Liver function in cirrhotic patients in the euthyroid versus the hypothyroid state

Thyroid Function and the Risk of Fibrosis of the Liver, Heart, and Lung in Humans: A Systematic Review and Meta-Analysis

Background: Fibrotic diseases have an unclear etiology and poor prognosis. Fluctuations in thyroid function may play a role in the development of fibrosis, but evidence is fragmented and inconclusive. This systematic review and meta-analysis aimed to investigate the association of thyroid function with fibrotic diseases of the liver, heart, and lung in humans. Methods: We searched PubMed, Medline Ovid, Embase Ovid, and Web-of-Science for studies published from inception to 14 June 2019, to identify observational studies that investigated the association of thyroid function with fibrosis of the liver, heart, and lung in humans. Study quality was evaluated by the Newcastle-Ottawa Scale. The Mantel-Haenszel method was used to pool the odds ratios (ORs) of studies investigating the association of hypothyroidism with liver fibrosis. Results: Of the 2196 identified articles, 18 studies were included in the systematic review, of which 11 studies reported on liver fibrosis, 4 on myocardial fibrosis, and 3 on pulmonary fibrosis. The population sample size ranged from 36 to 7259 subjects, with median mean age 51 years (range, 36-69) and median percentage of women 53 (range, 17-100). The risk of bias of studies was low to moderate to high. Higher serum thyrotropin and lower thyroid hormone levels were generally associated with higher likelihood of fibrosis. Compared with euthyroidism, overt and subclinical hypothyroidism was associated with a higher likelihood of fibrosis in the liver (six of seven studies), heart (three of three studies), and lung (three of three studies). Based on the results of the seven studies included in the meta-analysis, overt and subclinical hypothyroidism was associated with an increased risk of liver fibrosis (pooled OR, 2.81; 95% confidence interval [CI], 1.74-4.53; heterogeneity, I² 31.4%; pooled OR, 2.12; CI, 1.45-3.12; heterogeneity, I² 0%; respectively), without evidence of publication bias. Conclusions: This study suggests that low thyroid function is associated with increased likelihood of chronic fibrotic diseases of the liver, heart, and lung. However, the evidence is mainly based on cross-sectional data. Prospective studies and randomized clinical trials are needed to investigate the potential efficacy of thyroid hormone and its analogs on the occurrence and progression of fibrosis.

Liver cirrhosis and thyroid function: Friend or foe?

INTRODUCTION

The liver plays a central role in thyroid hormone metabolism, transport, and clearance. A normal function of both the thyroid gland and the liver is therefore necessary to maintain normal thyroid hormone levels and action. Data regarding thyroid function in patients with liver cirrhosis are scarce and variable. The most consistent finding is a decreased free triiodothyronine (fT3) level, which correlates with the severity of liver disease and has been proposed as a prognostic factor for liver-related complications.

AIM OF THE STUDY

To evaluate thyroid hormone values in patients with stable liver cirrhosis and to compare them with healthy controls without liver disease. We also assessed the prevalence of thyroid autoimmunity and whether liver function tests correlated with thyroid function.

MATERIAL AND METHODS

We performed a prospective case-control study in an endocrinological setting. Twenty-nine patients with stable cirrhosis (20 males and 9 females, mean age 60.97 ± 7.17 years) were included in the case group and 50 healthy subjects (22 males and 28 females, mean age 61.70 ± 13.00 years) in the control group. We excluded patients with confounding factors known to influence thyroid function. Levels of serum thyroid-stimulating hormone (TSH), fT3, free thyroxine (fT4) and anti-TPO-antibodies (TPO-Ab) were measured. These thyroid hormone values were compared in both groups. Biochemical indices of liver function (aspartate aminotransferase [AST], alanine aminotransferase [ALT], alkaline phosphatase [AP], gamma-glutamyl transpeptidase [GGT], INR, total bilirubin, and albumin levels) were correlated with thyroid function tests.

RESULTS

fT3 en fT4 levels were significantly lower in patients with cirrhosis than in healthy subjects (p = 0.001 and 0.002, respectively). TSH levels were not statistically significantly different in the two groups. The level of TPO-Ab was not increased in patients with cirrhosis compared to healthy controls. fT3 correlated negatively with the Child-Pugh score.

DISCUSSION

These results indicate that, compared to healthy controls, patients with cirrhosis have decreased fT3 and fT4 levels and comparable TSH levels and may be consistent with findings of limited acquired central hypothyroidism as observed in the non-thyroidal illness syndrome (NTIS). fT3 levels correlated negatively with Child-Pugh score, a measure of severity of liver dysfunction. We did not find an increased prevalence of thyroid autoimmunity in these patients.

Occult endocrine dysfunction in patients with cirrhosis of liver

BACKGROUND

Liver dysfunction leads to endocrine disturbance due to the alteration in protein metabolism or synthesis. We studied the presence of occult endocrine dysfunction in liver cirrhosis and compared the same with underlying etiology.

MATERIALS AND METHODS

We evaluated thirty patients with liver cirrhosis in this cross-sectional, observational study. All subjects were assessed for pituitary, thyroid, adrenal, and gonadal function. The patients were divided into Group 1 (cirrhosis, n = 30) and Group 2 (controls, n = 15) and the data were analyzed with appropriate statistical tests.

RESULTS

The study participants (20 males, 10 females) had a mean age of 54.5 ± 12.4 years and duration of the cirrhosis 5.1 ± 2.7 years. Four patients were in Child Class A, 11 and 15 patients were in Child Classes B and C, respectively. Eleven out of thirty patients (37%) had endocrine disorders, that include subclinical hypothyroidism (n = 3), primary hypothyroidism (n = 1), Sick Euthyroid syndrome (n = 3), central hypothyroidism (n = 2), secondary hypogonadism (n = 3) and growth hormone deficiency in three patients. Two patients had partial hypopituitarism and one patient had complete hypopituitarism.

CONCLUSION

Occult endocrine dysfunction of thyroid and gonadal axes is common in patients with cirrhosis of the liver. The hormonal abnormalities are not different based on the etiology of the cirrhosis.

Occult endocrine dysfunction in patients with cirrhosis of liver

BACKGROUND

Liver dysfunction leads to endocrine disturbance due to the alteration in protein metabolism or synthesis. We studied the presence of occult endocrine dysfunction in liver cirrhosis and compared the same with underlying etiology.

MATERIALS AND METHODS

We evaluated thirty patients with liver cirrhosis in this cross-sectional, observational study. All subjects were assessed for pituitary, thyroid, adrenal, and gonadal function. The patients were divided into Group 1 (cirrhosis, n = 30) and Group 2 (controls, n = 15) and the data were analyzed with appropriate statistical tests.

RESULTS

The study participants (20 males, 10 females) had a mean age of 54.5 ± 12.4 years and duration of the cirrhosis 5.1 ± 2.7 years. Four patients were in Child Class A, 11 and 15 patients were in Child Classes B and C, respectively. Eleven out of thirty patients (37%) had endocrine disorders, that include subclinical hypothyroidism (n = 3), primary hypothyroidism (n = 1), Sick Euthyroid syndrome (n = 3), central hypothyroidism (n = 2), secondary hypogonadism (n = 3) and growth hormone deficiency in three patients. Two patients had partial hypopituitarism and one patient had complete hypopituitarism.

CONCLUSION

Occult endocrine dysfunction of thyroid and gonadal axes is common in patients with cirrhosis of the liver. The hormonal abnormalities are not different based on the etiology of the cirrhosis.

Higher Thyroid-Stimulating Hormone, Triiodothyronine and Thyroxine Values Are Associated with Better Outcome in Acute Liver Failure

Introduction

Changes in thyroid hormone levels, mostly as non-thyroidal illness syndrome (NTIS), have been described in many diseases. However, the relationship between acute liver failure (ALF) and thyroid hormone levels has not yet been clarified. The present study evaluates potential correlations of select thyroid functional parameters with ALF.

Methods

84 consecutively recruited ALF patients were grouped according to the outcome of ALF (spontaneous recovery: SR; transplantation or death: NSR). TSH, free thyroxine (fT4), free triiodothyronine (fT3), T4, and T3 were determined.

Results

More than 50% of patients with ALF presented with abnormal thyroid parameters. These patients had greater risk for an adverse outcome than euthyroid patients. SR patients had significantly higher TSH, T4, and T3 concentrations than NSR patients. Albumin concentrations were significantly higher in SR than in NSR. In vitro T3 treatment was not able to rescue primary human hepatocytes from acetaminophen induced changes in mRNA expression.

Conclusions

In patients with ALF, TSH and total thyroid hormone levels differed significantly between SR patients and NSR patients. This might be related to diminished liver-derived transport proteins, such as albumin, in more severe forms of ALF. Thyroid parameters may serve as additional indicators of ALF severity.

Assessment of thyroid and gonadal function in liver diseases

INTRODUCTION

Liver is involved with the synthesis of carrier proteins and metabolism of various hormones and liver diseases may, therefore, be associated with various endocrine disturbances. This study was conducted to assess thyroid and gonadal function in subjects with acute hepatitis (AH), chronic liver disease (CLD), and those who had undergone liver transplantation (LT).

MATERIALS AND METHODS

Patients with AH, CLD with Child-Pugh stage A (CLD-1) and Child-Pugh stage B or C (CLD-2), and LT seen at our tertiary level hospital were assessed clinically, biochemically, and for thyroid and gonadal functions besides 25 healthy controls.

RESULTS

Thyroid dysfunction and hypogonadism were present in 14 (16%) and 24 (28%) patients with liver diseases respectively. Among thyroid dysfunction, the commonest was sick euthyroid syndrome six (7%), followed by subclinical hypothyroidism in three patients (3.5%), subclinical hyperthyroidism and thyrotoxicosis in two patients each (2.3%) and overt hypothyroidism in one patient. Among patients with LT and AH groups, the only abnormality was significantly lower total T3 compared with healthy controls. The CLD2 group had significantly lower levels of all thyroid hormones compared with controls and CLD1 group. Hypogonadism was commonest in patients with CLD-2 (14; 50%) followed by LT (3; 33%), CLD-1 (4; 20%), and AH (3; 14%). Hypogonadism was predicted by older age, lower levels of serum albumin, total cholesterol, and triglycerides and higher levels of plasma glucose, serum bilirubin, aspartate transaminases, and international normalized ratio. Gonadal functions showed recovery following LT.

CONCLUSIONS

Thyroid dysfunction and hypogonadism form an important part of the spectrum of acute and CLD, and patients with LT. Deterioration of synthetic functions of liver disease predicts presence of hypogonadism.

The effects of hypothyroidism on liver status of cirrhotic patients

We have shown, in animal models as well as in retrospective human study, that some degree of decreased thyroid function is beneficial for subjects with liver damage of various etiologies. Therefore, we herein present the results of a cohort population study. Between 1991 and 1994, 18 patients (12 women and 6 men; mean age, 59 +/- 24 years) with both biopsy-proven active cirrhosis (5 hepatitis C virus, 4 hepatitis B virus, 1 immunocompromised host, 2 primary biliary cirrhosis, 1 alcoholic, and 5 cryptogenic; Child's-Pugh criteria: A-8, B-8, C-2) and primary or induced (by either drug or surgery) thyroxine-treated hypothyroidism were prospectively followed. Each patient was examined at least twice yearly and served as their own control. The thyroid of the profiled patients ranged between euthyroidism and subclinical hypothyroidism. Liver function tests were evaluated and compared in states of normal versus increased thyroid-stimulating hormone (TSH) blood levels. A significant improvement in alanine aminotransferase (p < 0.001), alkaline phosphatase (p < 0.0001), albumin (p < 0.001), and bilirubin (p < 0.01) was found in the increased TSH group. Prothrombin time was also found to be significantly better (p < 0.001). We conclude that euthyroid patients with liver cirrhosis might benefit from a controlled hypothyroidism.

Altered thyroid status modulates portal pressure in normal rats

BACKGROUND & AIMS

Disturbances in thyroid function in humans and experimental animal models have been associated with alterations in liver function and portal circulation. We have previously shown that hypothyroidism can significantly reduce portal pressure in portal vein ligated rats as well as inhibit the development of cirrhosis and fulminant hepatic failure following toxic liver injury. The aim of this study was to determine the effects of increased and decreased thyroid function on portal pressure in rats with normal liver histology and portal circulation.

METHODS

Three groups of 12 Wistar rats each were studied over a 30 day period: euthyroid (Group 1), hyperthyroid (Group 2) and hypothyroid (Group 3). Hyperthyroidism was induced by subcutaneous injection of triiodothyronine (400 microg/100g body weight) every ten days during the study period. Hypothyroidism was induced by methimazole (0.04% in drinking water) from 2 weeks prior to and throughout the 30 day study. Serum triiodothyronine (T3) and thyroid stimulating hormone (TSH) levels were determined to confirm the induction of hyper- and hypothyroidism. Portal pressure was assessed by direct catheterization of the portal vein prior to sacrifice. Indirect confirmation of changes in portal circulation was obtained by determining splenic weight at the time of sacrificing the animals. Animals were sacrificed at 10 day intervals throughout the 30 day study.

RESULTS

Triiodothyronine treated rats were hyperthyroid compared to controls, with an elevation in serum T3 levels (3.8+/-0.9 mmol/L vs 1.3+/-0.4 mmol/L, p<0.05). In rats treated with methimazole, hypothyroidism was confirmed by a 7-fold increase in serum TSH compared to controls (1.8+/-0.4 vs 0.24+/-0.04 mmol/L, p<0.01). Portal pressure was significantly higher in the triiodothyronine treated rats compared to controls (12.8+/-1.7 and 9.6+/-0.75 cm H2O, p<0.001). Splenic weights in hyperthyroid rats were significantly higher than in controls (579+/-44 vs 478+/-46 mg, p<0.01). Portal pressure was significantly lower in the methimazole treated group compared to the control group (8.13+/-0.68 vs 9.6+/-0.75 cm H2O, p<0.01) as were splenic weights (400+/-33 vs 478+/-46 mg, p<0.01).

CONCLUSION

These studies demonstrate that disturbed thyroid function exerts significant hemodynamic effects on the portal circulation in normal rats and complements results from previous similar studies in cirrhotic animals.