Relationship between nutritional status and clinical outcomes among older individuals using long-term care services: A systematic review and meta-analysis

BACKGROUND & AIMS

Nutritional status is a significant issue in an aging society; however, the impact of the nutritional status of older individuals using long-term care services on the caregiving burden remains unclear. This systematic review and meta-analysis aimed to investigate the impact of nutritional issues on adverse outcomes in older individuals using long-term care services.

METHODS

We used data from the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, Web of Science, CINAHL, and Ichu-shi Web databases. Original articles published in English or Japanese between January 2000 and July 2022 were included. The inclusion criteria were interventional and observational studies on individuals using long-term care services with aged ≥65 years and a focus on body weight or weight loss. Data on adverse outcomes related to caregiving burden, including the number of people requiring care, mortality, complications, activities of daily living (ADL), and quality of life, were collected.

RESULTS

The literature search yielded 7873 studies, of which 35 were ultimately included. Seven observational studies investigated mortality outcomes, and seven examined ADL outcomes. The meta-analysis revealed significantly higher mortality rates in individuals classified as underweight (BMI <18.5 kg/m2) than in those with BMI ≥18.5 kg/m2 (risk ratio [RR] 1.49; 95 % confidence interval [CI] 1.31 to 1.73, 0.22; I2 93 %). Further, on categorising the participants based on a BMI cutoff of 25 kg/m2, those with a BMI of <25 kg/m2 had a significantly increased mortality rate (RR 1.21; 95 % CI 1.04-1.40; I2 = 98 %). BMI and weight loss did not affect ADL.

CONCLUSIONS

Our findings indicate that underweight and weight loss are significantly associated with increased mortality in older individuals using long-term care services. Therefore, appropriate weight management is recommended for this population. However, further research is necessary owing to the high heterogeneity observed in this study.

Sensory Profile of Adults with Reduced Food Intake and the Potential Roles of Nutrition and Physical Activity Interventions

The sensory profile, referring to sight, smell, taste, hearing, and touch, plays an essential role in optimizing the habitual intake of energy and macronutrients. However, specific populations, such as older adults, are known to have impaired energy intake. In this paper, the relevance of sensory impairments in this older population is described, and the extent to which nutritional and physical activity interventions can modulate these sensory responses when food intake is insufficient is explored. With aging, all senses deteriorate, and in most cases, such deteriorations diminish the nutritional response. The only exception is sight, for which both positive and negative impacts on nutritional response have been reported. From a prevention perspective, nutritional interventions have been understudied, and to date, only hearing is known to be positively affected by a good nutritional profile. In comparison, physical activity has been more frequently studied in this context, and is linked to an improved preservation of 4 senses. Regarding treatment, very few studies have directly targeted sensory training, and the focus of research has tended to be on nutrition and physical activity intervention. Sensory training, and nutritional and physical activity treatments all have beneficial effects on the senses. In the future, researchers should focus on exploring gaps in the literature specifically concerning prevention, treatment, and sensory response to understand how to improve the efficacy of current approaches. In order to maintain sensory acuity and recover from sensory impairment, the current state of knowledge supports the importance of improving nutritional habits as well as physical activity early on in life. A combined approach, linking a detailed lifestyle profile with the assessment of numerous senses and one or more interventional approaches (nutrition, physical activity, sensory training, etc.), would be required to identify effective strategies to improve the nutritional state of older individuals.