The Frailty Factor: Unraveling the Hidden Impact on Chronic Kidney Disease

This is a summary of a presentation I attended at the National Kidney Foundation Spring Clinical Meeting on 10 April 2025.

Speaker: Jeanette Hasse PhD RD

Objectives:

• Define frailty
• Review frailty on patient outcomes
• Review assessment methods for frailty
• Pre-hab for patients with frailty.

Why do we care about frailty?

Frailty adversely affects patients’ quality of life, morbidity, mortality and health care resources. It can also impact outcomes post transplant.

What is frailty?

It is increased vulnerability to stressors.

Frailty overlaps with malnutrition and sarcopenia, but they are different.

• Malnutrition: weight loss, decreased nutrient intake, energy or protein deficit, can occur in obesity, can include micronutrient deficiencies
• Sarcopenia: means loss of muscle mass and function (mass assessed by DEXA, BIA, anthropometrics), function (hand grip strength, timed up and go, sit to stand)
• Frailty: is a clinical syndrome characterized by loss of reserves and increased vulnerability to stressors, can lead to adverse health outcomes such as falls, decreased QOL, increased health care use, non-home discharges and increased mortality.

Frailty is distinct from:

• Age
• Multimorability
• Disability
• Does not progress linearly

Types of frailty:

• Physical frailty – diminished strength of function
• Psychological fraility – mentally vulnerability
• Social Frailty – lack of social resources and isolation, low education, medical literacy

The overlapping conditions of malnutrition, frailty and sarcopenic can co-occur.

Why frailty matters?

Patients who start out robust may lose reserves after a health event, but patients who start frail but not be able to recover from a health event.

What causes frailty?

Key contributors include:

• Biological factors – chronic inflammation, oxidative stress; uremic toxins and metabolic imbalances, anemia and CVD disfunction
• Nutrition contributors – protein energy wasting, dietary restrictions leading to deficiencies (can be related to a history of bariatric surgery), vitamin D, protein and micronutrient depletion
• Physical and function – muscle wasting due to inactivity and metabolic changes, dialysis related muscle breakdown, physical inactivity and decondition
• Cognitive and psychological – depression, cognitive impairment, social isolation
• Medication burden – polypharmacy, medication side effects, drug interactions, non-adherence, risk of functional decline and falls.

How can we screen or measure frailty?

There are several frailty tests that can be used in clinical practice but here are some of the key ones.

1. Clinical Frailty Scale – measures frailty based on a clinical interview evaluating mobility, energy levels, physical activity and function, uses a scale of 1 through 8. Higher score indicates greater frailty, limitations: subjective, doesn’t include multimorbidity
2. Frail Scale – measured self reported questionnaire about fatigue, resistance, ambulation illness, and loss of weight.  Scoring is 0-5. Limitations: subjective, includes morbidity and disability. Scores at 3 or above indicate frailty.
3. Frailty Index – deficit accumulation model including comorbid illness, poor health attitudes, disease signs and self-reported disabilities.  This is a 4 page questionnaire that asks many questions related to these domains.  High value indicates greater frailty.  Limitations: components vary
4. 6-minute walk test – measures endurance and functional capacity based on distance walked in six minutes. Scoring is distance in meters, <350m suggests frailty.  There are online calculators that can be used to predict frailty. Limitations requires space.
5. Gait Speed Test – measures functional mobility by measuring walking speed over a short distance.  Scoring is less than 0.8m/s.  Limitations: requires space.
6. Handgrip Strength – measures upper body muscle function. Scoring <30kg for men, <20kg for women = frail. Patient squeezes a dynamometer with maximum effort for 3 seconds.  Repeat 3 times per hand.
7. Sit to stand test – measures lower body strength and endurance by counting the number of chair rises in 30 seconds. Less than 8 suggest frailty (though target is varies by age).  Can also get them to stand up 5 times, for many if they can’t do in under 12 seconds may be frail.
8. Timed Up and Go: Patient gets up, walks 3 meters and comes back.
9. Fried Physical Frailty Phenotype – measures unintentional weight loss, exhaustion, physical inactivity, weakness and slowness. Includes measuring hand grip strength and gait speed. 
10. Short physical performance battery – measures gait speed, balance and sit to stand tests. Limitations requires multiple assessments, time consuming. Scoring 0-12, with higher scores indicated better function.

None of these tests have been validated for CKD patients. 

She then demonstrated a few tests including the 4m walk test, get up and go and sit to stand 5 times.  In her (healthy) volunteer these tests took less than 10-30 seconds. This was a really cool demo as it really drove home how easy these assessments can be.

How common is frailty?

Occurs in 20-30% of patients and women are more likely to be frail. Frailty is associated with adverse outcomes including starting dialysis, death, death on waitlist of transplant patient, delayed graft function and worse immunosuppression tolerance, decreased cognitive function. 

What are the benefits of testing for frailty in transplant?

It can help us understand who will do better post transplant.  It may also help us understand who may do better on dialysis than in transplant.  It can also help rule in people who are older if they are found to physiologically “young”.  You can also then develop a pre-hab program – and give them time to get better prior to transplant.

What interventions are there for frailty?

The most important thing people can do is participate in structured exercise to improve both strength and endurance.  Directed nutrition therapy can also help – optimal protein intake, address any nutrient deficiencies. Drug therapy – e.g. hormone therapy as needed, improved DM control.

What resources are available?

The speaker highlighted CAN-RESTORE (way to go Canada!!!) a website with exercise resources.

Steps of developing a frailty program:

1. How do you use the results?
2. Which tools will you use?
3. Who will buy the equipment?
4. Who will measure the parameters?
5. How will you report the results?
6. How often will you redo testing?

Steps of developing a prehabilition program:

1. What plans can be implements?
2. What disciplines can participate?
3. Will patients be adherent
4. Who will pay for programs?
5. How will you track outcomes?