Primary Hypothyroidism Serum A¦Â40 Inflammatory Mediators And Brain Dysfunction Relationship

Objectives:To test the levels of amyloid beta-peptide 40 (AB40), tumor necrosis factor(TNF-a) and interleukin-1 (IL-1) in the serum of patients with primary hypothyroidism. And discuss the relationship between AB40, TNF-a, IL-1 and primary hypothyroidism, as well as their clinical significance.Methods:This study included 50 control and 120 patients with primary hypothyroidism which were equally divided into three groups according to their level of the thyroid hormone (mild/moderate/severe group). AB40, TNF-a, IL-1 were detected by enzyme-linked immunosorbent assay (ELISA) respectively. Meanwhile, the levels of thyroid stimulating hormone(TSH), free triiodothyronine(FT3). free tetraiodothyronine(FT4), total cholesterol(TC), triglyceride(TG), low density lipoprotein cholesterol(LDL) and high density lipoprotein cholesterol(HDL) were also detected. Results were expressed as means±SE (x±s). Analysis of variance (ANOVA) was used for the comparison of three groups with primary hypothyroidism and control group. Multivariate analysis was performed with stepwise logistic regression and linear correlation analysis was used to examine the relationship among AB40, TNF-a, IL-1 and other variables.Results:According to the study, the levels of serum's AB40, TNF-a and IL-1 levels in the severe group with hypothyroidism were significantly higher than that of the mild and control groups (P<0.01), as well as the moderate group (P<0.05). The levels of serum's Aβ40, TNF-a and IL-1 levels in the moderate group of hypothyroidism were higher than that of control group (P<0.01, P<0.01 and P<0.05 respectively). There was positive correlation between AB40 levels in serum of primary hypothyroidism and TSH, TNF-a, IL-1, TC, TG, LDL (P<0.01), negative correlation and FT3. FT4 and HDL(P<0.01 or P<0.05). Compared with that of control group, levels of serum's TC, TG, LDL of the hypothyroidism groups were significantly elevated (P<0.01), while the level of HDL were significantly decreased (P<0.01). The levels of serum's TC, LDL levels in the moderate and severe groups with hypothyroidism were higher than that of the mild group (P<0.01 or P<0.05), while the level of HDL were significantly decreased (P<0.01). The levels of serum's TG levels in the severe group with hypothyroidism were higher than that of the mild and moderate groups (P<0.01). Levels of TNF-a and IL-1 in the serum were positively correlated with TC, TG, LDL, and negatively correlated with HDL (P<0.01 or P<0.05).Conclusion:Levels of serum's AB40, TNF-a and IL-1 of patients with primary hypothyroidism were significantly correlated with those of FT3, FT4 and TSH. The levels of serum's AB40, TNF-a and IL-1 in patients with severe and moderate hypothyroidism were significantly elevated, which suggested that inflammatory reactions maybe involved in the hypothyroidism state. Injury of the function of central nervous system would occur in the state of severe hypothyroidism, which would play an important part in the judgment of functional brain injury. The level of serum's AB40, TNF-a and IL-1 were related to TC, TG, LDL and HDL, that prompted obvious lipid metabolism with hypothyroidism. AB production was related to lipoprotein metabolism in the brain. Dyslipidemia may promote the formation and deposition of AB40 by inducing the release of inflammatory cytokines.