Environmental mineral density and thyroid malignancy: A multicenter cross-sectional study

Table 1 Sociodemographic characteristics of the study participants according to the type of nodule, n (%)

Variables	All (n = 529)	Single (n = 74)	Multiple (n = 455)	P value
Age (years)	44.2 ± 14.6	45.0 ± 14.9	44.0 ± 14.2	0.21
≤ 20	35 (6.6)	8 (10.8)	7 (5.9)
21-30	54 (10.2)	2 (2.7)	52 (11.4)
31-40	135 (25.5)	19 (25.7)	116 (25.5)
41-50	127 (24.0)	19 (25.7)	108 (23.7)
51-60	96 (18.1)	14 (18.9)	82 (18.0)
> 60	82 (15.5)	12 (16.2)	70 (15.4)
Sex				0.36
Male	82 (15.6)	13 (17.6)	69 (15.3)
Female	444 (84.4)	61 (82.4)	383 (84.7)
Marital status				0.63
Married	373 (75.1)	51 (77.3)	322 (74.7)
Single	115 (23.1)	13 (19.7)	102 (23.7)
Divorced/widowed	9 (1.8)	2 (3.0)	7 (1.6)
Province of residence				0.28
Kinshasa	468 (88.5)	64 (86.5)	404 (88.8)
Katanga	18 (3.4)	1 (1.4)	17 (3.7)
South Kivu	43 (8.1)	9 (12.2)	34 (7.5)

Table 2 Clinical characteristics of the study participants according to the type of nodule, n (%)

Variables	All (n = 529)	Single (n = 74)	Multiple (n = 455)	P value
Parity				0.67
Nulliparous	65 (14.6)	10 (16.4)	55 (14.3)
Primiparous	40 (9.0)	5 (8.2)	35 (9.1)
Pauciparous	102 (22.9)	17 (27.9)	85 (22.1)
Multiparous	239 (53.6)	29 (47.5)	210 (54.5)
Gravida				0.51
Nulligravid	71 (16.0)	11 (18.0)	60 (15.6)
Primigravid	40 (9.0)	3 (4.9)	37 (9.6)
Multigravid	334 (75.1)	47 (77.0)	287 (74.7)
Abortion	83 (18.7)	15 (24.6)	68 (17.7)	0.14
Family history of thyroid pathology	352 (66.5)	51 (68.9)	301 (66.2)	0.37
First degree	205 (58.2)	30 (60.0)	175 (57.9)
Second degree	147 (41.8)	20 (40.0)	127 (42.1)
Anterior-cervical mass	503 (95.1)	71 (95.9)	391 (95.8)	0.1
Overweight	195 (36.9)	23 (31.1)	172 (37.8)	0.16
Obesity	187 (35.3)	28 (37.8)	159 (34.9)	0.36
Clinical lymphadenopathy	46 (8.7)	10 (13.5)	36 (7.9)	0.09
Systolic blood pressure	135.6 ± 58.6	131.4 ± 13.8	135.8 ± 65.5	0.79
Diastolic blood pressure	72.6 ± 8.9	73.9 ± 8.5	72.3 ± 9.2	0.48
Body mass index	29.8 ± 12.1	29.5 ± 3.1	29.9 ± 13.6	0.96
Heart rate	83.0 ± 11.0	82.0 ± 11.6	83.1 ± 10.6	0.56
Total volume	70.9 ± 31.5	68.5 ± 30.8	70.8 ± 32.2	0.6
Thyroid function				0.63
Euthyroid	464 (87.7)	63 (85.1)	401 (88.1)
Hyperthyroid	50 (9.5)	9 (12.2)	41 (9.0)
Hypothyroid	15 (2.8)	2 (2.7)	13 (2.9)

Table 3 Ultrasonographic features of thyroid nodules, n (%)

Variables	All (n = 529)	Simple (n = 74)	Multiple (n = 408)	P value
Echostructure				0.84
Solid	382 (72.2)	53 (71.6)	329 (72.3)
Liquid	12 (2.3)	1 (1.4)	11 (2.4)
Mixed	135 (25.5)	20 (27.0)	115 (25.3)
Echogenicity				0.33
Hypoechoic	447 (84.5)	59 (79.7)	388 (85.3)
Isoechoic	81 (15.3)	15 (20.3)	66 (14.5)
Anechoic	1 (0.2)	0 (0.0)	1 (0.2)
Size				0.36
Macronodule	315 (59.8)	50 (67.6)	265 (58.5)
Micronodule	82 (15.6)	9 (12.2)	73 (16.1)
Mixed	130 (24.7)	15 (20.3)	115 (25.4)
Microcalcifications				0.5
No	453 (85.6)	64 (86.5)	389 (85.5)
Yes	76 (14.4)	10 (13.5)	66 (14.5)
Adenopathy				0.35
No	447 (84.5)	61 (82.4)	386 (84.8)
Yes	82 (15.5)	13 (17.6)	69 (15.2)

Table 4 Histopathological characteristics of thyroid nodules, n (%)

Variables	Number (n = 529)
Histopathology
Benign nodules	441 (77.7)
Malignant nodules	118 (22.3)
Benign nodules
Colloid goiter	302 (73.5)
Adenomatoid goiter	36 (8.8)
Follicular adenoma	20 (4.9)
Macrofollicular adenoma	18 (4.4)
Follicular cyst	8 (1.9)
Adenomatoid nodule	5 (1.2)
Thyroid abscess	3 (0.7)
Follicular adenoma	3 (0.7)
Microfollicular adenoma	3 (0.7)
Reactive lymphadenopathy	3 (0.7)
Chronic strumitis	3 (0.7)
Grave’s disease	2 (0.5)
Non toxic adenoma	1 (0.2)
Toxic adenoma	1 (0.2)
Granulomatous thyroid	1 (0.2)
Dequervain's subacute thyroiditis	1 (0.2)
Hashimoto’s thyroiditis	1 (0.2)
Malignant nodules
Papillary carcinoma	79 (66.9)
Follicular carcinoma	26 (22.0)
Anaplastic carcinoma	9 (7.6)
Lymphoma	3 (2.5)
Medullary carcinoma	1 (0.8)

Table 5 Sociodemographic and clinical characteristics of thyroid nodules, based on histopathology, n (%)

Variables	N	Benign nodule	Malignant nodule	P value
Age (years)				0.003
≤ 20	35	31 (87.1)	4 (12.9)
21-60	412	333 (80.8)	79 (19.2)
> 60	82	47 (57.3)	35 (42.7)
Sex				0.061
Male	82	58 (70.7)	24 (29.3)
Female	444	352 (79.3)	92 (20.7)
Residential province				0.044
Kinshasa	468	364 (77.8)	104 (22.2)
Katanga	18	10 (55.6)	8 (44.4)
South Kivu	43	37 (86.0)	6 (14.0)
Marital status				0.26
Married	373	293 (78.6)	80 (21.4)
Single	115	85 (73.9)	30 (26.1)
Divorced/widowed	9	7 (77.8)	2 (22.2)
Parity				0.16
Nulliparous	65	46 (70.8)	19 (29.2)
Primiparous	40	32 (80.0)	8 (20.0)
Pauciparous	102	87 (85.3)	15 (14.7)
Multiparous	239	187 (78.2)	52 (21.8)
Gravida				0.311
Nulligravid	71	51 (71.8)	20 (28.2)
Primigravid	40	32 (80.0)	8 (20.0)
Multigravid	334	268 (80.2)	66 (19.8)
Family history of thyroid pathology				0.022
No	177	147 (83.1)	30 (16.9)
Yes	352	264 (75.0)	88 (25.0)
Body mass index				0.51
Normal	25	22 (88.0)	3 (12.0)
Overweight	195	150 (76.9)	45 (23.1)
Obesity	187	146 (78.1)	41 (21.9)
Lymphadenopathy				< 0.001
No	100.0	397 (82.2)	86 (17.8)
Yes	100.0	14 (30.4)	32 (69.6)

Table 6 Ultrasound characteristics of benign and malignant thyroid nodules, n (%)

Variables	N	Benign nodule	Malignant nodule	P value
Echostructure				< 0.001
Solid	382	268 (70.2)	114 (29.8)
Liquid	12	12 (100.0)	0 (0.0)
Mixed	135	4 (97.0)	4 (3.0)
Echogenicity				< 0.001
Hypoechoic	447	330 (73.8)	117 (26.2)
Isoechoic	81	80 (98.8)	1 (1.2)
Anechoic	1	1 (100.0)	0 (0.0)
Number				0.284
Single	74	55 (74.3)	19 (25.7)
Multiple	455	356 (79.2)	99 (20.8)
Size				< 0.001
Macronodule	315	211 (67.0)	104 (33.0)
Micronodule	82	81 (98.8)	1 (1.2)
Mixed	130	119 (91.5)	11 (8.5)
Calcifications				< 0.001
No	453	376 (83.0)	77 (17.0)
Yes	76	35 (46.1)	41 (53.9)
Adenopathy				< 0.001
No	447	382 (85.5)	65 (14.5)
Yes	82	29 (35.4)	53 (64.6)

Table 7 Sociodemographic, clinical and ultrasonographic features associated with malignancy in thyroid nodules

Variables	Univariate analysis		Multivariate analysis
	P value	OR (95%CI)	P value	Adjusted OR (95%CI)
Age (years)
≤ 20		1		1
21-60	0.319	1.52 (0.67-3.46)	0.614	1.32 (0.26-2.24)
> 60	0.003	2.81 (1.37-5.78)	0.025	2.81 (1.14-6.94)
Province of origin of the sample
South Kivu		1		1
Kinshasa	0.212	1.76 (0.72-4.29)	0.116	2.47 (0.80-7.62)
Katanga	0.014	4.93 (1.39-17.54)	0.036	8.19 (1.14-12.45)
Family history of thyroid pathology
No		1		1
Yes	0.022	1.63 (1.03-2.59)	0.105	1.65 (0.90-3.34)
Clinical LAD
No		1		1
Yes	< 0.001	10.55 (5.40-20.62)	0.760	1.20 (0.38-3.82)
Echostructure
Liquid		1		1
Solid	< 0.001	15.21 (5.50-42.07)	0.001	7.69 (2.40-24.58)
Echogenicity
Isoechoic		1		1
Hypoechoic	< 0.001	18.72 (3.95-28.68)	0.017	14.19 (1.60-25.93)
Size
Micronodule		1		1
Macronodule	< 0.001	5.33 (2.75-10.33)	< 0.001	9.13 (4.19-19.89)
Calcification
No		1		1
Yes	< 0.001	5.72 (3.42-9.55)	0.017	2.60 (1.19-5.70)
Sonographic LAD
No		1		1
Yes	< 0.001	10.74 (6.36-18.13)	< 0.000	6.94 (2.79-17.25)

LAD: Lymphadenopathy; OR: Odds ratio.