ObjectiveTo evaluate possible associations between cardiovascular autonomic dysfunction and peripheral artery disease (PAD) in patients with type 2 diabetes mellitus.Research design and methodsIn this cross-sectional study, 67 patients with type 2 diabetes were included. PAD was identified by Doppler ultrasonography: systolic ankle-brachial pressure index <0.9. Cardiovascular autonomic function, besides five conventional cardiovascular autonomic function tests, was assessed by heart rate variability (HRV; 24-h ambulatory ECG recording) in time and frequency domains (spectral analyses) and three dimensional return maps. Power spectral analyses (PSA) were quantified in low frequency (LF), high frequency (HF), and very low frequency.ResultsPatients with PAD (n = 30) had longer diabetes duration, higher systolic blood pressure (BP), waist-to-hip ratio, HbA1C test, and urinary albumin excretion (UAE) than patients without PAD. Most HRV indices in time domain were lower in patients with than without PAD. These patients also had lower PSA indices (LF=0.19±0.07 vs. 0.29±0.11 n.u.; LF/HF ratio=1.98±0.9 vs. 3.35±1.83; P<0.001) and indices of sympathetic (three-dimensional return map: P1-night 61.7±9.4 vs. 66.8±9.7; P=0.04) and vagal (24-h P2 54.5±15.2 vs. 62.7±2.9; P< 0.02) activities (arbitrary units) than patients without PAD. Multivariate logistic regression analyses, adjusted for systolic BP, DM duration, HbA1C test, and UAE, confirmed the associations between impaired autonomic modulation and PAD, except for P1 index.ConclusionIn conclusion, patients with type 2 diabetes with PAD had lower HRV indices than patients without PAD, reflecting a dysfunction of cardiovascular autonomic modulation.

RESUMOO diabetes melito (DM) é um fator de risco independente para doença arterial coronariana, acidente vascular cerebral, doença vascular periférica e insuficiência cardíaca, que são as principais causas de morte nesses pacientes. Além disso, pacientes com DM e doença cardiovascular têm pior prognóstico, por apresentarem menor sobrevida, maior risco de recorrência da doença e pior resposta aos tratamentos propostos. Os avanços diagnósticos e terapêuticos das últimas décadas já mostram uma redução do risco de eventos cardiovasculares nesses pacientes, mas o risco absoluto desses é ainda duas vezes maior em relação ao dos pacientes não diabéticos. Portanto, é prioritária a adoção de um manejo intensivo, com controle rígido dos fatores de risco cardiovasculares. Esta revisão trata das principais características clínicas e apresenta uma abordagem prática do rastreamento, diagnóstico e tratamento da doença macrovascular nos pacientes com DM. Arq Bras Endocrinol Metab. 2009;53(6):699-708 Descritores Diabetes melito; doença cardiovascular; doença arterial coronariana; fatores de risco; tratamento; diagnóstico ABSTRACTDiabetes mellitus (DM) is an independent risk factor for coronary heart disease, stroke, peripheral arterial disease and heart failure, which are the main causes of death in these patients. Moreover, patients with DM and cardiovascular disease have a worse prognosis than nondiabetics, present lower short-term survival, higher risk of recurrence of the disease and a worse response to the treatments proposed. In the last decades, diagnostic and therapeutic progress had already shown benefits concerning cardiovascular risk reduction in these patients, but their absolute mortality risk is still twice that of non-diabetic patients. Because of this, the adoption of intensive treatment, with strict cardiovascular risk factor control, is a priority. The present study presents the main clinical characteristics and also the practical approach for screening, diagnosis and treatment of patients with diabetic macrovascular disease.

Asymmetric dimethylarginine (ADMA), which is the main endogenous inhibitor of nitric oxide synthase, plays a critical role in the process of endothelial dysfunction.

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