FDA warning: biotin interferes with heart test

The FDA has now released a new warning against biotin interference with troponin, an essential heart blood test. Biotin or vitamin B7 is a water-soluble molecule found in many over-the-counter supplements such as multivitamins, prenatal, and in those that are meant to improve or protect the health of hair, skin, and nail.

Vitamin B7 is a central catalyst in many laboratory tests, especially those measuring troponin and thyroid hormone levels. When patients take high doses of biotin, especially >30 micrograms daily, it has the potential to underestimate the blood troponin concentration. Troponin measurements are critical in identifying adults with heart disease and particularly those having an acute event such as heart attack or myocardial infarction.

High doses of biotin intake, up to 300 mg daily, have been documented in patients with multiple sclerosis. These extraordinary doses may translate up to 1,200 ng/mL blood concentrations. Biotin has a short half-life of about two hours. It may be reasonable to suspend vitamin B7 intake for two to three days before undergoing any laboratory testing that incorporates biotin-analyte technology.

Patients, physicians, and laboratory personnel should be aware of possible interference of oral biotin with blood troponin and thyroid hormone testing, particularly in decisive clinical circumstances. A grave example would be a biotin user who presents clinically with a heart attack, and yet troponin measurements appear to be normal. Non-elevated troponin can lead to missed diagnosis and life-saving intervention.


Heart strain in adults with diabetes

Technology is rapidly advancing in detecting subclinical heart disease at a much earlier stage. Global heart strain, better known as Left Ventricular Global Longitudinal Strain (LV-GLS) is such an example. It utilizes speckle tracking imaging of transthoracic echocardiography.

LV-GLS identifies left ventricular dysfunction at its embryo before the ejection fraction has declined, a definition of heart failure. Investigators have tested it in a variety of heart anomalies, including ischemic, atherosclerotic, viral, hypertrophic, and dilated myopathies.

Authors applied LV-GLS technology to adults with type 2 diabetes. Retrospectively, they followed about 400 diabetes patients for six years and documented their all-cause mortality.

The article defined abnormal global heart strain when LV-GLS measurement was greater than two positive standard deviations (>-17%). All-cause mortality was significantly higher, by 2.8-fold, in adults with abnormal LV-GLS versus those with normal LV-GLS.

Prospective research would need to validate these results in outcome-driven interventional randomized clinical trials. I anticipate positive results and wide-spread use of LV-GLS technology in the future.

Fortunately, we have SGLT-2 inhibitors as a unique class of medication that could potentially treat and manage patients with diabetes and abnormal heart strain.