Understanding the relationship between chemosensory complaints and sleep: a cross-sectional study of adults in Aotearoa New Zealand

Sleep and chemosensory function (smell and taste) both are closely tied to health and wellbeing, yet their long-term interrelationship remains underexplored. Although experimental studies have demonstrated that sleep deprivation can acutely alter chemosensory perception, it is unclear whether individuals who report ongoing smell or taste dysfunction also experience habitual disruptions to sleep. This study aimed to understand whether individuals with self-reported smell or taste complaints experience shorter and/or poorer quality sleep, independent of health and demographic factors, using a healthy adult sample. A cross-sectional online survey was conducted. Chemosensory complaints were measured using the NHANES smell and taste protocol, and sleep was assessed using the Pittsburgh Sleep Quality Index. Linear regression models examined associations between chemosensory complaints and sleep duration and quality, adjusting for age, gender, ethnicity, socioeconomic status, wellbeing, BMI, health conditions, medications, caffeine intake, and night shift work. Of the 769 participants who provided complete responses, 50.6% reported smell and/or taste complaints. While our models did not show that chemosensory complaints were a significant predictor for sleep duration or sleep quality after controlling for health-related variables, when chemosensory complaints were separated by modality, taste complaints were significantly associated with poorer sleep quality even after full adjustment (aMD = 0.64, 95% CI 0.14 to 1.14, p = 0.012). Subjective taste complaints may be a useful and accessible marker of poor sleep quality. These findings highlight the need to consider chemosensory health in sleep-related research and public health initiatives.