By Professor Dr Tan Maw Pin, consultant geriatrician, President of the Malaysian Society of Geriatric Medicine (MSGM) and member of Malaysian Influenza Working Group (MIWG), Dr Aslannif Roslan, Internal Medicine Specialist and Cardiologist from Institut Jantung Negara (IJN), and Associate Professor Dr Lim Lee Ling, Head of the Diabetes Care Unit and Senior Consultant Endocrinologist, University of Malaya Medical Centre.
The risk of developing severe disease is higher in the presence of non-communicable diseases (NCDs), also known as chronic diseases such as diabetes, heart disease, stroke, or chronic lung disease. Too, advancing age makes us a person more susceptible to infectious diseases.
This was an important observation made during the time of the Covid-19 pandemic.Similar to Covid-19, older persons are at a higher risk of developing severe influenza, also known as the flu.
Influenza or commonly known as flu is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. The body’s first response to influenza infection is known as acute inflammation occurring at the site of infection to limit or get rid of the virus.
If this response is insufficient, then a more complex immune response occurs at both the site of infection and in the entire body. This response is necessary to fight off infections, however, sometimes with influenza, this response might be excessive and here is where the danger lies, according to Immunise4Life, a community education programme by the Ministry of Health, Malaysian Paediatric Association, and the Malaysian Society of Infectious Diseases and Chemotherapy.
Approximately 90% of influenza-related deaths and 50-70% of influenza-related hospitalisations occur among those aged 65 years and older. Despite this, there are someimportant gaps that surround influenza.
Immunise4Life recentlyran a poll on social media to see just how ‘flu-ent’ (pun-intended) the older folk are on influenza.The 518 respondents had at least one chronic disease.
It had beenfound thatmany did not fully grasp the severity of influenza:48% are wrong about the ability of influenza to cause serious complications; 50% did not know that up to 85% of influenza-related deaths occurred in people aged 65 years and older; and 57% did not realiseinfluenza can trigger a heart attack or stroke even without a history of heart disease.
Weighing in on the knowledge gap
According to Professor Dr Tan Maw Pin, older persons are at greater risk of developing severe complications from influenza due to the changes that occur in the immune system that leads to a decline in the ability of the body to fight off infections such as influenza; this is known as immunosenescence.Besides this, there is something known as inflammaging which is a chronic low-grade, non-infectious inflammation. This reaction could aggravate existing medical problems or lead to strokes and heart attacks.
“Older persons who take to their beds for a few days lose muscle far quicker than younger people. We call this deconditioning. This may lead to an increased risk of falls and reduced mobility after a bout of influenza. Many of these older persons then struggle to regain their pre-illness physical condition, “, said DrTan, adding that flu vaccination for older persons is recommended.
“Annual influenza vaccination is recommended for individuals aged ≥ 60 years, particularly those with chronic medical conditions or residing in aged care facilities (ACFs), “, Tan said.
Flu may lead to other severe complications
Dr Aslannif Roslan said that influenza can cause or worsen existing heart disease. “A bad case of influenza – such as one that is complicated by pneumonia – can worsen your existing heart disease. Even those without heart disease but have the risk factors (such as old age, smoking, and type 2 diabetes) are at greater risk of developing a heart attack because of influenza. The risk is also higher if you have underlying chronic diseases. Recent studies have shown that the risk of heart attack increases by more than ten times in the first seven days after contracting influenza, “ Dr Aslannif said, citing information from the World Heart Federation.
According to Dr Aslannif, Influenza can result in severe pneumonia which causes a reduction of oxygen levels in the arteries. This in turn results ina reduced oxygen supply to the heart muscle. At the same time, the fever and increased heart rate caused by influenza further increase the metabolic needs of your body leading to a greater demand for oxygen by the heart.
Influenza can also trigger an inflammatory response so great that it may cause rupture of atherosclerotic plaques, which is the build-up of fat, cholesterol, and other substances in the arteries, and it may also cause inflammation of the heart muscle (myocarditis).The reduced oxygen levels and rupture of atherosclerotic plaque can trigger a heart attack.
For this reason, Dr Aslannif also recommends annual influenza vaccination to reduce risk of developing a heart attack.
Shedding light on flu’s impact on diabetes
Associate Professor Dr Lim Lee Ling said that when a patient with diabetes, is a well-known risk factor for serious influenza infections. gets influenza, the body releases stress hormones as part of its defence mechanism to fight off the infection. As a result, more glucose is released into the bloodstream.
Eating less than usual and being dehydrated due to being sick could further disrupt your blood glucose control. This in turn can worsen diabetes-related complications such as abnormal kidney function, heart failure, stroke, and heart attack. These patients are also at a higher risk of developing pneumonia, often resulting in prolonged hospitalisation.
In addition, studies have shown that there is a greater risk of becoming admitted following an influenza infection with a three times higher risk of death in patients with diabetes.[1]
So, why are patients with diabetes more likely to develop influenza related complications such as pneumonia?
Dr Lim explained that normally, the body’s immune system would detect an invading offender such as the influenza virus, work its way to remove it and produce antibodies in the process. In patients with diabetes however, this mechanism is flawed. Inefficient blood sugar control also causes small blood vessel changes in the lungs in patients with type 2 diabetes. In addition, continuous exposure to high blood sugar levels leads to formation of harmful compounds which are involved in the development of vascular complications, worsening of inflammation, and scarring of lung tissue. Many times, patients with diabetes get admitted for pneumonia due to influenza, especially among those with either poorly controlled diabetes or concomitant chronic conditions. Some even require admission into the intensive care unit (ICU).
Thus, Dr Lim furthered that optimum control of blood sugar levels is extremely important to prevent complications. Compared to those without diabetes, patients with diabetes are at a higher risk of developing prolonged illness, hospitalisation and even death caused by influenza, even though diabetes is well managed.
This is why both international (American Diabetes Association, World Health Organization, International Diabetes Federation) and local professional societies recommend all patients with diabetes aged 6 months and above receive the annual influenza vaccination. Notably, influenza is preventable, and its vaccination can reduce diabetes-related hospital admissions and death.
Annual flu jab is recommended
According to Professor Datuk Dr Zulkifli Ismail, Technical Committee Chairman of the Immunise4Life programme, the Ministry of Health Malaysia recommends the annual influenza vaccination to protect against influenza among older persons.
He added, that Influenza vaccination has a good safety record. The side effects are generally mild, and these include soreness, redness and/or swelling at the injection site, headache, fever, and muscle aches, all of which will go away on their own after a few days.
“It is also advisable to wash your hands properly, avoid contact with those having influenza symptoms and disinfect frequently touched surfaces, “ he said, adding that making influenza prevention is one of the proactive ways to improve the quality of life in your golden years.
References:
Influenza death and hospitalisations https://www.cdc.gov/flu/spotlights/2018-2019/hopitalization-rates-older.html
Influenza and risk of heart attack https://world-heart-federation.org/influenza/
Risk of hospitalisation https://www.openaccessjournals.com/articles/short-and-long-term-impact-of-influenza-infection-on-individuals-with-type-2-diabetes-effect-on-healthcare-utilization-a.pdf