摘要: 目的：基于RGB颜色模型探讨冠状动脉粥样硬化性心脏病人群与正常人群舌象特征的区别。方法：纳入2020年在天津市南开区采集参与天津市冠心病筛查的社区居民舌象，冠状动脉粥样硬化性心脏病人群209例，正常人群203例，采集其全舌、舌尖、舌中、舌根、左舌边、右舌边共6个舌象分区特征参数，采用RGB颜色模型，比较其舌象差异。结果：两种人群间舌色分布差异显著，苔色分布无明显区分；整体舌色参数对比，冠心病人群在全舌、舌中、舌左、舌右等关键区域的RGB-R值多低于正常人群，全舌、舌左、舌尖等区域的RGB-G、RGB-B值多高于正常人群，整体苔色参数对比，全舌、舌根、舌左、舌右、舌尖等区域的苔色RGB-R、RGB-G、RGB-B值均为冠心病人群高于正常人群；按照亚组分析，白苔亚组：全舌、舌根、舌左、舌右、舌尖区域的舌苔RGB参数存在差异(P < 0.05或P < 0.01)，仅舌中区域无差异，黄白相兼苔亚组：全舌、舌中、舌根、舌左、舌右、舌尖6个区域的舌苔RGB参数均存在统计学差异；淡舌差异集中于全舌、舌中、舌右、舌尖的RGB-R及舌尖RGB-G，冠心病人群参数均低于正常人群，舌根、舌左区域无差异，淡红舌冠心病人群全舌、舌中、舌右的RGB-R低于正常人群，舌左RGB-B、舌尖RGB-G/B高于正常人群，红舌的所有18个舌色RGB参数均无统计学差异；淡紫舌差异仅存在于RGB-G/B通道，冠心病人群全舌、舌中、舌左、舌尖的RGB-G/B值高于正常人群，尤其舌尖RGB-G/B差异极显著。结论：黄白相兼苔是差异覆盖最全面、区分度最强的苔色类型，提示黄白相兼苔的RGB参数在冠心病诊断中可能有较高临床价值，淡红舌两种人群的舌象参数差异覆盖度最广，是舌色参数中区别最大的类型；淡紫舌冠心病人群全舌、舌中、舌左、舌尖的RGB-G/B值高于正常人群，尤其舌尖RGB-G/B差异极显著，与淡紫舌色“瘀滞”的中医辨证相符合，是该类人群潜在的生物标志物。
Abstract: Objective: To explore the differences in tongue image characteristics between patients with coronary atherosclerotic heart disease and normal individuals based on the RGB color model. Methods: Tongue images of community residents participating in the coronary heart disease screening in Nankai District, Tianjin in 2020 were collected. There were 209 patients with coronary atherosclerotic heart disease and 203 normal individuals. Six parameters of tongue image regions including the whole tongue, tip of the tongue, middle of the tongue, root of the tongue, left side of the tongue, and right side of the tongue were collected. Using the RGB color model, the differences in tongue images were compared. Results: There were significant differences in the distribution of tongue color between the two groups. There was no obvious distinction in the distribution of coating color. When comparing the overall tongue color parameters, the RGB-R values of the key areas such as the whole tongue, middle of the tongue, left side of the tongue, and right side of the tongue in the coronary heart disease group were lower than those in the normal group. The RGB-G and RGB-B values of the areas such as the whole tongue, left side of the tongue, tip of the tongue, etc. were higher in the coronary heart disease group than in the normal group. When comparing the overall coating color parameters, the RGB-R, RGB-G, and RGB-B values of the areas such as the whole tongue, root of the tongue, left side of the tongue, right side of the tongue, and tip of the tongue in the coronary heart disease group were higher than those in the normal group. According to subgroup analysis, for the white coating subgroup: there were differences in the RGB parameters of tongue coating in the areas of the whole tongue, root of the tongue, left side of the tongue, right side of the tongue, and tip of the tongue (P < 0.05 or P < 0.01), while there was no difference in the middle area. For the yellow-white mixed coating subgroup: there were statistical differences in the RGB parameters of tongue coating in the areas of the whole tongue, middle of the tongue, root of the tongue, left side of the tongue, right side of the tongue, and tip of the tongue; for the pale tongue subgroup: there were statistical differences in the RGB parameters of tongue coating in the areas of the whole tongue, root of the tongue, left side of the tongue, right side of the tongue, and tip of the tongue. For the pale red tongue subgroup: the RGB-R, RGB-G, and RGB-B values of the tongue coating in the areas of the whole tongue, middle of the tongue, left side of the tongue, right side of the tongue, and tip of the tongue in the coronary heart disease group were lower than those in the normal group, while there was no difference in the tongue root and left side areas. For the pale red tongue, the RGB-G/B values of the tongue coating in the areas of the whole tongue, middle of the tongue, left side of the tongue, and tip of the tongue in the coronary heart disease group were lower than those in the normal group, while the RGB-G/B value of the tip of the tongue was significantly higher than that in the normal group. For the red tongue, all 18 RGB parameters of the tongue color were not statistically different. For the pale purple tongue, the differences were only in the RGB-G/B channel. The RGB-G/B values of the whole tongue, middle of the tongue, left side of the tongue, and tip of the tongue in the coronary heart disease group were higher than those in the normal group, especially the RGB-G/B value of the tip of the tongue was extremely significant. Conclusion: The yellow-white mixed coating is the type of coating with the most comprehensive differences and the strongest distinction. This suggests that the RGB parameters of the yellow-white mixed coating may have high clinical value in the diagnosis of coronary heart disease. The pale red tongue has the widest coverage of tongue image parameter differences and is the type with the greatest distinction in tongue color parameters. The RGB-G/B values of the entire tongue, the middle part of the tongue, the left part of the tongue, and the tip of the tongue in the population with mild purple tongue and coronary heart disease were higher than those of the normal population. Especially, the difference in RGB-G/B values at the tip of the tongue was extremely significant, which is in line with the traditional Chinese medicine diagnosis of “stagnation of blood stasis” for the pale purple tongue color, and is a potential biomarker for this group of people.
1. 引言
舌诊是中医四诊的主要内容之一，舌象可以灵敏的反映人体脏腑的生理和病理状态。在中医临床实践中，通过观察舌象的变化可以评估人体内病邪的深浅和性质、正气的盛衰、测知病情的轻重，进而判断疾病的转归和预后[1]。目前舌象客观化研究的主要内容是利用数码相机采集舌象彩色图片(即数码图像)，得到舌象的相关数据信息包括舌色、苔色和苔质等参数情况[2]，目前舌象客观化研究已经在舌象颜色、纹理等特征的提取分析、舌象参数统计分类任务上取得了较好的进展[3] [4]。
中医学认为健康人群的舌象应为“淡红舌，薄白苔”，但通过真实世界研究发现正常人群也可出现红舌、淡白舌等舌色，白苔、黄苔等苔色[5]。在实际应用中，正常人群和患病人群出现相同的舌色或苔色时，其参数的客观数值是否存在不同，对于舌象客观化是否存在影响尚需深入研究。本研究通过采集相同年龄段正常人群舌象及冠状动脉粥样硬化性患病人群的舌象，并以其为例，对两种人群舌色及苔色参数进行对照研究，以期为舌象客观化研究提供更多数据基础及试验资料。
2. 资料与方法
2.1. 一般资料
本研究于2020年在天津市南开区采集参与天津市冠心病筛查的社区居民舌象，根据体检的理化检查结果将其分为正常人群及冠状动脉粥样硬化性心脏病患病人群。
2.2. 诊断标准
本研究纳入的冠状动脉粥样硬化性心脏病包括稳定型心绞痛、不稳定型心绞痛心绞痛、非ST段抬高型心肌梗死和急性ST段抬高型心肌梗死。参照中华医学会心血管病学分会制定的《慢性稳定性心绞痛诊断与治疗指南》[6]、《不稳定性心绞痛和非ST段抬高心肌梗死诊断与治疗指南》[7]、《急性ST段抬高型心肌梗死诊断和治疗指南》[8]相关标准。
2.3. 纳入标准
① 年龄在55~70岁之间；② 无吸烟史或已戒烟5年以上(为排除染苔情况)；③ 自愿参与检查并签署知情同意书；④ 冠状动脉粥样硬化性心脏病人群符合稳定型心绞痛、不稳定型心绞痛心绞痛、非ST段抬高型心肌梗死和急性ST段抬高型心肌梗死诊断标准；⑤ 正常人群体检指标(包括血常规、尿常规、肝肾功能、空腹血糖、血脂、胸部X光片、腹部B超及体格检查)未见明显异常。
2.4. 排除标准
① 患有严重精神疾病、恶性肿瘤、严重肝肾功能不全及感染性疾病者；② 有染苔、刮苔者；③ 采集图像不清楚、伸舌不完整、舌面拍摄不全、舌体严重颤抖者；④ 舌象采集前3天患感冒、腹泻等影响舌象疾病者；⑤ 因未配合相关检测导致数据缺失者。
2.5. 数据采集
2.5.1. 采集设备
本研究采用上海道生医疗科技有限公司的手持式舌诊仪进行舌面彩色图像数据的采集。采集完成后，使用手持式舌诊仪对舌象参数进行分类。
2.5.2. 采集操作及注意事项
拍摄前，对仪器下颌托处及拍摄区域使用75%酒精棉片进行消毒，要求志愿者端正坐姿，身体微向前倾，下颌贴于仪器下颌托处，嘱志愿者尽量张嘴，将舌体自然吐出，舌尖向下，舌体放松，尽量保持静止。
2.5.3. 舌体分割
在拍摄过程中尽管已经通过调整志愿者姿势、仪器状态及位置等方法尽可能获得最大的舌体原始图像，但由于每个被检测人的情况不同，因此非舌体的部分如脸颊、牙齿等仍会存在。原始图像中非舌部分对舌体和舌苔的颜色鉴定及舌苔的纹理特性有影响，因此从原始图像中检测与分离出舌体是有必要的。本研究为获得精确的舌体图像并将舌质舌苔分割开来，选择采用手工分割的方法进行苔质分离和舌体分割。并按照中医诊断学将舌体分割为舌尖、舌中、舌根、左舌边、右舌边五个部分。按照中医相关理论，不同的舌体区域与不同的内脏具有关联关系，具体为舌尖对应的是心肺，舌中对应的是脾胃，舌根为肾和膀胱，左肝右胆[9]。
2.5.4. 舌象参数
采用RGB颜色模型进行分析并收集舌象参数，包括舌色(全舌、舌尖、舌中、舌根、左舌边、右舌边)、苔色(全舌、舌尖、舌中、舌根、左舌边、右舌边)。
2.6. 统计学方法
采用SPSS27.0统计软件对数据进行分析。采用Kolmogorov-Smirnov检验行正态性分析，不符合正态分布的计量资料以中位数(四分位数)[M (P25, P75)]表示，组间比较采用Mann-Whitney U检验。计数资料用百分率(%)表示，比较采用卡方检验。P < 0.05为差异有统计学意义。
3. 结果
3.1. 两组一般资料比较
正常人群203例，冠心病人群209例，冠心病人群年龄为62.00 (58.00~66.50)，正常人群年龄为63.00 (59.00~67.00)，Z值为−0.171，P = 0.864，大于0.05，说明两组在年龄上无显著差异；在性别构成上，冠心病组男性102例(48.80%)、女性107例(51.20%)，健康组男性106例(52.21%)、女性97例(47.79%)，x2值为0.480，P值为0.488，大于0.05，说明两组在性别分布上也无明显差异。综上，冠心病组和健康组的年龄、性别等基线资料均衡可比，见表1。
Table 1. Comparison of basic information
表1. 基本资料比较
基线资料 |
冠心病组(n = 209) |
健康组(n = 203) |
x2/Z值 |
P值 |
年龄 |
62.00 (58.00~66.50) |
63.00 (59.00~67.00) |
−0.171 |
0.864 |
性别 |
|
|
0.480 |
0.488 |
男 |
102 (48.80) |
106 (52.21) |
|
|
女 |
107 (51.20) |
97 (47.79) |
|
|
冠心病组舌色淡者23人(11%)、淡红113人(54.07%)、红23人(11%)、暗红6人(2.87%)、淡紫44人(21.05%)、紫暗0人(0%)；健康组舌色淡者31人(15.27%)、淡红141人(69.46%)、红15人(7.39%)、暗红6人(2.96%)、淡紫9人(4.43%)、紫暗1人(0.49%)。x2值为29.988，P = 0.001，提示冠心病组与健康组舌色分布存在显著差异。具体来看，冠心病组淡红舌占比54.07%，健康组淡红舌占比69.46%；冠心病组淡紫舌占比21.05%，健康组淡紫舌占比4.43%，可见冠心病组淡红舌占比低于健康组，淡紫舌占比高于健康组。
冠心病组黄苔3人(1.44%)、白苔72人(34.45%)、黄白相兼134人(64.11%)；健康组黄苔1人(0.49%)、白苔62人(30.54%)、黄白相兼140人(68.97%)。x2值为1.791，P = 0.408，P > 0.05，说明冠心病组与健康组在苔色分布上无显著统计学差异，见表2。
Table 2. Comparison of tongue image data
表2. 舌象资料比较
基线资料 |
冠心病组(n = 209) |
健康组(n = 203) |
x2/Z值 |
P值 |
舌色 |
|
|
29.988 |
0.001 |
淡 |
23 (11.00) |
31 (15.27) |
|
|
淡红 |
113 (54.07) |
141 (69.46) |
|
|
红 |
23 (11.00) |
15 (7.39) |
|
|
暗红 |
6 (2.87) |
6 (2.96) |
|
|
淡紫 |
44 (21.05) |
9 (4.43) |
|
|
紫暗 |
0 (0.00) |
1 (0.49) |
|
|
苔色 |
|
|
1.791 |
0.408 |
黄苔 |
3 (1.44) |
1 (0.49) |
|
|
白苔 |
72 (34.45) |
62 (30.54) |
|
|
黄白相兼 |
134 (64.11) |
140 (68.97) |
|
|
3.2. 两组舌象参数比较
对冠心病人群与正常人群舌色参数进行比较。结果显示，冠心病组与健康组在舌色的诸多区域RGB参数上存在统计学差异，如舌色–全舌RGB-R、舌色–全舌RGB-B、舌色–舌中RGB-R、舌色–舌左RGB的R、G、B，舌色–舌右RGB-R以及舌色–舌尖RGB的G、B等参数，冠心病组与健康组相比，R值多更低，G、B值多更高；但舌色–全舌RGB-G、舌色–舌中RGB-G、RGB-B，舌色–舌根RGB-R、RGB-G、RGB-B，舌色–舌右RGB-G、RGB-B等参数，两组比较无统计学差异。总体而言，冠心病组与健康组在舌色多个区域的RGB参数上存在不同，但主要差异集中在红色颜色分量的数值，见表3。
Table 3. Comparison of tongue color parameters between the two groups
表3. 两组舌色参数比较
参数 |
冠心病组(n = 209) |
健康组(n = 203) |
Z |
P |
舌色–全舌RGB-R |
151.330 (143.4, 158.4) |
154.010 (147.2, 161.5) |
−3.072 |
0.002** |
舌色–全舌RGB-G |
98.900 (91.8, 107.3) |
97.860 (91.6, 104.4) |
−1.572 |
0.116 |
舌色–全舌RGB-B |
98.030 (92.5, 104.3) |
95.860 (90.9, 102.6) |
−2.465 |
0.014* |
舌色–舌中RGB-R |
168.370 (159.7, 177.1) |
173.410 (165.9, 179.8) |
−3.933 |
0.000** |
舌色–舌中RGB-G |
116.120 (106.4, 127.4) |
116.740 (107.3, 124.8) |
−0.190 |
0.849 |
舌色–舌中RGB-B |
114.680 (105.4, 122.3) |
114.670 (108.5, 122.4) |
−0.103 |
0.918 |
舌色–舌根RGB-R |
124.950 (113.1, 137.2) |
127.520 (116.4, 139.8) |
−1.630 |
0.103 |
舌色–舌根RGB-G |
87.970 (77.2, 98.6) |
85.910 (76.8, 95.0) |
−0.979 |
0.328 |
舌色–舌根RGB-B |
83.450 (75.4, 93.0) |
82.960 (75.2, 91.4) |
−0.877 |
0.381 |
舌色–舌左RGB-R |
149.600 (141.4, 156.4) |
152.340 (144.3, 160.2) |
−2.255 |
0.024* |
舌色–舌左RGB-G |
96.300 (88.7, 104.3) |
94.270 (87.0, 100.7) |
−2.152 |
0.031* |
舌色–舌左RGB-B |
95.520 (89.5, 103.0) |
91.820 (86.9, 98.6) |
−3.708 |
0.000** |
舌色–舌右RGB-R |
148.810 (140.0, 155.0) |
152.400 (145.1, 159.8) |
−4.031 |
0.000** |
舌色–舌右RGB-G |
95.900 (89.0, 103.5) |
95.830 (88.8, 102.0) |
−0.759 |
0.448 |
舌色–舌右RGB-B |
95.120 (89.0, 103.0) |
93.640 (88.8, 99.9) |
−1.575 |
0.115 |
舌色–舌尖RGB-R |
169.270 (163.0, 176.2) |
168.920 (161.3, 177.0) |
−0.101 |
0.920 |
舌色–舌尖RGB-G |
105.490 (98.9, 114.0) |
101.430 (93.2, 110.3) |
−4.036 |
0.000** |
舌色–舌尖RGB-B |
108.190 (102.7, 114.6) |
102.770 (96.6, 108.6) |
−5.975 |
0.000** |
注：*P < 0.05，**P < 0.01。
对冠心病人群与正常人群舌苔参数进行比较。可见，冠心病人群与正常人群在舌苔全舌、舌中、舌根、舌左、舌右、舌尖的RGB-R、RGB-G、RGB-B参数上，多数存在显著统计学差异。其中，冠心病组各区域舌苔的RGB-R、RGB-G、RGB-B值均高于健康组，仅舌苔–舌中RGB-R参数，两组比较无统计学差异。综上，冠心病组与健康组的舌苔RGB参数整体存在明显不同，见表4。
Table 4. Comparison of tongue coating parameters between the two groups
表4. 两组舌苔参数比较
参数 |
冠心病组(n = 380) |
健康组(n = 334) |
Z |
P |
舌苔–全舌RGB-R |
72.550 (55.8, 95.8) |
58.510 (34.8, 89.4) |
−4.395 |
0.000** |
舌苔–全舌RGB-G |
49.030 (38.1, 65.8) |
38.740 (23.0, 60.1) |
−4.715 |
0.000** |
舌苔–全舌RGB-B |
47.890 (37.8, 62.9) |
37.980 (22.6, 57.3) |
−5.025 |
0.000** |
舌苔–舌中RGB-R |
84.930 (61.6, 123.2) |
74.200 (40.6, 127.0) |
−1.859 |
0.063 |
舌苔–舌中RGB-G |
58.890 (42.2, 84.4) |
51.500 (28.1, 86.8) |
−2.258 |
0.024* |
舌苔–舌中RGB-B |
59.470 (41.4, 86.8) |
51.470 (28.4, 88.8) |
−2.188 |
0.029* |
舌苔–舌根RGB-R |
80.490 (59.6, 110.0) |
69.370 (40.0, 106.2) |
−2.940 |
0.003** |
舌苔–舌根RGB-G |
56.110 (42.1, 79.2) |
44.310 (27.3, 74.0) |
−3.486 |
0.000** |
舌苔–舌根RGB-B |
55.180 (42.6, 71.5) |
45.750 (27.2, 68.3) |
−3.680 |
0.000** |
舌苔–舌左RGB-R |
64.070 (46.6, 91.4) |
48.390 (24.4, 80.1) |
−4.225 |
0.000** |
舌苔–舌左RGB-G |
43.270 (29.9, 61.8) |
32.460 (15.8, 52.3) |
−4.498 |
0.000** |
舌苔–舌左RGB-B |
43.200 (30.8, 61.3) |
31.950 (16.2, 50.8) |
−4.881 |
0.000** |
舌苔–舌右RGB-R |
68.420 (49.9, 93.6) |
53.120 (27.2, 81.7) |
−4.486 |
0.000** |
舌苔–舌右RGB-G |
45.540 (31.3, 62.5) |
35.360 (17.9, 54.5) |
−4.801 |
0.000** |
舌苔–舌右RGB-B |
45.450 (32.7, 63.3) |
34.730 (18.2, 52.9) |
−5.107 |
0.000** |
舌苔–舌尖RGB-R |
71.290 (36.2, 112.2) |
43.940 (24.8, 88.3) |
−4.573 |
0.000** |
舌苔–舌尖RGB-G |
47.950 (23.7, 67.5) |
28.170 (16.6, 52.5) |
−4.844 |
0.000** |
舌苔–舌尖RGB-B |
49.060 (24.4, 72.4) |
28.250 (16.2, 55.5) |
−4.938 |
0.000** |
注：*P < 0.05，**P < 0.01。
3.3. 不同苔色下两组间比较
对冠心病人群白苔组(n = 72)与正常人群白苔组(n = 62)的苔色RGB参数展开比较，结果显示：除舌中区域的苔色–舌中RGB-R、苔色–舌中RGB-G、苔色–舌中RGB-B无统计学差异外，全舌、舌根、舌左、舌右、舌尖区域的舌苔RGB参数均存在显著统计学差异；且冠心病白苔组各差异区域的RGB-R、RGB-G、RGB-B值均高于健康白苔组，其中苔色–舌尖RGB-G和苔色–舌尖RGB-B差异最为显著，两组数值差值分别达25.110 (58.060~32.950)、27.265 (61.345~34.080)，见表5。
Table 5. Comparison among different white tongue coating groups
表5. 白苔组间比较
参数 |
冠心病白苔(n = 72) |
健康白苔(n = 62) |
Z值 |
P |
舌苔–全舌RGB-R |
71.510 (53.0, 89.8) |
50.590 (29.8, 82.9) |
−2.874 |
0.004** |
舌苔–全舌RGB-G |
45.670 (32.8, 57.2) |
33.470 (19.3, 52.9) |
−3.128 |
0.002** |
舌苔–全舌RGB-B |
47.225 (35.6, 61.4) |
34.135 (20.3, 56.6) |
−3.106 |
0.002** |
舌苔–舌中RGB-R |
85.105 (59.2, 134.6) |
92.550 (47.5, 131.1) |
−0.297 |
0.767 |
舌苔–舌中RGB-G |
56.205 (39.9, 84.1) |
58.410 (31.1, 82.9) |
−0.437 |
0.662 |
舌苔–舌中RGB-B |
59.665 (41.6, 91.3) |
62.055 (32.7, 89.3) |
−0.580 |
0.562 |
舌苔–舌根RGB-R |
63.180 (44.9, 82.2) |
45.455 (29.1, 69.4) |
−2.896 |
0.004** |
舌苔–舌根RGB-G |
42.705 (31.9, 56.9) |
30.685 (20.0, 44.7) |
−3.414 |
0.001** |
舌苔–舌根RGB-B |
45.280 (33.0, 61.7) |
31.545 (20.6, 47.2) |
−3.347 |
0.001** |
舌苔–舌左RGB-R |
55.730 (37.8, 89.9) |
33.430 (19.7, 71.5) |
−2.767 |
0.006** |
舌苔–舌左RGB-G |
38.475 (24.2, 55.4) |
21.680 (12.7, 45.0) |
−3.115 |
0.002** |
舌苔–舌左RGB-B |
39.925 (24.4, 60.5) |
21.645 (13.0, 46.8) |
−3.090 |
0.002** |
舌苔–舌右RGB-R |
65.355 (41.5, 87.5) |
52.515 (24.0, 80.7) |
−2.686 |
0.007** |
舌苔–舌右RGB-G |
41.930 (26.9, 58.7) |
32.925 (15.5, 49.9) |
−2.963 |
0.003** |
舌苔–舌右RGB-B |
43.560 (28.0, 62.1) |
35.155 (15.8, 53.7) |
−2.932 |
0.003** |
舌苔–舌尖RGB-R |
93.965 (49.1, 126.5) |
52.495 (29.2, 90.7) |
−3.802 |
0.000** |
舌苔–舌尖RGB-G |
58.060 (33.2, 76.3) |
32.950 (18.3, 53.8) |
−3.945 |
0.000** |
舌苔–舌尖RGB-B |
61.345 (34.4, 84.5) |
34.080 (17.7, 56.6) |
−3.909 |
0.000** |
注：*P < 0.05，**P < 0.01。
对冠心病人群黄白相兼苔组(n = 134)与正常人群黄白相兼苔组(n = 140)的舌苔RGB参数进行Mann-Whitney检验，结果显示：所有区域的舌苔RGB参数均存在统计学差异；其中，苔色–舌右RGB-B差异最显著，冠心病人群数值与正常人群差值达10.830；且冠心病人群黄白相兼苔组所有区域的RGB-R、RGB-G、RGB-B值均高于正常人群黄白相兼苔组，见表6。
Table 6. Comparison among the yellow and white mixed coating groups
表6. 黄白相兼苔组间比较
参数 |
冠心病黄白相间(n = 134) |
健康黄白相间(n = 140) |
Z值 |
P |
苔色–全舌RGB-R |
72.570 (56.0, 98.3) |
60.590 (36.9, 92.3) |
−3.347 |
0.001** |
苔色–全舌RGB-G |
50.285 (38.3, 68.3) |
40.755 (24.8, 62.9) |
−3.624 |
0.000** |
苔色–全舌RGB-B |
47.765 (37.9, 63.1) |
40.000 (24.4, 58.6) |
−3.924 |
0.000** |
苔色–舌中RGB-R |
83.115 (61.7, 117.8) |
71.435 (39.5, 121.8) |
−2.044 |
0.041* |
苔色–舌中RGB-G |
60.595 (42.8, 83.4) |
48.615 (24.3, 90.7) |
−2.311 |
0.021* |
苔色–舌中RGB-B |
58.845 (41.1, 81.3) |
46.245 (25.6, 86.1) |
−2.239 |
0.025* |
苔色–舌根RGB-R |
96.140 (65.6, 120.5) |
90.175 (51.6, 112.0) |
−2.061 |
0.039* |
苔色–舌根RGB-G |
69.265 (46.4, 87.1) |
63.435 (34.9, 81.8) |
−2.576 |
0.010** |
苔色–舌根RGB-B |
61.670 (45.0, 78.5) |
58.175 (33.4, 73.9) |
−2.635 |
0.008** |
苔色–舌左RGB-R |
64.880 (49.1, 92.8) |
49.805 (30.8, 88.9) |
−3.271 |
0.001** |
苔色–舌左RGB-G |
45.795 (34.4, 62.9) |
34.135 (20.7, 61.1) |
−3.520 |
0.000** |
苔色–舌左RGB-B |
44.350 (33.8, 61.1) |
32.765 (20.9, 56.9) |
−3.846 |
0.000** |
苔色–舌右RGB-R |
69.700 (50.6, 94.1) |
53.275 (30.7, 81.7) |
−3.653 |
0.000** |
苔色–舌右RGB-G |
45.685 (34.5, 64.3) |
36.480 (19.7, 55.3) |
−3.865 |
0.000** |
苔色–舌右RGB-B |
45.520 (35.1, 63.1) |
34.690 (19.4, 51.3) |
−4.217 |
0.000** |
苔色–舌尖RGB-R |
64.955 (32.7, 97.5) |
42.665 (24.6, 76.0) |
−2.936 |
0.003** |
苔色–舌尖RGB-G |
43.910 (21.9, 62.7) |
26.915 (16.2, 51.3) |
−3.132 |
0.002** |
苔色–舌尖RGB-B |
43.300 (22.5, 63.9) |
27.250 (16.0, 52.2) |
−3.223 |
0.001** |
注：*P < 0.05，**P < 0.01。
3.4. 不同舌色下两组间比较
对冠心病淡舌色组(n = 136)与健康淡舌色组(n = 31)的舌色RGB参数进行Mann-Whitney检验，结果显示：仅5个舌分区RGB参数存在统计学差异，分别为舌色–全舌RGB-R、舌色–舌中RGB-R、舌色–舌右RGB-R、舌色–舌尖RGB-R、舌色–舌尖RGB-G，且冠心病淡舌色组这5个参数的数值均低于健康淡舌色组；其余13个参数(如舌根全区域、舌左全区域等)均无统计学差异，其中舌色–舌根RGB-R是差异最不明显的参数，见表7。
Table 7. Comparison among groups of pale tongue
表7. 淡舌组间比较
参数 |
冠心病组淡(n = 136) |
健康组淡(n = 31) |
Z值 |
P |
舌色–全舌RGB-R |
151.600 (142.1, 158.7) |
154.640 (149.8, 163.2) |
−2.062 |
0.039* |
舌色–全舌RGB-G |
97.545 (91.2, 105.7) |
101.270 (96.1, 107.8) |
−1.410 |
0.159 |
舌色–全舌RGB-B |
97.585 (92.1, 103.1) |
95.320 (92.8, 104.4) |
−0.274 |
0.784 |
舌色–舌中RGB-R |
169.295 (159.8, 177.4) |
173.210 (169.2, 183.4) |
−2.130 |
0.033* |
舌色–舌中RGB-G |
115.400 (104.5, 126.7) |
121.000 (110.1, 129.2) |
−1.399 |
0.162 |
舌色–舌中RGB-B |
114.455 (104.4, 121.7) |
116.180 (106.5, 122.4) |
−0.566 |
0.571 |
舌色–舌根RGB-R |
123.815 (111.8, 137.4) |
122.470 (115.3, 133.8) |
−0.093 |
0.926 |
舌色–舌根RGB-G |
86.195 (75.4, 97.7) |
80.770 (76.0, 90.5) |
−0.924 |
0.355 |
舌色–舌根RGB-B |
81.945 (74.1, 92.3) |
77.940 (72.5, 87.4) |
−1.136 |
0.256 |
舌色–舌左RGB-R |
150.205 (140.8, 157.3) |
153.350 (146.7, 160.9) |
−1.912 |
0.056 |
舌色–舌左RGB-G |
94.420 (87.0, 103.2) |
99.980 (91.0, 104.6) |
−1.550 |
0.121 |
舌色–舌左RGB-B |
94.815 (88.0, 102.3) |
94.800 (89.5, 100.5) |
−0.307 |
0.759 |
舌色–舌右RGB-R |
148.715 (138.8, 154.8) |
152.530 (149.1, 158.6) |
−2.846 |
0.004** |
舌色–舌右RGB-G |
94.555 (88.7, 101.8) |
98.260 (91.7, 104.6) |
−1.708 |
0.088 |
舌色–舌右RGB-B |
94.070 (88.5, 101.0) |
92.440 (89.9, 101.5) |
−0.198 |
0.843 |
舌色–舌尖RGB-R |
169.095 (163.5, 175.9) |
174.780 (165.4, 179.2) |
−2.037 |
0.042* |
舌色–舌尖RGB-G |
105.200 (99.0, 113.3) |
110.440 (103.7, 118.6) |
−2.000 |
0.045* |
舌色–舌尖RGB-B |
107.800 (102.7, 113.1) |
107.170 (101.5, 116.2) |
−0.500 |
0.617 |
注：*P < 0.05，**P < 0.01。
对冠心病人群淡红舌(n = 113)与正常人群淡红舌(n = 141)的舌色RGB参数进行Mann-Whitney检验，结果显示：共8个舌色RGB参数存在统计学差异，其中舌色–舌中RGB-R和舌色–舌尖RGB-B差异最显著；冠心病人群淡红舌的舌色–全舌RGB-R、舌色–舌中RGB-R、舌色–舌右RGB-R数值低于正常人群，舌色–舌左RGB-B、舌色–舌尖RGB-G、舌色–舌尖RGB-B数值高于正常人群；其余10个参数(如舌根全区域、舌尖RGB-R等)无统计学差异，见表8。
对冠心病人群红舌(n = 23)与正常人群红舌(n = 15)的舌色RGB参数进行Mann-Whitney检验，结果显示：所有18个舌色RGB参数均无统计学差异(P > 0.110)，其中舌色–舌中RGB-G (P = 0.940)是差异最不明显的参数，舌色–舌根和舌色–舌尖RGB-B是最接近差异标准但未达标的参数；两组在各区域的RGB-R、RGB-G、RGB-B数值上虽有小幅波动，但均未达到统计学差异水平，是唯一舌色参数全区域无差异的舌色类型，见表9。
Table 8. Comparison among the pale red tongue groups
表8. 淡红舌组间比较
|
冠心病组淡红(n = 113) |
健康组淡红(n = 141) |
Z值 |
P |
舌色–全舌RGB-R |
151.870 (145.0, 159.0) |
155.690 (148.1, 162.0) |
−2.472 |
0.013* |
舌色–全舌RGB-G |
97.960 (91.0, 105.5) |
97.180 (91.6, 104.5) |
−0.527 |
0.598 |
舌色–全舌RGB-B |
98.240 (93.4, 103.4) |
96.210 (91.3, 102.6) |
−1.786 |
0.074 |
舌色–舌中RGB-R |
169.330 (161.0, 176.2) |
174.350 (166.7, 180.0) |
−3.592 |
0.000** |
舌色–舌中RGB-G |
113.880 (104.6, 123.6) |
115.980 (106.2, 124.8) |
−0.803 |
0.422 |
舌色–舌中RGB-B |
114.750 (105.4, 121.2) |
114.670 (109.0, 122.5) |
−0.400 |
0.689 |
舌色–舌根RGB-R |
127.430 (117.0, 138.2) |
130.010 (117.9, 142.6) |
−1.427 |
0.153 |
舌色–舌根RGB-G |
88.430 (78.3, 98.0) |
87.440 (77.4, 96.8) |
−0.373 |
0.709 |
舌色–舌根RGB-B |
86.010 (77.9, 93.9) |
84.950 (76.3, 92.3) |
−0.939 |
0.348 |
舌色–舌左RGB-R |
149.900 (140.9, 157.8) |
153.160 (144.7, 161.1) |
−1.816 |
0.069 |
舌色–舌左RGB-G |
94.240 (88.0, 101.6) |
93.520 (87.1, 100.8) |
−1.089 |
0.276 |
舌色–舌左RGB-B |
95.820 (89.8, 102.6) |
92.310 (87.0, 98.6) |
−2.763 |
0.006** |
舌色–舌右RGB-R |
149.320 (140.8, 155.6) |
153.900 (146.5, 160.5) |
−3.392 |
0.001** |
舌色–舌右RGB-G |
95.060 (88.7, 100.9) |
95.830 (88.5, 102.6) |
−0.249 |
0.803 |
舌色–舌右RGB-B |
94.550 (89.8, 101.1) |
94.990 (88.9, 100.1) |
−0.739 |
0.460 |
舌色–舌尖RGB-R |
170.160 (163.5, 176.5) |
168.990 (161.3, 177.2) |
−0.620 |
0.536 |
舌色–舌尖RGB-G |
103.690 (98.4, 111.9) |
99.590 (92.6, 109.4) |
−3.281 |
0.001** |
舌色–舌尖RGB-B |
107.340 (103.5, 112.3) |
102.750 (96.0, 108.0) |
−4.985 |
0.000** |
注：*P < 0.05，**P < 0.01。
Table 9. Comparison among red tongue groups
表9. 红舌组间比较
参数 |
冠心病组红(n = 23) |
健康组红(n = 15) |
Z值 |
P |
舌色–全舌RGB-R |
145.440 (137.3, 153.9) |
147.430 (141.6, 154.8) |
−1.090 |
0.276 |
舌色–全舌RGB-G |
96.790 (82.3, 106.3) |
90.310 (81.2, 103.4) |
−0.642 |
0.521 |
舌色–全舌RGB-B |
93.870 (87.1, 97.3) |
88.620 (83.3, 94.3) |
−1.090 |
0.276 |
舌色–舌中RGB-R |
161.220 (153.2, 174.7) |
170.520 (158.4, 176.5) |
−1.150 |
0.250 |
舌色–舌中RGB-G |
109.920 (97.6, 127.5) |
118.510 (99.9, 123.0) |
−0.075 |
0.940 |
舌色–舌中RGB-B |
107.820 (96.5, 113.5) |
106.900 (100.7, 116.7) |
−0.642 |
0.521 |
舌色–舌根RGB-R |
115.540 (107.0, 122.4) |
121.710 (111.1, 134.5) |
−1.568 |
0.117 |
舌色–舌根RGB-G |
81.150 (70.8, 88.0) |
79.750 (74.8, 92.3) |
−0.732 |
0.464 |
舌色–舌根RGB-B |
75.050 (65.3, 78.3) |
77.510 (67.7, 86.1) |
−0.851 |
0.395 |
舌色–舌左RGB-R |
147.000 (132.1, 155.7) |
145.930 (138.3, 152.9) |
−0.552 |
0.581 |
舌色–舌左RGB-G |
94.010 (82.5, 103.7) |
88.470 (80.3, 99.1) |
−0.791 |
0.429 |
舌色–舌左RGB-B |
91.620 (85.9, 95.3) |
84.630 (79.5, 91.8) |
−1.209 |
0.226 |
舌色–舌右RGB-R |
146.630 (135.5, 153.7) |
144.310 (139.7, 150.8) |
−0.493 |
0.622 |
舌色–舌右RGB-G |
92.990 (80.0, 108.9) |
88.830 (79.2, 98.4) |
−0.612 |
0.540 |
舌色–舌右RGB-B |
91.590 (84.5, 96.8) |
86.250 (81.2, 95.3) |
−1.329 |
0.184 |
舌色–舌尖RGB-R |
166.240 (157.7, 172.5) |
164.980 (159.2, 173.0) |
−0.105 |
0.917 |
舌色–舌尖RGB-G |
103.380 (86.2, 113.5) |
95.250 (90.6, 110.5) |
−1.120 |
0.263 |
舌色–舌尖RGB-B |
103.580 (98.2, 112.4) |
97.510 (93.6, 101.0) |
−1.598 |
0.110 |
对冠心病人群淡紫舌(n = 44)与正常人群淡紫舌(n = 9)的舌色RGB参数进行Mann-Whitney检验，结果显示：共6个舌色RGB参数存在统计学差异，其中舌色–舌尖RGB-G和舌色–舌尖RGB-B差异最显著；冠心病淡紫舌的舌色–全舌RGB-G、舌色–舌中RGB-G、舌色–舌左RGB-G、舌色–舌左RGB-B、舌色–舌尖RGB-G、舌色–舌尖RGB-B数值均高于正常人群；其余12个参数(如舌根全区域、全舌RGB-R等)无统计学差异，舌色–舌中RGB-R (P = 0.850)是差异最不明显的参数，见表10。
Table 10. Comparison among the pale purple tongue groups
表10. 淡紫舌组间比较
参数 |
冠心病组淡紫(n = 44) |
健康组淡紫(n = 9) |
Z值 |
P |
舌色–全舌RGB-R |
148.205 (143.3, 157.8) |
147.990 (140.0, 156.4) |
−0.663 |
0.507 |
舌色–全舌RGB-G |
103.215 (96.2, 110.7) |
98.000 (87.5, 101.0) |
−2.298 |
0.022* |
舌色–全舌RGB-B |
101.610 (95.5, 109.4) |
97.500 (90.7, 104.2) |
−1.635 |
0.102 |
舌色–舌中RGB-R |
168.030 (160.9, 178.1) |
163.970 (163.1, 174.5) |
−0.190 |
0.850 |
舌色–舌中RGB-G |
124.345 (113.8, 132.7) |
115.380 (108.3, 120.3) |
−2.014 |
0.044* |
舌色–舌中RGB-B |
118.785 (111.4, 129.1) |
116.240 (111.1, 125.9) |
−0.592 |
0.554 |
舌色–舌根RGB-R |
127.670 (112.4, 141.7) |
125.640 (115.1, 134.0) |
−0.308 |
0.758 |
舌色–舌根RGB-G |
93.370 (81.1, 105.7) |
85.980 (82.8, 97.3) |
−0.746 |
0.456 |
舌色–舌根RGB-B |
85.570 (77.6, 99.2) |
84.610 (78.6, 94.2) |
−0.284 |
0.776 |
舌色–舌左RGB-R |
146.980 (141.9, 155.7) |
144.280 (135.2, 153.1) |
−0.829 |
0.407 |
舌色–舌左RGB-G |
101.370 (92.5, 108.6) |
94.000 (81.8, 97.2) |
−2.250 |
0.024* |
舌色–舌左RGB-B |
100.340 (93.2, 108.0) |
92.040 (85.3, 100.5) |
−2.037 |
0.042* |
舌色–舌右RGB-R |
147.155 (139.3, 154.9) |
144.280 (135.5, 154.2) |
−0.355 |
0.722 |
舌色–舌右RGB-G |
99.350 (92.9, 109.2) |
95.410 (84.5, 98.8) |
−1.777 |
0.076 |
舌色–舌右RGB-B |
99.770 (90.0, 107.8) |
95.540 (88.0, 101.9) |
−1.374 |
0.169 |
舌色–舌尖RGB-R |
166.725 (158.2, 174.1) |
160.700 (154.0, 169.7) |
−1.137 |
0.256 |
舌色–舌尖RGB-G |
112.090 (101.1, 115.7) |
96.210 (89.2, 99.9) |
−3.719 |
0.000** |
舌色–舌尖RGB-B |
112.025 (103.2, 119.1) |
101.570 (95.2, 104.9) |
−3.080 |
0.002** |
注：*P < 0.05，**P < 0.01。
4. 研究结论
4.1. 整体分析
本研究通过对冠心病人群(209例)与正常人群(203例)的舌色与苔色分布及舌象RGB参数展开数据分析，结合不同苔色(白苔、黄白相兼苔)与不同舌色(淡舌色、淡红舌色、红舌色、淡紫舌色)亚组的分层对比，得出以下结论：(1) 两组间舌色分布差异显著，苔色分布无明显区分。从整体舌象定性特征来看，两组舌色分布存在极显著差异：冠心病人群淡红舌占比(54.07%)显著低于正常人群(69.46%)，淡紫舌占比(21.05%)显著高于正常人群(4.43%)，提示淡紫舌可能是冠心病患者舌色的典型特征之一；而两组苔色分布无统计学差异，冠心病人群与正常人群的黄苔、白苔、黄白相兼苔占比接近，说明苔色在冠心病与健康人群的初步区分中可能不甚明显；(2) 舌象RGB参数差异明确，为舌诊客观化研究提供数据支撑：① 整体舌色参数：冠心病人群红色颜色分量数值较小，绿蓝色颜色分量数值较大，两组整体舌色RGB参数对比显示，冠心病人群在全舌、舌中、舌左、舌右等关键区域的RGB-R值多低于正常人群，全舌、舌左、舌尖等区域的RGB-G、RGB-B值多高于正常人群，客观印证了冠心病人群舌色偏暗、可能伴随瘀象的特征，与中医“心脉瘀阻”病机相契合；② 整体苔色参数：冠心病人群与正常人群的苔色RGB参数整体存在显著差异，除舌中RGB-R (P = 0.063)外，全舌、舌根、舌左、舌右、舌尖等区域的苔色RGB-R、RGB-G、RGB-B值均为冠心病人群高于正常人群，表明冠心病人群苔色在红、绿、蓝三通道的色彩强度上显著高于健康人群，可为苔色客观化评估提供量化依据。
4.2. 亚组分析
(1) 不同苔色亚组：由于黄苔例数较少，所以未对两组黄苔进行对比分析。白苔亚组：全舌、舌根、舌左、舌右、舌尖区域的舌苔RGB参数存在差异(P < 0.05或P < 0.01)，仅舌中区域无差异，差异覆盖度有限；黄白相兼苔亚组：全舌、舌中、舌根、舌左、舌右、舌尖6个区域的舌苔RGB参数均存在统计学差异，无任何区域例外，且冠心病人群所有参数值均高于正常人群，是差异覆盖最全面、区分度最强的苔色类型，提示黄白相兼苔的舌苔RGB参数在冠心病诊断中可能有较高临床价值。
(2) 不同舌色亚组：淡舌差异集中于全舌、舌中、舌右、舌尖的RGB-R及舌尖RGB-G，冠心病人群参数均低于正常人群，舌根、舌左区域无差异，诊断需聚焦非舌根区域的红色调与舌尖绿色调；淡红舌差异呈“双向性”，冠心病人群全舌、舌中、舌右的RGB-R低于正常人群，舌左RGB-B、舌尖RGB-G/B高于正常人群，差异覆盖度最广，是舌色参数中区别最大的类型；红舌的所有18个舌色RGB参数均无统计学差异；淡紫舌差异仅存在于RGB-G/B通道，冠心病人群全舌、舌中、舌左、舌尖的RGB-G/B值高于正常人群，尤其舌尖RGB-G/B差异极显著，与淡紫舌色“瘀滞”的中医辨证相符合，是该类人群潜在的生物标志物。
5. 讨论
本研究通过定性与定量结合，明确了冠心病患者舌象的核心特征：舌色以淡紫舌占比较高、红色调偏浅为主要特征，舌苔以全区域色彩强度升高为典型表现，且不同苔色、舌色亚组的差异参数可为冠心病的分层评估提供细化依据。这些发现不仅丰富了中医舌诊在冠心病诊断中的客观化证据，也为后续开发基于舌象RGB参数的冠心病辅助诊断工具奠定了数据基础；同时本研究也存在一定局限性，首先是样本量较小，后续仍需继续扩大舌象采集的样本量，为正常人群和患病人群的舌象对比提供更多的数据基础，提升结果的精确性；其次，本研究仅基于RGB颜色模型进行分析研究，但还有多种颜色模型也应用于舌象客观化研究中，是否有精确度更高、反应舌象更真实的颜色模型选择尚需进一步研究；最后，本研究仅涉及正常人群和冠心病患病人群的舌象数据对比分析，但正常人群与其他疾病患病人群是否存在差异，尚需进一步对比分析，同时在不断扩展舌象采集样本量的基础上，应收集更多基线资料与临床信息，以求更精确的对不同人群的舌象参数进行分类对比，为后续开发基于舌象的疾病辅助诊断工具、制定舌诊标准化流程提供数据支撑。
NOTES
*通讯作者。