title: Underweight/overweight and the risk of long-term care: follow-up study using data of the Japanese long-term care insurance system.
abstract: OBJECTIVE
  Both being underweight and overweight can lead to reduced activity of daily living, which subsequently can require long-term care. The aim of the present study was to clarify the association between underweight/overweight and the subsequent risk of long-term care introduction.
  
  
  METHODS
  We tracked the data of long-term care insurance for 1580 men and women aged ≥65 years who had participated in the official population-based health check-up program in 2001 in Tsunan town and Sekikawa village, Japan. The health check-up data and medical expenditure data for the fiscal year 2001 were used as baseline data. Participants were classified into underweight (body mass index (BMI) <18.5 kg/m(2) ), normal range (BMI = 18.5 to <25.0 kg/m(2) ) and overweight (BMI ≥25.0 kg/m(2) ); the normal range was used as a reference category in Cox proportional hazards models.
  
  
  RESULTS
  During the average 5.8 years of follow up, 156 participants were identified to start using long-term care services. Among the young-old elderly (65-74 years-of-age), underweight was significantly associated with the risk of long-term care introduction (multivariable-adjusted HR 4.26, 95% CI 1.69-10.72), whereas overweight was not (multivariable-adjusted HR 1.45, 95% CI 0.69-3.06). Neither underweight nor overweight were significantly associated with long-term care introduction among the old-old elderly (≥75 years-of-age).
  
  
  CONCLUSIONS
  Underweight could be a good predictor of long-term care introduction in the young-old elderly. We should pay attention to underweight in the elderly, as it might be a manifestation of some physical or mental problems related to future long-term care introduction.
authors.affiliation: Division of Health Promotion, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; Niigata Prefectural Government, Niigata, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Honda
authors.forename: Naohito
authors.initials: N
authors.lastname: Tanabe
authors.forename: Nao
authors.initials: N
authors.lastname: Seki
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Ogawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suzuki
mesh_terms: D000368:Aged; D044466:Asian People; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007353:Insurance, Long-Term Care / Q000706:statistics & numerical data*; D008134:Long-Term Care / Q000706:statistics & numerical data*; D008297:Male; D050177:Overweight; D018570:Risk Assessment; D013851:Thinness
keywords: cohort studies; long-term care; overweight; risk factors; thinness