LEP and dementia: We also identified a number of vascular and metabolic markers associated with dementia, many of which have previously been associated with dementia, cognitive impairment, or dementia brain pathology, including homocysteine [47], plasminogen activator inhibitor-1 (PAI-1) [48], cystatin C [49], and leptin [50,51], although results for leptin have been conflicting [52].