Subclinical hypothyroidism in atopic South Italian children

Abstract

Aim: To verify if subclinical hypothyroidism (SCH) could be associated to atopy in children.

Methods: Seven hundred and thirty-two Caucasian children from South Italy presenting symptoms of allergic disease were enrolled and submitted to atopy, obesity, chronic low grade inflammation, and SCH work up.

Results: Four hundred and forty-five out of 705 (63.12%) children affected by allergic disease were diagnosed as atopic and 260 (36.88%) as not atopic. The SCH prevalence was 6.3%. Significant higher prevalence of SCH among atopic children with average (group 2) and high (group 3) low grade chronic inflammation compared to atopic children with mild (group 1) low grade chronic inflammation was present. Moreover, group 1 and group 2 presented an OR to show SCH of 2.57 (95%CI: 1.55-6.26) and 2.96 (95%CI: 1.01-8.65), respectively. Both in atopic and not atopic children we found C3 serum levels significantly higher in group 3 respect to group 2 and group 1. Noteworthy, among atopic patients, also total immunoglobulin E (IgE) serum levels, were significantly higher in group 3 compared to group 2 and group 1 children. In atopic children, C3 and total IgE serum values increased in parallel with the increase of C-reactive protein values, while in not atopic children this phenomenon was not evident.

Conclusion: The possibility exists that an increasing atopic inflammation contributes to SCH occurrence. So far this is the first report in literature showing an association between SCH and atopy but further studies are needed to confirm our data.

Keywords: Atopy; Children; Low grade chronic inflammation; Subclinical hypothyroidism; Thyroid derangement.

Figure 1

Complement C3 and total IgE serum levels values according to low grade inflammation in both atopic (A) and not atopic (B) children affected by allergic disease. CRP values < 0.1 mg/dL identify children with low grade of chronic low grade inflammation (group 1). CRP values between 0.1 and 0.3 mg/dL identify children with average grade of chronic low grade inflammation (group 2). CRP values > 0.3 and < 1 mg/dL identify high grade of chronic low grade inflammation (group 3). In atopic children, C3 and total IgE serum values increased in parallel with the increase of CRP values, while in not atopic children this phenomenon is not evident. A: For C3, group 1 vs group 3, P = 1.86e^-8; group 1 vs group 2, P = 0.027; group 2 vs group 3, P = 0.00021. For total IgE, group 1 vs group 3, P = 0.000017; group 1 vs group 2, P > 0.05; group 2 vs group 3, P = 0.00045; B: For C3, group 1 vs group 3, P = 0.000053; group 1 vs group 2, P = 0.0085; group 2 vs group 3, P = 0.024. For total IgE, group 1 vs group 3, P > 0.05; group 1 vs group 2, P > 0.05; group 2 vs group 3, P ≥ 0.05.