Genome-wide association study of the age of onset of childhood asthma

BACKGROUND

Childhood asthma is a complex disease with known heritability and phenotypic diversity. Although an earlier onset has been associated with more severe disease, there has been no genome-wide association study of the age of onset of asthma in children.

OBJECTIVE

We sought to identify genetic variants associated with earlier onset of childhood asthma.

METHODS

We conducted the first genome-wide association study of the age of onset of childhood asthma among participants in the Childhood Asthma Management Program (CAMP) and used 3 independent cohorts from North America, Costa Rica, and Sweden for replication.

RESULTS

Two single nucleotide polymorphisms (SNPs) were associated with earlier onset of asthma in the combined analysis of CAMP and the replication cohorts: rs9815663 (Fisher P= 2.31 × 10(-8)) and rs7927044 (P= 6.54 × 10(-9)). Of these 2 SNPs, rs9815663 was also significantly associated with earlier asthma onset in an analysis including only the replication cohorts. Ten SNPs in linkage disequilibrium with rs9815663 were also associated with earlier asthma onset (2.24 × 10(-7)

CONCLUSIONS

We have identified 2 SNPs associated with earlier onset of childhood asthma in 4 independent cohorts.

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Key Words

• asthma
• pediatrics
• age of onset
• asthma genetics
• c1orf100
• genome-wide association study
• pediatric asthma

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MESH Headings

• Adolescent
• Age of Onset
• Asthma/epidemiology
• Asthma/genetics
• Child
• Cohort Studies
• Costa Rica/epidemiology
• Female
• Genetic Predisposition to Disease
• Genome-Wide Association Study/methods
• Genotype
• Humans
• Linkage Disequilibrium
• Male
• North America/epidemiology
• Polymorphism, Single Nucleotide/genetics
• Sweden/epidemiology

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Grants

• R00 HL096840 NHLBI NIH HHS
• N01-HR-16051 NHLBI NIH HHS
• M01 RR002719 NCRR NIH HHS
• N01-HR-16044 NHLBI NIH HHS
• N01-HR-16048 NHLBI NIH HHS
• M01 RR000036 NCRR NIH HHS
• N01-HR-16045 NHLBI NIH HHS
• M01RR02719-14 NCRR NIH HHS
• M01 RR000051 NCRR NIH HHS
• HL66289 NHLBI NIH HHS
• R01 HL066289 NHLBI NIH HHS
• N01HR16044 NHLBI NIH HHS
• N01-HR-16047 NHLBI NIH HHS
• WT084703MA Wellcome Trust
• N01-HR-16046 NHLBI NIH HHS
• N02-HL-6-4278 NHLBI NIH HHS
• K01 HL004370 NHLBI NIH HHS
• N01-HR-16049 NHLBI NIH HHS
• RR00036 NCRR NIH HHS
• N01-HR-16052 NHLBI NIH HHS
• R37 HL066289 NHLBI NIH HHS
• N01-HR-16050 NHLBI NIH HHS
• Wellcome Trust
• M01RR00051 NCRR NIH HHS
• M01RR0099718-24 NCRR NIH HHS

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Critically ill patients with 2009 influenza A(H1N1) infection in Canada

CONTEXT

Between March and July 2009, the largest number of confirmed cases of 2009 influenza A(H1N1) infection occurred in North America.

OBJECTIVE

To describe characteristics, treatment, and outcomes of critically ill patients in Canada with 2009 influenza A(H1N1) infection.

DESIGN, SETTING, AND PATIENTS

A prospective observational study of 168 critically ill patients with 2009 influenza A(H1N1) infection in 38 adult and pediatric intensive care units (ICUs) in Canada between April 16 and August 12, 2009.

MAIN OUTCOME MEASURES

The primary outcome measures were 28-day and 90-day mortality. Secondary outcomes included frequency and duration of mechanical ventilation and duration of ICU stay.

RESULTS

Critical illness occurred in 215 patients with confirmed (n = 162), probable (n = 6), or suspected (n = 47) community-acquired 2009 influenza A(H1N1) infection. Among the 168 patients with confirmed or probable 2009 influenza A(H1N1), the mean (SD) age was 32.3 (21.4) years; 113 were female (67.3%) and 50 were children (29.8%). Overall mortality among critically ill patients at 28 days was 14.3% (95% confidence interval, 9.5%-20.7%). There were 43 patients who were aboriginal Canadians (25.6%). The median time from symptom onset to hospital admission was 4 days (interquartile range [IQR], 2-7 days) and from hospitalization to ICU admission was 1 day (IQR, 0-2 days). Shock and nonpulmonary acute organ dysfunction was common (Sequential Organ Failure Assessment mean [SD] score of 6.8 [3.6] on day 1). Neuraminidase inhibitors were administered to 152 patients (90.5%). All patients were severely hypoxemic (mean [SD] ratio of Pao(2) to fraction of inspired oxygen [Fio(2)] of 147 [128] mm Hg) at ICU admission. Mechanical ventilation was received by 136 patients (81.0%). The median duration of ventilation was 12 days (IQR, 6-20 days) and ICU stay was 12 days (IQR, 5-20 days). Lung rescue therapies included neuromuscular blockade (28% of patients), inhaled nitric oxide (13.7%), high-frequency oscillatory ventilation (11.9%), extracorporeal membrane oxygenation (4.2%), and prone positioning ventilation (3.0%). Overall mortality among critically ill patients at 90 days was 17.3% (95% confidence interval, 12.0%-24.0%; n = 29).

CONCLUSION

Critical illness due to 2009 influenza A(H1N1) in Canada occurred rapidly after hospital admission, often in young adults, and was associated with severe hypoxemia, multisystem organ failure, a requirement for prolonged mechanical ventilation, and the frequent use of rescue therapies.

Expenditure on health care in obese women with and without sleep apnea

STUDY OBJECTIVES

To determine the effect of obesity and sleep apnea on health care expenditure in women over 10 years.

DESIGN

Retrospective observational study

SETTING

Tertiary university-based medical center

PATIENTS AND CONTROLS

Three groups of age-matched women: 223 obese women with OSAS (body mass index: 39.3 +/- 0.6 kg/m2), and from the general population, 223 obese controls (BMI 36.3 +/- 0.4) and 223 normal weight controls (BMI 23.9 +/- 0.4).

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

We examined health care utilization in the 3 matched groups for the 10 years leading up to the documentation of OSAS. The mean physician fees and the number of physician visits were significantly higher in obese controls than in normal weight controls during the observed period. Physician fees and physician visits progressively increased in the 10 years before diagnosis in the OSAS cases and were significantly higher than in the matched obese controls. Physician fees, in Canadian dollars, one year before diagnosis in the OSAS cases were higher than in obese controls: $547.49 +/- 34.79 vs $246.85 +/- 20.88 (P<0.0001). More was spent for OSAS cases on physician fees for circulatory, endocrine and metabolic diseases, and mental disorders than the obese controls. Physician visits one year before diagnosis in the OSAS cases were more frequent than in the obese controls: 13.2 +/- 0.73 visits vs 7.26 +/- 0.49 visits (P<0.0001).

CONCLUSIONS

Obese women are heavier users of health services than normal weight controls. Obese women with OSAS use significantly more health services than obese controls. Since OSAS imposes a greater financial burden, treatment of OSAS may reduce other comorbidities and lower overall medical costs.