The prognostic impact of general and abdominal obesity in peripheral arterial disease.

OBJECTIVE: Obesity is an independent cardiovascular risk factor, but its prognostic role in patients with peripheral arterial disease (PAD) is not well defined. Accordingly, we assessed the impact of body mass index (BMI) and waist circumference (WC) on cardiovascular risk in a homogeneous cohort of PAD patients. METHODS: BMI and WC were measured in 190 consecutive PAD patients with ABI <0.90, referred to our university hospital for intermittent claudication. The occurrence of cardiac, cerebrovascular and peripheral events was prospectively assessed. The ability to classify risk was determined by calculating the hazard ratios (HRs) and c-statistics. RESULTS: During a median follow-up of 31.5 months, 63 patients (33.2%) had a cardiovascular event. Considered as continuous variables, both adiposity indices were significantly associated with increased cardiovascular risk, even after adjustment for possible confounding factors (HR=1.08, 95% CI 1.01-1.15, P=0.045 for BMI and HR=1.04, 95% CI 1.01-1.07, P=0.004 for WC). When BMI and WC were included together in a fully adjusted Cox model, the significant association between BMI and cardiovascular risk disappeared (HR=0.98, 95% CI 0.88-1.10, P=0.772), whereas WC remained significantly associated with a worse outcome (HR=1.04, 95% CI 1.01-1.08, P=0.033). The better discriminative ability of WC vs BMI was confirmed by the c-statistic, which was significantly higher for WC (0.63, 95% CI 0.56-0.70) than for BMI (0.56, 95% CI 0.51-0.63, P=0.038). CONCLUSIONS: Abdominal obesity and, to a lesser degree, general obesity worsen the prognosis of PAD patients independently of possible confounding factors. Weight reduction should be integrated in the active management of these patients.

Metabolic syndrome and cardiovascular risk prediction in peripheral arterial disease.

BACKGROUND AND AIMS: Metabolic syndrome (MetS) was reported to be associated with increased cardiovascular risk in various settings, however its prognostic impact in peripheral arterial disease (PAD) is scanty. METHODS AND RESULTS: We prospectively studied 173 patients with intermittent claudication and ankle/brachial index (ABI)<0.90, in whom MetS was defined using the criteria of both the revised version of the Adults Treatment Panel III (rATP III) and the International Diabetes Federation (IDF). Of these patients, 52.6% met the rATP III and 54.9% the IDF criteria for MetS. During a median follow-up of 31 months, 54 cardiovascular events occurred. Kaplan-Meier curves showed a greater incidence of ischemic events in patients with MetS than in those without. However, adjusted Cox analyses revealed that only IDF-MetS was independently associated with increased cardiovascular risk (HR=1.91, 95% CI 1.03-3.51, p=0.038). Kaplan-Meier curves for the four groups of patients delineated according to the bootstrapped ABI cut-off value (0.73) and the presence or absence of IDF-MetS revealed that the syndrome improved the predictive power of ABI alone. Actually, among patients with an ABI≤0.73, those with IDF-MetS had a higher cardiovascular risk than those without the syndrome (HR=2.55, 95% CI 1.22-5.12, p=0.012). This was confirmed by c-statistic, which was 0.56 for ABI alone and increased to 0.65 (p=0.046) when IDF-Mets was added to the pressure index. CONCLUSION: In PAD, IDF-MetS, but not rATP III-MetS, is associated with an increased risk of cardiovascular events. Furthermore, IDF-MetS adds to the prognostic value of ABI, currently the most powerful prognostic indicator in PAD.

Relationship between insulin-like growth factor-1 system and exercise tolerance in patients with intermittent claudication.

AIM: Insulin-like growth factor-1 (IGF-1) plays an important role in exercise physiology. We aimed the present study at assessing whether IGF-1 system and its changes with exercise are related to walking capacity in intermittent claudication (IC). METHODS: In 45 IC patients, blood samples for the measurement of IGF-1, IGF binding protein-3 (IGFBP-3), and acid labile subunit (ALS) were taken at rest and immediately after a treadmill exercise performed until initial claudication distance (ICD), i.e. until the occurrence of claudication pain in the affected limb. Control group consisted of 45 age- and sex-matched subjects without previous myocardial infarction or stroke. RESULTS: When IC patients were divided into two groups according to ICD value, ANOVA showed significant group differences for IGFBP-3 and ALS. Indeed, resting levels of IGFBP-3 were 3537+/-109 microg/L in controls, moderately lower (3399+/-204 microg/L) in IC patients with ICD >or= median, and markedly lower (2580+/-196 microg/L) in those with ICD