Hyperhomocysteinemia and Atherosclerotic Vascular Disease

Abstract

Hyperhomocysteinemia has recently been identified as an important risk factor for atherosclerotic vascular disease. This article reviews homocysteine metabolism, causes of hyperhomocysteinemia, the pathophysiological findings of this disorder, and epidemiological studies of homocysteine and vascular disease. Screening for hyperhomocysteinemia should be considered for patients at high risk for vascular disease or abnormalities of homocysteine metabolism. For primary prevention of vascular disease, treatment of patients with homocysteine levels of 14 micromol/L or higher should be considered. For secondary prevention, treatment of patients with homocysteine levels of 11 micromol/L or higher should be considered. Treatment is most conveniently administered as a folic acid supplement (400-1000 microg) and a high-potency multivitamin that contains at least 400 microg of folate. Higher doses of folic acid and cyanocobalamin supplements may be required in some patients. Until prospective clinical trial data become available, these conservative recommendations provide a safe, effective, and evidence-based approach to the diagnosis, evaluation, and management of patients with hyperhomocysteinemia.

Smoking cessation, but not smoking reduction, reduces plasma homocysteine levels

“…13 Recently, hyperhomocysteinemia has emerged as an independent risk factor for atherosclerosis in the coronary, carotid, and peripheral arterial beds. 1,2,6,7 The adverse effects of smoking cigarettes on atherosclerotic vascular disease is well known; however, the pathophysiology underlying the relationship between cigarette smoking and atherosclerosis is complex and multifactorial. 8 One of the many adverse effects of smoking is increasing Hcy levels, which may contribute to endothelial injury and atherosclerosis.…”

“…[1][2][3][4][5][6][7] Cigarette smoking, the leading avoidable cause of death and morbidity in the United States, has been associated with increased Hcy levels. [1][2][3][4][5]8 In the Hordaland Homocysteine Study, smoking ≥ 20 cigarettes daily was associated with a 2.01 µmol/l increase in Hcy levels, a finding that may be related to enhanced catabolism of vitamin B 6 and folate.…”

Plasma homocysteine concentration and blood pressure in healthy Iranian adults: the Tehran Homocysteine Survey (2003–2004)

“…32 We also considered total Hcy ¼ 10-30 mmol/l and 30-100 mmol/l as mild and moderate HHcy, respectively. 33,34 Diabetes was defined according to the current American Diabetes Association guidelines. 35 Mean BP was calculated with (SBP þ 2 DBP)/3 and pulse BP with SBP minus DBP formula.…”

Homocysteine as a ñardiovascular risk factor in patients with hypothyroidism

“…ϳäâèùåííÿ ð³âíÿ Ãö íà 5 ìêìîëü/ë ïðèçâîäèòü äî çðîñòàííÿ ðè-çèêó àòåðîñêëåðîòè÷íîãî ïîøêîäaeåííÿ ñóäèí íà 80% ó ae³íîê ³ íà 60% ó ÷îëîâ³ê³â. ϳäâèùåííÿ ð³âíÿ Ãö äîñë³äíèêè âèÿâëÿþòü ó 13-47% õâîðèõ íà ³øåì³÷íó õâîðîáó ñåðöÿ òà ââàaeàþòü êðèòåð³-ºì, ÿêèé º ïåðåäóìîâîþ ðîçâèòêó ãîñòðèõ åï³çî-ä³â ñåðöåâî-ñóäèííèõ óñêëàäíåíü [7,[12][13][14]17].…”

“…ϳäâèùåííÿ ð³âíÿ Ãö ïîíàä ñåðåäí³é ïîêàçíèê êîíòðîëüíî¿ ãðóïè (7,42±0,43 ìêìîëü/ë) ñïîñòåð³ãàëè ó 33%, 50%, 44% õâîðèõ 1-3-¿ ãðóï â³äïîâ³äíî. ª ïîâ³äîìëåííÿ, ùî çá³ëüøåííÿ Ãö íà 5 ìêìîëü/ë ï³äâèùóº ðèçèê ñåðöåâî-ñóäèííèõ çàõâîðþâàíü ³ çàãàëüíî¿ ñìåðòíîñò³ â 1,3-1,7 ðàçó [17].…”