Low LDL and haemorrhagic stroke

• Intraparenchymal hemorrhage, which has a low survival rate and a high risk of disability, has unique pathological and epidemiological characteristics that distinguish it from coronary heart disease
  • type of stroke is caused primarily by hypertension and possibly by low concentrations of low-density lipoprotein (LDL) cholesterol (1,2)
    
    
• low LDL cholesterol levels are associated with elevated risk of death due to haemorrhagic stroke (particularly intraparenchymal hemorrhage) (3)
  • however there was no association between subarachnoid haemorrage and low LDL choleserol levels
    • the study revealed a U-shaped relationship between LDL cholesterol and combined death due to intraparenchymal hemorrhage and coronary heart disease, with a nadir at LDL cholesterol levels of 120 to 139 mg/dL (3.10 to 3.61 mmol/L), because these 2 outcomes have an opposite direction in the association with LDL cholesterol (3)
    • however in this Japan based study, the authors observed inverse associations of LDL cholesterol with death due to total cardiovascular disease and all-cause mortality, because the Japanese population had high rates of death due to total stroke, with a high proportion of intraparenchymal hemorrhage, and low rates of death due to coronary heart disease compared with Americans
      • a previous study of Americans showed a U-shaped relationship between LDL cholesterol and all-cause mortality, with a nadir at LDL cholesterol levels of 160 to 189 mg/dL (4.14 to 4.90 mmol/L) for men and 130 to 159 mg/dL (3.36 to 4.12 mmol/L) for women (4)
  • the authors concluded that low LDL cholesterol may be an independent risk factor for intraparenchymal hemorrhage (3)

Reference:

• 1) Konishi M et al. Associations of serum total cholesterol, different types of stroke, and stenosis distribution of cerebral arteries. Stroke. 1993; 24: 954-964
• 2) Takayama Y. Effects of an atherogenic diet on arterial lesions of hypertensive rats. J Jpn Coll Angiol. 1975; 15: 455-464. J5 (1986).Input Input.
• 3) Noda H et al. Low-density lipoprotein cholesterol concentrations and death due to intraparenchymal hemorrhage: the Ibaraki Prefectural Health StudyCirculation. 2009 Apr 28;119(16):2136-45.
• 4) Psaty BM et al. The association between lipid levels and the risks of incident myocardial infarction, stroke, and total mortality: the Cardiovascular Health Study. J Am Geriatr Soc. 2004; 52: 1639-1647