Association of obesity and metabolic syndrome with the severity and outcome of intermittent claudication
Received 2 August 2006; accepted 1 September 2006. published online 29 November 2006.
Background
Obesity is recognized as an independent predictor of coronary artery disease; however, its importance in peripheral arterial disease is less clear. The aim of this study was to assess the association between obesity and the severity and outcome of intermittent claudication.
Methods
This study was a prospective cohort study based at a tertiary referral center. Sixty patients with intermittent claudication selected for conservative treatment were assessed for obesity and metabolic syndrome by using the International Diabetes Federation definition. Other risk factors, including diabetes, hypertension, smoking history, serum lipids, adipocytokines, and C-reactive protein, were measured by clinical and blood assessment. Obesity and metabolic syndrome were related to the severity of peripheral arterial disease, defined by ankle-brachial pressure index and graded treadmill measured maximum walking distance (MWD) and initial claudication distance, by using multiple linear regression analysis allowing for traditional atherosclerotic risk factors. Patients were followed up for 24 months, and combined outcome was reported in terms of death, cardiovascular events, or requirement for revascularization. The effect of obesity and metabolic syndrome on outcome was investigated by using Kaplan-Meier and Cox proportional hazard analysis.
Results
Obesity and serum adiponectin were independently associated with the severity of peripheral arterial disease measured by ankle-brachial pressure index (P = .03 and .001), initial claudication distance (P = .009 and .03), and MWD (P = .001 and .04). Metabolic syndrome was independently associated only with MWD (P = .02). By 24 months, outcome events occurred in 37% ± 7% and 43% ± 9% of patients with metabolic syndrome or obesity, respectively, compared with 0% and 11% ± 6% of those without these diagnoses. Waist circumference independently predicted the likelihood of outcome events (relative risk, 1.16; 95% confidence interval, 1.08-1.26; P < .001).
Conclusions
These findings, if confirmed in other cohorts, suggest the importance of treating obesity in patients with intermittent claudication. Serum adiponectin concentrations may be an important guide to the efficacy of treatment in patients with intermittent claudication and obesity.
aVascular Biology Unit, James Cook University, Townsville, Queensland, Australia
cInstitute of Sport and Exercise Science, James Cook University, Townsville, Queensland, Australia
Reprint requests: Jonathan Golledge, MChir, MA, FRCS, FRACS, The Vascular Biology Unit, James Cook University, Townsville, Queensland 4811, Australia.
Supported by funding from the National Health and Medical Research Council (279408/379600), National Institutes of Health (R01 HL080010-01), and James Cook University.
ABSTRACT