title: Relationship of low plasma klotho with poor grip strength in older community-dwelling adults: the InCHIANTI study.
abstract: Handgrip strength is a strong indicator of total body muscle strength and is a predictor of poor outcomes in older adults. The aging suppressor gene klotho encodes a single-pass transmembrane protein that is secreted as a circulating hormone. In mice, disruption of klotho expression results in a syndrome that includes sarcopenia, atherosclerosis, osteoporosis, and shortened lifespan, and conversely, overexpression of klotho leads to a greater longevity. The objective was to determine whether plasma klotho levels are related to skeletal muscle strength in humans. We measured plasma klotho in 804 adults, ≥65 years, in the InCHIANTI study, a longitudinal population-based study of aging in Tuscany, Italy. Grip strength was positively correlated with plasma klotho at threshold <681 pg/mL. After adjusting for age, sex, education, smoking, physical activity, cognition, and chronic diseases, plasma klotho (per 1 standard deviation increase) was associated with grip strength (beta = 1.20, standard error = 0.35, P = 0.0009) in adults with plasma klotho <681 pg/mL. These results suggest that older adults with lower plasma klotho have poor skeletal muscle strength.
authors.affiliation: Department of Ophthalmology, The Johns Hopkins University School of Medicine, Smith Building, M015, 400 N. Broadway, Baltimore, MD 21287, USA. rdsemba@jhmi.edu
authors.forename: Richard D
authors.initials: RD
authors.lastname: Semba
authors.forename: Anne R
authors.initials: AR
authors.lastname: Cappola
authors.forename: Kai
authors.initials: K
authors.lastname: Sun
authors.forename: Stefania
authors.initials: S
authors.lastname: Bandinelli
authors.forename: Mansi
authors.initials: M
authors.lastname: Dalal
authors.forename: Candace
authors.initials: C
authors.lastname: Crasto
authors.forename: Jack M
authors.initials: JM
authors.lastname: Guralnik
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D015536:Down-Regulation; D005260:Female; D005966:Glucuronidase / Q000097:blood*; D018737:Hand Strength; D006801:Humans; D057187:Independent Living; D007558:Italy / Q000453:epidemiology; D000090265:Klotho Proteins; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D015999:Multivariate Analysis; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000503:physiopathology*; D018570:Risk Assessment; D012307:Risk Factors; D055948:Sarcopenia / Q000097:blood* / Q000453:epidemiology / Q000503:physiopathology*
chemical_list: D015415:Biomarkers; D005966:Glucuronidase; D000090265:Klotho Proteins