Progression to impaired glucose metabolism in first-degree relatives of patients with type 2 diabetes in Isfahan, Iran.
BACKGROUND
The aim of this study was to estimate the progression rates from normal glucose tolerance (NGT) to impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and diabetes, and from IFG and IGT to diabetes in first-degree relatives (FDRs) of individuals with type 2 diabetes mellitus.


METHODS
A total of 701 non-diabetic FDRs of consecutive patients with type 2 diabetes aged 20-70 years in 2003-2005 were followed through 2007 for the occurrence of IGT, IFG and type 2 diabetes. Glucose tolerance classification was based on the criteria of the American Diabetes Association and standard 75 g 2-h oral glucose tolerance test (OGTT).


RESULTS
The progression rate from NGT to IFG, IGT and diabetes were 8.6% (95% confidence interval (CI) 6.8-10.6), 3.7% (95% CI: 2.5-5.1) and 0.5% (95% CI: 0.1-1.2) per year after an average of 27.6 months, respectively. Progression rates from IFG and IGT to diabetes were 5.1% (95% CI: 2.1-10.2) and 9.9% (95% CI: 7.7-12.6) per year.


CONCLUSIONS
To our knowledge, these are the first estimate of progression rates from NGT to IFG, IGT and diabetes in FDRs of individuals with type 2 diabetes in Iran. The progression rates to diabetes in these participants are high, and intensive follow-up and intervention strategies are recommended for these high-risk individuals.
Janghorbani
Mohsen
M
Department of Epidemiology and Biostatistics, School of Public Health, Isfahan University of Medical Sciences, Isfahan, Iran. janghorbani@yahoo.com
Amini
Masoud
M
D000328:Adult; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000453:epidemiology* / Q000209:etiology / Q000235:genetics; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D018450:Disease Progression; D005190:Family; D005260:Female; D020022:Genetic Predisposition to Disease; D018149:Glucose Intolerance / Q000453:epidemiology* / Q000209:etiology / Q000235:genetics; D005951:Glucose Tolerance Test; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009765:Obesity; D012307:Risk Factors; D013223:Statistics as Topic; D011795:Surveys and Questionnaires