Case Study Endocrinology 2026-02-21

Using Physical Function Assessment (SPPB) in Endocrinology Practice

Functional significance and implementation guide for patients with diabetes, obesity, and GLP-1 therapy — This case study shows how using SPPB in endocrinology can help predict mortality risk in diabetic patients and monitor functional outcomes during GLP-1 therapy.

21%
Rate of functional limitation
in long-term T1D survivors (SPPB <10)
3x↑
Increased mortality risk
when SPPB is below 5
0.7 pts
Average SPPB improvement
with 5–6% gradual weight loss
0.5 pts
Threshold for functional
significance (MCID)

Executive Summary

A Paradigm Shift in Professional practice

Recent endocrine disease treatment is expanding its goals beyond simple numerical management (Glucose, BMI) to qualitative improvement of body composition and preservation of physical function. SPPB (Short Physical Performance Battery) is emerging as a key indicator for predicting patient prognosis and evaluating treatment quality amid this shift.

Traditional Functional focus

  • Blood glucose (HbA1c) management
  • BMI-based weight reduction

Strategic Shift Direction →

  • Muscle Quality assessment
  • Physical Function preservation and improvement

Why Physical Function Should Be Assessed Alongside Endocrine Care

1.1

Decline in Muscle Quality

Diabetes and obesity can cause intramuscular fat infiltration (myosteatosis) and impaired mitochondrial function.

Impact: Even with the same muscle mass, reduced quality leads to significantly lower actual physical performance.
1.2

Limitations of BMI and Body Composition Imbalance

BMI is inaccurate for predicting physical function in older patients. The fat-free mass to fat mass (FFM/FM) ratio is a more meaningful indicator.

Role of SPPB: Assesses whether body composition imbalances manifest as functional limitations in daily life, such as difficulties with walking and chair rising.
1.3

An Independent Prognostic Indicator

The SPPB score is not merely a measure of exercise capacity. It is a meaningful indicator independently associated with mortality, hospitalization, and cardiovascular events in chronic disease patients.

Independent mortality predictor Hospitalization risk predictor Independent cardiovascular event indicator

Evidence-Based Data in Diabetic Patients

2.1  Type 1 Diabetes — EDIC Study

21% of patients
with functional limitation (SPPB <10)

1 in 5 long-term survivors with a mean age of approximately 60 years shows functional decline with SPPB below 10.

Correlation with HbA1c

Higher HbA1c (poor glycemic control) is linearly associated with lower SPPB scores.

Reference: DCCT/EDIC Research Group. Diabetes Care.

2.2  Type 2 Diabetes — SPPB Score and Mortality Risk

Lower SPPB scores are associated with a sharp increase in mortality risk.  *Visualization based on Italian cohort study

Warning: Patients with SPPB ≤5 have been reported to have approximately 3 times higher mortality risk compared to the high-function group (≥10 points).

The Importance of Functional tracking During Weight Loss Treatment

Category Key Points Notes
Quality of Weight Loss Diet restriction alone may cause lean mass loss and reduced lower-extremity strength SPPB improves when combined with exercise and protein
Functional significance Gradual weight loss of 5–6% leads to average SPPB improvement of 0.7 points Improvement threshold is ≥0.5 points (MCID)

Diet Restriction Alone

  • A significant portion of weight lost comes from muscle (lean mass)
  • Reduced lower-extremity strength; SPPB may plateau or decline

Exercise + Protein Supplementation

  • Fat-predominant weight loss maximally preserves muscle mass
  • Expected improvement in SPPB score (achievable MCID ≥0.5 points)

The Necessity of Functional Assessment with GLP-1 Therapy

Risk of Lean Mass Loss

With GLP-1 receptor agonists such as semaglutide, a significant portion of the weight lost may come from lean mass. Caution required in older patients.

Expanding Treatment Goals

The medical community proposes expanding the standard for obesity treatment from 'weight loss' to 'maintaining and improving function'.

Ongoing Research

NCT05786521: A research study is underway tracking SPPB score changes as a primary variable when combining GLP-1 therapy with lifestyle interventions.

MCID Minimal Important Difference

A change of 0.5 points or more in SPPB score must be observed to be considered a meaningful improvement in function. It is recommended to set this threshold as a treatment goal when combining GLP-1 therapy.

Staging of Sarcopenic Obesity

2022 ESPEN/EASO Consensus — Function-centered classification system

Obese Patient (Obesity)

Meets BMI or waist circumference criteria

Muscle mass and function assessment (including SPPB)

Stage I

Body composition change Yes

Functional decline No

SPPB within normal range
Caution Stage II

Body composition change Yes

Functional decline Yes

Reduced SPPB score

Stage II Classification Criteria

Obese patients with concurrent functional decline are classified into a separate, more severe stage. SPPB is included as an essential assessment tool for stage classification.

Stage II Treatment Principles

Resistance exercise prescription and enhanced protein intake are essential. A shift from simple weight loss goals to functional improvement goals is required.

Practical implications

Key Application Points

① Introducing Routine SPPB Measurement

Regularly performing SPPB for diabetes and obesity patients in endocrinology outpatient settings can proactively identify those at risk of functional decline before numerical indicators worsen.

② Concurrent Functional tracking During GLP-1 Therapy

Measure SPPB baseline before initiating GLP-1 therapy, and track changes of 0.5 points (MCID) or more during treatment to quantitatively evaluate treatment response.

③ Sarcopenic Obesity Stage Classification

Differentiate obese patients into Stage I (function preserved) and Stage II (functional decline present) to tailor treatment intensity and exercise prescription accordingly.

④ Function First, Before Body Composition

Even when BMI or muscle mass values are within the normal range, a low SPPB score should be regarded as a qualitative decline in muscle quality, and function-centered treatment goals should be established.

Related Case Study

SPPB in Occupational Health Screening — Early Detection of Functional Risk Strategy →

AndanteFit – Selected Reference Institutions

  • Korea University Ansan Hospital / Anam Hospital
  • Yonsei University Severance Hospital / Yongin Severance Hospital
  • Catholic University of Korea Seoul St. Mary's Hospital / Bucheon St. Mary's Hospital
  • Seoul National University Bundang Hospital / Inha University Hospital / Ajou University Medical Center
  • Chungnam National University Hospital / Hwasun Chonnam National University Hospital
  • Daejeon Endo Internal Medicine Clinic and specialty clinics nationwide

Key References

  1. 1. RehabMeasures Database. MCID for SPPB in older adults.
  2. 2. Diabetes & Metabolism Journal, 2023. Muscle quality and type 2 diabetes.
  3. 3. Frontiers in Endocrinology, 2023/2025. Myosteatosis/Body composition and functional outcomes.
  4. 4. DCCT/EDIC Research Group. Diabetes Care. Functional limitations in T1D.
  5. 5. ESPEN/EASO Consensus Statement, 2022. Sarcopenic obesity staging.
  6. 6. Vaduganathan et al. Ann Intern Med, 2025. Expanding GLP-1 use.
  7. 7. MOVE UP Study, GLP-1 meta-analysis (NCT05786521).