Weight loss severity and functional decline among the oldest old in a middle-income country: The FIBRA study longitudinal findings

Background and aims: Nutritional status is a key modifiable risk factor associated with disability, and further evidence suggests that weight change is also linked to this adverse outcome. Thus, this study aims to evaluate weight loss severity and functional decline in instrumental activities of daily living (IADL) in a seven-year period among a sample of Brazilian oldest-old adults. Methods: Longitudinal prospective study using data from the FIBRA study (Frailty in Older Brazilians), a population-based investigation carried out in 2008/2009, with follow-up data collected in 2016/2017 from participants who were 80 years and older in the follow-up in Campinas, Brazil. Of the 167 participants with complete data in 2016–2017, 16 had improved their functional status and were excluded, so the final sample was restricted to 151 participants who maintained or declined functional status. We considered functional decline when a subject had greater IADL dependencies at follow-up than baseline. Logistic regression was performed to assess the effect of weight loss, according to severity (moderate weight loss: 5–10% of body weight; severe weight loss >10%) in increasing the number of disabilities than the group with stable weight, controlling for covariates (gender, age, education, and morbidity). An alpha level of <5% was adopted. Results: During the follow-up period, 60.3% of the participants kept stable weight, 21.8% had moderate weight loss, and 17.9% had severe weight loss. During the follow-up, only severe weight loss was associated with a higher risk of functional decline (OR = 2.74; p = 0.032). Conclusions: Severe weight loss was associated with functional decline. This finding reinforces the importance of early identification of weight loss among older adults.