Phase angle reference values derived from bioelectrical impedance analysis in chinese multi-ethnic adults

The study aimed to develop age-, sex-, and ethnicity-specific reference values for Phase Angle (PhA) in Chinese adults aged 20-80 years.

A total of 13256 healthy participants (4793 men and 8463 women) aged 20-80 years from Han, Korean, and Yao ethnic groups in the China National Health Survey were included. PhA was measured using bioelectrical impedance analysis (BIA) at 50 kHz. Generalized Additive Models for Location, Scale, and Shape were used to construct age-, sex-, and ethnicity-specific 5^th, 10^th, 25^th, 50^th, 75^th, 90^th, and 95^th percentile values for PhA.

The study population comprised 9616 Han individuals, 2136 Korean individuals, and 1504 Yao individuals. In men, PhA values peaked between 30-39 years for the Han and Korean populations and 40-49 years for the Yao population, with a steep decline after 50 years. The peak was observed in women at 40-49 years across all ethnic groups, followed by a gradual decline. Men consistently had higher PhA values than women across all ethnicities and age groups. The PhA reference values (5^th to 95^th percentiles) were 5.33-7.16° for Han men, 4.62-6.34° for Han women, 5.53-7.65° for Korean men, 5.04-6.79° for Korean women, 5.15-6.94° for Yao men, and 4.49-6.12° for Yao women.

This study provided age-, sex-, and ethnicity-specific reference values for PhA in diverse Chinese populations aged 20 to 80 years. The reference values for PhA derived from BIA hold the potential for enhancing the diagnosis and prognosis of various health conditions, further highlighting its utility in clinical settings.