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High-density lipoprotein particles are large in patients with variant angina
K Miwa1, N Yoshida, K Nakagawa
1Second Department of Internal Medicine, Toyama Medical and Pharmaceutical University, Japan.
Insights
Patients with variant angina exhibit larger, cholesterol-rich high-density lipoprotein (HDL) particles, despite low HDL-cholesterol and apolipoprotein A-I levels. These lipid abnormalities normalize with treatment for coronary vasospasm.
Area of Science:
- Cardiology
- Lipidology
- Biochemistry
Background:
- Dyslipidemia in coronary vasospasm often involves low high-density lipoprotein (HDL)-cholesterol and apolipoprotein (apo) A-I.
- Variant angina, a form of coronary vasospasm, warrants investigation into its specific lipid profile and HDL characteristics.
Purpose of the Study:
- To examine the high-density lipoprotein (HDL) particle size in patients diagnosed with variant angina.
- To compare HDL particle size and serum lipid levels in variant angina patients against control groups.
Main Methods:
- Serum lipid levels, including HDL-cholesterol and apolipoproteins (apo) A-I and A-II, were analyzed in 38 variant angina patients.
- HDL particle size distribution was assessed using electrophoresis and compared with 40 control subjects and 30 stable effort angina patients.
Main Results:
- Patients with variant angina and stable effort angina showed lower HDL-cholesterol, apoA-I, and apoA-II compared to controls.
- Variant angina patients displayed a higher HDL-cholesterol/apoA-I ratio and larger HDL particles, confirmed by electrophoresis.
- Lipid abnormalities normalized in variant angina patients after treatment for coronary vasospasm.
Conclusions:
- Variant angina is characterized by high HDL-cholesterol/apoA-I ratios alongside low HDL-cholesterol and apoA-I levels.
- The study indicates larger, cholesterol-rich, and potentially malfunctioning HDL particles in variant angina patients.
- Successful medical treatment of coronary vasospasm led to normalization of these abnormal serum lipid values.
Objective:
Dyslipidemia in patients with coronary vasospasm may be characterized by low level of high-density lipoprotein (HDL)-cholesterol as well as apolipoprotein (apo) A-I but not high level of low-density lipoprotein-cholesterol. This study sought to examine the HDL particle size in patients with variant angina.
Methods:
The HDL particle size was examined by analyzing serum lipid levels in 38 patients with variant angina to compare with those of 40 control subjects and 30 normocholesterolemic patients with stable effort angina. Also, actual HDL size distribution was assessed by electrophoresis.
Results:
The HDL-cholesterol, apoA-I and apoA-II levels were all lower (P < 0.01 for each) in patients with variant angina and patients with stable effort angina as compared with control subjects. The apoA-II level was lower (P < 0.01) in patients with variant angina than in patients with stable effort angina. The apoA-I/apoA-II ratio was lower (P < 0.01) in patients with stable effort angina, but not in patients with variant angina as compared with control subjects. In contrast, the HDL-cholesterol/apoA-I ratio was higher in patients with variant angina than in control subjects (P < 0.01) and also patients with stable effort angina (P < 0.01). The slope of the regression line, comparing HDL-cholesterol and apoA-I levels, was greater in patients with variant angina than in control subjects (P < 0.05) and patients with stable effort angina (P < 0.05), suggesting an increase in larger HDL particles. Native polyacrylamide gel electrophoresis revealed that HDL particles in patients with variant angina were skewed towards larger sizes compared with control subjects (P < 0.01) and patients with stable effort angina (P < 0.01). The abnormal serum lipid values were normalized in the patients with variant angina after the medical treatment and inactivation of the coronary spasm.
Conclusion:
High HDL-cholesterol/apoA-I levels associated with low serum HDL-cholesterol and apoA-I levels were characteristic in patients with variant angina, in whom HDL particles were large, cholesterol-rich and possibly malfunctioning.