Effect of specific allergen inhalation on serum adiponectin in human asthma.
BACKGROUND
Adiponectin is associated with asthma. The direction of this association is not known in humans. In mice, this association is bidirectional: allergen inhalation affects serum adiponectin, and exogenous adiponectin administration affects asthma. We sought to evaluate whether allergen inhalation affects serum adiponectin in human asthma.


METHODS
This study included eight sensitized subjects with mild asthma and six healthy control subjects. Asthmatic subjects were challenged with inhaled specific allergen (positive allergen skin test), methacholine, and irrelevant allergen (negative allergen skin test). Control subjects were challenged with irrelevant allergen. Sequential serum samples were obtained before and nine times after each challenge. Serum adiponectin- (primary outcome), leptin-, adiponectin-to-leptin ratio-, eotaxin-, and tumor necrosis factor-alpha-response curves, area under the curves, and baseline and peak concentrations were evaluated. Statistical analysis used repeated-measures analysis of variance and paired t tests.


RESULTS
There were no significant differences in outcome measures among the challenges in asthmatic subjects or when compared to control subjects. Type II error is an unlikely explanation for these findings because the study was adequately powered to detect changes in serum adiponectin, as reported in the literature. Further, pooled data showed that serum adiponectin diurnal variation curves were lower in asthmatic subjects than in control subjects.


CONCLUSIONS
Serum adiponectin concentrations are lower in asthmatic subjects than in control subjects. Specific allergen inhalation in asthmatic subjects does not acutely affect serum adiponectin concentrations. The reverse association (ie, effect of adiponectin on asthma) needs further study. If future studies prove adiponectin to be a protective factor for asthma, modulating adiponectin may open a new approach toward managing asthma.
Sood
Akshay
A
Department of Medicine, Lovelace Respiratory Research Institute, Albuquerque, NM. Electronic address: asood@salud.unm.edu.
Qualls
Clifford
C
Clinical Translational Sciences Center, University of New Mexico School of Medicine, Albuquerque, NM.
Seagrave
JeanClare
J
Experimental Toxicology Program, Lovelace Respiratory Research Institute, Albuquerque, NM.
Stidley
Christine
C
Department of Medicine, Lovelace Respiratory Research Institute, Albuquerque, NM.
Archibeque
Tereassa
T
Department of Medicine, Lovelace Respiratory Research Institute, Albuquerque, NM.
Berwick
Marianne
M
Department of Medicine, Lovelace Respiratory Research Institute, Albuquerque, NM.
Schuyler
Mark
M
Department of Medicine, Lovelace Respiratory Research Institute, Albuquerque, NM.
D052242:Adiponectin / Q000097:blood*; D000280:Administration, Inhalation; D000328:Adult; D000485:Allergens / Q000097:blood / Q000276:immunology*; D000704:Analysis of Variance; D001249:Asthma / Q000097:blood / Q000175:diagnosis / Q000276:immunology*; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D016535:Bronchial Hyperreactivity / Q000097:blood / Q000503:physiopathology; D001985:Bronchial Provocation Tests / Q000379:methods*; D016022:Case-Control Studies; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D006801:Humans; D016017:Odds Ratio; D011336:Probability; D012016:Reference Values; D012680:Sensitivity and Specificity; D055815:Young Adult
D052242:Adiponectin; D000485:Allergens; D015415:Biomarkers