Increased urinary atrial natriuretic peptide-like immunoreactivity excretion but decreased plasma atrial natriuretic peptide concentration in patients with hyperosmolar-hyperglycemic nonketotic syndrome.

OBJECTIVE: This study was undertaken to measure urinary atrial natriuretic peptide-like immunoreactivity (ANP-LI) and plasma ANP concentration in patients with hyperosmolar-hyperglycemic nonketotic syndrome (HHNS) to investigate the change of renal ANP-LI and cardiac ANP synthesis in volume-depleted diabetic patients. RESEARCH DESIGN AND METHODS: The urine ANP-LI:creatinine ratio, plasma ANP level, and plasma renin activity (PRA) were measured in 12 patients with HHNS during the acute stage and after recovery, in 28 oral hypoglycemic agent (OHA)-treated type 2 diabetic patients, and in 23 normal subjects. ANP and PRA were measured by radioimmunoassay. RESULTS: These HHNS patients had severe hyperglycemia and hyperosmolality as well as increased blood urea nitrogen, creatinine, and PRA levels, as compared with normal subjects and OHA-treated type 2 diabetic patients. In these patients, the urinary ANP-LI:creatinine ratio (11.69 +/- 2.11 pmol/mmol) was significantly increased in comparison with the normal group (1.78 +/- 0.11 pmol/mmol) and OHA-treated diabetic patients (2.43 +/- 0.45 pmol/mmol), whereas plasma ANP concentration (5.12 +/- 0.72 pmol/l) was significantly lower than the corresponding values of the normal group (7.39 +/- 0.85 pmol/l) and OHA-treated diabetic patients (8.43 +/- 1.05 pmol/l). All of these abnormalities were significantly ameliorated after insulin, fluid, and electrolyte replacement. CONCLUSIONS: Our data show that urinary ANP-LI was significantly increased, whereas plasma ANP concentration was decreased, in the face of raised PRA in HHNS patients. This study indicates that renal ANP-LI substances and cardiac ANP may exhibit different responsiveness in diabetic patients with HHNS.