Serum levels of matrix metalloproteinases MMP-2 and MMP-9 and their inhibitors in women with glucose intolerance in pregnancy and normal controls

Abstract

Matrix metalloprotenases (MMPs) are proteolytic enzymes active in inflammatory states. We have examined MMP-9, MMP-2, and their respective tissue inhibitors: TIMP-1 and TIMP-2 in sera of women with gestational diabetes mellitus (GDM) and various degrees of insulin resistance (IR) in the third trimester of pregnancy. Fasting serum levels of MMP-9, MMP-2, TIMP-1 and TIMP-2 were measured in 26th-28th week of gestation in 51 women divided according to their response to a 50-g glucose challenge test (GCT) and a 75-g OGTT: controls (n = 20): both tests normal; the GDM group (n = 16) both tests abnormal; the intermediate group (IG; n = 15) abnormal GCT and normal OGTT. MMPs and TIMPs were correlated with the parameters of IR: homeostasis model assessment (HOMA) and insulin resistance index (IRI). MMP-9, MMP-2, TIMP-1 and MMP-9/TIMP-1 ratio were not different among the groups. TIMP-2 levels were significantly higher in the GDM and IG groups than in controls (p < 0.01). MMP-2/TIMP-2 ratio was lower in the GDM group than in the other groups (p < 0.01) and was correlated to HOMA and IRI (r = -0.465 and r = -0.43 respectively, p < 0.01). Serum MMP levels do not reflect inflammation in GDM. Elevated TIMP-2 and consequently lower MMP-2/TIMP-2 levels in GDM need to be clarified, but are unlikely to be a consequence of inflammation.