Relation of IGF-1 and IGFBP-3 with prevalent and incident atrial fibrillation in a population-based study

BACKGROUND Insulin-like growth factor 1 (IGF-1) and its main binding protein insulin-like growth factor binding protein 3 (IGFBP-3) have been related to several cardiovascular diseases. The relation with atrial fibrillation (AF) is largely unknown. OBJECTIVE The objective of this study was to investigate the association of IG F-1 and IG FB P-3 levels with prevalent and incident AF in a large population-based study. METHODS Data from the Study of Health in Pomerania (SHIP) were collected. At presentation, a medical examination, standardized electrocardiographic assessment, and measurements of serum IGF1 and IGFB P-3 levels were performed. Incident AF was assessed in individuals without AF at baseline (SHIP-1) who developed AF during follow-up (SHIP-2; after a mean of 5.2 years). RESULTS Of 3160 participants, 66 (2.1%) exhibited AF at baseline. IGF-1 levels and IGF-1/IGFBP-3 ratios were significantly lower in individuals with AF than in those without AF (IGF-1: 104.2 +/- 41.6 ng/mL vs 142.9 +/- 53.5 ng/mL, P < .001 and IGF-1/IGFBP-3: 0.031 +/- (0.009 ng/mL vs 0.036 +/- 0.010 ng/mL, P = .006, respectively). Multivariable-adjusted logistic regression models showed that a low IGF-1/IGFBP-3 ratio was associated with prevalent AF (odds ratios 0.67; 95% confidence interval 0.48-0.94; P = .021). Of 1817 individuals without AF at baseline, 27 (1.5%) developed AF during follow-up. In these participants, IGF-1 levels, but not IGF-1/IGFBP-3 ratios, were significantly lower (IGF-1: 113.3 +/- 38.6 ng/mL vs 147.2 +/- 51.6 ng/mL, P = .013 and IGF-1/IGFBP3: 0.033 +/- 0.008 ng/mL vs 0.036 +/- 0.010 ng/mL, P = .176). CONCLUSION Low IGF-1/IGFBP-3 ratios are associated with a higher prevalence of AF. There seems to be a similar impact in incident AF.