Publications

OBJECTIVE

To investigate the cross-sectional association between COPD severity and disturbed sleep and the longitudinal association between disturbed sleep and poor health outcomes.

METHODS

Ninety eight adults with spirometrically-confirmed COPD were recruited through population-based, random-digit telephone dialing. Sleep disturbance was evaluated using a 4-item scale assessing insomnia symptoms as: difficulty falling asleep, nocturnal awakening, morning tiredness, and sleep duration adequacy. COPD severity was quantified by: FEV(1) and COPD Severity Score, which incorporates COPD symptoms, requirement for COPD medications and oxygen, and hospital-based utilization. Subjects were assessed one year after baseline to determine longitudinal COPD exacerbations and emergency utilization and were followed for a median 2.4 years to assess all-cause mortality.

RESULTS

Sleep disturbance was cross-sectionally associated with cough, dyspnea, and COPD Severity Score, but not FEV(1). In multivariable logistic regression, controlling for sociodemographics and body-mass index, sleep disturbance longitudinally predicted both incident COPD exacerbations (OR=4.7; p=0.018) and respiratory-related emergency utilization (OR=11.5; p=0.004). In Cox proportional hazards analysis, controlling for the same covariates, sleep disturbance predicted poorer survival (HR=5.0; p=0.013). For all outcomes, these relationships persisted after also controlling for baseline FEV(1) and COPD Severity Score.

CONCLUSIONS

Disturbed sleep is cross-sectionally associated with worse COPD and is longitudinally predictive of COPD exacerbations, emergency health care utilization, and mortality.

BACKGROUND

Decline in forced vital capacity (FVC) over time reliably predicts mortality in patients with idiopathic pulmonary fibrosis. The use of this measure in clinical practice is recommended by current evidence-based guidelines. It is unknown if the method of calculating decline in FVC (relative vs. absolute change) impacts its frequency or its ability to predict mortality.

METHODS

Patients with idiopathic pulmonary fibrosis from two prospective cohorts were included if they had a baseline and 12-month follow-up FVC. A ≥10% decline in FVC from baseline was calculated in two ways: a relative decline of 10% (e.g., from 60% predicted to 54% predicted) and an absolute decline of 10% (e.g., from 60% predicted to 50% predicted). The frequency of a ≥10% decline in FVC and its ability to predict 2-year transplant-free survival were compared between these two methods. Declines in FVC of ≥5% and ≥15% were similarly compared. Analyses were performed unadjusted and adjusted for age, gender, use of oxygen, baseline FVC and baseline diffusion capacity for carbon monoxide.

RESULTS

The frequency of any given FVC decline was significantly greater using the relative change in FVC method. For ≥10% decline, both methods predicted 2-year transplant-free survival with similar accuracy, and remained significant predictors after adjusting for baseline characteristics. The absolute change method appeared more predictive for ≥5% decline.

CONCLUSIONS

Using the relative change in FVC maximises the chance of identifying a ≥10% decline in FVC without sacrificing prognostic accuracy. This may not hold true for ≥5% decline in FVC. These findings have important implications for clinical practice and the design of clinical trials.

Cardiac calsequestrin (Casq2) is the major Ca2+ binding protein in the sarcoplasmic reticulum, which is the principle Ca2+ storage organelle of cardiac muscle. During the last decade, experimental studies have provided new concepts on the role of Casq2 in the regulation of cardiac muscle Ca2+ handling. Furthermore, mutations in the gene encoding for cardiac calsequestrin, CASQ2, cause a rare but severe form of catecholaminergic polymorphic ventricular tachycardia (CPVT). Here, we review the physiology of Casq2 in cardiac Ca2+ handling and discuss pathophysiological mechanisms that lead to CPVT caused by CASQ2 mutations. We also describe the clinical aspects of CPVT and provide an update of its contemporary clinical management.

PURPOSE OF THE STUDY

To assess the effects of receiving a research informational pamphlet produced by the federal Office for Human Research Protections on telephone survey participation rates of older Latinos, and illustrate the feasibility of nesting recruitment studies within other funded studies when stand alone funding for recruitment studies is limited.

DESIGN AND METHODS

Latino patients aged ≥50 with ≥1 visit during the preceding year (N=1314) were sampled from three community clinics and a multi-specialty medical group. Patients were randomly assigned to receive or not receive a pamphlet that contained information on research participation in the initial mailing for the telephone survey study. Survey participation rates were compared between the pamphlet and no pamphlet groups.

RESULTS

In a multivariate model, women (OR=1.4; 95% CI 1.1, 1.8), and those with public insurance (vs. no insurance; OR=1.7; 95% CI 1.1, 2.5) were more likely to participate, while those age 65+ (vs. age 50-54; OR=0.6; 95% CI 0.4, 0.8) were less likely to participate; there was no significant difference by pamphlet group (OR=0.8; 95% CI 0.7, 1.1). Nesting of the randomized trial of the recruitment pamphlet within the funded study required minimal additional resources.

IMPLICATIONS

Recruitment methods that are more intensive than a pamphlet may be needed to enhance survey participation rates among older Latinos. Nesting recruitment trials within funded studies is a promising and efficient approach for testing recruitment strategies.