The prevalence of subclinical hypothyroidism in a pre-diabetes population and an analysis of related factors

Figures & data

Table 1. Baseline data distribution of survey population.

Characteristics	Number of cases	Composition ratio
Area
Urban	1597	55.53%
Rural	1279	44.47%
Education
Illiteracy	346	12.03%
Primary school	282	9.81%
Junior high school	455	15.82%
Senior high school/technical secondary school	468	16.27%
Undergraduate/junior college	1252	43.53%
Postgraduate	73	2.54%
Profession
Worker	790	27.47%
Farmer	1079	37.52%
Staff	664	23.09%
Housework	53	1.84%
Student	97	3.37%
Other	193	6.71%
Annual household income (1000 yuan)
≤5	62	2.16%
5–10	178	6.19%
10–30	627	21.80%
30–50	570	19.82%
50–100	935	32.51%
>100	504	17.52%

Table 2. Comparison of general data in SCH and euthyroid group among PreDM population.

Characteristics	Total (n = 426)
	Euthyroid group n = 328	SCH group n = 98	t/z	P
Age	52.53 ± 14.33	49.95 ± 11.39	1.851	0.066
BMI (kg/m^2)	24.80 ± 3.25	24.98 ± 3.06	–0.481	0.631
SBP (mmHg)	134.10 ± 18.87	136.31 ± 17.44	–1.031	0.303
DBP (mmHg)	81.23 ± 11.48	82.03 ± 11.95	–0.601	0.548
FPG (mmol/L)	5.65 ± 0.64	5.76 ± 0.65	–1.593	0.112
TG (mmol/L)	1.82 ± 1.13	2.01 ± 1.97	–1.205	0.229
TC (mmol/L)	4.65 ± 0.96	4.85 ± 0.94	–1.853	0.065
LDL-C (mmol/L)	2.89 ± 0.72	2.91 ± 0.67	–0.267	0.789
HDL-C (mmol/L)	1.46 ± 0.36	1.47 ± 0.34	–0.038	0.970
HbA1c(%)	5.53 ± 0.53	5.43 ± 0.47	1.655	0.099
TSH (mIU/L)	2.65 ± 1.31	6.87 ± 3.69	–11.094	<0.001
serum calcium (mmol/L)	2.19 ± 0.14	2.21 ± 0.10	–1.448	0.148
Serum phosphate (mmol/L)	0.99 ± 0.16	1.05 ± 0.19	3.176	0.002
UIC M (P25,P75)/(μg/L)	213.35 (148.95, 296.03)	193.35 (134.68, 301.33)	–0.386	0.700
UA M (P25,P75)/(μmol/L)	286 (227, 358.5)	268 (218, 336)	–1.743	0.081
TPOAb M (P25,P75)/(IU/L)	9.42 (6.75, 13.98)	10.58 (7.81, 16.18)	2.223	0.026
TgAb M (P25,P75)/(IU/L)	10.87 (10.00, 17.80)	14.69 (10.00, 22.79)	2.824	0.005

Table 3. Comparison of thyroid-related indicators in SCH and euthyroid group among PreDM population.

Characteristics	Total (n = 426)
	Euthyroid group				SCH group
	Male (n = 189)	Female (n = 139)	t/z	P	Male, n = 39	Female, n = 59	t/z	P
TSH (mIU/L)	2.52 ± 1.31	2.82 ± 1.29	–2.062	0.04	6.43 ± 2.40	7.15 ± 4.34	–0.944	0.348
TPOAb M (P25, P75)/(IU/L)	8.73 (6.52, 12.38)	11.47 (7.30,19.34)	3.938	<0.001	9.36 (7.61, 14.06)	12 (9.08,19.24)	2.341	0.019
TgAb M (P25, P75)/(IU/L)	10 (10.00,15.09)	12.64 (10.00,22.07)	3.498	<0.001	13.21 (10.00, 17.42)	15.48 (10.00,60.21)	1.488	0.137

Table 4. Comparison of the prevalence of SCH in PreDM and its subtype population.

	Male		Female		P*	χ^2	Total
	n	n-SCH (%)	n	n-SCH (%)			n (%)	n-SCH (%)
PreDM	229	39 (17.03)	204	59 (28.92)	0.002	9.639	433	98 (22.63)
IFG	44	7 (15.91)	43	20 (46.51)	0.003	9.124	87	27 (31.30)
IGT	150	26 (17.33)	137	31 (22.63)	0.188	1.733	287	57 (19.86)
IFG + IGT	35	6 (17.14)	24	8 (33.33)	0.151	2.062	59	14 (23.73)
NGT	1114	192 (17.24)	1112	258 (23.20)	<0.001	13.533	2226	450 (20.22)
P^#	0.890		0.076		–		0.276
χ^2	0.019		3.158				1.188
Total	1343	231(17.20)	1316	317(24.09)	<0.001	19.273	2659	548 (20.61)

n: Total number of subjects; n-SCH: number of patients with subclinical hypothyroidism; P*: Comparison between male and female patients with SCH; P^#: Comparison between PreDM and NGT patients with SCH.

Figure 1. Distribution of SCH prevalence in different age groups under different glucose metabolism.

Table 5. SCH prevalence in different age groups under different glucose metabolism.

	NGT		PreDM		Prevalence of SCH in different subtypes of PreDM
					IFG		IGT		IFG + IGT
Age	n	n-SCH (n, %)	n	n-SCH (n, %)	n	n-SCH (n, %)	n	n-SCH (n, %)	n	n-SCH (n, %)
18–30	727	114 (15.68)	32	7 (21.88)	9	2 (22.22)	22	4 (18.18)	1	1 (100.00)
31–40	563	96 (17.05)	56	11 (19.64)	10	3 (30.00)	40	5 (12.50)	6	3 (50.00)
41–50	484	107 (22.11)	109	28 (25.69)	27	9 (33.33)	72	17 (23.61)	10	2 (20.00)
51–60	257	98 (38.13)	122	37 (30.33)	24	10 (41.67)	83	23 (27.71)	15	4 (26.67)
Total (18–60)	2031	415 (20.40)	319	83 (26.02)^#	70	24 (34.29)^#	217	49 (22.58)	32	10 (31.25)
≥61^a	195	35 (17.95)	114	15 (13.16)	17	3 (17.65)	70	8 (11.43)	27	4 (14.81)
≥65^a	131	12 (9.16)	79	5 (6.33)	13	1 (7.69)	49	0 (0.00)	17	4 (23.53)
Total^a (18–87)	2226	450 (20.22)	433	98 (22.63)	87	27 (31.03)^#	287	57 (19.86)	59	14 (23.73)
χ^2		71.810		11.343		3.459		8.615		6.836
P		<0.001		0.023		0.484		0.071		0.145
≥61^b	195	59 (30.26)	114	37 (32.45)	17	7 (41.18)	70	18 (25.71)	27	12 (44.44)
≥65^b	131	36 (27.48)	79	27 (34.18)	13	5 (38.46)	49	14 (28.57)	17	8 (47.06)
Total^b (18–87)	2226	474 (21.29)	433	120 (27.71)^#	87	32 (36.78)^#	287	74 (25.78)	59	22 (37.29)^#

n: Total number; n-TN: Number of patients with SCH; %: prevalence; P: Comparison of the prevalence of SCH among different ages; ^#: Comparison of SCH between PreDM/IFG/IGT/IFG + IGT population and NGT population, P < 0.05.

Figure 2. Thyroid antibodies in different populations.

Table 6. Thyroid antibodies in different populations.

Group	Total (2876)		P	χ^2	SCH (591)		P	χ^2	PreDM (433)		P	χ^2	SCH + PreDM(98)		P	χ^2
Gender	Male (1463)	Female (1413)			Male (249)	Female (342)			Male (229)	Female (204)			Male (39)	Female (59)
TPOAb (+)	72	169	<0.001	46.387	21	56	0.005	8.018	6	13	0.057	3.621	3	8	0.368	0.811
TgAb (+)	61	194	<0.001	81.301	16	67	<0.001	13.330	8	9	0.623	0.241	2	4	0.739	0.111
TPOAb (+) and TgAb (+)	35	93	<0.001	29.665	10	31	0.017	5.688	5	18	0.002	9.458	1	5	0.232	1.427
TPOAb (+) or TgAb (+)	63	177	<0.001	63.503	17	61	<0.001	15.244	14	22	0.079	3.088	4	7	0.805	0.061
Both negative	1365	1143	<0.001	99.203	222	250	<0.001	23.103	210	164	0.001	11.728	34	47	0.336	0.926

Table 7. Logistic regression analysis of SCH risk factors in PreDM and IFG populations.

	PreDM			IFG
	P	OR	95% Cl	P	OR	95% Cl
Gender	0.024	0.297	0.104–0.851	0.018	0.238	0.072–0.784
FPG	0.010	1.667	1.132–2.454	0.684	0.620	0.062–6.202
OGTT 2 h	0.217	0.891	0.742–1.070	0.043	1.894	1.020–3.514
TSH	<0.001	5.012	3.456–7.268	0.003	4.325	2.390–6.515
TPOAb	0.465	1.001	0.998–1.003	0.032	1.016	1.001–1.030

Data availability statement

The data that support the findings of this study are available from the corresponding author.