Insulin dependent diabetes mellitus and metabolic syndrome are independently associated with a greater likelihood of intracranial large-artery atherosclerosis and diabetic patients have a significantly higher number of diseased vessels compared to disease free individuals.[27,28] Dyslipidemia, high lipoprotein A levels [29], smoking and decreased level of endostatin (an angiogenesis promoter) are all associated with intracranial stenosis.[30]. This evidence concerns the gene COL18A1 and metabolic syndrome.