Different Roles of TP53 Codon 72 Polymorphism in Type 2 Diabetes and Its Complications: Evidence from a Case-Control Study on a Chinese Han Population

Figures & data

Table 1 The Distribution of TP53 Pro72Arg Polymorphism in the T2DM Patients and Non-Diabetic Controls

Genotype/Allele	Patients, N = 206 n (%)	Control, N = 446 n (%)	P value	OR (95% CI)
Pro/Pro	24 (11.7)	84 (18.8)	0.268
Pro/Arg	120 (58.3)	240 (53.8)
Arg/Arg	62 (30.0)	122 (27.4)
Pro/Arg+Arg/Arg	182 (88.3)	362 (81.2)	0.022 (vs Pro/Pro)	1.089 (1.018–1.164)
Arg72 variant	0.592	0.543	0.093	1.091 (0.987–1.207)
HWE test	χ^2 = 8.75 p = 0.003	χ^2 = 3.15 p = 0.076

Note: Bold type indicates a statistically significant difference (p<0.05).

Abbreviations: OR, odds ratio; 95% CI, 95% confidence interval; HWE, Hardy–Weinberg equilibrium.

Table 2 Clinical Characteristics of T2DM Patients, Stratified According to the TP53 Pro72Arg Polymorphism

	Pro/Pro	Pro/Arg	Arg/Arg	P value
Age at study (years old)	59.8 ± 13.1	62.0 ± 13.3	64.5 ± 10.8	0.239
Onset age (years old)	53.3 ± 11.9	52.2 ± 12.3	54.5 ± 8.9	0.455
Duration of diabetes (years)	5 (8)	7 (11.5)	8 (29.5)	0.198
Sex (Male/Female)	10/14	70/50	30/32	0.209
BMI (kg/m^2)	24.9 ± 3.24	23.7 ± 3.61	24.5 ± 3.63	0.173
Hypertension, n (%)	13 (54.2)	53 (44.2)	29 (46.8)	0.667
Family history, n (%)	7 (31.8)	30 (26.1)	19 (32.2)	0.656
HbAc (%)	9.39 ± 1.68	9.01 ± 1.93	9.02 ± 1.66	0.638
Triglyceride (mmol/L)	2.51 ± 2.17	1.98 ± 3.06	2.54 ± 2.78	0.402
Total cholesterol (mmol/L)	5.02 ± 1.28	4.97 ± 1.03	4.88 ± 1.41	0.451
HDL-cholesterol (mmol/L)	1.36 ± 0.53	1.31 ± 0.38	1.33 ± 0.45	0.854
LDL-cholesterol (mmol/L)	2.92 ± 1.42	3.06 ± 1.21	3.01 ± 1.31	0.877
Diabetic nephropathy, n (%)	8 (33.3)	42 (35.0)	19 (30.6)	0.840
Diabetic neuropathy, n (%)	6 (25.0)	22 (18.3)	4 (6.45)	0.044
Diabetic retinopathy, n (%)	7 (29.2)	36 (31.0)	9 (14.8)	0.058
Insulin use, n (%)	17 (70.8)	87 (72.5)	49 (79.0)	0.582

Notes: Data are presented as the mean ± standard deviation (SD), median (quartile range) or number (percentage), and the bold type indicates a statistically significant difference (p<0.05).

Abbreviations: BMI, body mass index; HbAc, hemoglobin A1c; HDL, high-density lipoprotein; LDL, low-density lipoprotein.

Figure 1 The diabetic complication rates of T2DM patients stratified according to TP53 Pro72Arg polymorphism. Numbers within the bars represent number of observed patients with complications and total number of surveyed patients. Significant level in multiple comparisons among the three genotype groups was adjusted using Bonferroni correction, and the p values in bold type were significant differences between the two groups.

Figure 2 Association of the TP53 common polymorphism with mtDNA content in T2DM patients. Relative mtDNA content of the MT-ND1 (A) and MT-CO2 (B) indexes in leukocytes isolated from T2DM patients. Each solid circle represents one checked sample of the mtDNA content analysis. Lines across the scatter dot represent the median. p<0.01 versus the merged group of Pro/Pro and Pro/Arg genotypes, by Mann–Whitney test.

Figure 3 Representative result of ethidium bromide-stained agarose gel electrophoresis showed no abnormal mtDNA sequence deletion in mtDNA4977 deletion detection of leukocytes from T2DM patients. Genotypes of the TP53 Pro72Arg polymorphism and patient IDs are shown, respectively.

Figure 4 Association of the TP53 common polymorphism with mtRNA expressions in T2DM patients. Each solid circle represents one checked sample in RT-qPCR analysis. Lines across the scatter dot represent the median. The p values in bold type were significant differences between the Arg/Arg group and the merged group of Pro/Pro and Pro/Arg genotypes, by Mann–Whitney test.