Circulating concentrations of vitamin E isomers: Association with bone turnover and arterial stiffness in post-menopausal women.
The effects of vitamin E on cardiovascular and bone health are conflicting with beneficial and detrimental findings reported. To investigate this further, we carried out a cross-sectional study to determine the relationship between circulating concentrations of the 2 vitamin E isomers, α- and γ-tocopherol (TP) with bone turnover and arterial stiffness. Two hundred and seventy eight post-menopausal women with mean age [SD] 60.9 [6.0] years were studied. Fasting serum α-TP and γ-TP, bone turnover markers; procollagen type 1 amino-terminal propeptide (P1NP) and C-terminal telopeptide of type 1 collagen (CTX), parathyroid hormone (PTH), total cholesterol (TC) and triglycerides (TG) were measured. Pulse wave velocity (PWV) and central augmentation index (AI) as markers of arterial stiffness were also determined. A positive correlation was observed between α-TP and γ-TP (r=0.14, p=0.022). A significant negative association between α-TP and P1NP only was seen in multiple linear regression analysis following adjustment for serum TC and TG (p=0.016). In a full multi-linear regression model, following correction for age, years since menopause, smoking habits, alcohol intake, use of calcium supplements, BMI, PTH, serum calcium, and estimated glomerular filtration rate (eGFR), the association between α-TP and P1NP remained significant (p=0.011). We did not observe any significant association between γ-TP or α-TP/γ-TP ratio with P1NP or CTX. P1NP was significantly lower in subjects with α-TP concentrations of >30 μmol/L (α-TP >30 μmol/L; P1NP: 57.5 [20.7], α-TP<30 μmol/L; P1NP: 65.7 [24.9] μg/L, p=0.005). PWV was significantly associated with α-TP/γ-TP ratio (p=0.04) but not with serum α-TP or γ-TP in a full multi-linear regression model adjusting for serum lipids, age, and blood pressure. The data suggest that high serum concentrations of α-TP may have a negative effect on bone formation. The balance of α-TP and γ-TP may be important in maintaining arterial compliance. Longitudinal studies are needed to investigate the impact of the vitamin E isomers on bone and cardiovascular health.
Department of Clinical Chemistry, Viapath, St Thomas' Hospital, London SE1 7 EH, UK; Osteoporosis Unit, King's College London, Division of Imaging Sciences and Biomedical Engineering, Guy's Campus, London SE1 9RT, UK. Electronic address: geeta.hampson@kcl.ac.uk.
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Hampson
Osteoporosis Unit, King's College London, Division of Imaging Sciences and Biomedical Engineering, Guy's Campus, London SE1 9RT, UK.
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Edwards
Department of Clinical Chemistry, Viapath, St Thomas' Hospital, London SE1 7 EH, UK.
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Sankaralingam
Nutristasis Laboratory, Viapath, St Thomas' Hospital, London SE1 7EH, UK.
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Harrington
Nutristasis Laboratory, Viapath, St Thomas' Hospital, London SE1 7EH, UK.
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Voong
Osteoporosis Unit, King's College London, Division of Imaging Sciences and Biomedical Engineering, Guy's Campus, London SE1 9RT, UK.
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Fogelman
Osteoporosis Unit, King's College London, Division of Imaging Sciences and Biomedical Engineering, Guy's Campus, London SE1 9RT, UK.
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Frost
D015502:Absorptiometry, Photon; D000368:Aged; D016723:Bone Remodeling / Q000187:drug effects*; D001842:Bone and Bones / Q000378:metabolism / Q000473:pathology; D002784:Cholesterol / Q000097:blood; D024042:Collagen Type I / Q000097:blood / Q000378:metabolism; D003430:Cross-Sectional Studies; D004548:Elasticity; D005260:Female; D006801:Humans; D016014:Linear Models; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D017698:Postmenopause / Q000097:blood*; D063177:Pulse Wave Analysis; D014280:Triglycerides / Q000097:blood; D059289:Vascular Stiffness / Q000187:drug effects*; D014810:Vitamin E / Q000097:blood*; D024502:alpha-Tocopherol / Q000627:therapeutic use; D024504:gamma-Tocopherol / Q000097:blood
D024042:Collagen Type I; C470125:PTH protein, human; D010281:Parathyroid Hormone; D010455:Peptides; D014280:Triglycerides; C052929:collagen type I trimeric cross-linked peptide; D014810:Vitamin E; D024504:gamma-Tocopherol; D002784:Cholesterol; D024502:alpha-Tocopherol
Arterial stiffness; Bone markers; Tocopherol; Vitamin E