Association between phase angle and inflammatory blood biomarkers in community-dwelling older adults: Itabashi...

Bioelectrical impedance analysis-derived phase angle (PhA) reflects the disruption of the cell membrane and intra- and extracellular fluid imbalances caused by chronic inflammation. This study examined the association between PhA and inflammatory markers in community-dwelling older adults.

A sex-stratified logistic regression analysis was conducted, with elevated C-reactive protein (CRP; ≥3.0 mg/L) and interleukin-6 (IL-6; >4.0 pg/mL) levels as the outcomes and whole-body and local PhAs as the exposures. The same analysis was conducted with further stratification for age, overweight status, history of inflammation-related non-communicable diseases, and dietary inflammatory index. The ability to identify inflammation in whole-body and local PhAs was assessed using a receiver operating characteristic (ROC) curve.

This study included 1664 participants (age: 76 [73-80] years; 855 women). In men, significant odds ratios (ORs) at the 95 % confidence interval (95 % CI) were observed for abnormal CRP and IL-6 levels for both whole-body and leg PhAs in the third quartile compared with the lowest quartile (OR [95 % CI] for abnormal CRP levels: 0.36 [0.18, 0.68] for whole-body PhA, 0.51 [0.27, 0.95] for leg PhA; OR [95 % CI] for abnormal IL-6 levels: 0.36 [0.15, 0.81] for whole-body PhA, 0.33 [0.12, 0.78] for leg PhA). The areas under the ROC curves (95 % CI) for identifying abnormal IL-6 were mild in men (0.62 [0.54, 0.70] for whole-body PhA and 0.62 [0.55, 0.70] for leg PhA). In men without a history of inflammation-related non-communicable diseases, it was 0.72 (0.59, 0.85) for whole-body PhA and 0.68 (0.54, 0.81) for leg PhA. In women, the PhA was not significantly associated with inflammatory markers.

PhA is associated with inflammation in community-dwelling older men, but may need to be combined with other information to identify inflammation.