The Influence of Nutritional Status and Sleep Quality on Gustatory Function in Older Adults.

Background and Objectives: Age-related declines in taste function are common. Taste acuity can be affected by nutritional status and sleep quality. This research aims to examine the effect of nutritional status and sleep quality on gustatory function in community-dwelling older adults. Materials and Methods: This cross-sectional study included 119 community-dwelling older adults (50.4% of whom were female). The gustatory function was evaluated using four liquid taste solutions (sweet, bitter, sour, and salty) each at four different concentrations and the Mini Nutritional Assessment (MNA) and Pittsburgh Sleep Quality Index (PSQI) was applied. Additionally, anthropometric measurements were taken. Results: The mean scores on the gustatory test for the sweet, bitter, sour, and salty tastes were 2.11 ± 1.27, 2.12 ± 1.03, 2.28 ± 1.03, and 1.98 ± 1.41, respectively. There were significant differences according to gender, polypharmacy, nutritional status, and sleep quality in identifying sweet tastes (all p < 0.05). It was also found that females and participants without polypharmacy had better scores for bitter tastes. When the gustatory functions were evaluated according to BMI classification, it was determined that underweight participants had a higher sour taste score than the obese ones. Multiple regression analysis revealed that age, MNA score, PSQI score, and gender accounted for a total of 20.4% of the variance in the sweet taste score. Conclusions: Determining the relationship between taste function, nutritional status, and sleep quality in older adults is important in terms of developing new strategies for older adults who have these problems.

Is sonic hedgehog expression in saliva related to taste sensitivity in adults?

Recent studies have demonstrated the critical role of the sonic hedgehog in the sensory perception of taste. Salivary sonic hedgehog stimulates taste bud stem cells, also acts as a taste bud growth factor, and contributes to the receptors' development and longevity in the taste buds. This study's objective was to investigate the possible relationship between taste sensitivity and sonic hedgehog expression in saliva in normal-weight and pre-obese/obese participants (totally 46 male (47.8%) and female (52.2%) aged 19-44 were recruited). Thresholds for the six tastes (sweet, salty, bitter, sour, umami and fat) were investigated using 3-Alternate Forced Choice Methodology. Saliva was collected with the draining method for sonic hedgehog expression analysis. The results indicated significantly higher thresholds for sweet, bitter and fat in pre-obese /obese adults than normal-weight adults (p<0.05). The sonic hedgehog expression was also lower in pre-obese /obese participants than normal-weight participants (p<0.05). Furthermore, sonic hedgehog expression was higher in hypersensitive participants than hyposensitive participants (p<0.05) only among normal-weight individuals, with no significant difference in sonic hedgehog expression level by taste sensitivity in pre-obese/obese individuals (p>0.05). Sonic hedgehog expression level was negatively correlated with body mass index, sweet, salty, bitter and fat taste threshold. The study results indicated that sonic hedgehog expression level acted on taste sensitivity in normal-weight participants, with greater expression in hypersensitive individuals than hyposensitive individuals.