title: Prevalent hyperglycemia in older obese population and age-dependent convergence of obese indices: Results of a cross-sectional study of Japanese generations over the adult life span.
abstract: OBJECTIVE
  An age-dependent decline has been observed in the association between obesity and type 2 diabetes, a major comorbidity of obesity, although the evidence is limited. Therefore, we investigated the association and the plausible underlying mechanism in a large epidemiological study.
  
  
  METHODS
  We examined the association between the degree of obesity and hyperglycemia in five age groups (20-39, 40-49, 50-59, 60-69, and 70-85 years) in a cross-sectional study of 78,776 apparently healthy Japanese men and women who underwent a checkup in 2012. Hyperglycemia was defined as glycosylated hemoglobin (HbA1c) of ≥5.7% and/or pharmacotherapy for diabetes.
  
  
  RESULTS
  The incidence of hyperglycemia was three times higher in the 70-85-year-old group (62%) than in the 20-39-year-old group (20%) in obese individuals (body mass index [BMI] ≥ 27.0 kg/m(2)). However, the incidence was 12 times higher in reference-weight individuals (21.0-22.9 kg/m(2); 48% and 4%, respectively). As age increased, mean BMI and waist circumference approached certain non-obese ranges (22-24 kg/m(2) and 80-86 cm, respectively), even in hyperglycemic subjects. Logistic regression analysis revealed an age-dependent decline in the association between obesity and hyperglycemia, relative to that in reference-weight individuals.
  
  
  CONCLUSIONS
  Our results confirmed the previously reported age-dependent decline in the association between obesity and hyperglycemia, although hyperglycemia was still prevalent in older obese subjects than in older reference-weight subjects. Therefore, the decline in the association may be accelerated due to an age-dependent increase in the prevalence of hyperglycemia in reference-weight individuals.
authors: a Division of Clinical Nutrition, Department of Medical Dietetics, Faculty of Pharmaceutical Sciences , Josai University , Saitama , Japan.|b Department of Metabolism , Kuki General Hospital , Kuki , Saitama , Japan.
authors: Kei
authors: K
authors: Nakajima
authors: c Department of Nephrology , Tokyo Kyosai Hospital , Tokyo , Japan.
authors: Eiichiro
authors: E
authors: Kanda
authors: d Saitama Health Promotion Corporation , Saitama , Japan.
authors: Kaname
authors: K
authors: Suwa
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000453:epidemiology*; D007564:Japan; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology*; D015995:Prevalence; D055815:Young Adult
keywords: Age-dependent decline; HbA1c; MHO; MONW; diabetes; hyperglycemia; obesity; reference-weight