Malnutrition in Portuguese older adults : prevalence and associated factors

Background: As the world population gets older, the research community puts its efforts in understanding how we can age better, with less disabilities and more quality of life. Nutrition is one of the well-known determinants of healthy ageing. Yet, several international studies identify malnutrition (here as a synonym of undernutrition) as a common problem among older adults. Malnutrition is a complex condition with a multitude of possible causes and negative health outcomes, such as increased risk of falls, longer hospitalisations and higher mortality. Despite its relevance, nationally representative data on older adults’ nutritional status was missing in Portugal. Moreover, international evidence on the links between dietary intake and malnutrition in advanced age is very scarce. Therefore, the main aims of the present work were to (a) characterise the nutritional status of the Portuguese population aged 65 years or over living in the community or in nursing homes (NHs), and to (b) Identify and characterise malnutrition-associated (demographic, socioeconomic, health-related, psychosocial, and dietary) factors in this population. Methods: The present study followed a cross-sectional design and included national representative samples of the Portuguese population aged ≥ 65 years living in the community setting or in NHs. Data was collected through face-to-face, computerassisted, structured interviews and anthropometric measurements, by trained nutritionists. Data included sociodemographic and economic characteristics, nutritional status, dietary intake and habits, health status, cognitive function, functional status, depressive symptomatology, and loneliness feelings. Complex sample procedures were used for the main analyses to consider the distribution of the Portuguese population and the design effect. Logistic or linear regression models were used to examine the associations between malnutrition risk (‘at risk of malnutrition’ + ‘malnutrition’ in a jointed category) and the other variables under study. Dietary patterns (DPs) were derived a posteriori based on two 24-hour recalls by a latent class transition model. Results: A total of 1120 community-dwellers (mean age: 76.0 years, 49.0% women), and 1186 NH residents (mean age: 83.4 years, 72.8% women) from all seven main Portuguese regions (NUTS II) participated in this observational study. According to the Mini Nutritional Assessment full form (MNA®), 4.8% (95% confidence interval [CI] 3.2, 7.3) of NH residents were malnourished, and 38.7% (95% CI 33.5, 44.2) at risk of malnutrition, whereas among community-dwellers these percentages were 0.5 (95% CI 0.2, 1.7), and 16.4 (95% CI 13.3, 19.9), respectively. Malnutrition, cognitive impairment, limitations in instrumental activities of daily living, symptoms of depression, and loneliness feelings were more frequent among NH residents, women, and in the oldest individuals. The living setting (NHs vs community) was not significantly associated with risk of malnutrition/ malnutrition after adjusting for functional status, symptoms of depression and loneliness (odds ratio [OR] = 1.03, 95% CI 0.67, 1.58). In the final adjusted model (OR, 95% CI), a monthly income of 485–970€ (NH only: 2.58, 1.07–6.23), reporting a ‘very poor or poor’ general health status (NH: 3.54, 1.42–8.82; community: 3.54, 1.71–7.32), and symptoms of depression (NH: 4.96, 2.93–8.41; community: 5.12, 3.18–8.25) were associated with higher odds of being at malnutrition risk. Three DPs were identified among community-dwellers: ‘Protein-based foods’ DP (22.0% of the studied population), ‘Mediterranean’ DP (59.1%), and ‘In-between’ (switching between DPs; 18.9%). After adjustment, following a ‘Protein-based foods’ DP was associated with better MNA score (EXP(β) = 0.72, 95% CI 0.53, 0.96), compared to the ‘Mediterranean’ DP, particularly for total energy intake up to 2200 kcal/day. A higher energy intake was associated with lower odds of malnutrition risk in both settings, but only significant among NH residents after adjusting for confounders (NH: OR = 0.66, IC 95% 0.50, 0.86; community: OR = 0.64, IC 95% 0.37, 1.10). The intake of carbohydrates, fibre, vitamin C (in NH), protein, vitamin B6, folates, calcium, magnesium (in the community), fat, sodium, potassium (in both settings) was inversely associated with malnutrition risk. But only significantly for sodium and magnesium in the community after further adjustment for energy intake. The prevalence of inadequate nutrient intake was generally higher for those at malnutrition risk. Conclusions: Risk of malnutrition and malnutrition are prevalent conditions among older community-dwellers, and even more in NHs residents. A monthly income of 485–970€ (in NHs), poorer health status, and symptoms of depression, but not the living setting, were positively associated with malnutrition risk. In the community, following a ‘Protein-based foods’ DP was associated with better nutritional status, while in NHs total energy intake seems more relevant to nutritional status. These findings stress out the need for defining and implementing public health policies, as well as local protocols and programs to identify and treat malnutrition in a timely manner in these settings. Malnutrition requires a multidimension approach, including nutritional support, and managing other physical and mental health-related causes. These actions are crucial for healthy ageing.Mecanismo Financeiro do Espaço Económico Europeu 2009–2014 (EEA Grants