Estudo sobre a progressão da aterosclerose carotídea, a mortalidade e a síndrome metabólica em pacientes com lúpus eritematoso sistêmico

Abstract

Patients with systemic lupus erythematosus (SLE) have a high frequency of atherosclerotic cardiovascular disease (CVD) and traditional risk factors for coronary heart disease (CHD). The subclinical carotid atherosclerosis has already been described in lupus patients. Nevertheless, few data has been published about the rate and determinants of progression of carotid atherosclerosis in these patients. The mortality in SLE has significantly improved in the past decades in developed countries, although CVD has been identified as an important cause of late death in these individuals. The frequency of metabolic syndrome (MetS) in lupus patients has been described with different results. Its diagnosis indicates an increased relative risk of diabetes and cardiovascular events in general population. Objectives: To determine the rate and determinants of carotid atherosclerosis progression in a group of patients attending the Rheumatology Service of Hospital das Clínicas/UFMG. To study the causes of death and to identify the risk factors for death in this cohort. To determine the frequency of MetS and the variables associated with it in lupus patients. Patients and Methods: Carotid intima-media thickness (IMT) and plaque were obtained by ultrasound in 157 lupus patients out of 181 patients initially included in a prospective study. Progression of atherosclerosis was defined by either an increase of common carotid IMT>0.15mm or a higher plaque score. Traditional risk factors for CHD and SLE-related factors were assessed longitudinally and the predictors of progression were assessed. The 181 patients initially enrolled from May 2005 to February 2006 were followed up to either the last visit at outpatient clinic, death or end of study visit (from October 2008 to July 2009). Causes of death were defined on the basis of death certificates, medical records and information collected from doctors and relatives. Variables predicting mortality were studied. At baseline the frequency of MetS and the variables associated to it diagnosis were analyzed. Results: Progression of atherosclerosis was identified in 43 (27.4%) patients, at an interval of 39(37- 42) months. Independent determinants of atherosclerosis progression were: lupus duration and nephrotic proteinuria at baseline. The mortality could be evaluated in 179 patients. Among them, 13 (7.3%) patients died due to end-organ failure (5), infection (5), disease activity (1) and atherosclerosis (1). Independent predictors of mortality were a higher damage index score, cyclophosphamide use and antiphospholipid syndrome. The frequency of MetS in the 162 females patients [38.8 (11.2) years old] was 32.1%. Obesity, LDL cholesterol>100mg/dl, older age at lupus diagnosis, higher lupus damage index and nephrotic proteinuria were independently associated with MetS. Conclusions: Atherosclerosis progresses in a substantial number of young SLE patients during short-term follow up. SLE-related risk factors were associated with IMT and plaque progression after controlling for the traditional risk factors for CHD. This study presents a high frequency of late mortality in lupus patients due to SLE itself and infection. This result is not in agreement with the proposed bimodal pattern of lupus mortality and with the high frequency of atherosclerosis as a cause of death in developed countries. MetS was frequent in patients with lupus. The syndrome was associated not only with traditional risk factors for CHD, but also with lupus characteristics