Phase angle is associated with frailty in community-dwelling older adults

Age-related changes in bioelectrical impedance analysis-derived phase angle (PhA) and the association between PhA and sarcopenic obesity in Chinese adults

There are limited studies on the phase angle (PhA) and sarcopenic obesity (SO) in the Chinese population. This study aimed to establish 50 kHz-PhA reference data for SO population, and to evaluate the correlation between 50 kHz-PhA and SO. A total of 10,312 participants including 5415 men and 4897 women were enrolled in this study, and their resistance and reactance at 50 kHz, and body composition parameters were measured a segmental multifrequency bioelectrical impedance analysis device (InBody 720). Participants were compared between the SO and non-SO groups. Then, age and fat parameters related changes in PhA were evaluated. Furthermore, Receiver Operating Characteristic (ROC) curves were used to identify the optimal PhA cutoff values for detecting SO in males and females. The results showed significant differences in PhA and body composition parameters between the SO group and the non-SO group in both sexes (P < .001), and the prevalence rates of SO increase with age in both sexes (P < .001). The PhA values decrease with age, with a significant decrease beginning at age 65 years for males and 66 years for females. The accumulation of excess adipose tissue was also found to be associated with decrease in 50 kHz-PhA value. Furthermore, PhA was negatively associated with SO, independent of age and sex. The area under the ROC curve (AUC) of PhA for SO was 0.790 (95% CI: 0.746-0.833, P < .001) in males and 0.763 (95% CI: 0.702-0.825, P < .001) in females. The optimal cutoff value was ≤ 5.55° (specificity 0.693, sensitivity 0.759) for males and ≤4.79° (specificity 0.687, sensitivity 0.738) for females. In conclusion, 50 kHz-PhA can be used as a predictor of SO, with cutoff values of ≤5.55° for males and ≤4.79° for females. This simple and practical method of using 50 kHz-PhA to predict SO could be valuable in clinical practice.

Correlation between Phase Angle and the Number of Medications in Older Inpatients: A Cross-Sectional Study

BACKGROUND

Muscle weakness in older adults elevates mortality risk and impairs quality of life, with the phase angle (PhA) indicating cellular health. Polypharmacy, common in geriatric care, could influence PhA. This investigates whether the number of medications and polypharmacy with PhA as a biomarker of muscle quality in older inpatients aged ≥65 and determines the extent to which multiple medications contribute to the risk of reduced muscle quality.

METHODS

This retrospective cross-sectional study analyzed data from older inpatients requiring rehabilitation. PhA was measured using bioelectrical impedance analysis. The number of medications taken by each patient was recorded at admission. Polypharmacy was defined as the concurrent use of five or more medications at admission.

RESULTS

In this study of 517 hospitalized older adults (median age 75 years; 47.4% men), 178 patients (34.4%) were diagnosed with sarcopenia. Polypharmacy was present in 66% of patients. The median PhA was 4.9° in men and 4.3° in women. Multivariate linear regression analysis was performed separately for men and women. In men, PhA was negatively correlated with the number of medications (β=-0.104, p=0.041) and polypharmacy (β=-0.045, p=0.383). In women, PhA was negatively correlated with the number of medications (β=-0.119, p=0.026) and polypharmacy (β=-0.098, p=0.063). Analyses were adjusted for age, body mass index, sarcopenia, C-reactive protein, and hemoglobin levels.

CONCLUSION

The number of medications at admission negatively impacted PhA in older inpatients, highlighting the importance of reviewing prescribed drugs and their interactions.

Assessment of phase angle as a novel indicator for sarcopenic obesity according to the ESPEN/EASO criteria in older adults with diabetes mellitus

BACKGROUND

Sarcopenic obesity (SO) is a clinical condition in which sarcopenia and obesity occur together, and is associated with more poor clinical outcomes, increased mortality, and morbidity than sarcopenia. Phase angle (PhA), a parameter derived from bioimpedance analysis (BIA), provides data on cellular health, membrane integrity, and cellular function. This study aimed to evaluate the relationship between SO and PhA among older adults with type 2 diabetes mellitus (DM).

METHODS

We performed a cross-sectional study in a tertiary hospital, and all participants underwent a comprehensive geriatric assessment, the hand-grip strength test (HGST), the chair stand test (CST) for muscle strength evaluation, the 4-meter walking test, and the timed up-and-go (TUG) test for physical performance assessment. The diagnosis of SO was made according to the ESPEN/EASO criteria. The PhA was determined automatically by the BIA using resistance and reactance at 50 kHz for each participant.

RESULTS

A total of 322 participants were included in the study. The mean age of the participants was 72.5 ±5.8, and 203 (63%) of them were female; 63 (19.6%) of them were sarcopenic obese. In multivariable logistic regression analyses, a significant relationship was found when the model was adjusted for age, female gender, MNA-sf scores, HbA1c level, and CCI scores (OR: 0.53, 95%CI: 0.29-0.98, P = 0.04). In ROC analyses, for PhA in predicting SO diagnosis, the AUC was 0.586 (95%CI: 0.505-0.678, P = 0.033). At the cut-off score 4.4, sensitivity was 57.1% and specificity was 61.4%; positive predictive value (PPV) was 26.5%; negative predictive value (NPV) was 85.5%.

CONCLUSIONS

The study identified a significant relationship between SO and PhA among older adults with type 2 DM. However, larger prospective studies are needed to confirm the potential utility of PhA as a biomarker for SO.