Palo Alto-based Azumio, which offers a suite of health and wellness apps, has added a nitric oxide testing feature to its comprehensive health and fitness app, Argus. Azumio has partnered with Berkeley Test, a company that makes salivary nitric oxide test strips, for this offering.

Nitric oxide, according to Azumio, is a helpful metric to measure for maintaining a healthy blood pressure, increasing athletic endurance, and delaying vascular aging.

Argus users who want to track their nitric oxide can take pictures of their nitric oxide test strip after they've done the test, which changes color based on the results. The app will record the results, measure the user's nitric oxide status, and maintain a history of all nitric oxide tests that the user takes.

"Calorie counters just don’t tell the whole story," Azumio Chief Product Officer Tom Xu said in a statement. "They are based on averages, with no regard for whether the natural food source is rich in the necessary bioactive ingredient and whether the body has properly metabolized it for a beneficial outcome. Now, consumers have the ability to measure metabolites in saliva, allowing Argus to immediately inform users about the value of what they eat, helping keep track of the benefits of the plant-based portion of their diets.”

Azumio makes a number of different health tracking apps that track different biometrics including activity, heart rate, sleep, and diet, but the company has been working on integrating them all into its Argus app, which launched July 2013.

Earlier this week, Azumio announced that it partnered with Stanford University to make deidentified, anonymized data from a cohort of 5 million users available for research purposes. The study will be sponsored by a grant from the National Institutes of Health.

Nitric oxide, when tracked via breath, can also serve as a biomarker of asthma and other respiratory diseases. Last year, Spirometrix, a company working on a breath analysis sensor for early detection and treatment of asthma and COPD, raised $8.6 million for a device that measures nitric oxide in the breath. The Fenom sensor system will work similarly to a spirometer — the user will exhale into the device for 10 seconds and get results returned in a minute. But the test has a high sensitivity — it can detect NO in 5 parts per billion.