Approved Research

Biochemical estimation of muscle mass and unbiased assessment of kidney function using serum creatinine and cystatin-C. A prognostic validation study within UK Biobank.

Lay summary

Multimorbidity is a word used to describe a person with two or more long-term health conditions. It is a growing problem for healthcare as we are living longer. This means we are more likely to develop long-term health conditions.

Kidney disease is an important long-term condition linked to heart disease. Heart disease is a leading cause of death. Patients with kidney disease need more hospital appointments and blood tests to stay healthy. They are more likely to be admitted to hospital with a serious illness than a healthy person. One of the main jobs of your kidney is to filter waste and toxins. A blood marker called creatinine is used to diagnose kidney disease. It is used to estimate how well your kidney is filtering waste and toxins. Muscle creates most of creatinine.

As you get older, losing some of the muscle you have is normal. It also does not work as well as it used to. When you are sick this happens faster than usual. This process is sarcopenia. We know that people who have sarcopenia when they are sick are more likely to die. They are also less likely to recover well from their illness. 

People who are sick will make less creatinine if they have sarcopenia. This means that diagnosing people with kidney disease when they are unwell may not be accurate. Cystatin-C is another blood marker of kidney function. It is not affected by the amount of muscle you have. It can be used to diagnose people with kidney disease. It may be a better marker of kidney disease when people are unwell.

We will explore the link between kidney disease, muscle mass, creatinine and cystatin-C. We will do this using the UK Biobank data.

We aim to answer the following questions:

- Can this link predict patient outcomes after admission to hospital? This will include death or the development of kidney and heart conditions.

- Can we use cystatin-C to better predict the development of kidney disease after someone is unwell?

We expect this project to take 3 years to complete. Our goal is to improve the identification of kidney disease in patients with critical illness. This means that we will be able to prevent and treat more kidney disease. This will have a positive impact on multimorbidity.