You are doing a new patient consultation for an 81-year-old man who has recently joined the practice. You notice that he is very thin and wonder if he may be malnourished. According to NICE, what is the cut-off body mass index (BMI) for diagnosing malnutrition?
A. < 17 kg/m
B. < 17.5 kg/m
C. < 18 kg/m
D. < 18.5 kg/m
E. < 19 kg/m
Answer: D. < 18.5 kg/m
Discussion:
Malnutrition is an important consequence of and contributor to chronic disease. It is clearly a complex and multi factorial problem that can be difficult to manage but there are a number of key points to remember for the exam.
NICE define malnutrition as the following:
a Body Mass Index (BMI) of less than 18.5; or
unintentional weight loss greater than 10% within the last 3-6 months; or
a BMI of less than 20 and unintentional weight loss greater than 5% within the last 3-6 months
Around 10% of patients aged over 65 years are malnourished, the vast majority of those living independently, i.e. not in hospital or care/nursing homes. Screening for malnutrition is mostly done using MUST (Malnutrition Universal Screen Tool). The algorithm is shown below:
it should be done on admission to care/nursing homes and hospital, or if there is concern. For example an elderly, thin patient with pressure sores
it takes into account BMI, recent weight change and the presence of acute disease
categorises patients into low, medium and high risk
Management of malnutrition is difficult.
NICE recommend the following points: