Primary carnitine deficiency: adult onset lipid storage myopathy with a mild clinical course

Vielhaber, Stefan; Feistner, Helmut; Weis, Joachim; Kreuder, Joachim; Sailer, Michael; Schröder, Johann Michael; Kunz, Wolfram S.

doi:10.1016/j.jocn.2003.11.019

Cited by 22 publications

(11 citation statements)

References 37 publications

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“…Indeed, skeletal muscle contains ∼98% of the body's total store of carnitine (16, 33), and ascorbate is required for its synthesis through its action as a cofactor for the metalloenzymes trimethyllysine hydroxylase and γ-butyrobetaine hydroxylase (35). Carnitine deficiency has been reported in human skeletal muscle, and deficient biosynthesis has been implicated in some cases (34, 36, 37). The effect of vitamin C deficiency on human skeletal muscle carnitine concentrations has not been explored but has been shown to result in a ≤50% reduction in skeletal muscle carnitine in guinea pigs (38–41).…”

Section: Discussionmentioning

confidence: 99%

Human skeletal muscle ascorbate is highly responsive to changes in vitamin C intake and plasma concentrations

Carr¹,

Bozonet²,

Pullar³

et al. 2013

The American Journal of Clinical Nutrition

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Background: Vitamin C (ascorbate) is likely to be essential for skeletal muscle structure and function via its role as an enzyme cofactor for collagen and carnitine biosynthesis. Vitamin C may also protect these metabolically active cells from oxidative stress.Objective: We investigated the bioavailability of vitamin C to human skeletal muscle in relation to dietary intake and plasma concentrations and compared this relation with ascorbate uptake by leukocytes.Design: Thirty-six nonsmoking men were randomly assigned to receive 6 wk of 0.5 or 2 kiwifruit/d, an outstanding dietary source of vitamin C. Fasting blood samples were drawn weekly, and 24-h urine and leukocyte samples were collected before intervention, after intervention, and after washout. Needle biopsies of skeletal muscle (vastus lateralis) were carried out before and after intervention.Results: Baseline vastus lateralis ascorbate concentrations were ∼16 nmol/g tissue. After intervention with 0.5 or 2 kiwifruit/d, these concentrations increased ∼3.5-fold to 53 and 61 nmol/g, respectively. There was no significant difference between the responses of the 2 groups. Mononuclear cell and neutrophil ascorbate concentrations increased only ∼1.5- and ∼2-fold, respectively. Muscle ascorbate concentrations were highly correlated (P < 0.001) with dietary intake (R = 0.61) and plasma concentrations (R = 0.75) in the range from 5 to 80 μmol/L.Conclusions: Human skeletal muscle is highly responsive to vitamin C intake and plasma concentrations and exhibits a greater relative uptake of ascorbate than leukocytes. Thus, muscle appears to comprise a relatively labile pool of ascorbate and is likely to be prone to ascorbate depletion with inadequate dietary intake. This trial was registered at the Australian New Zealand Clinical Trials Registry (www.anzctr.org.au) as ACTRN12611000162910.

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Section: Discussionmentioning

confidence: 99%

Human skeletal muscle ascorbate is highly responsive to changes in vitamin C intake and plasma concentrations

Carr¹,

Bozonet²,

Pullar³

et al. 2013

The American Journal of Clinical Nutrition

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“…Carnitine transports lipid into the mitochondria, and carnitine deficiency can produce a myopathy that may become more apparent with prolonged exercise. 29 Furthermore, heterozygosity for mutations in the carnitine palmitoyltransferase II (CPT II) gene was 13-fold higher in subjects with severe statin myopathy. 16 Complex II.…”

Section: Discussionmentioning

confidence: 99%

Transcriptional deficits in oxidative phosphorylation with statin myopathy

et al. 2011

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“…Primary systemic L-carnitine deficiency is caused by several defects in the biosynthesis and transport of L-carnitine. This leads to increased excretion of L-carnitine and decreased L-carnitine accumulation in tissues (Longo et al, 2006, Vielhaber et al, 2004. Secondary L-carnitine deficiency occurs due to genetically defined disturbances in fatty acid oxidation and amino acid homeostasis.…”

Section: L-cartinine In the Cnsmentioning

confidence: 99%