ABSTRACT
Background: Soluble urokinase plasminogen activator receptor (suPAR) has emerged as a novel biomarker for various inflammatory conditions and has been proposed to associate with the severity of asthma. However, the relationship between suPAR and clinical asthma features is poorly understood. Objective: To examine associations of serum suPAR levels with clinical characteristics of asthma and to define the phenotype with high suPAR levels in patients with adult-onset asthma. Methods: Serum suPAR levels were measured with ELISA from patients with adult-onset asthma participating in the 12-year follow-up visit in the Seinäjoki Adult Asthma Study. Results: In total, 201 patients were divided into quartiles according to suPAR values. High suPAR patients had more severe asthma symptoms and poorer asthma control. They also had higher levels of interleukin 8 (IL-8), interleukin 6 (IL-6), matrix metalloproteinase 9 (MMP-9), and blood neutrophil counts than those with low suPAR levels. The use of high-dose inhaled and oral corticosteroids was more common in patients with elevated suPAR. Such patients also had visited healthcare more frequently during the follow-up period, had more comorbidities, and were physically less active than those with low suPAR levels. The above-mentioned results remained similar after excluding the patients with co-existing COPD; only association to hospitalizations was lost. In multivariable binary regression analyses, the highest suPAR quartile was associated with higher cumulative dispensed oral corticosteroid use, more severe symptoms, and uncontrolled asthma. Conclusion: High suPAR levels occur in uncontrolled adult-onset asthma patients characterized by neutrophilic inflammation, high corticosteroid use, frequent healthcare visits, and multimorbidity with unhealthy lifestyle. This biomarker could be useful in determining asthma phenotypes and target new asthma treatments.
ABSTRACT
Background: There is a lack of knowledge on the association between daily physical activity and lung function in patients with asthma. Objective: This study aims to examine the association between daily physical activity and asthma control, lung function, and lung function decline in patients with adult-onset asthma. Design: This study is part of Seinäjoki Adult Asthma Study (SAAS), where 201 patients were followed for 12 years after asthma diagnosis. Daily physical activity was assessed at follow-up by a structured questionnaire and used to classify the population into subgroups of low (≤240 min) or high (>240 min) physical activity. Three spirometry evaluation points were used: 1. diagnosis, 2. the maximum lung function during the first 2.5 years after diagnosis (Max0-2.5), 3. follow-up at 12 years. Results: High physical activity group had slower annual FEV1 (p<0.001) and FVC (p<0.018) decline. Additionally, the high physical activity group had higher FEV1 values at follow-up, and higher FEV1/FVC ratios at follow-up and diagnosis. There was no difference in BMI, smoking, medication, or frequency of physical exercise between high and low physical activity groups. Differences remained significant after adjustments for possible confounding factors. Conclusion: This is the first demonstration of an association between long-term FEV1 decline and daily physical activity in clinical asthma. Low physical activity is independently associated with faster decline in lung function. Daily physical activity should be recommended in treatment guidelines in asthma.
ABSTRACT
Objective. Obstructive sleep apnea (OSA) decreases sleep spindle density and frequency. We evaluated the effects of continuous positive airway pressure (CPAP) treatment on different features of sleep spindles. Methods. Twenty OSA patients underwent two night polysomnographies in a diagnostic phase and one night polysomnography after 6 months of CPAP treatment. The control group comprised 20 healthy controls. Sleep spindles were analyzed by a previously developed automated method. Unilateral and bilateral spindles were identified in central and frontopolar brain locations. Spindle density and frequency were determined for the first and last half of the NREM time. Results. The density of bilateral central spindles, which did not change in the untreated OSA patients, increased towards the morning hours during CPAP treatment and in the controls. Central spindles did not become faster with sleep in OSA patients and the central spindles remained slow in the left hemisphere even with CPAP. Conclusion. CPAP treatment normalized spindle features only partially. The changes may be associated with deficits in thalamocortical spindle generating loops. Significance. This study shows that some sleep spindle changes persist after CPAP treatment in OSA patients. The association of these changes to daytime symptoms in OSA patients needs to be further evaluated.
