GHRL and metabolic syndrome: Several previous studies have suggested that short sleep durations are related to CVD risk via the following mechanisms: (a) obesity and disorders in glucose metabolism that are caused by changes in dietary consumption via alterations in circulating levels of leptin and ghrelin [4]; (b) low-grade inflammatory states due to increased levels of circulating leukocytes and cytokines [32]; and (c) HTN and dyslipidemia per se [34].