Aumento da probabilidade diagnóstica de Síndrome de Cushing subclínica em amostra de população de pacientes obesos com diabetes mellitus do tipo 2

Abstract

Endogenous Cushing’s syndrome (CS) is unusual. Patients with subclinical CS (SCS) present altered cortisol dynamics without obvious manifestations. CS occurs in 2-3% of obese poorly controlled diabetics. We studied 103 overweight adult outpatients with type 2 diabetes to examine for cortisol abnormalities and SCS. All collected salivary cortisol at 23:00h and salivary and serum cortisol after a 1mg dexamethasone suppression test (DST). Patients whose results were in the upper quintile for each test (253ng/dL, 47ng/dL and 1.8ìg/dL, respectively for the 23:00h and post-DST saliva and serum cortisol) were re-investigated. Average values from the upper quintile group were 2.5- fold higher than in the remaining patients. After a confirmatory 2mgx2day DST the investigation for CS was ended for 61 patients with all normal tests and 33 with only one (false) positive test. All 8 patients who had two abnormal tests had subsequent normal 24h-urinary cortisol, and 3 of them were likely to have SCS (abnormal cortisol tests and positive imaging). However, a final diagnosis could not to be confirmed by surgery or pathology. Although not confirmatory, the results of this study suggest that the prevalence of SCS is considerably higher in populations at risk than in the general population.

A sindrome de Cushing (SC) endogena e rara. Pacientes com SC subclinica (SCS) apresentam hipercortisolismo sem manifestacoes clinicas. SC ocorre em 2-3% de diabeticos mal controlados. Estudamos 103 pacientes adultos obesos ambulatoriais com diabetes mellitus tipo 2 para avaliar alteracoes do cortisol e SCS. Todos coletaram cortisol salivar as 23:00h e cortisol salivar e serico apos teste de supressao com 1mg de dexametasona (DST). Pacientes cujos resultados de qualquer teste estavam no quintil superior (253ng/dL, 47ng/dL e 1,8ƒÊg/dL, respectivamente para cortisol salivar 23:00h e salivar e serico pos-DST) foram reavaliados. Os valores medios desse grupo encontravam-se 2,5 vezes acima dos valores dos demais pacientes. Apos um teste confirmatorio com 2mgx2dias DST a investigacao da SC foi encerrada para 61 pacientes com todos os testes normais e 33 com apenas um teste (falso) positivo. Todos os 8 pacientes com dois testes alterados apresentaram cortisol urinario normal, mas 3 deles mostraram maior probabilidade diagnostica de SCS (hipercortisolismo e alteracoes em exames de imagem). Contudo, o diagnostico final nao pode ser confirmado por cirurgia ou patologia em nenhum deles. Embora nao confirmatorios, os resultados deste estudo sugerem que a prevalencia de SCS seja maior em populacoes de risco do que na populacao geral.