Low levels of insulin-like growth-factor-binding protein-1 (IGFBP-1) are prospectively associated with the incidence of type 2 diabetes and impaired glucose tolerance (IGT): The Söderåkra Cardiovascular Risk Factor Study

AimTo explore the association between baseline levels of insulin-like growth-factor-binding protein-1 (IGFBP-1), a marker of insulin sensitivity, and the development of type 2 diabetes or impaired glucose tolerance (IGT) in a specifically defined middle-aged population.MethodsThis cross-sectional population-based screening study was conducted in 1989–1990 and included baseline data for 664 non-diabetic subjects aged 40–59 years. Clinical data were collected and blood samples analyzed for blood glucose, serum lipids and insulin. Blood specimens were frozen at baseline and later analyzed for IGF-I, IGFBP-1 and C-reactive protein (CRP). At the follow-up in 2006, the incidence of type 2 diabetes and IGT was reported based on primary-care medical records.ResultsDuring the 17-year observation period, 42 subjects (6.3%) developed type 2 diabetes/IGT. Those in the lowest quintile of IGFBP-1 (≤24 μg/L) at baseline had a diabetes incidence of 12.6% while, in the highest quintile of IGFBP-1 (≥59 μg/L), the incidence was 1.5%. Cox's proportional-hazards model regression analyses were used to determine the incidence of type 2 diabetes/IGT, corrected for age and gender, in relation to IGFBP-1, CRP and waist circumference. Subjects in the lowest IGFBP-1 quintile showed an independently increased risk of type 2 diabetes/IGT [hazards ratio (HR): 3.54; 95% CI 1.18–10.6; P = 0.024]. For CRP and waist circumference, the corresponding figures were HR: 6.81; 95% CI 2.50–18.6; P < 0.001 and HR: 3.33; 95% CI 1.47–7.6; P = 0.004, respectively.ConclusionLow levels of IGFBP-1 predicted the long-term development of type 2 diabetes or IGT in a middle-aged population. The association was independent of CRP and abdominal obesity.