Prevalence of low ankle brachial index and relationship with cardiovascular risk factors

BACKGROUND AND OBJECTIVE Peripheral arterial disease (PAD) is an important marker of subclinical coronary heart disease and atherosclerosis. PAD is usually asemptomatic and individuals with PAD has an increased risk of mortality and morbidity. Treatment and preventive measures should be planned for patients with PAD and individuals under risk for PAD, in the context of the natural history and the modifiable risk factors of the disease.In many countries community based studies on PAD and its determinants are conducted however such studies are limited in Turkey. The purpose of this study is to determine the prevalence of low ankle brachial index which is used as the diagnostic criteria for detecting PAD and to determine the associations between cardiovascular disease risk factors.METHOD In this cross-sectional study, the population consisted of 4600 individuals residing in Onur Neighbourhood of Balçova District who participated to screening part of BAK Project. The sample size of 660 was calculated assuming 95% confidence level, 80% power, a ratio between individuals with and without PAD 1:9, prevalence of coronary heart disease among non-PAD:8%, Odds ratio for CHD among people with PAD as 2.8. The sample size was expanded by 20% to overcome low response rate and it was aimed to reach 720 individuals. PAD was diagnosed by measuring ankle brachial index using vascular type hand doppler. Dependent variable was ABI<0.90. Sociodemographic charecteristics, anthropometric measurements, blood lipids, blood sugar, and chronic diseases consisted independent variables. Chi-square test, t-test, logistic regression and linear regression analyses were used.RESULTS The prevalence of low ABI was 6.3% in the Balçova Onur District. In age- and gender-adjusted logistic regression analyses, current smoking (OR 5.07, 95% CI 1.85 to 13.88) cardiovascular disease history (OR 6.83, 95% CI 3.00 to 15.53), hypertension (OR 2.58, 95% CI 1.06 to 6.33), diabetes (OR 3.25, 95% CI 1.51 to 6.98), and high waist circumference (OR 2.24, 95% CI 1.02 to 4.94) were positively associated with prevalent PAD. When ABI measurement was taken into account %3.5 of low or intermediate risk patients were reclassified as high-risk ifthey presented ABI < 0.9.CONCLUSION Age, current smoking, number of pack years, HT, DM, history of coronary heart disease or stroke and waist circumference increased the risk of low ABI significantly. These findings highlight the importance of risk factor management and screening individuals who have one of these cardiovascular risk factors for PAD.Key words: Ankle Brachial Index, peripheral artery disease, Framingham risk score