ABSTRACT
Metabolic syndrome (MetS) is characterized by the symptoms of central obesity, insulin resistance, atherogenic dyslipidemia, and hypertension (Deedwania and Gupta 2006). Raised triglyceride (TG) levels, decreased high-density lipoprotein (HDL), elevated blood pressure, and diabetes mellitus constitute the important criteria for MetS (Cornier et al. 2008; Alberti et al. 2009). The prevalence of MetS in general population ranges from 17% to 25% (Grundy 2008; Al Saraj et al. 2009), but the prevalence is around 59%–61% in diabetes mellitus (Saraj et al. 2009). A high prevalence of MetS is noted with an increase in age (Ford et al. 2002). With regard to the inuence of gender on MetS, some studies have shown that the incidence of MetS is higher in men than in women (Fezeu et al. 2007; Ahonen et al. 2009), whereas another study on Chinese has demonstrated that the prevalence of MetS is higher in women than in men (He et al. 2006). In a study
4.1 Introduction ............................................................................................................................29 4.2 Metabolic Syndrome: Its Pathophysiology .............................................................................30 4.3 Insulin Resistance as the Cause of Metabolic Syndrome ....................................................... 31 4.4 Role of Adipose Tissue and Adipokines in Metabolic Syndrome .......................................... 32 4.5 Adipocytes, Obesity, and Vascular Dysfunction .................................................................... 32 4.6 Vascular Dysfunction in Metabolic Syndrome ....................................................................... 33 4.7 Dyslipidemia ...........................................................................................................................34 4.8 Melatonin ................................................................................................................................34 4.9 Melatonin Receptors ............................................................................................................... 35 4.10 Role of Melatonin in Metabolic Syndrome ............................................................................ 35 4.11 Melatonin Studies in Obesity and Metabolic Syndrome ........................................................ 35 4.12 Melatonin as an Antioxidant...................................................................................................36 4.13 Melatonin and Metabolic Syndrome: Studies on Patients with Metabolic Syndrome ........... 37 4.14 Melatonin, Insulin Resistance, and Metabolic Syndrome ...................................................... 37 4.15 Melatonin’s Amelioration of Impaired Antioxidant Status during Diabetic Complications ...... 39 4.16 Melatonin, Circadian Rhythms, and Metabolic Syndrome ....................................................40 4.17 Conclusion ..............................................................................................................................40 References ........................................................................................................................................ 41
conducted on Nigerians with type 2 diabetes mellitus (T2DM), the occurrence of MetS was found to be similar in both sexes, although the prevalence increased in aged subjects (70-79 years, 89%) when compared to young subjects (20-29 years, 11%; Ogbera 2010). Asians are more prone to MetS, and a recent study has shown that the prevalence of MetS in Indians ranges from 35.8% to 45.3% (Ravikiran et al. 2010). The percentage of MetS in Chinese is known to range from 30.5% to 31.5% (Zuo et al. 2009).
