Premature atherosclerosis is not systematic in phytosterolemic patients: Severe hypercholesterolemia as a confounding factor in five subjects

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• 作者：Boris Hansel^a ; ^b ; ^c ; ^{boris.hansel@gmail.com" class="auth_mail} ; ^{boris.hansel@bch.aphp.fr" class="auth_mail} ; Alain Carrié ; ^b ; ^d ; ^e ; Nathalie Brun-Druc^f ; Geoffroy Leclert^g ; Sandrine Chantepie^h ; Anne-Sophie Coiffard^b ; ^d ; Jean-Franç ; ois Kahn^g ; M. John Chapman^b ; ^e ; Eric Bruckert^b ; ^e ; ^g
• 关键词：Sitosterolemia ; Phytosterolemia ; Plant sterols ; Hypercholesterolemia ; Cardiovascular disease ; Premature atherosclerosis
• 刊名：Atherosclerosis
• 出版年：May, 2014
• 年：2014
• 卷：234
• 期：1
• 页码：162-168
• 全文大小：456 K

文摘

Objective

Phytosterolemia is a rare autosomal recessive disorder characterized by dramatically elevated circulating levels of plant sterols (PS). Phytosterolemia is believed to be responsible for severe premature atherosclerosis. The clinical, biological and molecular genetic features of 5 patients with phytosterolemia and transient severe hypercholesterolemia challenge this hypothesis.

Methods

Our patients were referred for suspected homozygous familial hypercholesterolemia. Despite the phenotype, this diagnosis was invalidated and phytosterolemia was confirmed by the identification of mutations in the ABCG5/ABCG8 transporter complex. Plasma PS were analyzed with a mass spectrometric-gas chromatographic procedure. Vascular status was assessed with carotid ultrasonography and completed (for 4 of the 5 patients) with femoral ultrasonography; additional examinations of cardiovascular status included a stress test, determination of coronary calcium score, echocardiography, non-invasive assessment of endothelium-dependent dilatation and coronarography.

Results

The 5 patients displayed markedly elevated levels of both 尾-sitosterol and campesterol (15-30 fold higher than normal values). However, none displayed significant signs of infraclinical premature atherosclerosis (respectively at the ages of 32, 27, 29, 11 and 11 years). All patients were characterized by very high levels of total (>450聽mg/dl) and LDL-cholesterol (>350聽mg/dl) at diagnosis which decreased markedly on dietary intervention alone. Treatment with cholestyramine or Ezetimibe聽卤聽atorvastatin normalized cholesterol levels, although plasma PS concentrations remained elevated.

Conclusion

The clinical and biological characteristics of our patients, considered together with reports of cases which equally lack CVD, support the contention that the premature atherosclerosis associated with phytosterolemia in some patients may be due at least in part to mechanisms independent of elevated circulating phytosterol levels.