Shining a light on rare diseases: an interview with Dr Zoe Davidson
Treating and
managing rare diseases is exceptionally challenging - which is compounded by a
dearth of research and evidence available to guide clinical practice. One such
rare disease is Duchenne Muscular Dystrophy (DMD). Seeing a lack of evidence to
guide the nutritional management of boys with DMD, researcher and dietitian Dr
Zoe Davidson has dedicated her research efforts towards improving the quality
of life of these boys. We sat down with Zoe on Rare Disease Day to learn more
about the challenges around improving patient outcomes through research for
those with a rare disease.
Globally over 300 million people are living with a rare disease
[1]. These types of diseases are typically genetic in nature, with onset mostly
occurring in childhood [1] The long-term goal of Rare Disease Day over the next decade is
increased equity for people living with a rare disease and their families. Rare
Disease Day is a call to action for people living with a rare disease to have
equal opportunities to realise their potential for participation in family,
work and social life. Dr Zoe Davidson is one such individual working towards
this goal through her research over the past twelve years to increase the
evidence base for the nutritional management of individuals with Duchenne
Muscular Dystrophy (DMD).
What are the challenges of conducting
nutrition research in respect to rare diseases?
Before the challenges, there are many positive aspects of
researching the role of nutrition in rare diseases. I really enjoy working with
families who - despite some of the huge challenges that they face with the
diagnosis of a neuromuscular condition - have such a great outlook. They are
some of the best problem solvers I’ve ever met. The boys (with DMD) make me
laugh a lot!
From a research perspective, there are some challenges when
working in rare diseases generally. The first, obviously, is recruitment. This
can be particularly tricky in nutrition research. There can be lots of
variation in nutrition outcomes - which is traditionally overcome by large
study sample sizes. This can be tricky to achieve in rare disease groups and
also where there is a lot of other exciting research happening - especially on
potential treatment options for those with DMD. Part of what we do is to think
creatively about using research techniques that reduce participant burden and
also assist with gathering larger sample sizes. An example of this is adopting
an observational research design using existing clinical data.
Research collaboration is also key to working with a rare
disease! The neuromuscular research community in Australia and internationally
is very collaborative, working together to overcome some of these challenges
and to consider how to progress research in some of these smaller areas of need
that can impact on individual quality of life whilst treatments move through
trial pipelines. To emphasise this collaborative nature, nutrition was the
focus of an international workshop in 2018 held by the Duchenne Parent Project
in the Netherlands [2]. They also opened a nutrition funding scheme in 2018.
It's through these types of initiatives that nutrition research can progress.
What made you become involved with Duchenne
Muscular Dystrophy (DMD)?
I started my research on nutrition in DMD in 2008. It was an
area where individuals clearly face many nutritional challenges, but there was
very little evidence to support practice. I wanted to increase the evidence
base for nutritional management of individuals with DMD.
How does your relationship with the Royal
Children's Hospital (RCH) and the Murdoch Children’s Research Institute (MCRI)
influence your research and the impact you can have on those with DMD?
The Neuromuscular Clinic at the RCH provides care for most
children in Victoria diagnosed with a neuromuscular condition. It is a
multidisciplinary clinic involving medical and allied health professionals.
There is also a very active clinical research group that sits alongside the
clinic. I have an appointment at MCRI as a Research Dietitian and an honorary
appointment at RCH. These appointments support me to conduct nutrition research
directly with children with neuromuscular disorders. Also, working alongside
the many health professionals involved in the neuromuscular clinic offers
multiple opportunities for collaboration and working together to progress
different research ideas. For example, I have been working with allied health
professionals in Melbourne and across Australia to generate best practice
guidelines for allied health assessment and management of individuals with DMD.
How does nutrition impact those with DMD?
During childhood, boys with DMD experience excess weight gain.
There are several factors contributing to weight gain including reduced
activity (especially at the time of transition into a wheelchair) and long-term
corticosteroid use. Overweight and obesity can impact physical function,
respiratory function (including sleep) as well as psychosocial outcomes. In
more advanced stages of the condition, undernutrition can be common which can
also impact clinical outcomes alongside swallowing problems and a range of
gastrointestinal symptoms. Long-term corticosteroid use also has significant
implications for growth and bone health.
There has also been a large interest in the use of supplements
or “nutriceuticals” to increase strength and/or function. We are currently
analysing data from a supplement trial we conducted in DMD to provide more
research to assist clinicians and families to make decisions about these
supplements. This research has been made possible by support from MuscularDystrophy Australia and Save Our Sons Duchenne Foundation.
Has your research influenced the way
clinicians are working with patients with DMD?
We have been able to increase the evidence base to assist
practitioners in managing individuals with DMD. Our research has been used in
the latest Care Considerations for DMD [3].
Why should we invest more time, money and
focus into rare disease and nutrition research?
DMD is no longer a disease of childhood; life expectancy for
individuals with DMD is continually increasing. We know that overweight and
obesity in childhood progresses to overweight and obesity in adulthood and is
accompanied by several comorbidities. To prevent this relatively new population
of adult men living with DMD being burdened by additional metabolic
co-morbidities related to obesity, it is crucial that we understand and address
childhood obesity in this population.
There are many exciting treatment options for neuromuscular
disorders progressing through the clinical trial pipeline. The use of
Nusinersen for spinal muscular atrophy [4]
is a wonderful example of successful treatment development. As these
treatments are developed, we want to optimise nutrition in all individuals with
neuromuscular disorders so they are fit to participate in trials and benefit
from treatments.
Ultimately, by improving nutritional outcomes we want to
improve clinical and health outcomes as well as quality of life.
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More information:
Learn more about Rare Disease Day here: https://www.rarediseaseday.org/
Dr Zoe Davidson is an Advanced Accredited Practising Dietitian
at the Monash University Department of Nutrition, Dietetics and Food,
specialising in paediatric nutrition. Zoe's research focuses on advancing the
evidence base for the nutritional management of boys with Duchenne Muscular
Dystrophy - this body of work is the first of its kind. Zoe is continuing
research in this area in a postdoctoral post with Murdoch Children's Research
Institute with a specific focus on energy expenditure and body composition in
children with neuromuscular disorders. You can access Zoe’s research profile here. You can follow Zoe on
Twitter via @davidson_zoe.
Stay connected with Monash Nutrition on Twitter (@MonashNutrition) and Facebook (@MonashNutrition).
Images kindly supplied by Muscular Dystrophy Australia. Visit
them via https://www.mda.org.au/
References
1. Nguengang Wakap S, Lambert DM, Olry A. Estimating
cumulative point prevalence of rare diseases: analysis of the Orphanet
database. Eur J Hum Genet [Internet]. 2020 Feb [cited 2020 Feb 25];
28(2):165–173. Available from: https://doi.org/10.1038/s41431-019-0508-0
2. Verhaart IC, van den Engel-Hoek L, Fiorotto ML,
Franken-Verbeek M, Vroom E. Nutrition in Duchenne muscular dystrophy
16–. Neuromuscular Disorders. 2018 Mar;28(8):680-9.
3. Birnkrant DJ, Bushby K, Bann CM, Apkon SD, Blackwell A,
Brumbaugh D, et al. Diagnosis and management of Duchenne muscular dystrophy,
part 1: diagnosis, and neuromuscular, rehabilitation, endocrine, and
gastrointestinal and nutritional management. Lancet Neurol. 2018
Mar;17(3):251-67.
4. Gidaro T, Servais L. Nusinersen treatment of spinal
muscular atrophy: current knowledge and existing gaps. Dev Med Child Neurol
[Internet]. 2019 [2020 Feb 25]; 61(1):19–24. Available from: https://www.ncbi.nlm.nih.gov/pubmed/30221755 doi:10.1111/dmcn.14027
