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Heart failure with preserved ejection fraction in older adults
Published in Wilbert S. Aronow, Jerome L. Fleg, Michael W. Rich, Tresch and Aronow’s Cardiovascular Disease in the Elderly, 2019
Bharathi Upadhya, Dalane W. Kitzman
Haykowsky and colleagues further extended their results by using dual-energy X-ray absorptiometry and found that percent body fat and percent leg fat were significantly increased, whereas percent body lean and leg lean mass were significantly reduced, and the slope of the relation of peak VO2 with percent leg lean mass was markedly reduced in the older HFpEF patients versus a healthy control group (94). These data suggest that poor “quality” of skeletal muscle may contribute to the reduced peak VO2 found in older HFpEF patients. These investigators later assessed thigh muscle composition using phase-contrast MRI, which showed abnormal fat infiltration into the thigh skeletal muscle, associated with reduced peak exercise VO2 in HFpEF (95). Indeed, Bhella et al. (92), using phosphate-31 magnetic resonance spectroscopy during and after performing static leg lifts, showed impaired skeletal muscle oxidative metabolism in patients with HFpEF. Thus, a number of potential intramuscular fat-mediated structural and biochemical alterations may decrease oxygen transport to and/or utilization by the active muscles.
Exercise in the Older Adult
Published in K. Rao Poduri, Geriatric Rehabilitation, 2017
Body composition also changes with aging. There is an increase in adipose mass and a decline in fat-free mass (FFM). Adipose tissue deposition patterns shift, increasing both visceral and truncal adiposity. There is a decrease in muscle mass (sarcopenia) and type 2 (fast twitch) muscle fiber types. There is an increase in intramuscular fat and connective tissue, with a decline in muscle quality. There is also decreased bone mass and density, with an increase in bony fragility.
Stroke
Published in John M. Saxton, Exercise and Chronic Disease, 2011
Frederick M. Ivey, Alice S. Ryan, Charlene E. Hafer-Macko, Richard F. Macko
Bilateral mid-thigh computer tomography (CT) scans can be used to illustrate the severe atrophy caused by chronic hemiparesis (Figure 4.2) (Ryan et al. 2002). There is extreme gross muscular atrophy in the paretic leg mid-thigh CT scans, showing 20 per cent lower muscle area compared to the non-paretic thigh. In addition, intramuscular area fat is 25 per cent greater in the paretic thigh compared to the non-paretic thigh (Ryan et al. 2002). Elevated intramuscular fat is linked to insulin resistance and its complications (Frontera et al. 1997). These body composition abnormalities may impact upon whole body metabolic health and function.
High Visceral Fat is Associated with a Worse Survival after Liver Resection for Intrahepatic Cholangiocarcinoma
Published in Nutrition and Cancer, 2022
Laurence Lacaze, Damien Bergeat, Chloé Rousseau, Laurent Sulpice, David Val-Laillet, Ronan Thibault, Karim Boudjema
Body composition parameters were measured at L3 level on abdominal CT scans performed with the most recent scanner available (median: 26.5 day before surgery, maximum 151 day). This was made in a semi-automated way using the ImageJ® software (National Institutes of Health, Bethesda, Maryland, USA).20 The density threshold was set between −29 and +150 Hounsfield Units (HU)20 for muscle, and between −190 and −30 HU for fat.21 Measurements were performed by a single observer (LL). Two measurements were made on two successive slices of CT scan at the level of L3 and the average of the two areas was considered for analysis. Abdominal skeletal muscle area (SMA) was measured as the sum of psoas muscle, external and internal oblique muscles, transverse muscle and paravertebral muscles areas. Skeletal muscle index (SMI) (cm2/m2) was calculated as SMA/height (m)2. Intramuscular fat was measured in the same area and distinguished from the muscle by its difference of density. Visceral fat area (VFA), subcutaneous fat area (SCFA), and intramuscular fat area (IMFA) were also measured. Total fat area was calculated as the sum of VFA, SCFA and IMFA. The respective fat indexes (cm2/m2) (visceral (VFI), subcutaneous (SCFI), intramuscular (IMFI), total fat) were calculated as normalized by height, as for a SMI calculation.
Gender difference in the relationship between lipid accumulation product index and pulse pressure in nondiabetic Korean adults: The Korean National Health and Nutrition Examination Survey 2013–2014
Published in Clinical and Experimental Hypertension, 2022
Hyun Ho Sung, Mi Young Gi, Ju Ae Cha, Hye Eun Cho, Ae Eun Moon, Hyun Yoon
Visceral or intra-abdominal fat surrounds internal organs inside the peritoneal cavity, in contrast to subcutaneous fat, which is found underneath the skin, and intramuscular fat, which is found interspersed in skeletal muscle (1). An increase in visceral fat is associated with an increased risk of cancer, cardiovascular disease (CVD), and all-cause mortality (2). The lipid accumulation product (LAP) is a gender-specific index based on waist circumference (WC) and triglycerides (TGs) and reflects the physiological changes related to intra-abdominal lipid over-accumulation (3). LAP has been suggested as an effective marker of lipid accumulation in ectopic sites, such as the skeletal system and liver (4). Previous studies have revealed that LAP is a better predictor of increased risk of CVD events and all-cause morbidity and mortality compared to body mass index (BMI) or WC (3,5,6).
Age-related degeneration of lumbar muscle morphology in healthy younger versus older men
Published in The Aging Male, 2020
Alexander Dallaway, John Hattersley, Michael Diokno, Jason Tallis, Derek Renshaw, Adrian Wilson, Sarah Wayte, Andrew Weedall, Michael Duncan
Fat infiltration appears to have a global effect on the LPMs whereas atrophy appears to be muscle-specific. Mechanisms for this remain undetermined, although the suggestions in the previous paragraph provide a plausible explanation. Increase in intramuscular fat tissue is likely due to slow-twitch fibre distribution in the postural muscles and propensity for these fibres to accumulate fatty deposits with aging. Muscle-specific atrophy likely concerns the specific functions of the lumbar muscles and their exposure to reduced mechanical loading resulting from a shift in the locus of function in motor performance with aging [115]. Furthermore, accretion of intramuscular fat may be an early change in muscle as it ages, which may explain why fat infiltration was the more apparent degenerative feature in the lumbar musculature.