The associations of phase angle with the structural severity and quadriceps strength among patients with hip osteoarthritis: the SPSS-OK study

Segmental bioelectrical impedance analysis can detect differences between the affected and non-affected limbs in individuals with hip osteoarthritis

OBJECTIVE

To analyze the bioelectrical impedance parameters of the lower limbs of individuals with hip osteoarthritis and healthy individuals.

DESIGN

Cross-sectional study.

SETTING

The study was carried out at the Hip Surgery Outpatient Clinic.

PARTICIPANTS

The volunteers had to be between 45 and 70 years of age, of both sexes, with a clinical and radiological diagnosis of hip osteoarthritis for at least three years, unilateral involvement, or a significant complaint in one hip.

METHODS

This was a cross-sectional study. Fifty-four individuals were recruited for the study, 31 individuals with hip osteoarthritis (OA group) and 29 healthy individuals for the control group (C group). Demographic and anthropometric data were collected and then the Numerical Pain Rating Scale, WOMAC, Harris Hip Score, and bioimpedance assessment were applied.

MAIN OUTCOME MEASURE(S)

Electrical bioimpedance parameters. Phase angle (PhA), impedance, reactance, and muscle mass.

RESULTS

There was a significant difference in phase angle (PhA), impedance, and muscle mass at 50 kHz frequency on the side affected by OA when compared to the contralateral side. In the OA group, there was a significant decrease in phase angle (PhA) -0.54 (-0.85 to -0.23) and muscle mass - 0.29 (-0.40 to -0,19), as well as an increase in impedance at the 50 kHz frequency on the side affected by OA when compared to contralateral side 21.71 (13.69 to 29.74). In the C group, there was no difference between the dominant and non-dominant sides (P > 0.05).

CONCLUSION

The segmental electrical bioimpedance equipment can detect differences between limbs affected and unaffected by hip osteoarthritis.

Not only muscle mass but also muscle quality is associated with knee extension muscle strength in patients with hip fractures

Our results revealed that the decrease in isometric knee extension muscle strength on the operated and nonoperated sides in patients with hip fractures was associated with not only a decrease in skeletal muscle mass but also a decrease in muscle quality, characterized by a decreased PhA.

PURPOSE

This study aimed to assess the relationship between isometric knee extension muscle strength on the operated or nonoperated sides and PhA in patients with hip fractures at approximately 6 months postoperatively.

METHODS

This study was a cross-sectional study. Skeletal muscle index (SMI), PhA, knee extension muscle strength on the operated and nonoperated sides, and other physical function variables were assessed at approximately 6 months postoperatively. To identify predictors of knee extension muscle strength on the operated and nonoperated sides, hierarchical multiple regression analysis was performed.

RESULTS

A total of 90 patients with hip fractures were included (mean age, 80.1 ± 6.9 years). SMI (0.45) and PhA on the operated side (0.27) were the significant associated factors extracted for isometric knee extension muscle strength on the operated side (standardized partial regression coefficients), independent of age, sex, and body mass index (BMI). Movement control during one-leg standing on the nonoperated side (0.26), SMI (0.32), and PhA on the nonoperated side (0.40) were the significant associated factors extracted for isometric knee extension muscle strength on the nonoperated side, independent of age, sex and BMI.

CONCLUSIONS

Our results revealed that the decrease in isometric knee extension muscle strength on the operated and nonoperated sides in patients with hip fractures at approximately 6 months postoperatively was associated with not only a decrease in skeletal muscle mass but also a decrease in muscle quality, characterized by a decreased PhA.

Association between phase angle and functional disability among patients with lumbar spinal stenosis: The SPSS-OK study

BACKGROUND

Whether the lower phase angle associated with worse physical function is a result of pain and muscle weakness in patients with lumbar spinal stenosis (LSS) is unclear.

OBJECTIVE

To evaluate the association between phase angle and back pain-specific disabilities in patients with LSS.

METHODS

In this single-center, cross-sectional study, 491 participants with LSS were enrolled. The phase angle and back pain-specific disability were measured using bioelectrical impedance analysis and the Oswestry Disability Index, respectively. General linear models were used to examine associations between phase angle and the Oswestry Disability Index with or without adjustment for age, sex, low back and lower limb pain, numbness in the lower extremities, total fat mass, and lower limb muscle mass.

RESULTS

The mean (SD) phase angle was 4.4∘ (1.0∘), and the mean Oswestry Disability Index was 36.1 (14.1) points. Greater phase angles were associated with less Oswestry Disability Index points (p= 0.037) independent of fat mass, low back pain, and hip or lower limb pain.

CONCLUSIONS

A lower phase angle was associated with worse functional disability. Low phase angle may be an indicator of functional impairment due to low back pain associated with LSS.