Objective

2

To provide references for the syndrome differentiation-based diagnosis and treatment through observing traditional Chinese medicine (TCM) tongue images of the yin-deficiency pattern in hypertensive patients.

Methods

2

A total of 314 hypertensive patients were recruited

and divided into non yin-deficiency pattern group (

n

=122)

mild yin-deficiency pattern group (

n

=124) and severe yin-deficiency pattern group (

n

=68) based on the yin-deficiency pattern score. Standard tongue image of each patient was collected by using a TCM tongue image instrument

and analyzed for tongue image characteristics of RGB and HIS color space

index of thickness of tongue coating

and texture indexes.

Results

2

As the severity of yin-deficiency pattern in hypertensive patients increased

R and I values of tongue body were increased

and B value was lowered

and R

B and H values of tongue coating were increased. For characteristics of the tongue texture

zhiASM was decreased

while zhiENT was increased. With the aggravation of yin-deficiency syndrome

the tongue color tended to be red

the tongue coating developed yellow and the tongue texture was rougher.

Conclusions

2

Objective indexes of the tongue image are sensitive in reflecting the yin-deficiency pattern of hypertension

which are basically consistent with TCM theories and clinical conclusions. Therefore

observation of tongue image and relevant indexes is unique and can be applied in the diagnosis of hypertension.