To elucidate the relationship between various sleep-wake-related indicators and nutritional status.

Cross-sectional study.

Community-based survey between 2017 and 2022 in Yilan City, Taiwan.

1,905 community-dwelling older adults aged ≥65 years.

Nutritional status was evaluated using the Mini Nutritional Assessment, and participants were classified into normal nutritional status and undernutrition groups. Regarding sleep-wake-related indicators, specific items or component scores of the Pittsburgh Sleep Quality Index were used to assess sleep-wake schedule, subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, presence of sleep disturbances, hypnotic use, and dysfunction in maintaining enthusiasm. The 5-item Athens Insomnia Scale and the Epworth Sleepiness Scale were used to evaluate insomnia and excessive daytime sleepiness, respectively.

Of the 1,905 participants, the mean age was 75.6±7.1, with 52.2% being ≥75 years old, 58.9% were women, and 11.4% had undernutrition. After controlling for covariates, short sleepers were less likely to have undernutrition (OR: 0.63; 95% CI: 0.41–0.97); in contrast, long sleepers were more likely to exhibit undernutrition (OR: 1.52; 95% CI: 1.06–2.17). In addition, poor habitual sleep efficiency (OR:1.69; 95% CI:1.15–2.50), taking hypnotics in the past month (OR: 1.58; 95% CI: 1.12–2.24), and dysfunction in maintaining enthusiasm (OR: 1.93; 95% CI: 1.24–2.99) were associated with increased risk of undernutrition.

Among older adults, various sleep-wake-related indicators differed in their relationships with nutritional status. Specific sleep-wake disturbances may indicate undernutrition in this population.