title: Body mass index and the risk of dementia among Louisiana low income diabetic patients.
abstract: BACKGROUND
  The association between obesity and dementia risk remains debatable and no studies have assessed this association among diabetic patients. The aim of our study was to investigate the association between body mass index (BMI) and dementia risk among middle and low income diabetic patients.
  
  
  RESULTS
  The sample included 44,660 diabetic patients (19,618 white and 25,042 African American) 30 to 96 years of age without a history of dementia in the Louisiana State University Hospital-Based Longitudinal Study. During a mean follow-up period of 3.9 years, 388 subjects developed incident dementia. The age- and sex-adjusted hazards ratios (HRs) for incident dementia at different levels of BMI (≤ 25, 25-26.9, 27-29.9, 30-34.9, and ≥ 35 kg/m(2)) were 1.00, 0.53 (95% CI 0.34-0.83), 0.29 (0.18-0.45), 0.37 (0.25-0.56), and 0.31 (0.21-0.48) (P(trend)<0.001) in white diabetic patients, and 1.00, 1.00 (95% CI 0.62-1.63), 0.62 (0.39-0.98), 0.56 (0.36-0.86), and 0.65 (0.43-1.01) (P(trend) = 0.029) in African American diabetic patients. Further adjustment for other confounding factors affected the results only slightly. There was a significant interaction between race and BMI on dementia risk (χ(2) = 5.52, 1df, p<0.025), such that the association was stronger in white patients. In stratified analyses, the multivariate-adjusted inverse association between BMI and risk of dementia was present in subjects aged 55-64 years, 65-74 years, and ≥ 75 years, in men and women, in non-smokers and smokers, and in subjects with different types of health insurance.
  
  
  CONCLUSIONS
  Higher baseline BMI was associated with a lower risk of dementia among diabetic patients, and this association was stronger among white than among African American diabetic patients.
authors.affiliation: Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States of America. gang.hu@pbrc.edu
authors.forename: Gang
authors.initials: G
authors.lastname: Hu
authors.forename: Ronald
authors.initials: R
authors.lastname: Horswell
authors.forename: Yujie
authors.initials: Y
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Jay
authors.initials: J
authors.lastname: Besse
authors.forename: Ke
authors.initials: K
authors.lastname: Xiao
authors.forename: Honglei
authors.initials: H
authors.lastname: Chen
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Keller
authors.forename: Steven B
authors.initials: SB
authors.lastname: Heymsfield
authors.forename: Donna H
authors.initials: DH
authors.lastname: Ryan
authors.forename: Peter T
authors.initials: PT
authors.lastname: Katzmarzyk
mesh_terms: D000328:Adult; D001741:Black or African American; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D015331:Cohort Studies; D003704:Dementia / Q000150:complications* / Q000473:pathology*; D048909:Diabetes Complications / Q000473:pathology*; D003920:Diabetes Mellitus / Q000473:pathology*; D005260:Female; D006761:Hospitals; D006801:Humans; D008145:Louisiana; D008297:Male; D008875:Middle Aged; D011203:Poverty; D012306:Risk; D013997:Time Factors; D044465:White People