The phase angle can be calculated from measurements taken with Bioelectrical Impedance Analysis (BIA). This correlates with body composition, nutritional status and prognosis for a number of conditions.
Parameters:
(1) reactance in Ohms
(2) resistance in Ohms
phase angle in degrees =
= arctan ((reactance) / (resistance)) * 180 / PI()
where:
• Arctan returns a value in radians.
• The 180/PI() converts radians to degrees.
• A calculator set to degrees does not require the conversion step.
Impression:
• A low phase angle is associated with a poor outcome in a number of conditions (such as breast cancer, lung cancer, COPD, cirrhosis, AIDS).
• Gupta et al found that women with breast cancer and a phase angle <= 5.6 degrees had a worse prognosis.
Reference ranges from Barbosa-Silva et al
|
Age in Years |
Female 5th Percentile |
Female 95th Percentile |
Male 5th Percentile |
Male 95th Percentile |
|
18 to 20 |
5.9 |
8.9 |
7.0 |
8.8 |
|
20 to 29 |
5.6 |
8.6 |
6.8 |
9.2 |
|
30 to 39 |
5.6 |
8.4 |
6.6 |
9.5 |
|
40 to 49 |
5.6 |
8.3 |
6.5 |
9.0 |
|
50 to 59 |
5.5 |
8.0 |
6.1 |
8.7 |
|
60 to 69 |
4.7 |
7.5 |
5.4 |
8.9 |
|
>= 70 |
4.2 |
7.0 |
4.8 |
8.0 |
ICD-10: ,
