Thyroid dysfunction as a long-term post-COVID-19 complication in mild-to-moderate COVID-19

Figures & data

Table 1. Characteristics of all study participants (n = 113).

Characteristics
Age (years)	43.0 (38.0–49.0)
BMI (kg/m^2)	29.0 (25.0–34.0)
Sex
Male	35 (31%)
Female	78 (69%)
Family history of thyroid disease
No	78 (69%)
Yes	35 (31%)
COVID-19 clinical classification
Mild	85 (75.2%)
Moderate	28 (24.8%)
Thyroid function two months after COVID-19
Euthyroid	44 (38.9%)
Subclinical hypothyroidism	54 (47.8%)
Hypothyroidism	6 (5.3%)
Subclinical hyperthyroidism	9 (8.0%)
Antithyroid antibodies
Negative for both TPOAb and TgAb	47 (41.6%)
Positive for both TPOAb and TgAb	34 (30.1%)
TgAb Positive	55 (48.7%)
TPOAb Positive	45 (39.8%)
Thyroid function three months after COVID-19
Euthyroid	81 (71.7%)
Subclinical hypothyroidism	32 (28.3%)
Hypothyroidism	0
Subclinical hyperthyroidism	0

The continuous data are presented as median values [interquartile range] due to the non-parametric distribution. Categorical data are shown as a number (percentage).

Table 2. Effects of the family history of thyroid disease and severity of COVID-19 manifestation on the thyroid status and required treatment two months after the initial SARS-CoV-2 infection.

Studied parameters	Family history of thyroid disease		p-value	COVID-19 clinical manifestation		p-value
	No	Yes		Mild	Moderate
	(n = 78)	(n = 35)		(n = 85)	(n = 28)
TSH [mIU/L]	4.33 ± 2.21	4.17 ± 1.90	ns	4.20 ± 1.70	4.50 ± 3.06	ns
fТ4	14.24	14.23	ns	14.28	14.27	0.091
[pmol/L]	[13.02–16.32]	[12.83–16.56]		[13.21–16.26]	[12.08–16.36]
TgAb positive	35 (44.9%)	20 (57.1%)	ns	36 (42.4%)	19 (67.9%)	0.028
TPOAb positive	24 (30.8%)	21 (60.0%)	0.006	32 (37.6%)	13 (46.4%)	ns
Thyroid dysfunction^a	48 (61.5%)	21 (60.0%)	ns	45 (52.9%)	24 (85.7%)	0.002
Levothyroxine treatment necessity	5 (6.4%)	8 (22.9%)	0.022	4 (4.7%)	9 (32.1%)	<0.001
Glucocorticoid treatment	13 (16.7%)	5 (14.3%)	ns	0	18 (64.3%)	<0.001

Data are mean values ± SD or median [interquartile range]. Categorical data are shown as numbers (percentage). Differences between the two groups were determined using the independent-samples t- and Mann–Whitney U-tests according to the distribution of the studied variables. Categorical variables were analyzed by the Chi-square test.

^aThyroid dysfunction: subclinical hyperthyroidism, subclinical or overt hypothyroidism.

ns: not significant.

Figure 1. Comparative analysis on thyroid-stimulating hormone (TSH) levels: (A) at two months (baseline) and three months after the initial COVID-19 infection in the whole patient cohort (n = 113); (B) at two months (baseline) and three months after the initial COVID-19 infection only in the patients with persistent thyroid dysfunction at the third month and without levothyroxine therapy (n = 24); (C) between patients with mild (n = 85) and moderate manifestation (n = 28) of COVID-19 at the follow-up visit three months after the initial COVID-19.

Data availability statement

The data supporting the findings in this study are available from the corresponding author upon reasonable request.