3-Hydroxypropylmercapturic Acid

3-Hydroxypropylmercapturic acid (3-HPMA) is a urinary metabolite formed from acrolein, a harmful aldehyde found in cigarette smoke, automobile exhaust, industrial emissions, and some processed foods. 

Acrolein, once in the body, binds with the antioxidant glutathione and undergoes further metabolic processing to become 3-HPMA.  The presence of 3-HPMA in urine is a key biomarker used to assess exposure to acrolein from various sources. 

Elevated levels of 3-HPMA in urine can indicate significant exposure to this toxicant, making it a valuable tool in both clinical and environmental health studies.

What is 3-HPMA?  [1., 5.] 

3-Hydroxypropylmercapturic acid (3-HPMA) is a metabolite formed as a result of exposure to acrolein, a reactive aldehyde present in various environmental sources.  Acrolein is found in some processed foods, cigarette smoke, automobile exhaust, and certain industrial processes, as well as being used as an herbicide.  [7.] 

When acrolein enters the body, it undergoes a series of metabolic reactions. First, it conjugates with glutathione, a cellular antioxidant. This conjugate then undergoes further metabolic processing, including reduction and conversion to a mercapturic acid derivative, resulting in the formation of 3-HPMA.

The presence of 3-HPMA in urine serves as a biomarker to assess exposure to acrolein from different sources.  [5.] 

It has been detected in the urine of cigarette smokers, indicating exposure to acrolein from tobacco smoke.  Additionally, studies have investigated the relationship between urinary 3-HPMA levels and the formation of acrolein-DNA adducts in the lungs, which are associated with potential carcinogenic effects.  [1.] 

Furthermore, 3-HPMA has been used as a biomarker to evaluate environmental exposure to acrolein, as it is present in various pollutants and can be ingested through contaminated food, water, or air.

Laboratory Testing for 3-HPMA

Test Information, Sample Collection, and Preparation

Laboratory testing for 3-HPMA is primarily done in urine.   The sample may be collected in a clinical setting, or from the comfort of home.  

It is essential to consult with the ordering provider prior to sample collection, as specific preparation measures may be required.  

Interpretation of of Lab Results for 3-HPMA

Optimal Levels of 3-HPMA

Because 3-HPMA is the metabolite of a toxic compound, optimal levels are undetectable, or very low.  It is essential to consult with the laboratory company used to determine their recommended reference range.

Clinical Significance of Elevated Levels of 3-HPMA

Elevated levels of 3-HPMA signify exposure to acrolein.  Because it is detoxified via glutathione, supporting glutathione levels, for example with NAC supplementation,  in the setting of acrolein toxicity is increasingly recommended.  [4., 8.] 

Clinical Significance of Decreased Levels of 3-HPMA

Low or undetectable levels of 3-HPMA is considered optimal.  

Natural Ways to Support Healthy Glutathione Levels

Many diet and lifestyle practices have shown benefit in supporting healthy glutathione and antioxidant levels in the body:

• Eat plenty of fruits and vegetables which contain an array of vitamins, minerals and healthy antioxidants to reduce inflammation and support healthy glutathione levels

• Eat a diet rich in sulfur-containing foods like cruciferous vegetables (broccoli, brussels sprouts, cabbage), alliums (garlic, onions), eggs, and whey protein to provide cysteine for glutathione synthesis  [6.] 

• Include selenium-rich foods like fish, organ meats, and Brazil nuts, as selenium is a cofactor for glutathione production  [6.] 

• Drink green tea, which is rich in antioxidant polyphenols that can boost glutathione levels [6.] 

• Get adequate sleep, as sleep deprivation can deplete glutathione  [3.] 

• Limit alcohol consumption, as alcohol can deplete glutathione stores  [2.] 

Order 3-HPMA Testing

Click here to compare testing options and order tests for 3-HPMA and other environmental toxin metabolites.