Non-obese adult onset diabetes with oral hypoglycemic agent failure: islet cell autoantibodies or reversible beta cell refractoriness?

Pancreatic ß cell function and insulin sensitivity, analyzed by the homeostasis model assessment, before and after 24 weeks of insulin therapy were studied and correlated with the presence of autoantibodies against ß cells (islet cell and anti-glutamic acid decarboxylase antibodies), in a group of 18 Brazilian lean adult non-insulin-dependent diabetes mellitus (NIDDM) patients with oral hypoglycemic agent failure (OHAF). Median fasting plasma glucose before and after insulin treatment was 19.1 and 8.5 mmol/l, respectively (P < 0.001); median HbA1c was 11.7 percent before vs 7.2 percent after insulin treatment (P < 0.001). Forty-four percent of the patients were positive (Ab+) to at least one autoantibody. Fasting C-peptide levels were lower in Ab+ than Ab- patients, both before (Ab+: 0.16 ± 0.09 vs Ab-: 0.41 ± 0.35 nmol/l, P < 0.003) and after insulin treatment (Ab+: 0.22 ± 0.13 vs Ab-: 0.44 ± 0.24 nmol/l, P < 0.03). Improvement of Hß was seen in Ab- (median before: 7.3 vs after insulin therapy: 33.4 percent, P = 0.003) but not in Ab+ patients (median before: 6.6 vs after insulin therapy: 20.9 percent). These results show that the OHAF observed in the 18 NIDDM patients studied was due mainly to two major causes: autoantibodies and ß cell desensitization. Autoantibodies against ß cells could account for 44 percent of OHAF, but Ab- patients may still present ß cell function recovery, mainly after a period of ß cell rest with insulin therapy. However, the effects of ß cell function recovery on the restoration of the response to oral hypoglycemic agents need to be determined

Aspectos da fase näo-insulinodependente do diabetes mellitus do tipo I / Aspects of non-insulin-dependent phase of type I diabetes mellitus

Trata-se de um caso de diabetes mellitus do tipo I(DMI) no qual tivemos a oportunidade de diagnosticá-lo 23 meses antes das suas manifestaçöes clínicas mais freqüentes. Durante esse período foram observadas alteraçöes como o retorno de enurese, diminuiçäo na velocidade de crescimento e episódios de hiperglicemia e/ou glicosúria transitórios, apresentadas pela paciente, que podem näo ser devidamente valorizadas, na rotina clínica. Como, também, o aparecimento de marcadores imunológicos (ICA) e alteraçöes precoces na secreçäo de insulina (diminuiçäo na sua primeira fase de liberaçäo) vários meses antes do DMI manifesto. Esses marcadores imunológicos e essas alteraçöes endócrinas deveriam, se possível, ser pesquisados em pacientes com o quadro clínico inicial aqui apresentado, e em parentes jovens de DMI, no sentido de se detectar indivíduos com elevado risco de evoluírem para a fase manifesta dessa moléstia. O seguimento desses pacientes possibilitaria o diagnóstico precoce do DMI e a aplicaçäo de medidas no sentido de impedir a deteriorizaçäo total das células beta-pancreáticas e a evoluçäo para distúrbios metabólicos mais graves, como a cetoacidose diabética, com morbidade e mortalidade reconhecida