Posterior pituitary function in Sheehan's syndrome.
OBJECTIVE
We studied posterior pituitary function in 27 patients with Sheehan's syndrome and 14 controls.


METHODS
All patients were investigated by water deprivation test and 26 of them by 5% hypertonic saline infusion test. None of the patients had symptoms of diabetes insipidus and all patients were on adequate glucocorticoid and thyroid hormone replacement therapy before testing.


RESULTS
According to dehydration test, 8 (29.6%) patients had partial diabetes insipidus (PDI group) and 19 (70.3%) had normal response (non-DI group). During the 5% hypertonic saline infusion test, the maximal plasma osmolality was higher in PDI (305 +/- 4.3) and non-DI (308 +/- 1.7) groups when compared with controls (298 +/- 1.7 mOsm/kg; P < 0.005), but the maximal urine osmolality was lower in PDI group (565 +/- 37) than in non-DI (708 +/- 45) and control (683 +/- 17 mOsm/kg) groups (P < 0.05). The osmotic threshold for thirst perception was higher in PDI (296 +/- 4.3) and non-DI (298 +/- 1.4) groups when compared with control group (287 +/- 1.5 mOsm/kg) (P < 0.005). Basal plasma osmolalities were also higher in PDI (294 +/- 1.0) and non-DI (297 +/- 1.1) groups than in controls (288 +/- 1.2 mOsm/kg; P < 0.001).


CONCLUSIONS
Our findings demonstrated that patients with Sheehan's syndrome have an impairment of neurohypophyseal function. The thirst center may be affected by ischemic damage and the osmotic threshold for the onset of thirst in patients with Sheehan's syndrome is increased.
Atmaca
Hulusi
H
Department of Endocrinology, Zonguldak Karaelmas University Medical School, Zonguldak, Turkey.
Tanriverdi
Fatih
F
Gokce
Cumali
C
Unluhizarci
Kursad
K
Kelestimur
Fahrettin
F
D000328:Adult; D000368:Aged; D003894:Deamino Arginine Vasopressin / Q000494:pharmacology; D005260:Female; D006801:Humans; D007018:Hypopituitarism / Q000097:blood / Q000503:physiopathology* / Q000652:urine; D008875:Middle Aged; D009994:Osmolar Concentration; D010904:Pituitary Gland, Posterior / Q000503:physiopathology*; D012462:Saline Solution, Hypertonic; D018709:Statistics, Nonparametric; D013894:Thirst; D014868:Water Deprivation / Q000502:physiology
D012462:Saline Solution, Hypertonic; D003894:Deamino Arginine Vasopressin