COMPENDIUM ON FUNCTIONAL MEDICINE - Flipbook - Page 112
As population health declines with increasing rates of chronic
disease, reference ranges tend to widen. What was considered
"high" or "low" decades ago may now fall within "normal" ranges,
masking potential dysfunction [2,6].
Geographic Variation
Reference ranges can vary significantly between laboratories,
states, and countries. A value considered "normal" in one location
might be flagged as abnormal in another [1,2].
Failure to Detect Dysfunction
Perhaps most importantly, normal ranges are too broad to detect
early dysfunction. By the time values fall outside conventional
ranges, significant physiological damage may have already
occurred [1,3,4].
The Gray Zones: Where Dysfunction Begins
Functional blood chemistry analysis introduces the concept of
"gray zones" - areas that fall within conventional normal ranges but
outside optimal ranges. These gray zones represent early
dysfunction before disease develops [1,2,8].
Consider these examples:
Biomarker
Conventional
Range
Functional
Range
Significance of Gray Zone
Fasting
Glucose
65-99 mg/dL
75-90
mg/dL
Values from 90-99 may
indicate early insulin
resistance [2,6]
TSH
0.5-5.0 μIU/mL
1.8-3.0
μIU/mL
Values from 3.0-5.0 may
indicate subclinical
hypothyroidism [4]
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