Variation by body mass index and age in waist-to-hip ratio associations with glycemic status in an aboriginal population at risk for type 2 diabetes in British Columbia, Canada
M. Daniel et al., Variation by body mass index and age in waist-to-hip ratio associations with glycemic status in an aboriginal population at risk for type 2 diabetes in British Columbia, Canada, AM J CLIN N, 69(3), 1999, pp. 455-460
Background: It is unclear whether obesity and age modify or confound relati
ons between abdominal adiposity and metabolic risk factors for type 2 diabe
tes.
Objective: Our objective was assess the consistency of relations between ab
dominal adiposity and glycemic variables across discrete categories of obes
ity and age.
Design: We performed a stratified analysis of prevalence data from a rural
screening initiative in British Columbia, Canada. Subjects were Salishan In
dians, all healthy relatives of individuals with type 2 diabetes [n = 151;
age: 18-80 y; body mass index (BMI, in kg/m(2)): 17.0-48.2]. We measured wa
ist-to-hip ratio (WHR) (2 categories); insulin, glycated hemoglobin (Hb A(1
c)), and 2-h glucose concentrations (2 categories); and BMI (4 categories).
BMI and age-specific odds ratios (ORs) and 95% CIs were calculated.
Results: WHR-glycemic variable relations were not consistent across BMI and
age errata. Risks associated with high WHR were: for persons with BMIs fro
m 25 to 29, elevated insulin (OR: 6.71; 95% CI: 1.41, 34.11) and Hb A(1c) (
OR: 16.23; 95% CI: 2.04, 101.73) concentrations; for persons aged 18-34 y,
elevated insulin concentrations [OR: indeterminate ((+infinity)); 95% CI: 1
.89, (+infinity)]; and, for persons aged 35-49 y, elevated Hb A(1c) (OR: (infinity); 95% CI: 3.17, (+infinity)) and 2-h glucose (OR: 9.15; 95% CI: 1.
74, 59.91) concentrations.
Conclusions: WHR discriminates risk of type 2 diabetes in overweight but no
t obese individuals. Abdominal adiposity is associated with elevated insuli
n concentrations in younger age groups and with impaired glucose control in
middle-aged groups, suggesting metabolic staging by age on a continuum fro
m insulin resistance to impaired glucose tolerance.