Metabolic Syndrome and General Anesthesia Complications

* Corresponding author: Assistant Professor and Head, International Enteric Vaccine Research Program, Division of Pediatric Infectious Diseases, Vanderbilt University School of Medicine, Medical Center North D6201, 1161 21st Avenue South, Nashville, TN 37232-2581, USA. E-mail: Oscar.gomez@vanderbilt.edu (O.G. Gomez Duarte). Metabolic syndrome is a reality based on five clinical criteria, associated with increased risk for cardiovascular disease and diabetes mellitus.1 The metabolic syndrome was originally described several decades ago and its definition has been the object of controversies and disagreement throughout its history. So much so, that several European and US health organizations have been arguing about the validity of their diagnostic criteria and definitions. Moreover, some trials have questioned its validity as a risk factor for cardiovascular disease.2-4 Despite the controversy about the definition of metabolic syndrome and its usefulness for identifying cardiovascular risk, it is evident that the number of cases of metabolic syndrome among the global population has been increasing, as well as the number of reports associating this entity with a risk factor for cardiovascular and metabolic diseases and complications during general anesthesia. In 2009 a consensus between the American Heart Association (AHA) and renowned international organizations (International Diabetes Federation Task Force on Epidemiology and Prevention, National Heart, Lung and Blood Institute, World Heart Federation, International Atherosclerosis Society and International Association for the Study of Obesity) agreed to define the metabolic syndrome as a clinical condition characterized by the presence of at least three of the following factors: a) large abdominal circumference; b) increased triglycerides (>150 mg/dL); c) reduced HDL ( 130/85 mmHg), and e) fasting glucose >100 mg/dL.5 Among these factors, the abdominal circumference measurement was the only factor requiring special considerations, considering that such measurement could vary significantly, depending on the population. While the parameters for abdominal circumference have been defined for populations in industrialized countries, the parameters according to age, gender and ethnicity in other developing countries are yet to be defined. In the United States, 31% of the population meet the criteria for metabolic syndrome and it is estimated to be the most important risk factor for cardiovascular disease, even more so than cigarette smoking.6 The metabolic syndrome has been reported in most industrialized countries as well as in developing countries, including Latin America, Africa and Asia.7-9 The increased prevalence of the metabolic syndrome worldwide is related to the global trend to sedentary life styles and obesity. Metabolic syndrome in Colombia has been the object of epidemiological studies in different populations and its prevalence has been reported to depend on multiple factors including age, geography and comorbidity of the population studied. While among the 15 to 20 age group the prevalence of metabolic syndrome is 9%, in the 20 to 55 year old group it is 21%, and among the 22 to 73 years old, the prevalence is 34%.10-13 Studies in young HIV positive patients receiving retroviral therapy, indicate a prevalence of 20%.14 Similar studies in hypertensive patients showed that the prevalence of the condition is significantly higher at around 81%.15 The increase in the number of metabolic syndrome cases and the risk that the pathology may represent for the general population during surgery under general anesthesia makes it compelling to make clinical prospective studies for its