Factors associated with silent myocardial ischemia, autonomic or peripheral neuropathies, and survival in diabetes mellitus type 2 patients without cardiovascular symptoms

Abstract

Introduction Complications from diabetes mellitus (DM) include cardiovascular system, peripheral neuropathy (PN), and autonomic dysfunction (AD). Goal: Assess the association of silent myocardial ischemia, AD, and PN in cardiovascular asymptomatic type 2 diabetics. Methods As part of a multicenter project, 40 patients with type 2 DM were studied, with > 5 years of known disease and a baseline electrocardiogram non suggestive of coronary artery disease. Myocardial SPECT was performed with exercise stress test measuring corrected QT interval (QTc) and heart rate recovery (HRR) post-exercise (abnormal QTc >= 450 ms at rest and HRR < 14 beats at the first minute in maximum exercise). After 3 years, it was possible to re-study 32 cases. PN was evaluated with Michigan Neuropathy Screening Instrument (MNSI). Logistic regression analysis was performed to determine associated factors for AD, PN, SI, and survival analysis. Results Thirty-four percent of the group had ischemia in SPECT; QTc was prolonged in 23.3%; 31% fulfilled criteria of PN; and 25% of AD due to HRR alteration. With bivariate and multivariate analyses, associations were observed between lipid, glycemic parameters, ischemia, PN, and AD. The follow-up (mean 119 months) consigned 4 cardiac-related deaths; ischemia, glycemic control parameters, and microalbuminuria had significant value in bivariate analysis. Conclusion In our small sample of asymptomatic cardiovascular type 2 DM patients, myocardial ischemia, glycemic control, and microalbuminuria have influence on survival, requiring a more intensive global therapeutic approach.