitial Lung Disease–associated Mortality

RATIONALE Mortality rates from rheumatoid arthritis-associated interstitial lung disease (RA-ILD) are largely unknown. OBJECTIVES We sought to determine mortality rates from rheumatoid arthritis-associated interstitial lung disease in the United States from 1988 through 2004. METHODS Using data from the National Center for Health Statistics, we calculated age-adjusted mortality rates from the deaths of persons with rheumatoid arthritis-associated interstitial lung disease, determined the prevalence of interstitial lung disease in all decedents with rheumatoid arthritis, and compared the age and underlying cause of death in these two cohorts of decedents. MEASUREMENTS AND MAIN RESULTS From 1988 to 2004, there were 39,138,394 deaths in U.S. residents and 162,032 rheumatoid arthritis-associated deaths. Of these deaths, 10,725 (6.6%) met criteria for rheumatoid arthritis-associated interstitial lung. Mortality rates from rheumatoid arthritis fell over the course of this study in both women and men. However, mortality rates from rheumatoid arthritis-associated interstitial lung disease increased 28.3% in women (to 3.1 per million persons in 2004) and declined 12.5% in men (to 1.5 per million persons in 2004). Because the rate of decline in rheumatoid arthritis outpaced rheumatoid arthritis-associated interstitial lung disease in men, the prevalence of rheumatoid arthritis-associated interstitial lung disease increased in both sexes over time. CONCLUSIONS Clinically significant RA-ILD occurs in nearly 10% of the RA population, and is associated with shortened survival and more severe underlying disease. Whereas overall mortality rates for RA have fallen, those associated with RA-ILD have increased significantly in older age groups.

Sarcoidosis-related mortality in the United States from 1988 to 2007.

RATIONALE It has been nearly 20 years since sarcoidosis mortality was examined at the population level in the United States. OBJECTIVES To examine mortality rates and underlying causes of death among United States decedents with sarcoidosis from 1988-2007. METHODS We used data from the National Center for Health Statistics to (1) calculate age-adjusted sarcoidosis-associated mortality rates; (2) examine how those rates differ by age, sex, and race and ethnicity; and (3) determine underlying causes of death among sarcoidosis decedents. MEASUREMENTS AND MAIN RESULTS From 1988-2007, there were 46,450,489 deaths in the United States and 23,679 decedents with sarcoidosis mentioned on their death certificates. Over this time, the age-adjusted, sarcoidosis-related mortality rate increased 50.5% in women and 30.1% in men. The greatest absolute increase in death rates was among non-Hispanic black females. Regardless of sex or race, mortality rates climbed most in decedents 55 years or older. The most common cause of death was sarcoidosis itself. Younger sarcoidosis decedents with pulmonary fibrosis were more likely to be black than white, and younger sarcoidosis decedents were more likely than similarly aged decedents in the general population to have a cardiac cause contribute to death. CONCLUSIONS From 1988-2007, sarcoidosis-related mortality rates increased significantly, particularly in non-Hispanic black females aged 55 years or older. The underlying cause of death in most patients with sarcoidosis was the disease itself. Among young sarcoidosis decedents, those with pulmonary fibrosis or a cardiac cause contributing to death were more likely to be black than white.

Heart Rate Recovery After 6-Min Walk Test Predicts Survival in Patients With Idiopathic Pulmonary Fibrosis

BACKGROUND In patients with idiopathic pulmonary fibrosis (IPF), our objectives were to identify predictors of abnormal heart rate recovery (HRR) at 1 min after completion of a 6-min walk test (6MWT) [HRR1] and 2 min after completion of a 6MWT (HRR2), and to determine whether abnormal HRR predicts mortality. METHODS From 2003 to 2008, we identified IPF patients who had been evaluated at our center (n = 76) with a pulmonary physiologic examination and the 6MWT. We used logistic regression to identify predictors of abnormal HRR, the product-limit method to compare survival in the sample stratified on HRR, and Cox proportional hazards analysis to estimate the prognostic capability of abnormal HRR. RESULTS Cutoff values were 13 beats for abnormal HRR1 and 22 beats for HRR2. In a multivariable model, predictors of abnormal HRR1 were diffusing capacity of the lung for carbon monoxide (odds ratio [OR], 0.4 per 10% predicted; 95% confidence interval [CI], 0.2 to 0.7; p = 0.003), change in heart rate from baseline to maximum (OR, 0.9; 95% CI, 0.8 to 0.97; p = 0.01), and having a right ventricular systolic pressure > 35 mm Hg as determined by transthoracic echocardiogram (OR, 12.7; 95% CI, 2.0 to 79.7; p = 0.01). Subjects with an abnormal HRR had significantly worse survival than subjects with a normal HRR (for HRR1, p = 0.0007 [log-rank test]; for HRR2, p = 0.03 [log-rank test]); these results held for the subgroup of 30 subjects without resting pulmonary hypertension (HRR1, p = 0.04 [log-rank test]). Among several candidate variables, abnormal HRR1 appeared to be the most potent predictor of mortality (hazard ratio, 5.2; 95% CI, 1.8 to 15.2; p = 0.004). CONCLUSION Abnormal HRR after 6MWT predicts mortality in IPF patients. Research is needed to confirm these findings prospectively and to examine the mechanisms of HRR in IPF patients.

Increased Risk of Pulmonary Embolism Among US Decedents With Sarcoidosis From 1988 to 2007

BACKGROUND A recently published report from the United Kingdom suggested an association between sarcoidosis and pulmonary embolism (PE). We sought to examine whether this association was present among US decedents with sarcoidosis. METHODS We used data from the National Center for Health Statistics to investigate the association between sarcoidosis and PE among US decedents from 1988 to 2007. RESULTS From 1988 to 2007, there were 46,450,489 deaths in the United States and 23,679 decedents with sarcoidosis mentioned on their death certificates. Among these, 602 (2.54%) had PE mentioned on their death certificates, compared with only 1.13% of the background population (P < .0001 for comparison). The association between sarcoidosis and PE was significant regardless of gender (OR, 2.07; 95% CI, 1.80-2.39; P < .0001 for men and OR, 1.76; 95% CI, 1.59-1.96; P ≤ .0001 for women) or race (OR, 1.57; 95% CI, 1.41-1.76; P < .0001 for blacks and OR, 1.87; 95% CI, 1.63-2.14; P < .0001 for whites). Among decedents with sarcoidosis, there was no difference in risk of PE between men and women (2.30% vs 2.54%, χ(2) = 1.32, P = .25) or between blacks and whites (2.60% vs 2.23%, χ(2) = 3.09, P = .08). The association between sarcoidosis and PE held regardless of age. CONCLUSIONS Using death certificate data from 1988 to 2007, we detected an association between sarcoidosis and PE regardless of gender, race, or age. Further investigation is needed to decipher the mechanisms of this apparent association.

Pulmonary function and survival in idiopathic vs secondary usual interstitial pneumonia.

BACKGROUND The usual interstitial pneumonia (UIP) pattern of lung injury may occur in the setting of connective tissue disease (CTD), but it is most commonly found in the absence of a known cause, in the clinical context of idiopathic pulmonary fibrosis (IPF). Our objective was to observe and compare longitudinal changes in pulmonary function and survival between patients with biopsy-proven UIP found in the clinical context of either CTD or IPF. METHODS We used longitudinal data analytic models to compare groups (IPF [n = 321] and CTD-UIP [n = 56]) on % predicted FVC (FVC %) or % predicted diffusing capacity of the lung for carbon monoxide (Dlco %), and we used both unadjusted and multivariable techniques to compare survival between these groups. RESULTS There were no significant differences between groups in longitudinal changes in FVC % or Dlco % up to diagnosis, or from diagnosis to 10 years beyond (over which time, the mean decrease in FVC % per year [95% CI] was 4.1 [3.4, 4.9] for IPF and 3.5 [1.8, 5.1] for CTD-UIP, P = .49 for difference; and the mean decrease in Dlco % per year was 4.7 [4.0, 5.3] for IPF and 4.3 [3.0, 5.6] for CTD-UIP, P = .60 for difference). Despite the lack of differences in pulmonary function, subjects with IPF had worse survival in unadjusted (log-rank P = .003) and certain multivariable analyses. CONCLUSIONS Despite no significant differences in changes in pulmonary function over time, patients with CTD-UIP (at least those with certain classifiable CTDs) live longer than patients with IPF--an observation that we suspect is due to an increased rate of mortal acute exacerbations in patients with IPF.

Assessing dyspnea and its impact on patients with connective tissue disease-related interstitial lung disease

RATIONALE Dyspnea is the cardinal symptom in patients with any type of interstitial lung disease (ILD); however, there are limited data on dyspnea among patients with connective tissue disease-related ILD (i.e., CTD-ILD). OBJECTIVES To explore the utility of two dyspnea instruments (the University of California San Diego Shortness of Breath Questionnaire [UCSD] and the Dyspnea-12 [D-12]) and use their scores to examine the impact of dyspnea on the lives of patients with CTD-ILD. METHODS Subjects were enrolled from the Autoimmune Lung Database (ALD) at National Jewish Health. Chronbachs alpha was used to assess the internal consistency reliability of the two dyspnea questionnaires. We used the Multi-Dimensional Health Assessment Questionnaire [MDHAQ] as a measure of health status and examined associations between health status and dyspnea by using Pearson product-moment correlation and linear regression. RESULTS The internal consistency reliability of each of the two dyspnea questionnaires was excellent (alpha=0.9 for each). There were significant correlations between either of the two dyspnea measures and MDHAQ components. While controlling for ILD severity, dyspnea as assessed by the UCSD, was a significant predictor of physical function (p=0.04), psychological well-being (p=0.005), and fatigue (p=0.02); dyspnea as assessed the D-12, was a significant predictor of psychological well-being (p=0.01) and global status (p=0.03). CONCLUSION Dyspnea significantly affects day-to-day functioning and global well-being in patients with CTD-ILD. The UCSD and D-12 yield meaningful information about these patients that measures of pulmonary physiology cannot. Future studies should examine other performance characteristics of these self-report measures in patients with CTD-ILD.

Ethnic and racial differences in the presence of idiopathic pulmonary fibrosis at death.

BACKGROUND In studies of idiopathic pulmonary fibrosis (IPF), whites makeup the vast majority of subjects. Whether ethnic/racial differences in idiopathic pulmonary fibrosis occur in the general population is unknown. METHODS To compare the presence of IPF between ethnic/racial groups of U.S. decedents from 1989 to 2007 by using the National Center for Health Statistics database. RESULTS There were 251,058 U.S. decedents with IPF; 87.2% were non-Hispanic whites (White), 5.1% were non-Hispanic African American (black), 5.4% were Hispanic, and 2.2% were from other ethnic/racial groups (other). Whites coded with IPF died older than those in the other groups (77.9 years vs. 72.1 years for blacks, 75.3 years for Hispanics, and 75.6 years for others; p < 0.0001 for all pairwise comparisons). When controlling for age and for sex, compared with whites, both Hispanics and Others were more likely to be coded with IPF (OR = 1.47, 95% CI 1.44-1.49, p < 0.0001 and OR = 1.29, 95% CI 1.26-1.36, p < 0.0001 respectively), while blacks were significantly less likely to be coded with IPF (OR = 0.48, 95% CI 0.47-0.49, p < 0.0001). Among decedents with IPF, Hispanics were more likely, and blacks were less likely, than whites to die from IPF (OR = 1.24, 95% CI 1.20-1.29, p < 0.0001 and OR = 0.91, 95% CI 0.87-0.94, p < 0.0001). CONCLUSION From 1989 to 2007, black decedents were less-and Hispanics were more-likely than whites to die of/with IPF. Research is needed to determine if genetic differences between ethnic/racial groups explain these findings.

Physical activity and activity space in patients with pulmonary fibrosis not prescribed supplemental oxygen

BackgroundPatients with pulmonary fibrosis (PF) have impaired quality of life, and research suggests that dyspnea and physical activity are primary drivers. As PF progresses, some patients notice the disease “shrinks their worlds”. The objective of this study is to describe movement (both physical activity and activity space) in a cohort of patients with PF of various etiologies who have not been prescribed supplemental oxygen (O2).MethodsSubjects with PF not on supplemental O2 during the day were enrolled from across the U.S. from August 2013 to October 2015. At enrollment, each subject completed questionnaires and, for seven consecutive days, wore an accelerometer and GPS tracker.ResultsOne hundred ninety-four subjects had a confirmed diagnosis of PF and complete, analyzable GPS data. The cohort was predominantly male (56%), Caucasian (95%) and had idiopathic pulmonary fibrosis (30%) or connective tissue disease related-PF (31%). Subjects walked a median 7497 (interquartile range [IQR] 5766-9261) steps per day. Steps per day were correlated with symptoms and several quality of life domains. In a model controlling for age, body mass index, wrist- (vs. waist) worn accelerometer and percent predicted diffusing capacity (DLCO%), fatigue (beta coefficient = −51.5 ± 11.7, p < 0.0001) was an independent predictor of steps per day (model R2=0.34).ConclusionsPatients with PF, who have not been prescribed O2 for use during the day, have wide variability in their mobility. Day-to-day physical activity is related to several domains that impact quality of life, but GPS-derived activity space is not. Wearable data collection devices may be used to determine whether and how therapeutic interventions impact movement in PF patients.Trial registrationNCT01961362. Registered 9 October, 2013.

Idiopathic pulmonary fibrosis co-morbidity: thromboembolic disease and coronary artery disease

Over the past decade, it has been increasingly recognized that patients with idiopathic pulmonary fibrosis (IPF) are at risk of both venous thromboembolic disease (VTE) and coronary artery disease (CAD). When present, these co-morbid conditions negatively affect outcomes. For this disease without effective therapy to improve survival, increased diagnosis and treatment of these co-morbid processes may improve outcomes. Better understanding of the mechanisms that place IPF patients at increased risk of VTE and CAD may also ultimately lead to novel therapeutic interventions.