This study is a cross-sectional study that wishes to investigate whether there is an increased incidence of sarcopenia in patients with chronic kidney disease compared to the Danish background population. A possible association between sarcopenia and fall, as well as the incidence of osteoporosis in patients with chronic kidney disease will also be described.

Sarcopenia is a condition diagnosed from different clinical findings such as low muscle mass, low muscle strength and possibly also poor physical performance. In the general population, the risk of fall and bone fracture increases, when sarcopenia is also present.

Sarcopenia is known to occur in patients with chronic kidney disease, but whether, and if so, how this differs from the incidence in patients without kidney disease has not previously been described.

Patients with chronic kidney disease have a 3 times higher risk of bone fracture compared to the Danish background population, and they also have an increased risk of falls.

The association between sarcopenia, risk of falls and osteoporosis in patients with kidney disease is until now sparsely described, and because of this, the investigators want to explore this further in this cross-sectional study.

Inclusion Criteria:

• Age ≥20 years
• Chronic kidney disease stage 4-5 not on dialysis (nonD) (corresponding to an estimated glomerular filtration rate (eGFR) ≤30 ml/min based on Kidney Disease Improving Global Outcomes (KDIGO) definition and not on dialysis)

Exclusion Criteria:

• Kidney transplanted
• Immobilized/hospitalized for more than 1 week within the last 6 weeks
• Active treatment with growth hormone or sex hormone
• Known muscle disease
• The lack of ability to speak or understand Danish
• The lack of ability to give an informed consent
• The lack of ability to participate in a clinical study based on the assessment by the local investigator

The patients will be recruited from the Department of Nephrology at both Herlev Hospital and Odense University Hospital during their regular visits to these outpatient clinics.

All subjects connected to the participating centers are screened to see if they are eligible for the study. Participants with a minimum age of 20 with eGFR ≤30 ml/min are asked if they wish to be examined further to see if they meet all the inclusion criteria and none of the exclusion criteria. Only participants meeting all the inclusion criteria and none of the exclusion criteria will be considered eligible for the trial.

For now no Individual Participant Data (IPD) are planned to be shared with other researchers.