OLDER patients with anorexia are survivors, often adept at hiding their disease, which makes it harder to diagnose and treat before irreversible damage is done, say experts.
Associate Professor Zane Andrews, chief investigator at the Biomedicine Discovery Institute at Monash University, told MJA InSight that “the problem with older people is that they’re old”.
“They are not as resilient and metabolically flexible as younger people.”
While only affecting a small proportion of older adults, anorexia presents a unique set of dangers when it occurs later in life.
“[There is] the speed at which it could lead to severe health problems, and the experienced ability of patients to avoid issues and hide problems,” Professor Andrews said.
Professor Andrews was commenting on a short report published in the MJA which discussed the case of an older patient presenting with anorexia nervosa.
When the 54-year-old woman was referred to the consultation liaison psychiatry service, she had a body mass index (BMI) of 13.8 and was in a life-threatening condition with acute kidney injury, anaemia, electrolyte disturbance and delirium.
The authors said that the patient provided a convincing history of extreme anorexia nervosa, marked by excessive walking of up to 50 kilometres each day.
The patient did not seem to realise that the level of caloric restriction she had placed on herself was abnormal, but she acknowledged something was wrong because she could no longer keep on walking.
“[The patient’s] treatment was supported by a treatment order under the Mental Health Act 2000 (Qld) because of an initial brief episode of psychosis, and then maintained until after a period of stable nutritional rehabilitation,” the authors wrote.
“Despite her severe illness … [the patient] had a generally cooperative attitude which further facilitated supportive psychological therapy. Her BMI increased to within the normal range over several months as her care was continued under psychiatric services.”
The authors said that “managing mature patients with considerable life experience who have survived despite disordered eating provides unique perspectives on the balance between autonomy and control”.
“Management of such patients requires greater flexibility,” they wrote.
Lead author of the report and psychiatry registrar at Redcliffe Hospital in Brisbane, Dr Faith Ng, said that over the past few decades, researchers have been trying to characterise the illness in patients well into their adulthood.
“Anorexia nervosa commonly begins during adolescence or young adulthood and resolves within a few years in a portion of these cases,” Dr Ng told MJA InSight.
“It can begin in people older than 40–60 years old, but this is not as common. Some will not live this long, as unfortunately, a proportion of people with anorexia will die from medical complications from the illness or from suicide.”
Dr Ng said that the patients who had lived with anorexia nervosa for a long time and carried the disease into late adulthood had become “experts by experience”.
These people are able to manage their symptoms and adapt their lives accordingly, sometimes at the cost of their employment and social contact, Dr Ng said.
It is important to recognise the point at which the physical damage caused by being anorexic could become irreversible in older patients. Professor Andrews said that bone metabolism was a particularly big concern here.
“Incidence of bone disease is higher in anorexic patients – this would probably be exacerbated in older people as bone metabolism slows with aging,” Professor Andrews said.
“Loss of body fat can paradoxically drive insulin resistance and increase chances of metabolic diseases like insulin resistant diabetes. This is primarily due to the loss of body fat.”
Professor Andrews added that there was also the problem of systemic inflammation, which affects a range of different biological processes and could increase neurological problems.
Anorexia in late adulthood was also complicated by the ageing process, meaning the condition would not always manifest as classic anorexia nervosa, Professor Andrews said.
As a person gets older, it is common for them to be eating less, and this is not always on purpose or down to wilful control of food intake. There could be other underlying conditions affecting their appetite.
“Diseases like Parkinson’s and Alzheimer’s are also associated with a loss of appetite,” Professor Andrews said.