[Association between central diabetes insipidus and type 2 diabetes mellitus]. / Asociación de diabetes insípida central y diabetes mellitus tipo 2.

Central diabetes insipidus is a rare disease of the hypothalamus and neurohypophysis. It is very unusually found in the adult with type 2 diabetes mellitus. It is manifested by a polydipsic polyuric syndrome, which must be distinguished from the poorly controlled type 2 diabetes mellitus. Given the similarity of both entities and the unusual nature of their coexistence, their suspicion is difficult. The case of a 72-year-old male with type 2 diabetes mellitus with poor insulin control (fasting hyperglycemia greater than 180 mg/dl) who had a long-standing polyuric syndrome is here presented. Hypernatremia and plasma osmolality elevated together with a low urinary osmolality led to the suspicion of diabetes insipidus, which was subsequently confirmed by the dehydration test and the administration of desmopressin sc. With 61% increase in the calculated urinary osmolarity one hour post desmopressin s.c., diabetes insipidus of central type was diagnosed. Nuclear Magnetic Resonance showed a bright spot with normal neurohypophysis, contributing to the diagnosis of the idiopathic form.

Asociación de diabetes insípida central y diabetes mellitus tipo 2 / Association between central diabetes insipidus and type 2 diabetes mellitus

La diabetes insípida central es una enfermedad rara del hipotálamo y de la neurohipófisis, y muy inusualmente se halla en el adulto con diabetes mellitus 2. Se manifiesta por un síndrome poliúrico polidípsico, que debe diferenciarse de la diabetes mellitus mal controlada. Ante la similitud de ambas entidades, y lo infrecuente de su coexistencia, se dificulta su sospecha. Se presenta el caso de un hombre de 72 años de edad, con diabetes mellitus 2 y pobre control de la misma (hiperglucemias de ayuno mayores a 180 mg/dl) que cursó un síndrome poliúrico de larga data. La hipernatremia y la osmolalidad plasmática elevadas, junto a una osmolalidad urinaria baja llevaron a la sospecha de diabetes insípida, que posteriormente se confirmó con la prueba de deshidratación y la administración de desmopresina s.c. Con un aumento del 61% de la osmolalidad urinaria calculada una hora post desmopresina s.c. fue diagnosticada como diabetes insípida del tipo central. La resonancia magnética nuclear mostró una mancha brillante con neurohipófisis normal, contribuyendo al diagnóstico de la forma idiopática.

Central diabetes insipidus is a rare disease of the hypothalamus and neurohypophysis. It is very unusually found in the adult with type 2 diabetes mellitus. It is manifested by a polydipsic polyuric syndrome, which must be distinguished from the poorly controlled type 2 diabetes mellitus. Given the similarity of both entities and the unusual nature of their coexistence, their suspicion is difficult. The case of a 72-year-old male with type 2 diabetes mellitus with poor insulin control (fasting hyperglycemia greater than 180 mg/dl) who had a long-standing polyuric syndrome is here presented. Hypernatremia and plasma osmolality elevated together with a low urinary osmolality led to the suspicion of diabetes insipidus, which was subsequently confirmed by the dehydration test and the administration of desmopressin sc. With 61% increase in the calculated urinary osmolarity one hour post desmopressin s.c., diabetes insipidus of central type was diagnosed. Nuclear Magnetic Resonance showed a bright spot with normal neurohypophysis, contributing to the diagnosis of the idiopathic form.