Determination of a measure of a glycation end-product or disease state using tissue fluorescence

A method of determining a model relating fluorescence and tissue state, where “tissue state” comprises any of (i) presence or likelihood of diabetes;

• (ii) the degree of progression of diabetes;
• (iii) a change in the presence, likelihood, or progression of diabetes;
• (iv) a probability of having, not having, developing, or not developing diabetes;
• (v) the presence, absence, progression, or likelihood of complications from diabetes, in each case based on long-term changes (greater than one month duration) in tissue, comprising:
• a. For each of a plurality of subjects:
• i. Determining a fluorescence property of a portion of the tissue of the subject, where the tissue is not the lens of the eye;
• ii. Determining a tissue state of the subject;
• b. Applying a multivariate method to the plurality of fluorescence property determinations and associated tissue state determinations to generate a model relating fluorescence property to tissue state.

An apparatus for the determination of a tissue state in an individual, where “tissue state” comprises any of (i) presence or likelihood of diabetes;

• (ii) the degree of progression of diabetes;
• (iii) a change in the presence, likelihood, or progression of diabetes;
• (iv) a probability of having, not having, developing, or not developing diabetes;
• (v) the presence, absence, progression, or likelihood of complications from diabetes, in each case based on long-term changes (greater than one month duration) in tissue, comprising:
• a. An illumination subsystem;
• b. A detection subsystem;
• c. An analysis subsystem, comprising a model relating fluorescence property of the skin of an individual to tissue state.

A method of determining a tissue state in an individual, where “tissue state” is any of (i) presence or likelihood of diabetes;

• the degree of progression of diabetes;
• (ii) a change in the presence, likelihood, or progression of diabetes;
• (iii) a probability of having, not having, developing, or not developing diabetes;
• (iv) the presence, absence, progression, or likelihood of complications from diabetes, in each case based on long-term changes (greater than one month duration) in tissue, comprising:
• a. Determining a fluorescence property of a portion of the skin of the individual;
• b. Using a multivariate method to determine a tissue state of the individual from the fluorescence property.