S1.7 The impact of appetite, low protein, and physical activity on function: the PROMISS study

Chair: Carol Jagger

Introduction: Malnutrition is a major concern in old age, with serious consequences for health and functioning. Although prevalence rates are higher in the institutionalised, the highest absolute numbers of malnourished older people live in the community. Protein malnutrition in particular may be a contributor to disability, mediated through muscle strength and physical function. Recent research has shown that poor appetite in older adults is associated with a significantly lower consumption of protein and dietary fibre, and a higher consumption of dairy foods, fats, oils, sweets, and sodas compared to those with a good appetite. However, whether this translates through to functional decline in older people, and strategies for management is unknown. Objectives: This symposium presents early results from the PRevention Of Malnutrition In Senior Subjects in the EU (PROMISS) study to explore the extent to which protein malnutrition affects physical function and the role of poor appetite and physical activity in this relationship. Overview: After a short introduction to the PROMISS study as a whole, we will report three complementary analyses in aged cohorts to tease out the relationship between appetite, protein intake, physical activity and physical function. Five ageing cohorts will be included: the US Health ABC Study, Longitudinal Ageing Study Amsterdam (LASA), Age, Gene/Environment Susceptibility-Reykjavik Study (AGES-RS), Newcastle 85+ Study, and the Danish Healthy Ageing Network of Competence (HANC).  Conclusions: These results begin the mapping of how poor appetite might affect physical function through protein malnutrition and how physical activity might modify this. The findings will inform other parts of the PROMISS study developing innovative food products and interventions, with the aim to directly benefit older people and increase healthy and active ageing.

S1.7.1 Physical function and poor appetite among community dwelling older adults:

Age, Gene/Environment Susceptibility-Reykjavik Study (AGES-RS)

Milan Chang Guðjónsson^1,2, Ólöf Guðný Geirsdóttir, Tamara B. Harris⁴, Laufey Steingrímsdóttir³, Vilmundur Gudnasson^3,5, Ingibjorg Gunnarsdóttir³

¹ The Icelandic Gerontological Research Institute, University of Iceland, ² Reykjavik University, Iceland, ³ University of Iceland, ⁴ National Institute on Aging, USA, ⁵ Icelandic Heart Association, Iceland

Background: Poor appetite is one of the causes for malnutrition among older adults. The aim of the current study is to investigate whether poor appetite is associated with activities of daily living (ADL), and other objective measures of physical function. Methods: Appetite was categorized dichotomously as poor appetite (PA, n=678) and no poor appetite (NPA, n=4199). The main outcomes were walking speed, timed up and go (TUG), leg extension strength, grip strength, and activities of daily living (ADL). Results: In the fully adjusted final linear regression model, the PA group had significantly lower performance in gait speed (0.16 sec/m), timed up and go (0.42 sec/m), knee extension strength (-12.58 newton), grip strength (-9.54 newton), and a higher number of ADL difficulties (0.18) compared with the NPA group. Conclusion: Our findings suggest that poor appetite is negatively associated with objectively measured physical function and positively associated with ADL difficulties among community-dwelling older adults. 

S1.7.2 Associations between accelerometer-assessed physical activity, sedentary

behavior, and handgrip strength from five cohorts across Europe and USA among older people

Li-Tang Tsai¹, Eleanor Boyle¹, Jan Brønd¹, Eric Shiroma², Tamara Harris², Annemarie Koster³, Marjolein Visser⁴, Carol Jagger⁵, Mike Catt⁶, Gudny Eiriksdóttir⁷, Vilmundur Gudnason^7,8, Nanna Y. Arnardóttir^7,9, Thorarinn Sveinsson⁸, Kong Chen¹⁰, Paolo Caserotti¹

¹ University of Southern Denmark, Odense, Denmark, ² National Institute of Aging, USA, ³ Maastricht University, The Netherlands, ⁴ VU University, Amsterdam, The Netherlands, ⁵ Newcastle University, UK, ⁶ National Innovation Centre for Ageing, Newcastle upon Tyne, UK, ⁷ Icelandic Heart Association, Iceland, ⁸ University of Iceland, Reykjavik, Iceland, ⁹ University of Akureyri, Iceland, ¹⁰ National Institute of Diabetes and Digestive and Kidney Diseases, USA

Background: To compare the amount of time and day-to-day variability in different intensities of physical activity, sedentary behaviour, and handgrip strength among older people measured by accelerometers across Europe and USA. Methods: Accelerometer raw data from five studies: Denmark (HANC), Netherlands (LASA), England (Newcastle 85+), Iceland (AGES), and USA (Health ABC) were re-processed with uniformed algorithms for each body position (hip or wrist). Physical activity intensity and day-to-day variation were characterized by counts in vector magnitude categorized as 0-50/51-100/100-350/350-750/750-1000/>1000/1000-2000/>2000. The relationship between physical activity and handgrip strength (tertiles) was examined by multinomial regression, adjusting for age and gender. Results: Preliminary results are reported from the Netherlands (n=1188) and Iceland (n=617) which form 67% of total participants, with age 70.7±7.9 (Netherlands) and 80.1±4.8 (Iceland) and with 51% and 61% female, respectively. Participants were highly sedentary during waking hours (48% of time in 0-50 counts and 5% in 50-100 counts categories). On average, participants spent 6% of time in activities at a higher intensity (>2000 counts). In most intensity groups, higher day-to-day variation increased the odds of weaker handgrip strength: counts 50-100?Odds ratio (OR) 7.0 (2.0-25.0); 100-350?OR 10.3 (2.6-41.3); 350-750?OR 9.2 (2.2-38.9); 750-1000?OR 9.6 (2.7-35.0); >1000?OR 3.7 (1.3-10.1); 1000-2000?OR 4.4 (1.5-12.5). Conclusions: Among older adults, higher day-to-day fluctuation in physical activity correlates with weaker handgrip strength, an indicator of overall function.

S1.7.3 Low protein intake, muscle strength and physical performance in the very old:

the Newcastle 85+ Study

Antoneta Granic^1-3, Nuno Mendonca^3-6, Avan Aihie Sayer^1-3 , Tom R Hill⁴, Karen Davies^1-3, Ashley Adamson⁴, Mario Siervo^3,, John C Mathers^3,4, Carol Jagger^3,4

¹ AGE Research Group, Newcastle University, Newcastle upon Tyne, UK, ² NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne Hospitals, UK, ³ Newcastle University Institute for Ageing, Newcastle upon Tyne, UK, ⁴ Newcastle University, Newcastle upon Tyne, United Kingdom  

Background: To investigate the effects of protein intake on muscle strength and physical performance in the Newcastle 85+ Study. Methods: 722 community-dwelling participants (60% women) at baseline were followed for 5 years for change in grip strength (GS) and Timed Up-and-Go (TUG) test. Results: Women with low protein intake (<1g protein /kg adjusted body weight/day) had 0.83 kg lower GS (? (SE) = -0.83 (0.41), p=0.05) and worse TUG (? (SE) = 0.04 (0.02), p=0.03) performance after adjustment for key covariates. The rate of decline in GS and TUG did not vary by protein intake. Higher physical activity was predictive of GS in the low and high protein intake groups. Conclusion: Low protein intake adversely affects muscle strength and physical performance in the very old, especially in women, independently of important covariates. Good protein intake and high physical activity might be needed to optimally decrease muscle strength loss.