title: Association of Serum Klotho with Loss of Bone Mineral Density and Fracture Risk in Older Adults.
abstract: Klotho deficiency has been previously linked to aging-like phenotypes such as osteoporosis, cognitive impairment, and sarcopenia. Low serum klotho was shown to be related to grip strength and disability. Nonetheless, no previous study has explored the association between serum klotho and fractures. The purpose of this report is to examine the relationship of serum klotho with bone mineral density (BMD) loss and fractures in older adults.
  
  
  
  The Health, Aging, and Body Composition (Health ABC) Study is a longitudinal cohort study of 3,075 community-dwelling older adults.
  
  
  
  US clinical centers.
  
  
  
  Two thousand seven hundred and seventy six well-functioning black and white adults aged 70 to 79 years with serum klotho measurements were followed up for a median of 5 years.
  
  
  
  Percent annualized BMD change and fracture risk were compared across klotho quartiles. A Poisson distribution was used to calculate age-adjusted fracture incidence rates, and Cox proportional hazards models for multivariable-adjusted hazard ratios.
  
  
  
  The annualized percent changes in hip, femoral neck, and vertebral BMD were similar across klotho quartiles. Participants experienced 507 nonspine fractures, 203 hip fractures, and 135 vertebral fractures. The Incidence rate (IR) of nonspine fractures was 17 per 1,000 person-years. The most frequent site was hip (IR = 6 per 1,000 person-years) and the IR of vertebral fractures was 3 per 1,000 person-years. There was no association between the lowest quartile of plasma klotho and nonspine (hazard ratio (HR) = 1.19, 95% confidence interval (CI) = 0.86-1.65), hip (HR = 1.34, 95% CI = 0.79-2.27), or vertebral fractures (HR = 1.17, 95% CI = 0.65-2.11).
  
  
  
  Although klotho gene is a susceptible gene for reduced BMD, klotho blood concentration does not appear to be a predictor of bone loss or fracture risk in well-functioning older adults.
authors.affiliation: Intramural Research Program, Laboratory of Epidemiology and Population Sciences, National Institute on Aging, National Institutes of Health, Bethesda, Maryland.
authors.forename: Didier
authors.initials: D
authors.lastname: Chalhoub
authors.affiliation: Intramural Research Program, Laboratory of Epidemiology and Population Sciences, National Institute on Aging, National Institutes of Health, Bethesda, Maryland.
authors.forename: Elisa
authors.initials: E
authors.lastname: Marques
authors.affiliation: Intramural Research Program, Laboratory of Epidemiology and Population Sciences, National Institute on Aging, National Institutes of Health, Bethesda, Maryland.
authors.forename: Osorio
authors.initials: O
authors.lastname: Meirelles
authors.affiliation: Department of Ophthalmology, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Semba
authors.affiliation: Longitudinal Studies Section, National Institute on Aging, Baltimore, Maryland.
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
authors.affiliation: Department of Preventive Medicine, University of Tennessee, Memphis, Tennessee.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Satterfield
authors.affiliation: Department of Epidemiology and Biostatistics, UCSF School of Medicine, San Francisco, California.
authors.forename: Michael
authors.initials: M
authors.lastname: Nevitt
authors.affiliation: Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Jane A
authors.initials: JA
authors.lastname: Cauley
authors.affiliation: Intramural Research Program, Laboratory of Epidemiology and Population Sciences, National Institute on Aging, National Institutes of Health, Bethesda, Maryland.
authors.forename: Tamara
authors.initials: T
authors.lastname: Harris
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology*; D015577:Geriatric Assessment; D005966:Glucuronidase / Q000097:blood*; D006801:Humans; D015994:Incidence; D000090265:Klotho Proteins; D008137:Longitudinal Studies; D008297:Male; D010641:Phenotype; D018570:Risk Assessment; D012307:Risk Factors; D014481:United States
chemical_list: D015415:Biomarkers; D005966:Glucuronidase; D000090265:Klotho Proteins
keywords: aging; bone-muscle interactions; fracture risk assessment; osteoporosis; sarcopenia