INCREASED LEVELS OF SERUM FIBROBLAST GROWTH FACTOR-II IN DIABETIC PREGNANT-WOMEN WITH RETINOPATHY

Fibroblast growth factor-2 (FGF-2) is a potent mitogen and angiogenic factor normally absent from the adult circulation. Ne have previously shown that it appears in normal maternal serum and that circulating FG F-2 levels are elevated in pregnancies complicated by diabetes. This s tudy was performed to determine whether serum FGF-2 is more abundant i n pregnant diabetic women with retinopathy than in those without. Seru m was collected monthly between 14-30 weeks gestation and every 2 week s from then until delivery (35-38 weeks) from 36 women with type 1 dia betes. FGF-2 was extracted by heparin-Sepharose affinity chromatograph y and quantified by specific RIA. Patients were divided according to t he White classification of diabetes. In 17 women without retinopathy ( White groups B, C, and D-0), immunoreactive FGF-2 was detectable at 14 weeks (mean +/- SEM, 154 +/- 39 pmol/L), was maximal after 26 weeks ( 306 +/- 38 pmol/L), after which values steadily declined to term(212 /- 48 pmol/L). In 19 women with simplex or proliferative retinopathy W hite groups D, and R), circulating levels of PGF-2 were significantly greater between 22-32 weeks gestation (22 weeks, 480 +/- 102 vs. 239 /- 38 pmol/L; P < 0.05). Serum FGF-2 was significantly correlated with hemoglobin A(1c) levels at 32, 30, and 34 weeks gestation. The mean b irth weight of the infants did not significantly differ between groups . Macroalbuminuria was absent in all patients, and creatinine clearanc e and blood pressure did not significantly differ between the two grou ps. The results suggest that serum FGF-2 is substantially elevated in pregnant diabetic women with retinopathy in second and early third tri mesters. It is unlikely that in these patients this Nas primarily due to altered FGF-2 clearance, but may relate to excessive production by the utero-placental compartment. The high circulating levels of FGF-2 may be causally related to the development of diabetic retinopathy.