IGF-binding protein 1 and abdominal obesity in the development of type 2 diabetes in women.
OBJECTIVE
Low levels of IGF-binding protein 1 (IGFBP1) are associated with metabolic syndrome and predict diabetes development in men. The aim of this study was to determine the levels of IGFBP1 in women who later develop diabetes, in relation to abdominal obesity, and to compare these levels with those of men.


METHODS
IGFBP1 levels were determined at baseline and after 8 years in a case-control, prospective study of Swedish women aged 35-56 years. Individuals with normal oral glucose tolerance test (OGTT) who developed abnormal glucose regulation (n=240) were pair matched to controls for age and family history of diabetes and also compared to men of the same age (n=355).


RESULTS
Low fasting IGFBP1 and increased waist measurement predicted development of diabetes in women (n=60; odds ratio (OR) 70, 95% confidence interval (CI) 8-661, lowest tertile and OR 27, 95% CI 5-141, highest tertile). In women developing diabetes, baseline IGFBP1 levels were lower than expected for fasting insulin values, were associated with impaired suppression after OGTT and increased during 8 years despite an increase in fasting insulin. All individuals in the highest tertile for waist and with <or=40% suppression of IGFBP1 developed diabetes within 8 years. Circulating IGFBP1 concentrations were higher in women compared to men. Women and men who developed diabetes had a similar degree of abdominal obesity, corrected for height.


CONCLUSIONS
We conclude that low IGFBP1 and elevated waist measurement predict diabetes development and that IGFBP1 production is suppressed by a novel factor(s) in women developing diabetes. Increasing levels of IGFBP1 during the emergence of diabetes in men and women suggest the emergence of hepatic insulin resistance.
Lewitt
Moira S
MS
Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden. moira.lewitt@uws.ac.uk
Hilding
Agneta
A
Brismar
Kerstin
K
Efendic
Suad
S
Ostenson
Claes-Göran
CG
Hall
Kerstin
K
D000328:Adult; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008875:Middle Aged; D056128:Obesity, Abdominal / Q000378:metabolism*; D016017:Odds Ratio; D011446:Prospective Studies; D011863:Radioimmunoassay; D012044:Regression Analysis; D013548:Sweden; D055105:Waist Circumference
D007328:Insulin; D018970:Insulin-Like Growth Factor Binding Protein 1; D007334:Insulin-Like Growth Factor I