The coexistence of various risk factors that play a role in the development of cardiovascular diseases and are thought to share a common etiopathogenesis is called metabolic syndrome. Metabolic syndrome is among the most important and common causes of atherosclerotic diseases and type 2 diabetes.
For the first time in 1988, Reaven drew attention to the frequent coexistence of various risk factors and stated that this association, which he called syndrome It has been suggested that insulin resistance plays a central role in this picture. Insulin sensitivity indicates the responsiveness of insulin to glucose uptake in various insulin-dependent tissues, especially skeletal muscle, and its ability to suppress lipolysis in adipose tissue and gluconeogenesis in the liver. Obesity, sedentary lifestyle, smoking, low birth weight and perinatal malnutrition have also been associated with the development of insulin resistance. Adipose tissue and the hormones secreted from this tissue, hypothalamic-pituitary-adrenal axis disorders, advancing age, genetic and environmental reasons are among other factors that play a role. Recent data show that low-grade inflammation is involved in various components of the metabolic syndrome, such as obesity, insulin resistance, cardiovascular diseases, type 2 diabetes and hypertension.2
The frequency of metabolic syndrome increases with advancing age and body weight increase, and it also varies according to the societies examined. In the United States, the prevalence of metabolic syndrome in people aged 20 and over was found to be 27%, and it was found that the frequency of metabolic syndrome was increasing more rapidly in women.3 In our country, according to the results of METSAR (Turkey Metabolic Syndrome Research) conducted in 2004, metabolic syndrome in adults aged 20 and over was found to be 27%. The syndrome frequency was found to be 35%. In this study, the frequency of metabolic syndrome in women was found to be higher than in men (41.1% in women, 28.8% in men).4 These results are based on the data obtained from the evaluation of waist circumference limits of 102 cm in men and 88 cm in women. When the 94-88 cm limits accepted today are taken into account, the rate increases even more.
The most widely accepted definition criteria for metabolic syndrome are:
Abdominal obesity: waist circumference >94 (or >102) cm in men, >80 (or >88) cm in women,
High triglyceride (≥150 mg/dl),
Low HDL cholesterol (<40 mg/dl in men, <50 mg/dl in women),
High blood sugar (fasting plasma glucose ≥100 mg/dl), High blood pressure (≥135/80 mmHg)
The presence of any three of these criteria in a person is considered metabolic syndrome.5 In the definition of the International Diabetes Federation, one of these three criteria must be abdominal obesity. 6 In our country, it is more appropriate to take the waist circumference of 94 cm for men and 84 cm for women as the limits for abdominal obesity.
Although it is not among the diagnostic criteria, proinflammatory and prothrombotic conditions are also included under the title of metabolic syndrome.
The primary approach in metabolic syndrome, which is a disease that occurs under the influence of environmental factors as well as genetic characteristics, should be the regulation of lifestyle. The aim is to prevent diabetes and cardiovascular diseases. Weight loss achieved through an appropriate nutrition and exercise program has a corrective effect on all disorders observed in metabolic syndrome. It has been shown that overall and cardiovascular mortality can be reduced with this approach.7
It is obvious that smoking and alcohol use in patients with metabolic syndrome will increase cardiovascular, metabolic and hepatic complications. Therefore, the issue of smoking and alcohol should also be emphasized when explaining lifestyle changes.
In cases where lifestyle changes are insufficient, pharmacological treatment is required. Lowering LDL cholesterol is the primary goal in the treatment of dyslipidemia. Statins are used for this purpose.8 Fibrate therapy may be considered for high triglyceride and low HDL cholesterol.9
Metformin and thiazolidinediones have effects on reducing insulin resistance. The effects of thiazolidinediones that cause weight gain prevent their use in metabolic syndrome. Metformin may be suitable for clinical use.
However, pharmacological treatment is not yet recommended solely to reduce insulin resistance in individuals without hyperglycemia.
Studies conducted with rimonobant, which targets endogenous cannabinoid receptors, showed weight loss and improvement in metabolic parameters.10 However, this drug was withdrawn from clinical use due to its psychiatric side effects.
In patients with metabolic syndrome, the effects of antihypertensive drugs on metabolic parameters as well as their effects on blood pressure should be taken into consideration. Antihypertensive treatment’s blood pressureIt is expected to control blood pressure, prevent target organ damage, positively affect metabolic parameters, or at least not negatively affect them.
In order to prevent atherothrombotic complications, low dose, 75–100 mg daily aspirin is recommended in high-risk patients.
RESOURCES
1 Reaven GM. Role of insulin resistance in human disease. Diabetes 37:1595-1607, 1988
2 Das UN. Minireview: Is metabolic syndrome X an inflammatory condition? Exp Biol Med 227: 989-997, 2002
3 Earl S. Ford ES, Giles WH, Mokdad AH. Increasing Prevalence of the Metabolic Syndrome Among U.S. Adults. Diabetes Care 27(10):2444-2449, 2004
4 Metabolic Syndrome Research Group. METSAR results. XXth National Cardiology Congress. Antalya, 2004.
5 Grundy SM, Cleeman JI, Daniels SR, Donato KA, Eckel RH, Franklin BA, Gordon DJ, Krauss RM, Savage PJ, Smith SC Jr, Spertus JA, Costa F; American Heart Association;
National Heart, Lung, and Blood Institute. Diagnosis and management of the metabolic syndrome: an American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement. Circulation 2005;112(17):2735-52.
6 Zimmet P, Magliano D, Matsuzawa Y, Alberti G, Shaw J. The metabolic syndrome: a global public health problem and a new definition. J Atheroscler Thromb. 2005;12(6):295-300
7 Gregg EW, Cauley JA, Stone K, Thompson TJ, Bauer DC, Cummings SR, et al., for the Study of Osteoporotic Fractures Research Group. Relationship of changes in physical activity and mortality among older women. JAMA;289:2379-86, 2003
8 Grundy SM et al. for the Coordinating Committee of the National Cholesterol Education Program. Implications of recent clinical trials for the National Cholesterol Education Program Adult Treatment Panel III guidelines. Circulation Jul 13; 110:227-39, 2004
9 Rubins HB, Robins SJ, Collins D, et al. Gemfibrozil for the secondary prevention of coronary heart disease in men with low levels of highdensity lipoprotein cholesterol. Veterans Affairs High-Density Lipoprotein Cholesterol Intervention Trial Study Group. N Engl J Med.;341:410–418, 1999
10 Pi-Sunyer FX, Aronne LJ, Heshmati HM, et al. Effect of rimonabant, a cannabinoid-1 receptor blocker, on weight and cardiometabolic risk factors in overweight or obese patients. RIO-North America: A randomized controlled trial. JAMA 295:761-775, 2006.
