Why is this a bombshell? When I look for a reference (so-called ‘normal’) range for ALT at the Mayo Clinic Lab today, the cutoff is 45, males and females included. This value of 45 is 36% higher than the guideline for males and 80% higher than that for females. The guideline authors realize that for some labs the ULN for ALT is 70, which is 212% higher for males and 280% higher for females. The authors freely acknowledge that this unbelievable guideline will make 36% of men and 28% of women ‘abnormal,’ but no matter, they persist in their recommendation. The authors freely acknowledge that the blood donation pool may be negatively affected because blood banks routinely test for ALT as indirect evidence for hepatitis, but no matter, they persist in their recommendation. The authors freely acknowledge that a study (2) of asymptomatic individuals found liver disease in only 3% of participants, although 27% of the participants had elevated ALT, but no matter, they persist in their recommendation.
This guideline is eerily reminiscent of the change in cutoff of blood glucose (sugar) which was decreased from 140 to 126 in 1997 (3), instantly creating nearly 2 million diabetics one day out of people who the day before were considered normal.
I also wonder how much this liver chemistry recommendation has to do with changes in colon cancer screening recommendations issued by the USPSTF (4) in which colonoscopy and sigmoidoscopy are put on an equal footing with fecal occult blood testing, which requires no purgative preparation as for colonoscopy and sigmoidoscopy and is ridiculously cheap compared to the cost of a colonoscopy or sigmoidoscopy. In addition, USPSTF recommends only screening adults aged 50-75, cutting out a big chunk of the Medicare community from routine screening. This recommendation must hurt the pocketbook of gastroenterologists.
But when you throw in a whole new huge population of folks with ‘liver disease’ that need an extensive workup with many tests, consultation, evaluation, liver biopsies etc etc, perhaps the pocketbook will feel a little better! In addition, as the guideline makes clear, these “worried-well” folk may feel OK today with the elevated ALT, but we must follow them longitudinally to make sure they don’t develop liver disease. That means they have to come to see the gastroenterologist at least once a year for tests, evaluation, perhaps a liver biopsy!
The guideline developers do mention that increased ALT levels are associated with our current obesity epidemic with associated non-alcoholic fatty liver disease (NAFLD; 5). Perhaps those primary care and urgent care practitioners should tell obese patients to lose weight!
In my book Blood Trails: Follow your medical lab work from beginning to end with everything that can go wrong in between, plus how doctors misunderstand and misuse blood tests (available at amazon.com as both print-on-demand as well as eBook) you can read a lot more about problems with definition of so-called normal ranges as well as overdiagnosis as a result of the rampant screening that is in vogue in modern American medicine.
1. Kwo PY et al. ACG Clinical Guideline: Evaluation of abnormal liver chemistries. Am J Gastroenterol 112: 18-35, 2017.
2. Wright C et al. Liver function testing in a working population: three strategies to reduce false-positive results. J Occup Environ Med 30: 693–697, 1988.
3. Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Report of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Diabetes Care 20: 1183–1197, 1997.
5. Ioannou et al. The prevalence and predictors of elevated serum aminotransferase activity in the United States in 1999-2002. Am J Gastroenterol 101: 76–82, 2006.