Association of polypharmacy with nutritional status, functional ability and cognitive capacity over a three-year period in an elderly population

Purpose To determine the association of polypharmacy with nutritional status, functional ability and cognitive capacity among elderly persons. Methods This was a prospective cohort study of 294 survivors from the population-based Geriatric Multidisciplinary Strategy for the Good Care of the Elderly (GeMS) Study, with yearly follow-ups during 2004 to 2007. Participants were the citizens of Kuopio, Finland, aged 75 years and older at baseline. Polypharmacy status was categorized as non-polypharmacy (0-5 drugs), polypharmacy (6-9 drugs) and excessive polypharmacy (10+drugs). A linear mixed model approach was used for analysis the impact of polypharmacy on short form of mini nutritional assessment (MNA-SF), instrumental activities of daily living (IADL) and mini-mental status examination (MMSE) scores. Results Excessive polypharmacy was associated with declined nutritional status (p = 0.001), functional ability (p < 0.001) and cognitive capacity (p < 0.001) when compared to non-polypharmacy group. Age, institutional living, poor self-reported health and time of measuring were also associated with the three outcome measures. In the excessive polypharmacy group, the proportion of malnourished or at risk of it increased from 31% to 50%, having difficulties in daily tasks from 48% to 74% and impaired cognition from 36% to 54% during the followup. The mixed model analysis revealed that polypharmacy status was not able to predict the progress of MNA-SF, IADL and MMSE scores over a three-year time. Conclusions Excessive polypharmacy is associated with decline in nutritional status, functional ability and cognitive capacity in elderly persons. However, the changes in nutrition, physical functionality and cognition over a three-year period cannot be predicted by polypharmacy status. Copyright (C) 2011 John Wiley & Sons, Ltd.