Normal versus Optimal
Today I wanted to address lab values. A common misconception, among physicians and patients, concerns equating “reference values” with “normal” values. In everyday English, this means that when you see your lab report, there is usually a “range” besides it. This range represents the reference values. If a value is above this range, it’s listed as high, and if below the range, it’s listed as low.
Do You Want to Settle for Normal?
However, all of the values within these ranges are not necessarily “normal,” and they certainly are not “optimal.” They merely represent the values that encompass 95% of the population measured. Think of a bell curve. The lab marches a number of folks through it, of all different ages and states of health, and then spits out the range of values that 95% of the subjects fall within. So 2.5% will be low, and 2.5% will be high.
For example, the reference value range for total testosterone in men is from 348 to 1197. Now, would anyone think levels as widely ranging as 349 and 1196 are both the same degree of “normal”? Of course not. In contrast, for women the reference value range for testosterone is 0.0 to 4.2. So, by definition, it’s virtually impossible to have a “low” value, as it would have to be a negative number! Yet, due to the statistically-generated reference ranges, we are told that “zero” is “normal.”
Here is another example that illustrates these ranges’ failure to represent desired labs results: Suppose we gathered a group of cars. Among these cars, the optimal tire pressure is 40 lbs, but the tire pressures that we measured ranged from 19 lbs to 67 lbs. They may all be able to drive the race track, but which cars do you think will have best times? The ones with a tire pressure closest to the optimal 40 lbs rather than the extremes of 19 lbs or 67 lbs.
Trust a Specialist
Physicians who treat specific types of problems are far more knowledgeable about the labs that relate to that specialization. I obviously read hormone-related labs all day long. I don’t do cardiac isoenzymes, and so would not be someone to ask about the lab values and treatments on that topic. The same should be said for providers who don’t frequently deal with hormones. It is highly likely that their interpretation of lab results would be based on reference ranges rather than an experience-based understanding of the values, which–as you saw–are not representative of optimal values.
If you ever have a question, please give our office a call or send a message. We will gladly provide you with an explanation.