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

PhA reference values (5th to 95th percentiles) were established for three Chinese ethnic groups across both sexes.

• Han men: 5.33–7.16°; Han women: 4.62–6.34°
• Korean men: 5.53–7.65°; Korean women: 5.04–6.79°
• Yao men: 5.15–6.94°; Yao women: 4.49–6.12°
• Percentiles derived were the 5th, 10th, 25th, 50th, 75th, 90th, and 95th
• PhA was measured using bioelectrical impedance analysis (BIA) at 50 kHz

Men consistently had higher PhA values than women across all ethnicities and age groups.

• This sex difference was observed across all three ethnic groups (Han, Korean, and Yao)
• The difference persisted across the full age range of 20–80 years
• The study included 4793 men and 8463 women

PhA values in men peaked between ages 30–39 years for Han and Korean populations and 40–49 years for the Yao population, with a steep decline after 50 years.

• Han and Korean men showed peak PhA in the 30–39 year age group
• Yao men showed peak PhA in the 40–49 year age group
• A steep decline in PhA was observed after age 50 years in men across all ethnic groups

PhA values in women peaked at ages 40–49 years across all three ethnic groups, followed by a gradual decline.

• The peak age decade for women (40–49 years) was later than for Han and Korean men (30–39 years)
• The decline in women after the peak was described as gradual, contrasting with the steep decline observed in men after age 50
• This pattern was consistent across Han, Korean, and Yao women

The study included 13,256 healthy participants from three Chinese ethnic groups drawn from the China National Health Survey.

• Total sample: 13,256 participants (4,793 men and 8,463 women) aged 20–80 years
• Ethnic composition: 9,616 Han, 2,136 Korean, and 1,504 Yao individuals
• Generalized Additive Models for Location, Scale, and Shape (GAMLSS) were used to construct percentile reference values
• Participants were required to be healthy adults