PhD Research Project: Investigating barriers to protein intake and protein responsiveness in frail o

Details

Research interests/description of main research theme:

UK data from the 2011 nutrition screening week concluded that 1 in 3 adults admitted to care homes had malnutrition. Such undernutrition is usually coupled with low protein intake presumably accelerating sarcopenia in adults with an already blunted responsiveness to anabolic stimuli (anabolic resistance), thus increasing frailty and other age-related health conditions. Protein requirements increase with age and with frailty, yet protein intake tends to reduce for a number of reasons including lack of appetite, poor saliva flow, and inadequate dentition and swallowing issues. In addition, even if the protein recommended nutrient intake (RNI) is met, anabolic resistance remains a potential barrier to muscle protein synthesis (MPS). This PhD studentship will focus on frail older adults living in nursing homes as they are one of the frailest groups within the population, at greatest risk of malnutrition and sarcopenia, yet the most under-researched. This is likely due to the high proportion of nursing home residents with cognitive and/or mobility impairment which may limit the application of conventional study procedures or render them prohibitive due to inability to leave the nursing home setting. There is an urgent need therefore to determine which existing methods and techniques are feasible and fit for purpose in nursing homes and which require adaptation. The project will also help to identify at which point intervention (exercise/ nutrition) may be neither possible nor effective to counteract sarcopenia in frail older adults.

Aim of the project: To characterise frail nursing home residents in terms of protein intake, muscle mass and muscle responsiveness to intervention.

Objectives:

1. Assess the feasibility of measurement of protein intake, physical activity, muscle mass and muscle protein synthesis in frail older adults using techniques applicable to a nursing home setting.
2. Increase knowledge, understanding and skill acquisition with respect to the barriers to protein intake applied across the oral-gut-muscle axis.
3. Design and assess the feasibility of a combined-intervention programme to improve nutritional and functional status.

Brief experimental plan:

This will include (i) an exploration of the feasibility of measurement of appetite and protein perception (questionnaires and scales, including visual analogue scale), saliva flow, protein intake (food record), physical activity (accelerometry), muscle mass using D3-creatine (D3-Cr) dilution (in urine) and muscle thickness (ultrasound) in n=30 frail older adults in a nursing home setting (ii) the design and conduct of a pilot feasibility physical activity/ nutrition (protein-fortified food) trial in n=20 nursing home residents.

The ability to optimise muscle protein accretion in response to ingested protein becomes a major nutritional goal in frailty research. Importantly, studies in older populations have not been stratified by protein intake, physical activity and muscle mass, to investigate the effectiveness of appropriate combined intervention strategies for optimisation of dietary intake and muscle responsiveness. Without this new research insight and interaction, health practitioners will continue to struggle in targeting those at greatest risk from undernutrition and sarcopenia.

Training in the measurement of muscle function and stable isotope technologies to measure muscle protein turnover will be provided by the University of Birmingham and Nottingham. The student will receive valuable interdisciplinary training across the oral-gut axis (for example investigating the influence of saliva flow on protein perception from protein fortified versus standard foods) via a secondment to the Department of Food and Nutritional Sciences, University of Reading (which hosts sensory labs and a fortified food manufacturing plant) to inform the design of a feasibility intervention study incorporating a set of robust outcome measures.

Person Specification

Applicants should have a strong background in physiology/ biomedical science, sport and exercise science, or physiotherapy and ideally some knowledge of musculoskeletal ageing and health. They should have a commitment to research in frailty and sarcopenia and hold or realistically expect to obtain at least an Upper Second Class Honours Degree in a relevant subject.

Informal enquiries should be directed to Dr Carolyn Greig c.a.greig@bham.ac.uk

Funding Notes

To be eligible for a full award, a student must have no restrictions on how long they can stay in the UK and have been ordinarily resident in the UK for at least 3 years prior to the start of the studentship. Students from EU countries other than the UK are generally eligible for a fees-only award. To be eligible for a fees-only award, a student must be ordinarily resident in a member state of the EU; in the same way as UK students must be ordinarily resident in the UK. Further information on eligibility is available online - https://mrc.ukri.org/skills-careers/studentships/studentship-guidance/student-eligibility-requirements/

References

Moore DR et al., Protein Ingestion to Stimulate Myofibrillar Protein Synthesis Requires Greater Relative Protein Intakes in Healthy Older Versus Younger Men. Journals of Gerontology Series a-Biological Sciences and Medical Sciences, 2015. 70(1): p. 57-62.

Bollwein J et al., Distribution but not amount of protein intake is associated with frailty: a cross-sectional investigation in the region of Nurnberg. Nutrition Journal, 2013. 12

Cawthon PM et al., Strong Relation between Muscle Mass Determined by D3-creatine Dilution, Physical Performance and Incidence of Falls and Mobility Limitations in a Prospective Cohort of Older Men. J Gerontol A Biol Sci Med Sci. 2018 Jun 12.

Methven L et al., Ageing and taste. Proceedings of the Nutrition Society, 2012. 71(4): p. 556-565.

Munk T et al., Positive effect of protein-supplemented hospital food on protein intake in patients at nutritional risk: a randomised controlled trial. Journal of Human Nutrition and Dietetics, 2014. 27(2): p. 122-132.