Exploratory Study of Circadian Relationships Between Social Behavior, Blood Pressure and Metabolomics

Cell phones with internet access (so-called smartphones) represent a rich source for user activity data. Each time one places a call, sends a text message, or uses an app, a data trace is being produced which overall reflects the user's social activity and behavior. This data is called 'social sensing data'. Researchers connected this type of data to the health status of the person operating the cell phone. An example is that an outbreak of seasonal flu may lead to fewer calls and text messages among cell phone users. Thus, the social sensing data may show for example how severe an outbreak is and how fast it is spreading.

"Circadian rhythmicity" describes the concept that many of the bodily functions follow a roughly 24-hour rhythm. Usually, the ability to do concentrated and focused work is best during daytime while rest and sleep occurs during nighttime. A disturbance of this pattern, for example by regular nightshift work, may lead to an increased disease risk, such as for the cardiovascular system, the heart and blood vessels. Natural factors within a body produce our 24-hour rhythm. This rhythm is affected by outside cues such as sunlight. Jet lag is a short-term form of a disturbed 24-hour rhythm. When a person travels fast through several time zones, by plane for example from the East to the West Coast of the US, s/he arrives with a time difference of 3 hours. Upon arrival, the body runs still at East Coast time, but is exposed to the environmental cues following the West Coast time, which may make the person feel groggy and disoriented at first. Within a couple of days the body time usually adjusts and the complaints discontinue.

The current study wishes to look for a relationship between patterns in the participant's cell phone use (Android only at this point) and several of the bodily functions. As bodily functions the investigators will measure blood pressure and breakdown products (metabolites) in urine, blood and saliva samples. The investigators will collect stool samples and use swabs to collect the microbes inhabiting the mouth as well as the rectum. The investigators will also measure messenger ribonucleic acid (mRNA), messenger products of the participant's heritable information, in the blood. A cell phone application called "Ginger.io" will collect the participants' cell phone usage information. This application will also ask the participant several questions during the installation, during participation as well as at the end. Furthermore, the investigators will ask the participant about the dietary intake and habits.

The aim is to learn how the 24-hour rhythm is connected to the social activity and behavior as well as blood pressure and metabolites as markers for the health status.