Now first things first, This kind of tattoo wouldn’t be a tattoo in the traditional sense, indeed there is no connection between being inked and a rise in blood glucose levels. No this tattoo would dye a patient’s skin a yellowy-orange colour and would last for about a week. The tattoo would then get lighter or darker if glucose levels changed and could be detected through a special handheld camera. The hope is that mobile phone companies would then develop an app for smart phones which would be able to read this information and tell the patient his glucose level. Scientists say that too few patients are checking their glucose levels, and that the tattoo would be more appealing than pricking your finger on a regular basis. However an actual tattoo diagnosis is certainly still a few years away.

Full story:  http://www.globalshift.org/2010/05/could-your-doctor-be-prescribing-a-tattoo-in-the-future/