The Effect of Long Term Inhaled Corticosteroids on the Risk of Cardiovascular Morbidities

The Effect of Long Term Inhaled Corticosteroids on the Risk of Cardiovascular Morbidities in Adults With Asthma :a Population Based Matched Controlled Study

Cardiovascular disease is a major cause of morbidity and mortality worldwide. It is the second leading cause of death in Hong Kong. The disease burden is huge and effective control measures should target at prevention level. As the disease pathophysiology is linked to chronic low grade systemic inflammation, any therapeutics having the potential to reduce systemic inflammation should be vigorously explored.

The use of long-term inhaled corticosteroid (ICS) treatment in recent 2 decades has become the cornerstone in the treatment of most patients with persistent asthma with reduction in its mortality and hospital utilization. The long term safety of ICS in adults is generally very high.

Recent epidemiological studies utilizing large numbers of patients with asthma have shown that long term use of ICS is independently associated with a protective effect towards the development of myocardial infarction and cardiovascular mortality, with protective risk at 0.35 (95%CI 0.13-0.93). This effect is possibly mediated through the reduction of low grade systemic inflammation as reflected by plasma hs-CRP, from systemic absorption of the ICS.

The purpose of this study is to explore the potential protective effect of ICS on cardiovascular morbidities and its underlying link with systemic inflammation in Chinese adults with asthma compared with matched controls from the general population.

Study Overview

• Status: Completed
• Conditions: Asthma

Detailed Description

Globally, cardiovascular disease is a major cause of mortality and morbidity. In the past 2 decades in Hong Kong, it has been the second leading cause of death, with death rate reaching 50/100,000 population in 2006, and the third leading cause of hospitalizations in Hospital Authority Hospitals between 2001-2005. The disease burden is huge and effective control measures should target at prevention level.

There has been substantial evidence from landmark epidemiological studies in the past 10 years that chronic low grade systemic inflammation, predominantly based on plasma hs-CRP, is an independent predictor for the development of hypertension, myocardial infarction, stroke, cardiovascular death and peripheral vascular disease. A dose-dependent risk association between hs-CRP and these cardiovascular morbidities has also been consistently demonstrated.

Asthma is a chronic inflammatory airway disorder associated with airflow obstruction and bronchial hyper-responsiveness, which affects about 10% of population in Hong Kong. It is a major respiratory disease in Hong Kong that carries significant morbidity and high hospitalization burden in all ages. The use of long-term inhaled corticosteroid (ICS) treatment in recent decades has become the cornerstone in the treatment of most patients with persistent asthma with reduction in its mortality and hospital utilization. The ultimate goal of treatment is to achieve optimal control of airway inflammation and to reduce mortality and morbidity.

Although the pathogenesis of asthma is incompletely understood, studies have shown that it is associated airway inflammation and a state of increased free radical formation, because cells derived from airways and peripheral blood of patients with asthma generate increased amount of reactive oxygen species, the level of which is related to severity of asthma. Recent preliminary studies have indicated that, apart from the presence of chronic airway inflammation, asthma may also be associated with chronic low grade systemic inflammation and increased oxidative stress. Intuitively, this asthma-related systemic inflammation may increase the risk for development of cardiovascular and cerebrovascular diseases.

Despite the propensity of asthma towards cardiovascular morbidity, recently, several epidemiological studies utilizing large numbers of patients with asthma have shown that long term use of ICS is independently associated with a protective effect towards the development of myocardial infarction and cardiovascular mortality, with protective risk at 0.35 (95%CI 0.13-0.93). This effect is possibly mediated through the reduction of low grade systemic inflammation as reflected by plasma hs-CRP from systemic absorption of the ICS.

This potential effect of ICS on reduction of chronic low grade systemic inflammation has an invaluable implication for its future application as a preventive medicine against the development of cardiovascular morbidities and mortality, especially in high risk patients.

ICS have been launched for more than 20 years, and is currently the first-line treatment for asthma. Their systemic side effects are much less than that of oral corticosteroids. Long term safety of ICS in adults is generally very high, but mild increases in risk of osteoporosis, cataracts and glaucoma have been reported in patients with high dose ICS use.

The purpose of this study is to explore the potential protective effect of ICS on cardiovascular morbidities and its underlying link with systemic inflammation in Chinese adults with asthma compared with matched controls from the general population.

• Study Type: Observational
• Enrollment (Actual): 1394

Contacts and Locations

Study Locations

• Hong Kong
  • Hong Kong, Hong Kong
    • Queen Mary Hospital
  • Hong Kong, Hong Kong
    • Queen Elizabeth Hospital
  • Hong Kong, Hong Kong
    • Kwong Wah Hospital
  • Hong Kong, Hong Kong
    • Kowloon Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 35 years to 74 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Asthma patients will be recruited from asthma clinics of 4 centres in Hong Kong, including Queen Mary Hospital, Queen Elizabeth Hospital, Kowloon Hospital and Kwong Wah Hospital.

Matched controls at 1:1 ratio from the general population database of Cardiovascular Risk Factor Prevalence Study II (CRISPSII) will be selected. Matching critera: age +/-5 years; same gender and BMI+/-10%.

Description

Inclusion Criteria:

• Adult Chinese asthma patients
• Stable persistent asthma who are current inhaled corticosteroid users OR
• Healthy controls will be non inhaled corticosteroid users matched for age, gender and BMI from the Hong Kong Cardiovascular Risk Factor Prevalence Study II (CRISPSII) carried out on a random population sample in Hong Kong

Exclusion Criteria:

• On maintenance oral steroid
• Systemic steroid use in recent 6 months
• Asthma exacerbation (GINA criteria) in recent 1 month (ie daytime or nocturnal symptoms increment, detectable wheezing on physical examination, drop in peak flow rate, drop in spirometry indexes, increase in asthma medication, emergency medical attendance for asthma, days off work for asthma etc)
• Inhaled corticosteroid use for < 6 months
• Pregnancy

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Asthma; Asthma patients on inhaled corticosteroids
Control; Select matched controls from the general population database of Cardiovascular Risk Factor Prevalence Study 2 (CRISPS2)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Estimated prevalence and prevalence OR of cardiovascular morbidites in asthma patients using ICS expressed in 95% confidence interval	1 year

Secondary Outcome Measures

Outcome Measure	Time Frame
Cumulative dose response relationship and effect modification of ICS on the OR of cardiovascular morbidities, 95% confidence interval	1 year
Cumulative Inhaled corticosteroids dose effect on the levels of hs-CRP. Adjusted change in level of hs-CRP in relation to change in ICS dosage, expressed in median and interquartile range	1 year

Collaborators and Investigators

• Sponsor: The University of Hong Kong
• Investigators: Principal Investigator: Kwan-ling Julie Wang, Hospital Authority

Study record dates

Study Major Dates

• Study Start: January 1, 2009
• Primary Completion (Actual): July 1, 2009
• Study Completion (Actual): July 1, 2009

Study Registration Dates

• First Submitted: August 9, 2009
• First Submitted That Met QC Criteria: August 12, 2009
• First Posted (Estimate): August 14, 2009

Study Record Updates

• Last Update Posted (Estimate): August 14, 2009
• Last Update Submitted That Met QC Criteria: August 12, 2009
• Last Verified: August 1, 2009

More Information

Terms related to this study

• Keywords: Asthma; Systemic inflammation; Inhaled corticosteroids; Cardiovascular morbidities
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Immune System Diseases; Lung Diseases; Hypersensitivity, Immediate; Bronchial Diseases; Lung Diseases, Obstructive; Respiratory Hypersensitivity; Hypersensitivity; Asthma
• Other Study ID Numbers: UW 08-407