Metabolic Syndrome

The metabolic syndrome is a cluster of common pathologies: abdominal obesity linked to an excess of visceral fat, insulin resistance, dyslipidemia and hypertension. At the molecular level, metabolic syndrome is accompanied not only by dysregulation in the expression of adipokines, cytokines, and chemokines but also by alterations in insulin and leptin signaling, oxidative stress, and chronic low grade inflammation. These changes affect immune responses and mediate chronic inflammation leading to alterations in the hypothalamic 'bodyweight/appetite/satiety set point'. It is becoming increasingly evident that metabolic syndrome is a risk factor for neurological disorders such as stroke, depression, and Alzheimer disease (AD). Family history, age, environmental and lifestyle factors (diet and physical inactivity, and exposure to toxins) are closely associated with predisposition for the development of metabolic syndrome as well as neurological disorders. The incidences of stroke are 2 to 4-fold higher in patients with metabolic syndrome and cardiovascular diseases compared to normal subjects of the same age. Similarly, patients with metabolic syndrome have a 2 to 3-fold increased risk for developing dementia and AD. Metabolic syndrome doubles the risk of depression. The molecular mechanism underlying the mirror relationship between metabolic syndrome and neurological disorders is not fully understood. However, biochemical alterations observed in metabolic syndrome like induction of chronic inflammation and oxidative stress, impairment of endothelial cell function, induction of insulin and leptin resistance, hyperglycemia-related increase in advanced glycation end-products, and micro-vascular injury may represent a pathological bridge between metabolic syndrome and neurological disorders. It is hoped that Metabolic Syndrome: An important risk factor for stroke, Alzheimer disease, and depression will be useful to postgraduate students, faculty, research scientists, pharmacologists, nutritionists, and physicians, who are curious about the molecular mechanisms that link metabolic syndrome with stroke, Alzheimer disease, and depression.