Interdialytic weight gain in patients on hemodialysis is associated with dry mouth and thirst.
BACKGROUND
Patients receiving hemodialysis (HD) have to maintain a fluid-restricted diet. Severe thirst can induce noncompliance to this diet, resulting in an increase of interdialytic weight gain (IWG = weight predialysis - postdialysis) associated with poor patient outcomes. Because oral dryness may contribute to experienced thirst, we investigated the possible relation between thirst, salivary flow rate, xerostomia, and IWG.


METHODS
Unstimulated (UWS) and stimulated (CH-SWS) whole saliva were collected from 94 HD patients (64 men, 54.8 +/- 15.5 years; 30 women, 59.5 +/- 18.7 years). Secretion rates of saliva were determined gravimetrically. Xerostomia was assessed with a validated Xerostomia Inventory (XI), and thirst with a newly developed Dialysis Thirst Inventory (DTI).


RESULTS
Before dialysis, 36.2% of the patients had hyposalivation (UWS < or =0.15 mL/min). The XI scores had a positive relation with IWG (r=.250, P < 0.001). Gender and age differences were observed for thirst, salivary flow rates, and xerostomia. The prevalence and severity of thirst and xerostomia were greater in younger subjects. Patients with urine output did not differ from those without urine output with respect to thirst, xerostomia, and IWG. Correlations were found between thirst (DTI) and both IWG and xerostomia (XI) (r=.329, P < 0.001, respectively; r=.740, P < 0.001). Other correlations were observed between xerostomia and both the salivary flow rate and total number of medications (r=-.252, P < 0.05, respectively; r=.235, P <.05).


CONCLUSIONS
In HD patients, xerostomia (XI) and thirst (DTI) are associated with a higher IWG. Our data provide evidence that, in HD patients, xerostomia is related to both salivary flow rate and thirst (DTI).
Department of Dental Basic Sciences, Oral Biochemistry Section, Academic Centre for Dentistry, Amsterdam, The Netherlands. c.bots@vumc.nl
Casper P
CP
Bots
Henk S
HS
Brand
Enno C I
EC
Veerman
Marianne
M
Valentijn-Benz
Barbara M
BM
Van Amerongen
Robert M
RM
Valentijn
Pieter F
PF
Vos
Joost A
JA
Bijlsma
Pieter D
PD
Bezemer
Piet M
PM
Ter Wee
Arie V Nieuw
AV
Amerongen
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004326:Drinking; D004327:Drinking Behavior; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications* / Q000503:physiopathology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012463:Saliva / Q000378:metabolism; D013894:Thirst; D015430:Weight Gain; D014987:Xerostomia / Q000209:etiology*