Medical Nutrition Therapy and Nutritional Supplements for Maple Syrup Urine Disease

Abstract

Maple syrup urine disease is a rare autosomal recessive congenital metabolic disorder in which branched-chain amino acids cannot be metabolized due to defects in the branched-chain α-ketoacid dehydrogenase enzyme complex. The inability to metabolize branched-chain amino acids results in the accumulation of branched-chain amino acids in plasma and related branched-chain ketoacids in urine. There are five subclinical phenotypes of the disease and dietary therapy and liver transplantation are among the available treatment modalities. Medical nutrition therapy has two phases: acute and long-term. A reduction in catabolism during acute episodes of metabolic crisis requires immediate nutritional intervention. After the regulation of acute metabolic crises, long-term nutritional therapy is initiated, in which the amount of branched-chain amino acids is restricted on the basis of the increased level of neurotoxic leucine. As nutritional support approaches in medical nutrition therapy, it has been reported that thiamine supplementation, which has been reported to increase patients' capacity to tolerate dietary branched-chain amino acids or the decrease in branched-chain amino acid levels in their plasma, and isoleucine and valine supplements, which are vital for growth and development, which have been reported to accelerate the decrease in plasma leucine levels and prevent various skin lesions, as well as L-carnitine and norleucine supplements may have positive effects on patients. Studied have shown that L-carnitine supplementation may have protective effects on DNA damage, prevent the oxidative damage to proteins and lipids observed in these patients and improve the antioxidant capacity of patients. Notably, norleucine may be a new treatment approach that can be used to prevent encephalopathy in this disease, but human studies are needed to prove these effects. In this review, we aimed to examine the medical nutrition therapy for maple syrup-related urine disease and nutritional supplements that may have significant effects on this disease. Keywords: Maple syrup urine disease, dietary supplements, L-carnitine, norleucine, medical nutrition therapy.

Keywords

• Maple syrup urine disease
• dietary supplements
• L-carnitine
• norleucine
• medical nutrition therapy

Akçaağaç Şurubu İdrar Hastalığında Tıbbi Beslenme Tedavisi ve Besin Destekleri

Abstract

Akçaağaç şurubu idrar hastalığı, dallı zincirli α-ketoasit dehidrogenaz enzim kompleksindeki hasarlar sebebiyle dallı zincirli amino asitlerin metabolize olamadığı otozomal resesif geçişli nadiren görülen doğuştan kalıtsal metabolizma hastalığıdır. Dallı zincirli amino asitlerin metabolize olamaması sonucunda plazmada dallı zincirli amino asitlerin ve idrarda ilgili dallı zincirli ketoasitlerin birikimi gerçekleşmektedir. Hastalığın beş alt klinik fenotipi bulunmakta olup tıbbi beslenme tedavisi ve karaciğer nakli mevcut tedavi yöntemleri arasındadır. Tıbbi beslenme tedavisi akut ve uzun dönem olmak üzere iki aşamalıdır. Akut metabolik kriz ataklarında katabolizmanın azaltılması acil beslenme girişimini gerektirmektedir. Akut metabolik krizlerin düzenlenmesinin ardından daha nörotoksik olan lösinin temel alınarak dallı zincirli amino asit miktarının kısıtlandığı uzun süreli beslenme tedavisine geçilmektedir. Tıbbi beslenme tedavisinde besin desteği yaklaşımları olarak, hastaların diyet yoluyla aldıkları dallı zincirli amino asitleri tolere etme kapasitelerinde artışa veya plazmalarındaki dallı zincirli amino asit seviyelerindeki düşüşe destek olan tiamin takviyesinin ve büyüme ve gelişme için hayati önem taşıyan, plazma lösin düzeylerinin düşmesini hızlandırdığı ve çeşitli cilt lezyonlarını önlediği bildirilen izolösin ile valin takviyelerinin yanı sıra L-karnitin ve norlösin takviyelerinin de hastalar üzerinde olumlu etkilerinin olabileceği bildirilmektedir. L-karnitin takviyesinin, bu hastalarda görülen protein ve lipidlerin oksidatif hasarlarının önlenmesi ve hastaların antioksidan kapasitelerinin iyileşmesine katkı sağlayabileceğinin yanında DNA hasarında koruyucu etkilere sahip olabileceği sonucuna varan çalışmalar mevcuttur. Norlösinin ise bu hastalıkta ensefalopatiyi önlemek amacıyla kullanılabilecek yeni bir tedavi yaklaşımı olabileceği ancak bu etkilerin kanıtlanabilmesi için insan çalışmalarının yapılması gerektiği vurgulanmaktadır. Bu derlemede, akçaağaç şurubu idrar hastalığının tıbbi beslenme tedavisinin ve hastalık üzerinde önemli etkiler gösterebilecek olan besin desteklerinin incelenmesi amaçlanmıştır. Anahtar Kelimeler: Akçaağaç şurubu idrar hastalığı, besin takviyeleri, L-karnitin, norlösin, tıbbi beslenme tedavisi.

Keywords

• Akçaağaç şurubu idrar hastalığı
• besin takviyeleri
• L-karnitin
• norlösin
• tıbbi beslenme tedavisi.

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