title: Effect of combined cardiovascular risk factors on individual and population medical expenditures: a 10-year cohort study of national health insurance in a Japanese population.
abstract: BACKGROUND
  Although obesity is required for some criteria defining metabolic syndrome, clustering of other risk factors also indicates an increased risk of cardiovascular disease. Whether the relationship between cardiovascular risk factor clustering and medical expenditures differs with body mass index (BMI) requires investigation, especially in a population with a low prevalence of obesity such as that in Japan.
  
  
  RESULTS
  A 10-year cohort study of 4,478 Japanese National Health Insurance beneficiaries aged 40-69 years in a community between 1990 and 2001 was carried out in the present study. The clustering of cardiovascular risk factors showed a positive and graded relationship to personal medical expenditures in participants who are overweight (BMI > or =25.0) and normal weight (BMI <25.0). The individual medical expenditures per month were 1.7-fold higher for participants with 2 or 3 risk factors and overweight than for those without these factors (26,782 vs 15,377 Japanese yen). Differences in the geometric means were similarly significant after adjustment for other confounding factors. However, the excess medical expenditures by risk clustering of normal weight categories within the total medical expenditures were higher than those of overweight categories because more participants were of normal weight.
  
  
  CONCLUSIONS
  Cardiovascular risk factor clustering and being overweight can be a useful predictor of medical expenditures in a Japanese population.
authors.affiliation: Department of Health Science, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu 520-2192, Japan. tokamura@belle.shiga-med.ac.jp
authors.forename: Tomonori
authors.initials: T
authors.lastname: Okamura
authors.forename: Koshi
authors.initials: K
authors.lastname: Nakamura
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Kanda
authors.forename: Takehito
authors.initials: T
authors.lastname: Hayakawa
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hozawa
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Murakami
authors.forename: Takashi
authors.initials: T
authors.lastname: Kadowaki
authors.forename: Yoshikuni
authors.initials: Y
authors.lastname: Kita
authors.forename: Akira
authors.initials: A
authors.lastname: Okayama
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Ueshima
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000191:economics / Q000453:epidemiology / Q000209:etiology*; D016000:Cluster Analysis; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications* / Q000191:economics* / Q000453:epidemiology; D008875:Middle Aged; D009313:National Health Programs / Q000191:economics; D009765:Obesity / Q000150:complications / Q000191:economics / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors