Relation between change in treatment for central diabetes insipidus and body weight loss.

BACKGROUND: Patients with central diabetes insipidus (CDI) are known to lose weight because their polydipsia interferes with their nutritional intake. We retrospectively examined weight changes in CDI patients when they switched from nasal to oral desmopressin. METHODS: Twenty-three patients with CDI were included. Weight change was defined as an increase or decrease of more than 3 kg or 3% body weight. As factors contributing to the weight change, we studied the patients' clinical characteristics and quality of life (QOL) scores as determined by our original questionnaire. RESULTS: Five patients showed a weight loss of 5.9 kg (2.4-9.0 kg), and two patients showed weight gain, while 16 out of 23 patients were weight neutral. When the patients with weight gain and weight neutral were analyzed together, the mean weight change was + 0.3 kg (-0.5 to + 1.1 kg). All the patients who lost weight had a Body Mass Index >= 22 kg/m(2) (38% vs. 0%, P=0.027) and higher frequencies of abnormally high serum levels of AST (40% vs. 0%, P=0.005). The sum of the QOL scores was similar between the two groups, but higher in patients who lost weight after switching to oral desmopressin (43.3 +/- 2.7) than in those who did not (38.2 +/- 5.0, P=0.01). CONCLUSIONS: Switching the treatment from nasal to oral desmopressin may cause weight loss in patients with CDI who seemed to have polydipsia-associated weight gain.