Author
S. B. Kritchevsky
Other affiliations: University of Tennessee Health Science Center, University of Tennessee
Bio: S. B. Kritchevsky is an academic researcher from Wake Forest University. The author has contributed to research in topics: Sarcopenia & Body mass index. The author has an hindex of 24, co-authored 43 publications receiving 6680 citations. Previous affiliations of S. B. Kritchevsky include University of Tennessee Health Science Center & University of Tennessee.
Topics: Sarcopenia, Body mass index, Overweight, Population, Lean body mass
Papers
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TL;DR: Although the loss of muscle mass is associated with the decline in strength in older adults, this strength decline is much more rapid than the concomitant loss of Muscle mass, suggesting a decline in muscle quality.
Abstract: BACKGROUND: The loss of muscle mass is considered to be a major determinant of strength loss in aging. However, large-scale longitudinal studies examining the association between the loss of mass and strength in older adults are lacking. METHODS: Three-year changes in muscle mass and strength were determined in 1880 older adults in the Health, Aging and Body Composition Study. Knee extensor strength was measured by isokinetic dynamometry. Whole body and appendicular lean and fat mass were assessed by dual-energy x-ray absorptiometry and computed tomography. RESULTS: Both men and women lost strength, with men losing almost twice as much strength as women. Blacks lost about 28% more strength than did whites. Annualized rates of leg strength decline (3.4% in white men, 4.1% in black men, 2.6% in white women, and 3.0% in black women) were about three times greater than the rates of loss of leg lean mass ( approximately 1% per year). The loss of lean mass, as well as higher baseline strength, lower baseline leg lean mass, and older age, was independently associated with strength decline in both men and women. However, gain of lean mass was not accompanied by strength maintenance or gain (ss coefficients; men, -0.48 +/- 4.61, p =.92, women, -1.68 +/- 3.57, p =.64). CONCLUSIONS: Although the loss of muscle mass is associated with the decline in strength in older adults, this strength decline is much more rapid than the concomitant loss of muscle mass, suggesting a decline in muscle quality. Moreover, maintaining or gaining muscle mass does not prevent aging-associated declines in muscle strength.
2,266 citations
TL;DR: A comprehensive review of the definitions and assessment tools on frailty in clinical practice and research was performed, combining evidence derived from a systematic review of literature along with an expert opinion of a European, Canadian and American Geriatric Advisory Panel (GAP).
Abstract: Frailty is a commonly used term indicating older persons at increased risk for adverse outcomes such as onset of disability, morbidity, institutionalisation or mortality or who experience a failure to integrate adequate responses in the face of stress. Although most physicians caring for older people recognize the importance of frailty, there is still a lack of both consensus definition and consensual clinical assessment tools. The aim of the present manuscript was to perform a comprehensive review of the definitions and assessment tools on frailty in clinical practice and research, combining evidence derived from a systematic review of literature along with an expert opinion of a European, Canadian and American Geriatric Advisory Panel (GAP). There was no consensus on a definition of frailty but there was agreement to consider frailty as a pre-disability stage. Being disability a consequence rather than the cause of frailty, frail older people do not necessary need to be disabled. The GAP considered that disability (as a consequence of frailty) should not be included in frailty definitions and assessment tools. Although no consensual assessment tool could be proposed, gait speed could represent the most suitable instrument to be implemented both in research and clinical evaluation of older people, as assessment of gait speed at usual pace is a quick, inexpensive and highly reliable measure of frailty.
842 citations
TL;DR: Serum markers of inflammation, especially IL-6 and CRP, are prospectively associated with cognitive decline in well-functioning elders, and these findings support the hypothesis that inflammation contributes to Cognitive decline in the elderly.
Abstract: Background: Several lines of evidence suggest that inflammatory mechanisms contribute to AD. Objective: To examine whether several markers of inflammation are associated with cognitive decline in African-American and white well-functioning elders. Methods: The authors studied 3,031 African-American and white men and women (mean age 74 years) enrolled in the Health, Aging, and Body Composition Study. Serum levels of interleukin-6 (IL-6) and C-reactive protein (CRP) and plasma levels of tumor necrosis factor-α (TNFα) were measured at baseline; cognition was assessed with the Modified Mini-Mental State Examination (3MS) at baseline and at follow-up. Cognitive decline was defined as a decline of >5 points. Results: In age-adjusted analyses, participants in the highest tertile of IL-6 or CRP performed nearly 2 points lower (worse) on baseline and follow-up 3MS ( p 2 years ( p = 0.01 for IL-6 and p = 0.04 for CRP) compared with those in the lowest tertile. After multivariate adjustment, 3MS scores among participants in the highest tertile of IL-6 and CRP were similar at baseline but remained significantly lower at follow-up ( p ≤ 0.05 for both). Those in the highest inflammatory marker tertile were also more likely to have cognitive decline compared with the lowest tertile for IL-6 (26 vs 20%; age-adjusted odds ratio [OR] = 1.34; 95% CI 1.06 to 1.69) and for CRP (24 vs 19%; OR = 1.41; 95% CI 1.10 to 1.79) but not for TNFα (23 vs 21%; OR = 1.12; 95% CI 0.88 to 1.43). There was no significant interaction between race and inflammatory marker or between nonsteroidal anti-inflammatory drug use and inflammatory marker on cognition. Conclusions: Serum markers of inflammation, especially IL-6 and CRP, are prospectively associated with cognitive decline in well-functioning elders. These findings support the hypothesis that inflammation contributes to cognitive decline in the elderly.
672 citations
TL;DR: In addition to general obesity, the distribution of body fat is independently associated with the metabolic syndrome in older men and women, particularly among those of normal body weight.
Abstract: Background:Themetabolicsyndromeisadisorderthat includes dyslipidemia, insulin resistance, and hypertension and is associated with an increased risk of diabetes andcardiovasculardisease.Wedeterminedwhetherpatterns of regional fat deposition are associated with metabolic syndrome in older adults. Methods: A cross-sectional study was performed that included a random, population-based, volunteer sample of Medicare-eligible adults within the general communities of Pittsburgh, Pa, and Memphis, Tenn. The subjects consisted of 3035 men and women aged 70 to 79 years, of whom 41.7% were black. Metabolic syndrome was defined by Adult Treatment Panel III criteria, including serum triglyceride level, high-density lipoprotein cholesterol level, glucose level, blood pressure, and waist circumference. Visceral, subcutaneous abdominal, intermuscular, and subcutaneous thigh adipose tissue was measured by computed tomography. Results:Visceral adipose tissue was associated with the metabolic syndrome in men who were of normal weight (odds ratio, 95% confidence interval: 2.1, 1.6-2.9), overweight (1.8, 1.5-2.1), and obese (1.2, 1.0-1.5), and in women who were of normal weight (3.3, 2.4-4.6), overweight (2.4, 2.0-3.0), and obese (1.7, 1.4-2.1), adjustingforrace.Subcutaneousabdominaladiposetissuewas associated with the metabolic syndrome only in normalweight men (1.3, 1.1-1.7). Intermuscular adipose tissue was associated with the metabolic syndrome in normalweight (2.3, 1.6-3.5) and overweight (1.2, 1.1-1.4) men. In contrast, subcutaneous thigh adipose tissue was inversely associated with the metabolic syndrome in obese men (0.9, 0.8-1.0) and women (0.9, 0.9-1.0). Conclusion: In addition to general obesity, the distribution of body fat is independently associated with the metabolic syndrome in older men and women, particularly among those of normal body weight. Arch Intern Med. 2005;165:777-783
626 citations
TL;DR: Elderly men and women with normal body weight may be at risk for metabolic abnormalities, including type 2 diabetes, if they possess an inordinate amount of muscle fat or visceral abdominal fat.
Abstract: OBJECTIVE —We examined whether regional adipose tissue distribution, specifically that of skeletal muscle fat and visceral abdominal fat aggregation, is characteristic of elderly individuals with hyperinsulinemia, type 2 diabetes, and impaired glucose tolerance (IGT) RESEARCH DESIGN AND METHODS —A total of 2,964 elderly men and women (mean age 736 years) were recruited for cross-sectional comparisons of diabetes or glucose tolerance, generalized obesity with dual-energy X-ray absorptiometry, and regional body fat distribution with computed tomography RESULTS —Approximately one-third of men with type 2 diabetes and less than half of women with type 2 diabetes were obese (BMI ≥30 kg/m 2 ) Despite similar amounts of subcutaneous thigh fat, intermuscular fat was higher in subjects with type 2 diabetes and IGT than in subjects with normal glucose tolerance (NGT) (112 ± 94, 103 ± 58, and 92 ± 59 cm 2 for men; 121 ± 61, 109 ± 65, and 94 ± 53 cm 2 for women; both P 2 for men; 162 ± 66, 141 ± 60, and 116 ± 54 cm 2 for women; both P 2 ) men ( r = 024 for intermuscular fat, r = 037 for visceral abdominal fat, both P r = 020 for intermuscular fat, r = 040 for visceral abdominal fat, both P CONCLUSIONS —Elderly men and women with normal body weight may be at risk for metabolic abnormalities, including type 2 diabetes, if they possess an inordinate amount of muscle fat or visceral abdominal fat
570 citations
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TL;DR: The European Working Group on Sarcopenia in Older People (EWGSOP) developed a practical clinical definition and consensus diagnostic criteria for age-related sarcopenia as discussed by the authors.
Abstract: The European Working Group on Sarcopenia in Older People (EWGSOP) developed a practical clinical definition and consensus diagnostic criteria for age-related sarcopenia. EWGSOP included representatives from four participant organisations, i.e. the European Geriatric Medicine Society, the European Society for Clinical Nutrition and Metabolism, the International Association of Gerontology and Geriatrics-European Region and the International Association of Nutrition and Aging. These organisations endorsed the findings in the final document. The group met and addressed the following questions, using the medical literature to build evidence-based answers: (i) What is sarcopenia? (ii) What parameters define sarcopenia? (iii) What variables reflect these parameters, and what measurement tools and cut-off points can be used? (iv) How does sarcopenia relate to cachexia, frailty and sarcopenic obesity? For the diagnosis of sarcopenia, EWGSOP recommends using the presence of both low muscle mass + low muscle function (strength or performance). EWGSOP variously applies these characteristics to further define conceptual stages as 'presarcopenia', 'sarcopenia' and 'severe sarcopenia'. EWGSOP reviewed a wide range of tools that can be used to measure the specific variables of muscle mass, muscle strength and physical performance. Our paper summarises currently available data defining sarcopenia cut-off points by age and gender; suggests an algorithm for sarcopenia case finding in older individuals based on measurements of gait speed, grip strength and muscle mass; and presents a list of suggested primary and secondary outcome domains for research. Once an operational definition of sarcopenia is adopted and included in the mainstream of comprehensive geriatric assessment, the next steps are to define the natural course of sarcopenia and to develop and define effective treatment.
8,440 citations
TL;DR: Since 1980, the American College of Cardiology and American Heart Association have translated scientific evidence into clinical practice guidelines (guidelines) with recommendations to improve cardiovascular health.
Abstract: Since 1980, the American College of Cardiology (ACC) and American Heart Association (AHA) have translated scientific evidence into clinical practice guidelines (guidelines) with recommendations to improve cardiovascular health. In 2013, the National Heart, Lung, and Blood Institute (NHLBI) Advisory
4,604 citations
TL;DR: This work has shown that abdominal obesity — the most prevalent manifestation of metabolic syndrome — is a marker of 'dysfunctional adipose tissue', and is of central importance in clinical diagnosis.
Abstract: Metabolic syndrome is associated with abdominal obesity, blood lipid disorders, inflammation, insulin resistance or full-blown diabetes, and increased risk of developing cardiovascular disease. Proposed criteria for identifying patients with metabolic syndrome have contributed greatly to preventive medicine, but the value of metabolic syndrome as a scientific concept remains controversial. The presence of metabolic syndrome alone cannot predict global cardiovascular disease risk. But abdominal obesity - the most prevalent manifestation of metabolic syndrome - is a marker of 'dysfunctional adipose tissue', and is of central importance in clinical diagnosis. Better risk assessment algorithms are needed to quantify diabetes and cardiovascular disease risk on a global scale.
4,002 citations
TL;DR: The next generation of scientists and decision-makers will have a greater understanding of what constitutes a credible threat to public health and how to protect them from that threat.
3,748 citations
Taipei Veterans General Hospital1, The Chinese University of Hong Kong2, Mahidol University3, University of Malaya4, South Korean Ministry for Health, Welfare and Family Affairs5, Ajou University6, Khon Kaen University7, Kyung Hee University8, National Cheng Kung University9, Chinese Ministry of Health10, Kyoto University11, University of Tokyo12
TL;DR: The AWGS consensus report is believed to promote more Asian sarcopenia research, and most important of all, to focus on sarc Openia intervention studies and the implementation of sarcopenian in clinical practice to improve health care outcomes of older people in the communities and the healthcare settings in Asia.
2,976 citations