Browsing by Author "Sayer AA"

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    Clinical risk factors, bone density and fall history in the prediction of incident fracture among men and women
    (2013) Edwards MH; Jameson K; Denison H; Harvey NC; Sayer AA; Dennison EM; Cooper C
    The FRAX(tr) algorithm uses clinical risk factors (CRF) and bone mineral density (BMD) to predict fracture risk but does not include falls history in the calculation. Using results from the Hertfordshire Cohort Study, we examined the relative contributions of CRFs, BMD and falls history to fracture prediction. We studied 2299 participants at a baseline clinic that included completion of a health questionnaire and anthropometric data. A mean of 5.5years later (range 2.9-8.8years) subjects completed a postal questionnaire detailing fall and fracture history. In a subset of 368 men and 407 women, bone densitometry was performed using a Hologic QDR 4500 instrument. There was a significantly increased risk of fracture in men and women with a previous fracture. A one standard deviation drop in femoral neck BMD was associated with a hazards ratio (HR) of incident fracture (adjusted for CRFs) of 1.92 (1.04-3.54) and 1.77 (1.16-2.71) in men and women respectively. A history of any fall since the age of 45years resulted in an unadjusted HR of fracture of 7.31 (3.78-14.14) and 8.56 (4.85-15.13) in men and women respectively. In a ROC curve analysis, the predictive capacity progressively increased as BMD and previous falls were added into an initial model using CRFs alone. Falls history is a further independent risk factor for fracture. Falls risk should be taken into consideration when assessing whether or not to commence medication for osteoporosis and should also alert the physician to the opportunity to target falls risk directly.
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    Mitochondrial oxidative capacity and NAD+ biosynthesis are reduced in human sarcopenia across ethnicities
    (Springer Nature Limited, 2019-12-20) Migliavacca E; Tay SKH; Patel HP; Sonntag T; Civiletto G; McFarlane C; Forrester T; Barton SJ; Leow MK; Antoun E; Charpagne A; Seng Chong Y; Descombes P; Feng L; Francis-Emmanuel P; Garratt ES; Giner MP; Green CO; Karaz S; Kothandaraman N; Marquis J; Metairon S; Moco S; Nelson G; Ngo S; Pleasants T; Raymond F; Sayer AA; Ming Sim C; Slater-Jefferies J; Syddall HE; Fang Tan P; Titcombe P; Vaz C; Westbury LD; Wong G; Yonghui W; Cooper C; Sheppard A; Godfrey KM; Lillycrop KA; Karnani N; Feige JN
    The causes of impaired skeletal muscle mass and strength during aging are well-studied in healthy populations. Less is known on pathological age-related muscle wasting and weakness termed sarcopenia, which directly impacts physical autonomy and survival. Here, we compare genome-wide transcriptional changes of sarcopenia versus age-matched controls in muscle biopsies from 119 older men from Singapore, Hertfordshire UK and Jamaica. Individuals with sarcopenia reproducibly demonstrate a prominent transcriptional signature of mitochondrial bioenergetic dysfunction in skeletal muscle, with low PGC-1α/ERRα signalling, and downregulation of oxidative phosphorylation and mitochondrial proteostasis genes. These changes translate functionally into fewer mitochondria, reduced mitochondrial respiratory complex expression and activity, and low NAD+ levels through perturbed NAD+ biosynthesis and salvage in sarcopenic muscle. We provide an integrated molecular profile of human sarcopenia across ethnicities, demonstrating a fundamental role of altered mitochondrial metabolism in the pathological loss of skeletal muscle mass and function in older people.
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    The importance of fall history in fracture risk assessment
    (2013) Edwards MH; Jameson KA; Denison H; Harvey NC; Sayer AA; Dennison EM; Cooper C