Detection and recognition thresholds to the 4 basic tastes in Mexican patients with primary Sjögren's syndrome.

Abstract

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease characterized by inflammatory lymphocytic infiltration of the salivary glands, leading to dryness of the mouth (xerostomia). It has been postulated that xerostomia is the preceding stage for the development of alterations in taste acuity (dysgeusia) in this type of patients. To determine detection and recognition thresholds to the 4 basic tastes (sweet, salty, sour and bitter) in pSS patients and compare them to a control group. To determine if the long-term consumption of chile peppers and spicy Mexican diets had an effect on the taste perception and acuity of the pSS patients. This study was done in the Department of Food Science and Technology of the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (INCMNSZ), a third-level hospital in Mexico City. The patient group consisted of 21 Mexican females (mean +/- s.d., age: 53.1 +/- 9.8 y) diagnosed with pSS (time of duration of the disease, 8.6 +/- 6.6 y, median 7 y, range 1-25 y) who were recruited at the outpatient service of the Department of Immunology and Rheumatology of the INCMNSZ. The control group consisted of 20 healthy nonsmokers age-matched Mexican women (50.3 +/- 11.9 y) most of them personnel of the INCMNSZ, and some friends and nonblood relatives to the patients (sisters-in-law) who volunteered to participate in the study. Detection and recognition thresholds were determined by the method of least noticeable differences on three occasions during three nonconsecutive days. Saliva production was determined by Saxon's test on two separate occasions. Although saliva production was severely reduced in pSS patients (1.35 +/- 0.55 ml/2 min, P<0.001) compared to controls (6.26 +/- 2.41 ml/2 min), all subjects recognized the 4 basic tastes when these were tested at suprathreshold concentrations. The detection thresholds for the sweet, sour and bitter tastes were higher in pSS patients, as well as the recognition thresholds for the salty, sour and bitter tastes. A relationship between time of evolution of the disease and saliva production with individual thresholds could not be established. pSS patients exhibited different degrees of dysgeusia depending on the taste being studied, that is, they were mildly dysgeusic for the sweet and salty tastes and clearly dysgeusic for the sour and bitter tastes. Although both pSS patients and controls had consumed 'typical Mexican diets' their entire lives, our results showed that the consumption of chile peppers and spicy foods did not have any effect on the taste perception and acuity of the pSS patients.