Effectiveness of Acute Asthma Care Among Inner-city Adults

BACKGROUND: Acute asthma often requires expensive emergency department visits and hospitalizations, especially among economically disadvantaged inner-city adults. However, few studies have examined approaches for improving acute asthma care in this population. METHODS: We conducted a cohort study involving patients who were discharged from a public hospital emergency department following acute asthma care between March 31, 1997, and August 5, 1999, to identify processes of care effective for improving peak expiratory flow rate at a 2- to 3-week follow-up. Adult patients who met the predetermined criteria for asthma, who underwent a baseline peak expiratory flow rate reading, and who did not have concurrent acute sinusitis or pneumonia were eligible (N = 448). Of the 365 patients enrolled in the study, 309 (84.7%) completed it. We used a multiple linear regression analysis adjusted for patient risk to assess the association between acute asthma care processes derived from the National Asthma Education Prevention Program guidelines (inhaled beta2-agonists, inhaled corticosteroids, systemic corticosteroids, asthma care follow-up, and patient asthma education) and percentage peak expiratory flow rate change at follow-up. RESULTS: Systemic corticosteroids had a significant effect for increasing percentage peak expiratory flow rate change at the 2- to 3-week follow-up for all asthma exacerbation severity levels (beta = 26.1; 95% confidence interval, 1.8-50.5; P =.04) and severity levels specified by the National Asthma Education Prevention Program guidelines (beta = 31.6; 95% confidence interval, 8.1-55.1; P =.01). CONCLUSION: Outpatient systemic corticosteroids were effective for improving lung function 2 to 3 weeks after acute asthma care, and their use should reduce asthma-related morbidity, especially among economically disadvantaged inner-city adults.     

New Insights Into the Relationship Between Chitinase-3-Like-1 and Asthma

Purpose of Review

CHI3L1 (also known as YKL-40), a member of “mammalian chitinase-like proteins,” is a serum protein lacking enzymatic activity. Although the protein is highly conserved in mammals, a consensus regarding its role in human pathologies is currently lacking. In an attempt to shed light on the many physiological functions of the protein, specifically with regard to asthma, a comprehensive overview of recent studies is provided.

Recent Findings

In asthma, CHI3L1 is secreted from macrophages and airway epithelial cells through an IL-13 related mechanism. Th2-associated inflammatory responses due to allergen exposure, resulting in airway hyper-responsiveness and smooth muscle contraction, play a role in tissue remodeling.

Summary

The importance of CHI3L1 in initiation and development of asthma is not limited to its involvement in highly orchestrated events of inflammatory cytokines but further research is needed for further elucidation. Levels of the protein are associated with severity for numerous pathologies, including asthma, suggesting limited specificity as a biomarker.

     

Combined inhibition of types I and II 5 alpha-reductase selectively augments the basal (nonpulsatile) mode of testosterone secretion in young men

CONTEXT: Testosterone (Te) is metabolized in the hypothalamus and pituitary gland, where untransformed steroid and activated products participate in feedback regulation of GnRH and LH secretion. Genetic inactivation of 5 alpha-reductase type I remains undescribed clinically, whereas deficiency of the type II isoenzyme elevates both LH and Te concentrations. OBJECTIVE: The aim of this study was to test the combined feedback contribution of 5 alpha-reduced steroids. SETTING/DESIGN/INTERVENTION: In a university setting, nine young men received placebo and a dual (type I/type II) 5 alpha-reductase inhibitor, dutasteride. METHODS/OUTCOMES: LH and Te dynamics were assessed by: 1) 10-min blood sampling for 26 h; 2) GnRH stimulation (100 ng/kg iv); 3) discrete peak detection; 4) deconvolution analysis; 5) cosinor analyses of 24-h rhythmicity; and 6) pattern regularity. RESULTS: Compared with placebo, dutasteride lowered 5 alpha-dihydro Te concentrations by 80% (P = 0.009), but did not alter any measure of LH dynamics. Conversely, dutasteride augmented: 1) total, bioavailable and free Te concentrations (0.002 < P < 0.032) without changing estradiol or SHBG concentrations; 2) nadir Te concentrations (P = 0.025); and 3) basal (P = 0.013) and thereby total (basal plus pulsatile) (P = 0.003) Te secretion. CONCLUSION: Combined antagonism of types I and II 5 alpha-reductase preferentially drives nonpulsatile Te secretion in healthy men. The concomitant stability of LH outflow could indicate that intragonadal 5 alpha-reduced androgens repress basal Leydig-cell steroidogenesis.