The role of echocardiography in monitoring the therapeutic effect of levothyroxine replacement therapy in subclinical hypothyroidism

Abstract Purpose Irisin is a newly discovered adipo-myokine known for having significant effects on body metabolism. Currently, there is a discussion regarding the relation between thyroid function and irisin concentration. This study was designed to evaluate the influential role of levothyroxine replacement therapy on circulating levels of irisin in patients with recently onset hypothyroidism following total thyroidectomy. Methods Circulating levels of thyroid hormones, irisin and other metabolic parameters, were assessed in 40 recently thyroidectomized patients (34 females, mean age 50.1 ± 15.2 years) at baseline (5–7 day after surgery) and after 2 months under replacement therapy with levothyroxine. Results At baseline, circulating levels of thyroid hormones were indicative of hypothyroidism (TSH 12.7 ± 5.0 μU/mL, FT3 1.9 ± 0.7 pg/mL, FT4 8.7 ± 3.6 pg/mL). Mean serum irisin concentrations significantly increased after 2 months under replacement therapy with levothyroxine (from 2.2 ± 0.6 to 2.9 ± 0.6 μg/mL, p < 0.0001). Variations of circulating levels of irisin under levothyroxine replacement therapy were directly correlated with those of FT3 (Rho = 0.454, p = 0.0033) and FT4 (Rho = 0.451, p = 0.0035). Multivariate regression analysis revealed that changes in thyroid hormones concentrations explained up to 10% of the variations of serum irisin levels under levothyroxine replacement therapy (FT3 R2 = 0.098, FT4 R2 = 0.103). Conclusion Our study suggests that levothyroxine replacement therapy mildly influences irisin metabolism in patients with recently onset hypothyroidism following total thyroidectomy.

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Benefits of Levothyroxine Replacement Therapy on Nonalcoholic Fatty Liver Disease in Subclinical Hypothyroidism Patients

International Journal of Endocrinology ◽

10.1155/2017/5753039 ◽

2017 ◽

Vol 2017 ◽

pp. 1-10 ◽

Cited By ~ 18

Author(s):

Lu Liu ◽

Yong Yu ◽

Meng Zhao ◽

Dongmei Zheng ◽

Xu Zhang ◽

...

Keyword(s):

Liver Disease ◽

Fatty Liver ◽

Replacement Therapy ◽

Nonalcoholic Fatty Liver Disease ◽

Subclinical Hypothyroidism ◽

Fatty Liver Disease ◽

Controlled Trial ◽

Effective Means ◽

Nonalcoholic Fatty Liver ◽

Levothyroxine Replacement

Objectives. To evaluate the effect of levothyroxine (LT4) replacement therapy on nonalcoholic fatty liver disease (NAFLD) in subclinical hypothyroidism (SCH) patients.Methods. This study was a post hoc analysis of a randomized controlled trial and involved 33 significant and 330 mild SCH patients. All of the significant SCH patients received LT4supplement. The mild SCH patients were grouped as LT4treated or not. After 15 months of follow-up, prevalence of NAFLD in each group was reevaluated. Subgroup analysis was conducted in mild SCH patients with dyslipidemia.Results. After treatment with LT4, the prevalence of NAFLD in significant SCH patients reduced from 48.5% to 24.2% (p=0.041). In mild SCH patients, prevalence of NAFLD and serum alanine aminotransferase (ALT) was not significantly affected by LT4supplementation. Nonetheless, mild SCH patients with dyslipidemia who received LT4treatment experienced decreases in the prevalence of NAFLD and serum ALT levels (p<0.05for both). In contrast, these parameters remained comparably stable in patients who were not treated.Conclusion. LT4supplementation has benefits on NAFLD in significant SCH patients or mild SCH patients with dyslipidemia. For NAFLD patients with SCH, appropriate supplementation of LT4may be an effective means of controlling NAFLD. The original trial was registered with ClinicalTrials.gov (NCT01848171).

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