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help........ (BIA and phase angle)
Aug 17, 2002

hi doctors, I need some advice. I had a BIA done and my phase angle sucks. I am so upset. What can I do to increase this number?? I run 20 miles a week, do resistance weights, eat an amazing diet (get 30 grams of protein at each meal), take all kinds of supplements, never had a low cd4 count...have a very high cd4 count now (and have for the last 5 years) no detectable virus etc etc.

I mean how important is this phase angle and do antiretrovirals affect this number???? I am carrying more fat than any other time in my life but it certainly has NO relation to my lifestyle, if anything my caloric intake is less than my requirements yet I don't lose from those areas. I also don't lose any weight at all and could definitely benefit from 10 less fat pounds from the right areas!!!! Any advice would be so appreciated.Thank you.

Response from Ms. Fields-Gardner

First we need to talk about what phase angle can and cannot mean. Phase angle is a ratio, and because of that you cannot make serious decision based on this number alone. So, start by tossing out the idea that making your phase angle better is the only thing that counts.

Now, what you need to know is how your body compartments are shaking out. The person who gave you test results should have evaluated it using appropriate equations and looking at your body's three compartments that BIA testing will estimate: body cell mass, extracellular mass, and fat. Here is your lesson for the day:

Body cell mass reflects an approximate weight of your muscle and organ tissue. This is the stuff that keeps you alive and well. This is the stuff you are keeping in shape with your exercise and adequate diet. This is the stuff that is compromised by infection and injury. So, we care most about this number.

You should know that there are different equations and different methods for interpreting the results. The bottom line here is, do you have enough to maintain your health and maybe even a little buffer for the rainy day when you might be sick or experience an injury (this includes surgery)? If the answer is yes, then you want to make sure that you keep this compartment intact and that will become a goal for your diet, exercise, and medications.

HIV is a chronic infection that yields a chronic inflammatory response. This challenges your body's body cell mass (also known as BCM). Antiretrovirals may help reduce the assault by HIV and certainly by opportunistic infections and cancers that can drain body cell mass. So, you have to be vigilant and make body composition a routine in your check-ups at least twice a year and more often if you are fixing a problem with it.

The next reading is extracellular tissue, which reflects the approximate weight of bone, collagen, and fluids outside of your cells. We watch this compartment because it can alert us to dehydration and to an inflammation or chronic condition that may make it difficult to maintain a good body composition profile through diet and exercise alone.

Then there is fat. And, if you are using the equations that better tell us about the approximate weight of body cell mass, fat is less likely to be very accurate and may contain a variety of fat tissues... stored and metabolically active. Fat under the skin is the stored variety and is gained or lost because of diet, exercise, and hormonal changes. Losing from the right areas depends more on hormonal and genetic issues, so it is a tougher goal to reach.

My advice: revisit the BIA with less emphasis on the phase angle (see more on this below), talk with a dietitian who can help you through the fat loss/weight loss maze, and keep up the good diet and exercise.

Phase angle is the arctangent of resistance and reactance multiplied by 180/pi. Thus it is a direct measure and that is its appeal. However, it changes for very different reasons. In a nutshell, phase angle can rise with more muscle (body cell mass) or less fat and fluid. More muscle may be a good thing, but less fluid could be one of two things. The good thing is if fluid declines because you are recovering from infection or injury. The bad thing is if fluid declines because you are dehydrating. A loss of fat can also increase phase angle, but that is not always a good thing.

Likewise, a drop in phase angle may reflect a loss of muscle tissues, which we think of as a bad thing. However, if you increase fluids and fat it will also decrease your phase angle. If you are rehydrating (a good thing) it drops your phase angle. If you regain needed subcutaneous fat (a good thing) it also drops your phase angle.

A low phase angle should simply alert you to looking into why that might be the case. So, you will have to look at the three body compartments estimated by BIA to find out if it is good, bad, or indifferent.

Hope that helps!

irritable bowel

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