Dr. Sunita Dodani AAssistant professor, Family Medicine

The Aga Khan UniversityKarachi, Pakistan

Dr. David MacLean Professor, Simon Fraser University,

Vancouver, Canada &

Dr. Michel Joffres Associate Professor, Dalhousie

University, Halifax, Canada

Risk factors for coronary Artery diseases in Pakistanis: A cross–sectional Study

Presentation Outline• Burden of CVD• CVD Mortality: Developed Vs Developing Countries• Eastern Mediterranean Region• Pakistan: a Developing Country• CVD in Pakistan: National Health Survey• Study Rationale

Presentation Outline Contd.

• Study Objectives• Study Design and Methods• Results• Limitations• Conclusion and Recommendations

Burden of CVD

Cardiovascular diseases (CVD), defined as Coronary Artery diseases (CAD) and Cerebrovascular diseases account for over 16 million deaths, or about 30% of total global deaths

C V D M o rta lity 1 9 8 5 - 1 9 9 7

5 14 8 4 6

1 6 1 7

2 4

0

1 0

2 0

3 0

4 0

5 0

6 0

1 9 8 5 1 9 9 0 1 9 9 7

Y e a rs

Perc

en

tag

es

D e ve lo p e d

D e ve lo p in g

CVD Mortality 1985-1997

(WHO Reports)

Total Mortality in 2000

30

70

1

2

30% CVD

70% Other

CVD Mortality According to Regions

(%)

Eastern Mediterranean Region (EMR)(Saudi Arabia, Iran, Iraq, Bahrain, Jordan, Pakistan)• Epidemiological transition

• Mortality and morbidity data on CVD risk factors are inadequate

• Age-specific mortality rate is declining• Increasing prevalence of the risk factors for CVD • Diets have high fat content, increasing diabetes with

increase in obesity• Smoking, widespread, especially among younger people • Physical activity is insufficient• Clustering of risk factors

What About Situation in Pakistan?

Pakistan: A Developing Country• Multiethnic and linguistic diversity

• 4 provinces & 2 territories• Population ~ 130 million• Growth Rate: 2.6%• Per capita income: $390

– <3% Gov Health Budget– Most of the money spent on

tertiary care hospital curative services

• Very limited health insurance

CVD in PakistanNational Health Survey of Pakistan 1990-1994 (NHSP)

Limited, population and hospital -based studies on CVD in Pakistan and many have significant limitations

• In 1990, first countrywide survey was done using random cluster sampling method

CVD in Pakistan NHSP 1990-1994 Contd.

• 4-year community based survey• Adult mortality of Ischaemic Heart Disease (IHD)

was reported as 12% • Risk factor prevalence assessed

Survey limitations:•Generalization. Covering 2.6% population•Methodological errors•All risk factors not defined by globally acceptable criteria

Study Rationale• Available data is of inadequate quality, limiting the

assessment of true magnitude of the problem Inability to debate and appropriately assess the

priorities in CAD prevention and health promotion on the basis of NHSP data in high socio economic class

Risk factors of CVD - prime target for surveillance, especially people in higher socio-economic class, considered as “early adopters” and ‘high risk’

Study Objectives:

• To estimate the prevalence of CAD and its risk factors and risk behaviors in patients attending preventive check-up clinics of a teaching hospital in Karachi, Pakistan.

• To assess the association of risk factors with CAD

Study Methodology and Sample Design

Routine general physical check-up clinics at the Aga Khan University Hospital (AKUH)- a teaching hospital in Karachi, Pakistan. Run by trained family physicians, 5 days a week

Design:Set up:

Cross sectional descriptive study

Study Methodology and Sample Design

(Contd.)• Mainly from the educated higher socioeconomic class

• General preventive check-up package: history and physical examination; laboratory investigations [complete blood count, total blood lipid profile, fasting glucose levels, electrolytes, urine detailed report]; chest X-ray and exercise tolerance test (ETT)

• Usually 3-5 patients are booked in one clinic • Total appointment time: 40-50 minutes

Study sample:

• Obesity (BMI)

• Hypertension

• Diabetes mellitus

• Total cholesterol

High density lipoprotein (HDL)

Low density lipoprotein (LDL)

• Triglycerides (TGs)

Study Methodology and Sample Design

(Contd.)Risk Factors in the Study

•Positive family history of

coronary heart disease•Smoking•Sedentary lifestyle

Study Methodology and Sample Design (Contd.)

• Assumed prevalence of 50% given largest sample size possible• Margin of error ± 4%• Stratified on age and gender…dichotomized into < 35 years, and > 35 years• Total patients interviewed: 600

Sample size estimation:

Study Methodology and Sample Design

(Contd.)1. Demographic variables…

Mean & SD for continuous variables Frequencies and percentages for categorical variable

2. Risk factor distribution…. frequencies and percentages3. Multi-variate analysis…

Univariate variate (P< 0.05) Logistic regression model (Odds ratio with 95% CI)

Dependent variable: heart diseases

Analysis:

Study Results

Socio-demographic variables in the study group

Variable n=600 %Age Group18-3435-6465+

46.1†73

51314

10.2‡12.285.5 2.3

GenderMaleFemale

 

471129

 

78.521.5   

Employment StatusFull Time (> 35hrs/wk)UnemployedRetired / StudentHousehold personRefused

 

4105

60115

3

 

68.30.810

19.20.5

   

Variablen=600 %Work Type

Professional ClericalSkilled ForemanManager/official/proprietierSales workerNon skilledRefusedMissing

 491626

316721

183

 11.2

3.86.2

75.81.70.50.2

LanguageUrduSindhiPunjabiPushtoBaluchiOthers

 286

81124

392941

 47.713.520.7

6.54.86.8

Education<MatriculationMatriculateIntermediateGraduatePost-graduate 

  12 51 104 389 44

 2.08.5

17.364.8

7.3† mean ‡ S.D.

Coronary Artery disease (CAD) Risk Factors

ETTPositiveNegative

 

485115

 

80.819.2

 Menopause (n=129)YesNoAge at Menopause 

 

6564

46.6 † 

 

50.449.67.6 ‡

 

BMI Categories* (WHO)Underweight (<18.5)Normal (18.5-24.9)Pre-obese (25-29.9)Obese (30-39.9)Obesity (> 40) 

 

5172290123

9 

 

0.828.748.420.6

1.5DiabetesYesNoIGT 

98473

29

 

16..378.8

4.8

Variable n=600 %

HypertensionYesNo

 

121 479

 

79.8 20.2

 

Coronary Artery disease (CAD) Risk Factors contd.Total Cholesterol**Desirable (<200)Borderline high (200-239)High (> 240) 

194.2†402118

80

37.2‡67.019.713..3

HDL CholesterolLow (<40)41-59High (> 60) 

39.8†300292

8

7.9‡50.048.7

1.3 

LDL CholesterolOptimal (<100)Near/above optimal (100-129)Borderline High (130-159)High (160-189)Very High (> 190)

124.5†113228177

7111

 

32.2‡18.838.029.511.8

1.8

TriglyceridesNormal (<200)Borderline High (200-399)High (400-1000)Very High (>1000) 

177.4/447131

139

200.4†74.521.8

2.21.5

Family History of IHDYesNoDon’t Know 

 

287293

20

 

47.848.8

3.3

Current smoking statusNever smokedFormer smokerRegular cigarette smokerOccasional cigarette smokerPipe or cigar smokerNot stated/Refused 

 

38854

13020

71

 

64.79.0

21.73.31.20.2

Regular exerciseYesNo 

 

169431

 

28.271.8

** according to NCEP ATP III guidelines

Table: Univariate analysis (n=600) 

Variable Coronary Artery DiseasesOR (95% CI){  P value

Negative PositiveAge n % n %    

<40 years 155(32.0%) 11 (9.6%)    40 years 330 (68.0%) 104 (24.0%) 4.4 (2.32, 8.5) <0.001

Gender        

Female 107 (22.1%) 22 (19.1%)    

Male 378 (77.9%) 93 (80.9%) 0.8 (0.5, 1.39) 0.492Menopause

       

No 59 (55.1%) 5 (22.7%)    

Yes 48 (44.9%) 17 (77.3%) 4.2(1.44, 12.15) 0.009BMI Categories

       

<25 151 (31.2%) 27 (23.5%)    

25-29.9 223 (46.1%) 66 (57.4%) 1.7 (1.01, 2.71) 0.04530 110 (22.7%) 22 (19.1%) 1.1 (0.61, 2.07) 0.721Diabetes        

No 416 (85.8%) 86 (17.1%)    

Yes 69 (14.2%) 29 (25.2%) 2.03(1.24, 3.33) 0.005

Table: Univariate analysis (n=600) Contd.

Hypertension       

No 392 (80.8%) 87 (75.7%)    Yes 93 (19.2%) 28 (24.3%) 1.4(0.84, 2.197) 0.215Cholesterol 200      

<200 mg/dl 345 (71.1%) 70 (60.9%)    200 mg/dl 140 (28.9%) 45 (39.1%) 1.6 (1.04, 2.42) 0.033Family History    

No 249 (53.1%) 44 (39.6%)    

Yes 220 (46.9%) 67 (60.4%) 1.7 (1.13, 2.63) 0.011Regular Exercise      

Yes 132 (27.2%) 37 (32.2%)    

No 353 (72.8%) 78 (67.8%) 0.8 (0.51, 1.22) 0.289Regular Smoking        

No 378 (78.8%) 84 (75.0%)    

Yes 102 (21.3%) 28 (21.5%) 1.2(0.76, 1.997) 0.389

 

VariableCoronary Artery Diseases

OR (95% CI){  P valueNegative Positive

Table: Multiple Logistic Regression (n=600) 

VariableETT  

OR (95% CI) 

P valueNegative PositiveAge n % n %    

<40 years 155 (32.0%) 11 (9.6%)    

40 years 330 (68.0%) 104 (24.0%) 3.9 (2.01, 7.52) <0.001         

Diabetes        

No 416 (85.8%) 86 (17.1%)    

Yes 69 (14.2%) 29 (25.2%) 1.7 (1.01, 2.9) 0.047       

Family History        

No 249 (53.1%) 44 (39.6%)    

Yes 220 (46.9%) 67 (60.4%) 1.8(1.15, 2.74) 0.010         

Cholesterol 200      

<200 mg/dl 345 (71.1%) 70 (60.9%)    

200 mg/dl 140 (28.9%) 45 (39.1%) 1.5 (0.94, 2.27) 0.096         

Limitations:

• Generalization of results

• Hospital data • Upper socio-economic class 

Conclusion and Recommendations• Study adds significant knowledge of increased prevalence of CVD risk factors and behaviors

in a high-risk group of a developing country• This group need to be targeted for risk factor modification… public health and clinical

approaches• Need for lifestyle interventions, screening and management of risk factors• Limited resources available… there is a need of population-based studies with the help of

NGOs• Further research needed to look into the causes of high CVD in Pakistanis e.g. insulin

resistance.