Low HDL levels implicated in variant angina pectoris
MedWire News: Low levels of high-density lipoprotein (HDL) cholesterol are a risk factor for variant angina pectoris (VAP), study results suggest.
Although the association was independent of other known variables, the underlying mechanism may involve endothelial dysfunction, the researchers suggest.
“HDL has been shown to mediate vasodilation as a result of its endothelium-enhancing property; however, the significance of low HDL in patients with VAP has not been clarified,” explain Yasuo Sugano (Saiseikai Utsunomiya Hospital, Tochigi, Japan) and team.
VAP is characterized by severe transient myocardial ischemia resulting from abrupt occlusive coronary vasoconstriction, but the precise pathogenesis is unknown.
To investigate, the team studied 174 consecutive patients with a suspected diagnosis of VAP. Spasm provocation testing confirmed the diagnosis in 103 (59%) patients, and these individuals were compared with patients who tested negative for VAP.
Writing in the International Journal of Cardiology, Sugano’s team reports that HDL cholesterol levels were significantly lower in patients with VAP than in those without (50.0 vs 57.9 mg/dl [1.29 vs 1.50 mmol/l]).
In multivariate analysis, being in the lowest quartile of HDL cholesterol levels (<43 mg/dl [<1.11 mmol/l]) was a significant independent predictor for VAP, with an odds ratio of 3.39. Other significant predictors were cigarette smoking and impaired fasting plasma glucose (FPG) or diabetes mellitus.
These three risk factors had a synergistic influence on risk, such that patients in the lowest HDL quartile who were also in the highest FPG quartile or who were current cigarette smokers had a respective 2.01-fold and a 1.88-fold increased risk for VAP.
“A low level of HDL cholesterol is an independent determinant for VAP,” the researchers conclude. “Endothelial dysfunction caused by a low HDL state may play a role in the development of VAP.”
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By Joanna Lyford