C-reactive protein, obesity, atopy and asthma symptoms in middle-aged adults

• Published in: The European respiratory journal Vol. 32; no. 1; pp. 77 - 84
• Main Authors: Butland, B. K, Strachan, D. P, Rudnicka, A. R
• Format: Journal Article
• Language: English
• Published: Leeds Eur Respiratory Soc 01.07.2008; Maney
• Subjects: Adult; Asthma - blood; Asthma - complications; Asthma - epidemiology; Biological and medical sciences; Body Mass Index; C-Reactive Protein - analysis; Chronic obstructive pulmonary disease, asthma; Female; Humans; Hypersensitivity - blood; Hypersensitivity - complications; Hypersensitivity - epidemiology; Immunoglobulin E - blood; Male; Medical sciences; Metabolic diseases; Middle Aged; Obesity; Obesity - blood; Obesity - complications; Obesity - epidemiology; Odds Ratio; Pneumology; Prevalence; Smoking - adverse effects; Smoking - blood; United Kingdom - epidemiology; Human; Allergy; Immunopathology; Lung disease; Obesity; C-reactive protein; Respiratory disease; Nutrition disorder; Asthma; Atopy; Body mass index; Symptomatology; Bronchus disease; Adult; Obstructive pulmonary disease; C reactive protein; Nutritional status; Pneumology
• ISSN: 0903-1936; 1399-3003
• DOI: 10.1183/09031936.00077207

Recent research has suggested an association between circulating C-reactive protein (CRP) and adult asthma, confined to those without evidence of allergic predisposition. The current authors investigated the role of smoking and obesity as possible explanations for this relationship. At 44-45 yrs of age, members of the British 1958 birth cohort participated in a biomedical survey involving the measurement of the following: CRP; the specific immunoglobulin E to grass, cat and dust mite; standing height; and weight. Information on asthma and related symptoms was collected by computer-aided interview when the subjects were 42 yrs of age. Complete data were available for a total of 6,490 subjects. CRP levels were positively correlated with the body mass index (BMI) and were found to be higher among females when compared with males, and higher among heavy smokers (> or = 20 cigarettes x day(-1)) when compared with never-smokers. After adjustment for sex and region, the odds ratios, comparing asthma prevalence in subjects above the fourth CRP quartile with subjects below the first quartile, were 1.85 (95% confidence interval 1.15-2.99) for nonatopics and 0.94 (0.62-1.41) for atopics, changing to 1.36 (0.80-2.32) and 1.07 (0.67-1.69), respectively, when additionally adjusted for smoking and BMI. Any association between C-reactive protein and asthma prevalence confined to nonatopics may be due to confounding factors. Alternatively, it may reflect a more general association of C-reactive protein with smoking-related obstructive airways disease.