Objective

2

To explore the tongue image characteristics of elderly individuals with dyslipidemia and to investigate the tongue manifestation patterns among different types of dyslipidemia based on partitioned tongue image parameters.

Methods

2

A total of 553 elderly individuals with dyslipidemia and 603 elderly individuals with normal lipid levels who underwent health examinations at Hongshan District Traditional Chinese Medicine Hospital in Wuhan between April and June 2023 were enrolled. Tongue image partition parameters were collected， including color parameters of the tongue body （tb） and tongue fur （tf）， segmented into six regions： the whole tongue （T）， center of the tongue （TC）， tongue root （TR）， tongue tip （TT）， left margin of the tongue （TML）， and right margin of the tongue （TMR）. Color space parameters for these regions were obtained using CIELab （Lab）， red-green-blue （RGB）， hue-saturation-intensity （HSI）， and luminance-chrominance （YCrCb） models. Differences in tongue manifestations were compared.

Results

2

The values of TCtb-L， TCtb-R， TTtb-R， TRtf-b， and TCtf-H in the dyslipidemia group were significantly lower than those in the normal lipid group （

P

<

0.05）. In participants with combined hyperglycemia， TCtb-R and TRtf-b were also significantly lower than in the normal lipid group （

P

<

0.05）. Among elderly individuals with different clinical types of dyslipidemia， 36 color parameters in the high total cholesterol （TC） group differed significantly from those in the normal lipid group. The L， R， and G values of the tongue body at TMR and TT， as well as those of the tongue coating in all six regions， were all lower（

P

<

0.05）. In the high triglyceride （TG） group， the L， R， and Y values of the whole tongue and tongue margins were higher than those in the high TC group（

P

<

0.05）. Additionally， elderly individuals with elevated low-density lipoprotein cholesterol （LDL-C） exhibited purple-dark discoloration in the TC and TT regions and thin or absent coating at the tongue tip.

Conclusion

2

In elderly individuals with dyslipidemia， tongue body abnormalities are mainly concentrated in the TC and TT regions， with the TC appearing dark purple and the TT tending toward bluish-purple. The tongue coating is generally thin and dark in color， and may be absent or peeled off on the TML， TMR， and TT regions. Partitioned tongue diagnostic parameters based on tongue region analysis can provide objective support for syndrome differentiation and clinical diagnosis of dyslipidemia in the elderly population.