Clustering of protective factors for glucose intolerance and insulin resistance: a cross-sectional study.
OBJECTIVE
A cluster of interrelated factors: a body mass index (BMI) < 25 kg/m(2), moderate exercise and alcohol intake, non-smoking and a favourable dietary pattern has been linked with markedly reduced risk of Type 2 diabetes. The aim of this study was to estimate the prevalence of a similar low-risk group in a sample of middle-aged Irish men and women, and determine whether this cluster is associated with a reduced risk of glucose intolerance (IFG and Type 2 diabetes according to ADA/WHO criteria) and insulin resistance [homeostasis model assessment (HOMA) score in upper quartile of distribution].


METHODS
A cross-sectional study involving a stratified random sample of 1018 general practice patients, aged 50-69 years. We defined a low-risk group based on the following variables: BMI < 25 kg/m(2); waist-hip ratio < 0.85 for women and 0.90 for men; never smoking status; participation in medium to high level of physical activity; light drinking (3.5-7 units of alcohol per week) and a 'prudent' dietary pattern. Valid data were available for glucose tolerance status and HOMA score and all exposure variables from 684 and 671 participants, respectively.


RESULTS
A total of 7.5% of participants had none of the 'protective factors', 24.9% had one, 31.0% two, 23.3% three, 10.0% four, 3.0% five and 0.3% had six protective factors. In multivariate analyses the odds ratios for insulin resistance were 0.59, 0.48, 0.14 and 0.04 in persons with one, two, three and four or more low-risk factors, respectively, relative to those with none. Similar linear inverse trends were observed for glucose intolerance.


CONCLUSIONS
The findings are consistent with an inverse linear relation between a cluster of core protective, lifestyle-related factors and the prevalence of both glucose intolerance and insulin resistance.
Perry
I J
IJ
University College Cork, Cork, Ireland. i.perry@ucc.ie
Villegas
R
R
Salim
A
A
Flynn
A
A
D000368:Aged; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D005260:Female; D018149:Glucose Intolerance / Q000453:epidemiology*; D006801:Humans; D007333:Insulin Resistance; D007494:Ireland / Q000453:epidemiology; D008019:Life Style; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D049629:Waist-Hip Ratio