Relationship of impaired olfactory function in ESRD to malnutrition and retained uremic molecules.
BACKGROUND
Olfactory function is impaired in patients with end-stage renal disease (ESRD) and may contribute to uremic anorexia. Only limited correlations of olfactory function and nutritional status were reported. This study examines the relationship of impaired olfactory function to malnutrition and levels of the retained uremic solutes monomethylamine, ethylamine, indoxyl sulfate, and P-cresol sulfate.


METHODS
Cross-sectional observational study.


METHODS
31 stable maintenance hemodialysis patients from an urban outpatient dialysis unit and 18 people with normal renal function participated.


METHODS
Nutritional status assigned by using Subjective Global Assessment (SGA) score; SGA score of 7 indicates normal nutritional status; SGA score of 5 to 6, mild malnutrition; and SGA score of 3 to 4, moderate malnutrition.


METHODS
The primary outcome is olfactory function, assessed using the University of Pennsylvania Smell Identification Test. Levels of retained uremic solutes were measured from a predialysis serum sample. Demographic data and laboratory values for nutritional status, adequacy of dialysis, and inflammation were collected.


RESULTS
Mean smell scores were 34.9 +/- 1.4 for controls, 33.5 +/- 3.3 for patients with SGA score of 7, 28.3 +/- 5.8 for patients with SGA score of 5 to 6, and 27.9 +/- 4.4 for patients with SGA score of 3 to 4 (P < 0.001 comparing healthy patients with all patients with ESRD). There was no difference in mean smell scores for healthy controls and patients with SGA score of 7. However, patients with lower smell scores had significantly lower SGA scores (P = 0.02) and higher C-reactive protein levels (P = 0.02). Neither smell score nor nutritional status was associated with levels of retained uremic solutes.


CONCLUSIONS
Small sample size, only cross-sectional associations can be described.


CONCLUSIONS
Our results suggest an association between poor nutritional status and impaired olfactory function in patients with ESRD. Additional research is needed to discover the uremic toxins mediating these processes.
Raff
Amanda C
AC
Department of Medicine, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA. araff@montefiore.org
Lieu
Sung
S
Melamed
Michal L
ML
Quan
Zhe
Z
Ponda
Manish
M
Meyer
Timothy W
TW
Hostetter
Thomas H
TH
D000328:Adult; D017677:Age Distribution; D000553:Ambulatory Care; D000704:Analysis of Variance; D003430:Cross-Sectional Studies; D005021:Ethylamines / Q000032:analysis; D005260:Female; D005500:Follow-Up Studies; D006436:Hemodialysis Units, Hospital; D006801:Humans; D015994:Incidence; D007200:Indican / Q000032:analysis; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D007677:Kidney Function Tests; D008297:Male; D044342:Malnutrition / Q000453:epidemiology* / Q000209:etiology; D008875:Middle Aged; D009752:Nutritional Status; D000857:Olfaction Disorders / Q000453:epidemiology* / Q000209:etiology; D011336:Probability; D006435:Renal Dialysis / Q000009:adverse effects* / Q000379:methods; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution
D005021:Ethylamines; D007200:Indican