title: Prognostic value of grip strength: findings from the Prospective Urban Rural Epidemiology (PURE) study.
abstract: BACKGROUND
  Reduced muscular strength, as measured by grip strength, has been associated with an increased risk of all-cause and cardiovascular mortality. Grip strength is appealing as a simple, quick, and inexpensive means of stratifying an individual's risk of cardiovascular death. However, the prognostic value of grip strength with respect to the number and range of populations and confounders is unknown. The aim of this study was to assess the independent prognostic importance of grip strength measurement in socioculturally and economically diverse countries.
  
  
  METHODS
  The Prospective Urban-Rural Epidemiology (PURE) study is a large, longitudinal population study done in 17 countries of varying incomes and sociocultural settings. We enrolled an unbiased sample of households, which were eligible if at least one household member was aged 35-70 years and if household members intended to stay at that address for another 4 years. Participants were assessed for grip strength, measured using a Jamar dynamometer. During a median follow-up of 4.0 years (IQR 2.9-5.1), we assessed all-cause mortality, cardiovascular mortality, non-cardiovascular mortality, myocardial infarction, stroke, diabetes, cancer, pneumonia, hospital admission for pneumonia or chronic obstructive pulmonary disease (COPD), hospital admission for any respiratory disease (including COPD, asthma, tuberculosis, and pneumonia), injury due to fall, and fracture. Study outcomes were adjudicated using source documents by a local investigator, and a subset were adjudicated centrally.
  
  
  RESULTS
  Between January, 2003, and December, 2009, a total of 142,861 participants were enrolled in the PURE study, of whom 139,691 with known vital status were included in the analysis. During a median follow-up of 4.0 years (IQR 2.9-5.1), 3379 (2%) of 139,691 participants died. After adjustment, the association between grip strength and each outcome, with the exceptions of cancer and hospital admission due to respiratory illness, was similar across country-income strata. Grip strength was inversely associated with all-cause mortality (hazard ratio per 5 kg reduction in grip strength 1.16, 95% CI 1.13-1.20; p<0.0001), cardiovascular mortality (1.17, 1.11-1.24; p<0.0001), non-cardiovascular mortality (1.17, 1.12-1.21; p<0.0001), myocardial infarction (1.07, 1.02-1.11; p=0.002), and stroke (1.09, 1.05-1.15; p<0.0001). Grip strength was a stronger predictor of all-cause and cardiovascular mortality than systolic blood pressure. We found no significant association between grip strength and incident diabetes, risk of hospital admission for pneumonia or COPD, injury from fall, or fracture. In high-income countries, the risk of cancer and grip strength were positively associated (0.916, 0.880-0.953; p<0.0001), but this association was not found in middle-income and low-income countries.
  
  
  CONCLUSIONS
  This study suggests that measurement of grip strength is a simple, inexpensive risk-stratifying method for all-cause death, cardiovascular death, and cardiovascular disease. Further research is needed to identify determinants of muscular strength and to test whether improvement in strength reduces mortality and cardiovascular disease.
  
  
  BACKGROUND
  Full funding sources listed at end of paper (see Acknowledgments).
authors.affiliation: Population Health Research Institute, McMaster University, Hamilton, ON, Canada; Hamilton Health Sciences, Hamilton, ON, Canada. Electronic address: leongd@phri.ca.
authors.forename: Darryl P
authors.initials: DP
authors.lastname: Leong
authors.affiliation: Population Health Research Institute, McMaster University, Hamilton, ON, Canada; Hamilton Health Sciences, Hamilton, ON, Canada.
authors.forename: Koon K
authors.initials: KK
authors.lastname: Teo
authors.affiliation: Population Health Research Institute, McMaster University, Hamilton, ON, Canada.
authors.forename: Sumathy
authors.initials: S
authors.lastname: Rangarajan
authors.affiliation: Fundacion Oftalmologica de Santander and Medical School, Universidad de Santander, Colombia.
authors.forename: Patricio
authors.initials: P
authors.lastname: Lopez-Jaramillo
authors.affiliation: Dante Pazzanese Institute of Cardiology, São Paulo University, Brazil.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Avezum
authors.affiliation: ECLA Foundation, Instituto Cardiovascular de Rosario, Rosario, Argentina.
authors.forename: Andres
authors.initials: A
authors.lastname: Orlandini
authors.affiliation: Universidad de La Frontera, Temuco, Chile.
authors.forename: Pamela
authors.initials: P
authors.lastname: Seron
authors.affiliation: Dubai Health Authority, Dubai, United Arab Emirates.
authors.forename: Suad H
authors.initials: SH
authors.lastname: Ahmed
authors.affiliation: Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Annika
authors.initials: A
authors.lastname: Rosengren
authors.affiliation: Isfahan Cardiovascular Research Center, Isfahan Cardiovascular Research Institute, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Roya
authors.initials: R
authors.lastname: Kelishadi
authors.affiliation: Independent University, Dhaka, Bangladesh.
authors.forename: Omar
authors.initials: O
authors.lastname: Rahman
authors.affiliation: St. John's Medical College, St. John's Research Institute, Bangalore, India.
authors.forename: Sumathi
authors.initials: S
authors.lastname: Swaminathan
authors.affiliation: Department of Community Health Sciences and Medicine, Aga Khan University, Karachi, Pakistan.
authors.forename: Romaina
authors.initials: R
authors.lastname: Iqbal
authors.affiliation: Fortis Escorts Hospital, Jaipur, India.
authors.forename: Rajeev
authors.initials: R
authors.lastname: Gupta
authors.affiliation: Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Lear
authors.affiliation: Department of Internal Medicine, Istanbul Medeniyet University, Istanbul, Turkey.
authors.forename: Aytekin
authors.initials: A
authors.lastname: Oguz
authors.affiliation: Universiti Teknologi MARA, Sungai Buloh, Selangor, Malaysia; UCSI University, Cheras, Kuala Kumpur, Malaysia.
authors.forename: Khalid
authors.initials: K
authors.lastname: Yusoff
authors.affiliation: Department of Social Medicine, Medical University of Wrocław, Wrocław, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Zatonska
authors.affiliation: University of Zimbabwe, Harare, Zimbabwe.
authors.forename: Jephat
authors.initials: J
authors.lastname: Chifamba
authors.affiliation: School of Public Health, University of the Western Cape, Cape Town, South Africa.
authors.forename: Ehimario
authors.initials: E
authors.lastname: Igumbor
authors.affiliation: Madras Diabetes Research Foundation, Chennai, India.
authors.forename: Viswanathan
authors.initials: V
authors.lastname: Mohan
authors.affiliation: Madras Diabetes Research Foundation, Chennai, India.
authors.forename: Ranjit Mohan
authors.initials: RM
authors.lastname: Anjana
authors.affiliation: State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: Hongqiu
authors.initials: H
authors.lastname: Gu
authors.affiliation: State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Population Health Research Institute, McMaster University, Hamilton, ON, Canada; Hamilton Health Sciences, Hamilton, ON, Canada.
authors.forename: Salim
authors.initials: S
authors.lastname: Yusuf
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data; D000328:Adult; D000367:Age Factors; D000368:Aged; D002318:Cardiovascular Diseases / Q000401:mortality* / Q000503:physiopathology; D002423:Cause of Death; D015444:Exercise / Q000502:physiology; D005260:Female; D014943:Global Health; D018737:Hand Strength / Q000502:physiology*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000401:mortality / Q000503:physiopathology; D011379:Prognosis; D011446:Prospective Studies; D012140:Respiratory Tract Diseases / Q000401:mortality / Q000503:physiopathology; D012307:Risk Factors; D012423:Rural Health; D012737:Sex Factors; D014504:Urban Health