Association of stress derived risk factors, Chlamydia pneumoniae and high sensitive C-reactive protein in Coronary Artery Disease patients
H Jha, A Vidya, J Prasad, A Mittal
factors, iga, medium socio economic status, migration, risk, sedentary life style
H Jha, A Vidya, J Prasad, A Mittal. Association of stress derived risk factors, Chlamydia pneumoniae and high sensitive C-reactive protein in Coronary Artery Disease patients. The Internet Journal of Cardiology. 2008 Volume 7 Number 1.
Coronary Artery Disease (CAD) is a major cause of morbidity and mortality in humans and is predicted to be the leading cause of death in the world. 12 Established risk factors for CAD such as elevated serum lipids, smoking, hypertension, diabetes, age, gender, and family history are associated with less than half of prevalence and severity of CAD. 3 Many patients with CAD lack conventional risk factors, suggesting that there are additional unidentified factors that contribute to vascular injury. 4 Epidemiological studies indicate that infectious agents may predispose patients to atherosclerosis and its adverse clinical events. 4 Organism implicated is intracellular pathogen including
Materials and Methods
A total of 192 CAD patients (148 males and 44 females) and 192 age matched controls with no evidence of CAD (142 males and 50 females) attending the Cardiology out patient department of Safdarjung hospital from March 2005 to September 2006 were enrolled after prior written consent. The study received clearance from Ethical committee, Safdarjung hospital. A detailed questionnaire was prepared to gather necessary information from each patient that included SES or source of income, migration form native place to work place, nature of work or life style.
Collection of samples
Venous blood (2 ml) was collected in non- heparinized tubes from CAD patients and controls. Serum was separated within 2 hrs of blood collection and kept at -80°C until used for detection of antibodies to
Serology and antibody level of atherosclerotic marker
Detection of antibodies for
hsCRP level and Conventional risk factors
CAD patients and controls that were positive for hsCRP were further divided into 14 groups on the basis of additional risk factors as follows (i) Group1- low SES (LSES) in patients, (ii) Group 2- LSES in controls, (iii) Group 3- medium SES (MSES) in patients, (iv) Group 4- MSES in controls, (v) Group 5- high SES (MSES) in patients, (vi) Group 6- HSES in controls, (vii) Group 7- non-migrant patients, (viii) Group 8- non-migrant controls, (ix) Group 9- immigrant CAD patients, (x) Group10- immigrant controls, (xi) Group 11- patients leading normal lifestyle (NLS), (xii) Group12- controls leading NLS, (xiii) Group13- patients leading sedentary lifestyle (SLS), (xiv) Group 14- controls leading SLS.
SPSS version 12.0 for Windows (SPSS Inc., Chicago, USA) was used for statistical testing. All serological results were dichotomized as positive or negative. For comparing diagnostic assays, the chi – square test, fisher-exact statistic for binary related variables was used. Simultaneously, an alpha level of 0.05 was set as the level of significance.
Association of IgA serology with Independent risk factors in CAD patients
In CAD patients with MSES and HSES significantly high seropositivity for
Levels of hsCRP in Independent risk factors
Socio-economic status (SES) was divided into three groups; LSES, MSES, and HSES. It was classified as (i) high for employer/owners with >five employees/ professionals of university level; owning a four-wheeler and earning >30,000 INR/ month (ii) medium for salaried employees with working skills and intermediate or graduate level of education; owning a two-wheeler and earning >10,000 INR/ month and (ii) low for under-employed or small property owners, generally with no permanent employment, with no working skills and with a monthly income of <10,000 INR. Median levels of hsCRP (mg/L) were measured in additional risk factors of CAD patients and controls. Levels of hsCRP was higher in CAD patients with LSES, MSES and HSES (mg/L 4.42, 7.48, and 3.61) compared to controls (mg/L 2.6, 1.43 and 1.82) respectively.
Migration status of CAD patients and controls were divided into two groups; non-migrants and migrants. Non-migrated and migrated CAD patients also showed higher levels of hsCRP (mg/L 3.27 and 5.8) compared to controls (mg/L 5.92 and 1.7).
Lifestyles led were classified using basic metabolic rate (BMR) as a cut-off. They were classified as (i) sedentary <1.6 BMR (which included chair-bound or bed-bound or seated work with no option of moving around and little or no strenuous leisure activity) (ii) normal as 1.6 to 1.9 (which included seated work with discretion and requirement to move around but little or no strenuous leisure activity or standing work; eg housewife, shop assistant) and (iii) strenuous > 1.9 (which included significant amounts of sport or strenuous leisure activity (3060 min 45 times per week) or strenuous work or highly active leisure). All participants were classified in the first two groups; that is, sedentary (SLS) and normal lifestyles (NLS) as the patients and controls were well matched. CAD patients with normal and SLS showed higher hsCRP levels (mg/L 4.92 and 5.84) compared to controls (mg/L 1.82 and 1.47) (Fig 1).
1= Low SES in CAD patients, 2= Low SES in controls, 3= Medium SES in CAD patients, 4= Medium SES in controls, 5= High SES in CAD patients, 6= High SES in controls, 7= Non-migrated in CAD patients, 8= Non-migrated in controls, 9= Migrated in CAD patients, 10= Migrated in controls, 11= Normal LS in CAD patients, 12= Normal LS in controls, 13= Sedentary LS in CAD patients, 14= Sedentary LS in controls.
The increase in CVD risk factor profile worldwide has been influenced by a cluster of lifestyle related variables, of which perceived stress is one of the most important factor. 12 Our study for the first time revealed that impact of socioeconomic status was very high as CAD migrated patients had highest risk (18 times) followed by SLS (14 times) and MSES (12 times) with
Authors wish to thank Mr. Yogendra Kumar and Mrs. Madhu badhwar for providing technical assistance. Indian council of Medical Research is acknowledged for providing financial assistance to Hem Chandra Jha in the form of fellowship. The study was funded by Department of Science and Technology, SR/SO/HS-6/2005, India.