Índices de sensibilidade à insulina em fêmeas caninas: efeito do ciclo estral e da piometra

Abstract

Ocurrence of estrous cycle and pyometra in female dogs are associated to insulin resistance status. Moreover, septic/ inflammatory environments such as pyometra may also course with reduced insulin sensitivity. The aim of this study was to check the effect of estrus cycle and pyometra on insulin sensitivity indexes. Based in blood basal glucose levels and serum insulin basal levels from bitches in different estrus cycle phases as well as in bitches with pyometra, different insulin sentivity indexes were calculated (HOMA B, HOMA R, insulinogenic index, amended insulin:glucose ratio, fructosamine and fructosamine:albumin ratio). The insulinogenic index and amended insulin:glucose ratio were more sensible in detecting relative hyperinsulinemic status, specially in pyometra patients. The lack of a cut-off point for HOMA indexes impairs its interpretation, notwithstanding their have been able to shown insulin resistance in female dogs with pyometra. Moreover, this different sensitivity indexes have prove to be really easy, cheap and useful and have some advantages comparing with basal insulin and glucose levels. Fructosamine was not a useful screening test in detecting differences in insulin sensitivity status despite there were a strong influence of hypoalbuminemia on fructosamine levels in bitches with pyometra. Fructosamine:albumina ratio is more reliable than fructosaminemia alone, and future studies are need to determine reference values for this ratio, as well to HOMA B and HOMA R indexes in female dogs.