Cross-Sectional Study of COPD Prevalence Among Smokers, Ex-smokers and Never-Smokers in Almaty, Kazakhstan
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|ClinicalTrials.gov Identifier: NCT02926534|
Recruitment Status : Completed
First Posted : October 6, 2016
Last Update Posted : October 30, 2017
|Condition or disease|
|Chronic Obstructive Pulmonary Disease (COPD)|
Hide Detailed Description
Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death worldwide. An estimated 0.5 million individuals in Kazakhstan may be affected by COPD, and the number of affected individuals and of deaths from COPD are expected to increase as the population ages. A better understanding of the epidemiology, causes, and social and other determinants of the disease is needed in order to develop effective treatments and prevention strategies.
Although COPD is traditionally defined by airflow obstruction in a spirometry test, smoking-associated effects on the lungs related to COPD also include emphysema, gas trapping, and chronic bronchitis. Symptoms such as productive cough, dyspnea, and exercise intolerance may be dismissed as normal aging, especially in older former smokers. Information is sparse about effects of smoking on individuals not diagnosed as having COPD (based on spirometry), and data from high-resolution computed tomography (CT) scanning in these individuals are limited.
COPD is strongly associated with smoking, but not all smokers will develop COPD. Cigarette smoking continues to be a common addiction in Kazakhstan despite efforts to reduce its prevalence. The study objectives are to assess true prevalence of COPD based on pulmonary function assessment and structural changes (emphysema and large and small airway inflammation with thickening) identified by high-resolution computer tomography (CT-scan) in addition to standard spirometric criteria and symptoms of dyspnea, exercise limitations, and chronic bronchitis. Such comprehensive approach will allow for objective comparisons of (1) current smokers of conventional cigarettes - 500 participants, (2) those subjects who quit smoking within the past 1 - 5 years - 200 participants, and (3) those subjects who never smoked cigarettes - 200 participants.
Using high resolution CT in addition to spirometry and other types of lung function assessment will help to determine COPD prevalence among non-smokers, smokers of conventional cigarettes and those who quit smoking. COPD prevalence will be defined based on abnormal respiratory function assessed by standard spirometric tests and by using COPD assessment test (CAT) questionnaire, 6-minute walk test and a high-resolution computed tomographic (HRCT) scan of the chest of those patients with preserved pulmonary functions but with clinical symptoms.
The cross-sectional study is retrospective in a sense, as it will allow to collect historical data on smoking, smoking cessation, address socio-demographic and other differentials of smoking. The investigators will also address the relationship of liver disease with COPD. This will be determined based on presence of hepatitis B and C tests (antigens and antibodies), liver enzyme levels and concentration of alpha-1-antitripsine, which is related to the development of COPD. Current or former smokers who had a concomitant diagnosis of asthma will not be excluded in the cross-sectional study. Instead, historical data on whether the participant had been diagnosed with asthma will be collected.
The cross-sectional study has several study groups based on the exposure (smoking behavior) status. Combinations of paired associations are as follows: smokers vs. never-smokers; smokers vs. ex-smokers; never-smokers vs. ex-smokers. Therefore, it bears some feature of a retrospective cohort study, specifically; it provides an opportunity to make comparisons between the groups. While calculating the required sample size, the investigators considered this opportunity as the most important one. In addition to calculating prevalence ratio of COPD for exposure statuses, the cross-sectional study will allow for assessment of prevalence of these conditions and other characteristics in different study groups.
Data to be collected
- Spirometry (FEV / FVC), bronchodilation test
- COPD assessment test (CAT) questionnaire,
- 6-minute walk test
- High-resolution computed tomographic (HRCT) scan of the chest
- Blood pressure
- Body mass index (BMI)
- Smoking status and history
- Passive smoking status
- Occupational exposure
- Exposure to indoor biofuel pollution
- Patient-reported comorbidities
- Laboratory testing for: blood cholesterol level, HDL (high-density lipoprotein), LDL (low-density lipoproteins), triglycerides, C-reactive protein, fibrinogen, glucose, Hepatitis B and C IgM and IgG antigens and antibodies, liver enzymes (ALT and AST), and alpha-1-antitrypsine.
The investigators plan to recruit subjects by using the following mechanisms, namely, through social media, a network of medical referral sites (polyclinics and ambulatory centers), and from large corporations, i.e. with more than 500 employees.
Information about current smoking behavior and very detailed historic information on smoking behavior will be used to for adjustments during the data analysis phase.
|Study Type :||Observational|
|Estimated Enrollment :||900 participants|
|Official Title:||A Cross-sectional Study of the Socio-demographic and Other Determinants of Chronic Obstructive Pulmonary Disease (COPD) Among Those Who Smoke, Quit Smoking and Never-smoking Cigarettes|
|Study Start Date :||September 2016|
|Actual Primary Completion Date :||May 2017|
|Actual Study Completion Date :||May 2017|
Individuals (men and women) between the ages of 35 and 59 (inclusive) who are currently smoking conventional cigarettes with a minimum of 10 pack-year smoking history
Individuals (men and women) between the ages of 35 and 59 (inclusive) with a minimum of 10 pack-year smoking history who stopped smoking cigarettes between 1 and 5 years ago
Individuals (men and women) between the ages of 35 and 59 (inclusive) who are current non-smokers and with no history of smoking (control group)
- Evidence of chronic obstructive pulmonary disease [ Time Frame: up to 1 week ]airflow obstruction based on the fixed ratio of post-bronchodilator FEV1 /FVC < 0.70 criterion
- Airflow obstruction through lung function test [ Time Frame: up to 1 week ]Items to be analyzed are pre/post bronchodilator FEV1, FVC, FEV1/FVC
- COPD CT score [ Time Frame: up to 2 weeks ]Semi-quantified measures performed by three CT scan readers to evaluate extent of emphysema, severity of bronchial dilatation, traction bronchiectasis, bronchial wall thickening, small airways disease
- Results of 6-minute walking test [ Time Frame: up to 1 week ]
- COPD assessment test (CAT) score [ Time Frame: up to 1 week ]
- Comorbidities of COPD [ Time Frame: up to 1 week ]
- Presence of metabolic syndrome [ Time Frame: up to 1 week ]Detection of metabolic syndrome based on the new International Diabetes Federation (IDF) definition that includes central obesity AND any two of the following factors: raised TG level; reduced HDL cholesterol; raised blood pressure; raised fasting plasma glucose
- 10 year risk of fatal CVD [ Time Frame: up to 1 week ]Systematic Coronary Risk Evaluation (SCORE) based on the European High Risk SCORE Chart by gender, age, systolic blood pressure, total cholesterol and smoking status
- Presence of an electrocardiogram abnormality [ Time Frame: up to 1 week ]Detection of abnormality during the electrocardiogram
- Concentrations of total cholesterol, low density lipoprotein (LDL) cholesterol, HDL cholesterol, triglyceride (TG), glucose, liver enzymes (ALT and AST), C-reactive protein, fibrinogen, and alpha-1-antitrypsin [ Time Frame: up to 1 week ]Serum laboratory testing for blood cholesterol level, HDL (high-density lipoprotein), LDL (low-density lipoproteins), triglycerides, C-reactive protein, fibrinogen, glucose, liver enzymes (ALT and AST), and alpha-1-antitrypsin
- Number of Participants With Positive or Negative Results of Testing for Anti-HCV and HBsAG [ Time Frame: up to 1 week ]
Biospecimen Retention: Samples Without DNA
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02926534
|Kazakhstan Academy of Preventive Medicine|
|Almaty, Kazakhstan, 050008|
|Principal Investigator:||Almaz T Sharman, MD, PhD||Kazakhstan Academy of Preventive Medicine|