Hypothalamic-pituitary-thyroid (HPT) axis in chronic alcoholism. I. HPT axis in chronic alcoholics during withdrawal and after 3 weeks of abstinence

Bidirectional negative relationship between thyrotropin and kidney function during alcohol intoxication in males

Introduction

Despite a well-established direct toxic effect of alcohol on renal cells, there is a salutary dose-dependent effect of alcohol consumption on common laboratory parameters related to kidney performance. Alcohol also impacts thyroid hormones, while thyroid status modulates kidney function. The modulation of kidney parameters with thyrotropin (TSH) and thyroid status indicates a possible interaction between alcohol, kidney, and thyroid functions. This retrospective study was conducted to test the hypothesis that the positive effect of alcohol use on the estimated glomerular filtration rate (eGFR) is mediated by alcohol's effect on thyroid hormones.

Methods

We reviewed the electronic medical records of 767 hospitalized adult patients free of thyroid disorders who received medical care in the Mayo Clinic Health System from June 2019 through June 2022 and had blood alcohol concentration (BAC), serum TSH, and serum creatinine measured during the hospitalization. We calculated the eGFR using both the re-expressed Modification of Diet in Renal Disease (MDRD II) study equation and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) Creatinine equation.

Results

We found a significant relationship of BAC with eGFR (CKD-EPI) and TSH in males only. BAC had a positive association with eGFR (b = 0.24, p = 0.0001) and negative with TSH (b=-0.17, p = 0.006). The covariance between the two outcomes (eGFR and TSH) was negative (b = -0.12, p = 0.049). The path analyses using the eGFR MDRD II equation were not significant in males, whereas females had no significant path analyses with either of the eGFR equations.

Discussion

We observed that BAC influences both eGFR and TSH, whereas eGFR and TSH influence each other. After considering important covariates (e.g., age, body mass index, diabetes mellitus, cardiovascular disease, chronic kidney disease, and chronic liver disease) and the negative bidirectional effect of TSH and eGFR, a positive impact of BAC on eGFR was observed in males.

Effect of Interaction Between Duration of Alcohol Consumption and Alcohol Dependence on Thyroid Function Test: Cross Sectional Observational Study

Dependence on alcohol, nicotine and duration of alcohol consumption are known to alter thyroid function tests. This study was conducted to assess the effect of interaction between the duration of alcohol consumption and alcohol dependence on TFT. The subjects consisted of 38 male patients with alcohol dependent syndrome co morbid with nicotine dependent syndrome, 33 male patients with alcohol dependent syndrome and 30 male normal healthy volunteers. Liver function tests, haematological parameters and thyroid function tests were assayed. Two way multivariate ANOVA was used to assess the interaction effect by SPSS 21 package. Multivariate analysis of combined TFT levels revealed no significant (P = .078) difference amongst groups based on alcohol dependence, significant difference (P = .001) amongst groups based on duration of alcohol consumption and no significant (P = .604) interaction effect between duration of alcohol consumption and alcohol dependence. Tests of between subject effects for individual TFT revealed significant (P = .014) difference in T3 between groups based on alcohol dependence, significant difference in the levels of fT4 (P = .001), T3 (P = .07) and T4 (P < .001) between groups based on duration of alcohol consumption was observed. Interaction between the effect of duration of alcohol consumption and alcohol dependence for individual TFT did not reveal any significance. fT4, TSH and T4 levels were significantly low in persons consuming alcohol for more than 20 years. TSH levels were significantly low in ADS compared to controls. Significant decrease in the levels of thyroid hormones was observed as the duration of alcohol consumption increased.

Thyroid Hormone Levels in Chronic Alcoholic Liver Disease Patients Before and After Treatment

INTRODUCTION

Alcoholic liver disease affects almost all aspects of the thyroid gland including the thyroid hormone levels and the thyroid gland size. The altered thyroid hormone levels in alcoholic liver disease may affect alcohol abstinence in withdrawal period by changing hormone milieu in brain, increasing withdrawal dysphoria and increasing craving.

AIM

The aim of the present study was to assess and compare the levels of thyroid hormones- free T3, free T4, Thyroid Stimulating Hormone (TSH) and Gamma Glutamyl Transferase (GGT) in chronic alcoholic liver disease patients before and after treatment.

MATERIALS AND METHODS

This study was conducted on 70 alcoholic liver disease patients. Two serum samples were taken from the patient once at the time of admission and the other at the time of discharge after atleast ten days of treatment. Serum free T3, free T4, TSH and GGT were assessed on auto analyzer Beckman Coulter. Statistical analysis is done by paired t-test and Pearson's Correlation test.

RESULTS

In present study, serum GGT levels decreased significantly (before treatment-207.46±66.90 U/L; after treatment-78.47±19.71 U/L) and free T3 levels increased significantly with treatment (before treatment-2.54±0.48 pg/mL; after treatment-2.88±0.37 pg/mL). Free T4 levels are also increased with treatment (before treatment-0.78±0.19 ng/dL; after treatment-0.88±0.13 ng/dL) and TSH levels are not altered significantly with treatment (before treatment-3.34±1.62 μIU/mL; after treatment-3.32±1.51 μIU/mL). Additionally, free T3 showed a significant correlation with GGT before (p-value<0.001) and after treatment (p-value-0.003) and free T4 and TSH showed a significant correlation with GGT after treatment (free T4: p-value<0.001) (TSH: p-value <0.001) and a suggestive significance exists before treatment (free T4: p-value= 0.098) (TSH: p-value=0.062).

CONCLUSION

Thyroid hormones levels, particularly free T3 and free T4, need to be evaluated in chronic alcoholic liver disease patients. Free T3 could be used as a marker of alcoholism and is very useful in assessing the treatment efficacy in chronic alcoholic liver disease. Also, assessing free thyroid hormones is necessary during the withdrawal and abstinent periods as decreased hormone levels may increase withdrawal effects and craving for alcohol.

Acute High-Dose and Chronic Lifetime Exposure to Alcohol Consumption and Differentiated Thyroid Cancer: T-CALOS Korea

Background

This study evaluated the effects of acute high-dose and chronic lifetime exposure to alcohol and exposure patterns on the development of differentiated thyroid cancer (DTC).

Methods

The Thyroid Cancer Longitudinal Study (T-CALOS) included 2,258 DTC patients (449 men and 1,809 women) and 22,580 healthy participants (4,490 men and 18,090 women) who were individually matched by age, gender, and enrollment year. In-person interviews were conducted with a structured questionnaire to obtain epidemiologic data. Clinicopathologic features of the patients were obtained by chart reviews. Odds ratios (ORs) and 95% confidence intervals (95%CI) were estimated using conditional regression models.

Results

While light or moderate drinking behavior was related to a reduced risk of DTC, acute heavy alcohol consumption (151 g or more per event or on a single occasion) was associated with increased risks in men (OR = 2.22, 95%CI = 1.27–3.87) and women (OR = 3.61, 95%CI = 1.52–8.58) compared with never-drinkers. The consumption of alcohol for 31 or more years was a significant risk factor for DTC for both men (31–40 years: OR = 1.58, 95%CI = 1.10–2.28; 41+ years: OR = 3.46, 95%CI = 2.06–5.80) and women (31–40 years: OR = 2.18, 95%CI = 1.62–2.92; 41+ years: OR = 2.71, 95%CI = 1.36–5.05) compared with never-drinkers. The consumption of a large amount of alcohol on a single occasion was also a significant risk factor, even after restricting DTC outcomes to tumor size, lymph node metastasis, extrathyroidal extension and TNM stage.

Conclusion

The findings of this study suggest that the threshold effects of acute high-dose alcohol consumption and long-term alcohol consumption are linked to an increased risk of DTC.

Impact of alcohol use on thyroid function

Alcohol is one of the commonest illicit psychoactive substances consumed globally and is the world's third largest risk factor for disease and disability. It has been reported to have multiple effects on the hypothalamo-pituitary-thyroid axis and the functioning of the thyroid gland. It has been reported to cause direct suppression of thyroid function by cellular toxicity, and indirect suppression by blunting thyrotropin-releasing hormone response. It causes a decrease of peripheral thyroid hormones during chronic use and in withdrawal. Alcohol use may also confer some protective effect against thyroid nodularity, goiter, and thyroid cancer. This article presents a review of the clinically relevant effects of alcohol on the functioning of the thyroid gland and also discusses the effect of medication used in treatment of alcohol dependence on thyroid function.

The relationship of appetitive, reproductive and posterior pituitary hormones to alcoholism and craving in humans

A significant challenge for understanding alcoholism lies in discovering why some, but not other individuals, become dependent on alcohol. Genetic, environmental, cultural, developmental, and neurobiological influences are recognized as essential factors underlying a person's risk for becoming alcohol dependent (AD); however, the neurobiological processes that trigger this vulnerability are still poorly understood. Hormones are important in the regulation of many functions and several hormones are strongly associated with alcohol use. While medical consequences are important, the primary focus of this review is on the underlying confluence of appetitive/feeding, reproductive and posterior pituitary hormones associated with distinct phases of alcoholism or assessed by alcohol craving in humans. While these hormones are of diverse origin, the involvement with alcoholism by these hormone systems is unmistakable, and demonstrates the complexity of interactions with alcohol and the difficulty of successfully pursuing effective treatments. Whether alcohol associated changes in the activity of certain hormones are the result of alcohol use or are the result of an underlying predisposition for alcoholism, or a combination of both, is currently of great scientific interest. The evidence we present in this review suggests that appetitive hormones may be markers as they appear involved in alcohol dependence and craving, that reproductive hormones provide an example of the consequences of drinking and are affected by alcohol, and that posterior pituitary hormones have potential for being targets for treatment. A better understanding of the nature of these associations may contribute to diagnosing and more comprehensively treating alcoholism. Pharmacotherapies that take advantage of our new understanding of hormones, their receptors, or their potential relationship to craving may shed light on the treatment of this disorder.

Importance of genetic background for risk of relapse shown in altered prefrontal cortex gene expression during abstinence following chronic alcohol intoxication

Alcoholism is a relapsing disorder associated with excessive consumption after periods of abstinence. Neuroadaptations in brain structure, plasticity and gene expression occur with chronic intoxication but are poorly characterized. Here we report identification of pathways altered during abstinence in prefrontal cortex, a brain region associated with cognitive dysfunction and damage in alcoholics. To determine the influence of genetic differences, an animal model was employed with widely divergent responses to alcohol withdrawal, the Withdrawal Seizure-Resistant (WSR) and Withdrawal Seizure-Prone (WSP) lines. Mice were chronically exposed to highly intoxicating concentrations of ethanol and withdrawn, then left abstinent for 21 days. Transcriptional profiling by microarray analyses identified a total of 562 genes as significantly altered during abstinence. Hierarchical cluster analysis revealed that the transcriptional response correlated with genotype/withdrawal phenotype rather than sex. Gene Ontology category overrepresentation analysis identified thyroid hormone metabolism, glutathione metabolism, axon guidance and DNA damage response as targeted classes of genes in low response WSR mice, with acetylation and histone deacetylase complex as highly dimorphic between WSR and WSP mice. Confirmation studies in WSR mice revealed both increased neurotoxicity by histopathologic examination and elevated triidothyronine (T3) levels. Most importantly, relapse drinking was reduced by inhibition of thyroid hormone synthesis in dependent WSR mice compared to controls. These findings provide in vivo physiological and behavioral validation of the pathways identified. Combined, these results indicate a fundamentally distinct neuroadaptive response during abstinence in mice genetically selected for divergent withdrawal severity. Identification of pathways altered in abstinence may aid development of novel therapeutics for targeted treatment of relapse in abstinent alcoholics.

Priapus is happier with Venus than with Bacchus

INTRODUCTION

The relationship between alcohol consumption and erectile function is still not completely clarified.

AIM

Aims of the present study are to explore a number of biological and clinical correlates of alcohol consumption in a sample of men consulting for sexual dysfunction, and to verify possible associations with the incidence of major adverse cardiovascular events (MACEs).

METHODS

A consecutive series of 1956 (mean age 55 ± 11.9 years old) attending our outpatient clinic for sexual dysfunction was retrospectively studied. A subset of the previous sample (N = 1687) was enrolled in a longitudinal study.

MAIN OUTCOME MEASURES

Different clinical, biochemical, instrumental (penile Doppler ultrasound [PCDU]), and intrapsychic (Middlesex Hospital Questionnaire [MHQ]) were evaluated. We considered alcohol abuse more than three drinks per day.

RESULTS

Among the patients studied 81% reported no or mild (<4 drinks/day) alcohol consumption whereas 14.3% and 3.9% declared a moderate (4-6 drinks/day) or severe (>6 drinks/day) alcohol abuse, respectively. After adjustment for confounders, both moderate or severe alcohol abuse was associated with low perceived partner's sexual desire, worse couple relationship, and smoking abuse. Furthermore, moderate and severe alcohol abuse was associated with low prolactin and thyroid-stimulating hormone levels, as well as an increase in triglycerides and total cholesterol levels. Penile blood flow was reduced in moderate and severe alcohol drinkers even after adjustment for confounders. In the longitudinal study, after adjusting for confounding factors, any kind of alcohol abuse was independently associated with a higher incidence of MACE (hazard ratio = 2.043 [1.059-3.943]; P < 0.0001).

CONCLUSIONS

Our findings demonstrate that, in subjects consulting for erectile dysfunction, severe alcohol consumption is associated with a worse sexual function and a higher incidence of MACE.

Effects of light to moderate alcohol consumption on thyroid volume and thyroid function

OBJECTIVE

To examine a possible relationship between alcohol consumption and thyroid volume and function.

SUBJECTS

A total of 1493 subjects (599 males aged 45-60 years and 894 females aged 35-60 years) with no known thyroid disorders who were participating in the SUpplémentation en VItamines et Minéraux AntioXydants (SU.VI.MAX) study.

MEASURES

Daily dietary intakes and alcohol consumption in grams per day were based on five 24-h dietary records. Thyroid volume and structure were measured by ultrasonography. At baseline, TSH and free T4 (FT4) were measured.

RESULTS

Male and female drinkers consumed (mean +/- SD), respectively, 30.6 +/- 23.3 and 14.2 +/- 13.4 g of ethanol per day. There was a decrease in carbohydrate intake with higher alcohol consumption among both male (P = 0.0001) and female drinkers (P = 0.06). Alcohol intake was associated with higher thyroid volume in males and females independently of iodine status. Multivariate odds ratios (ORs, with 95% confidence intervals) of thyroid enlargement (sex-specific 85th percentile values of > or = 20 ml for males, > or = 14 ml for females) in males and females who drank > or = 45 and > or = 20 g/day, respectively, were 2.22 (1.10-4.47) and 2.11 (1.15-3.90) compared with low drinkers, and 11.75 (2.15-64.12) and 2.03 (1.04-3.96) compared with abstainers. ORs were slightly increased when smokers were excluded. Alcohol intake was associated with low FT4 levels in male drinkers independently of TSH.

CONCLUSIONS

An increasing dose-response relationship was found between alcohol intake levels and ORs for thyroid enlargement in both males and females. Alcohol consumption was strongly associated with a higher risk in females.

Thyroid function in early and late alcohol withdrawal: relationship with aggression, family history, and onset age of alcoholism

AIMS

Thyroid dysfunction is a known finding in alcoholism. Most studies have reported the reduction in peripheral thyroid hormones in acute withdrawal and long-term abstinence periods of alcohol dependence. The aim of the present study was to investigate the alterations of free thyroid hormones in early and late withdrawal and their association with aggression, age of onset, and family history of alcoholism.

METHODS

Male inpatients (n = 39; mean age +/- SD: 42.55 +/- 8.02 years) in alcohol withdrawal were compared with healthy men (n = 28; mean age +/- SD: 38.31 +/- 9.26 years). Levels of free thyroxine (fT4), free triiodothyronine, (fT3) and thyrothrophin (TSH) were measured in early (first day) and late (28th day) withdrawal in the patients and only once in the controls.

RESULTS

In early withdrawal, levels of thyroid hormones did not differ from those in the controls. In late withdrawal, fT3 and fT4 levels (2.71 +/- 0.56 and 10.80 +/- 1.86 pg/ml) were lower than those of both controls (3.32 +/- 0.41 and 11.95 +/- 1.49 pg/ml, respectively, P < 0.05 in both cases) and patients in early withdrawal (3.18 +/- 0.72 and 12.68 +/- 2.50 pg/ml, respectively, P < 0.05 in both cases). Patients were divided into subgroups according to aggression level, onset age of alcoholism, and family history. While the high-aggression group had lower serum levels of fT3 and fT4 in late withdrawal (2.49 +/- 0.41 and 10.44 +/- 2.15 pg/ml) compared with those of controls (P < 0.05 in both cases), the low-aggression group only had lower serum levels of fT3 in late withdrawal (2.90 +/- 0.62 pg/ml) compared with those of controls (P < 0.05). fT3 and fT4 values in the family history-negative group (2.67 +/- 0.56 and 10.75 +/- 1.88 pg/ml) were lower than those of controls in late withdrawal (P < 0.05 in both cases). Both fT3 and fT4 levels in late withdrawal (2.69 +/- 0.54 and 10.83 +/- 1.96 pg/ml) were decreased in early-onset group compared with those of controls (P < 0.05 in both cases).

CONCLUSION

Decreased free thyroid hormone levels may be a result of heavy alcohol consumption or a trait marker of alcoholism, especially in high-aggressive, early-onset and family history-negative patients.

Long-term validity of biological markers of psychopathy and criminal recidivism: follow-up 6-8 years after forensic psychiatric investigation

This study is a follow-up investigation of a forensic psychiatric sub-population 6-8 years after forensic psychiatric evaluation. The aim was to examine the long-term validity of biological markers of psychopathy and antisocial behavior over time. Data on criminal records were obtained at follow-up from the National Council for Crime Prevention. Basic data included findings of psychiatric and psychological assessments, as well as values for serum triiodothyronine (T3) and free thyroxin (FT4), and platelet monoamine oxidase (MAO) activity, all obtained during the forensic psychiatric examination. Criminal recidivists at follow-up had higher serum T3 levels than non-recidivists, and much higher values than normal controls, while their levels of free T4 were lower. The T3 levels in criminal recidivists correlated to psychopathy- and aggression-related personality traits as measured by the Karolinska Scale of Personality. In violent recidivists, a remarkably high correlation was noted between T3 levels and Irritability and Detachment, traits that have previously been linked to the dopaminergic system. Stepwise multiple regression analyses confirmed the relationships of T3 levels and platelet MAO activity with personality traits in criminal recidivists. The predictive validity of biological markers of psychopathy, T3 and platelet MAO, measured during forensic psychiatric investigation, is stable over time. The results indicate chronic alterations of the hypothalamic-pituitary-thyroid axis in this group of subjects.

Dysregulation of the hypothalamic-pituitary-thyroid axis in alcoholism

Thyroid dysfunction is a prominent finding in alcoholism. Subclinical and clinical hypothyroidism have been associated with clinical depression and cognitive impairment and may increase the relapse risk among alcoholics. In spite of these important clinical associations, there is no consensus on thyroid dysfunction in alcoholism in the literature. In this paper, we present a review of the literature and develop a hypothesis that may explain dysfunction of the hypothalamic-pituitary-thyroid axis in alcoholism. Based on a Medline research of the years 1980-2001 we found 33 empirical studies that assessed thyroid function in alcoholism. The most consistent findings were a reduction in total thyroxine and total and free triiodothyronine concentrations during early abstinence. About one-third of all alcoholics also displayed a blunted thyroid stimulation hormone (TSH) response in the thyrotrophin-releasing hormone test (TRH-test). Blunting was observed frequently during detoxification, but was also present in some alcoholics after several weeks of abstinence. We suggest that a reduction in peripheral thyroid hormones may be caused by a direct toxic effect of alcohol on the thyroid gland, which induces a central compensatory activation of the hypothalamic-pituitary axis with an increased TRH release. The TRH release induces a downregulation of pituitary TRH receptors, which manifest as a blunted TSH response to the TRH test. We discuss further additional effects of alcohol on thyroid-hormone metabolizing deiodinases and on monoaminergic systems, which may interact directly with mood states among abstinent alcoholics.

Chronic ingestion of ethanol or glucose solutions affects hypothalamic and limbic TRH metabolism in dams and their pups

The effect of chronic ethanol consumption during pregnancy and lactation on thyrotropin releasing hormone (TRH) metabolism was investigated in the hypothalamus and limbic areas of female rats and their weaned pups. Pregnant female rats received ethanol or isocaloric glucose solution during pregnancy either alone, or also during the 3 weeks of lactation. Thyrotropin (TSH) and corticosterone levels were measured in serum; TRH and TRH-gly concentrations were determined in hypothalamus, hippocampus, n.accumbens, frontal cortex and amygdala of dams and pups at 21 days after parturition. Ethanol or glucose consumption during pregnancy and lactation produced a decrease in TSH levels compared with control animals fed at libitum; water replacement during lactation normalized TSH levels only in glucose-fed dams. Pups from ethanol or pair-fed dams showed low weight and increased TSH levels compared with normal rats. Variations in TRH metabolism were detected in limbic areas. Chronic ethanol caused a decrease in the levels of TRH in the hippocampus and frontal cortex of dams. In contrast, glucose chronic ingestion increased TRH content specifically in n.accumbens and amygdala of dams. Most of the variations in TRH content of limbic areas of pups were not specific for glucose or ethanol treatment and correlated with the deleterious effect of the mother's thyroid condition, although some differences were observed depending on pup's gender. These results support the involvement of TRHergic neurons in the limbic system of the female rat exposed to alcohol or glucose during pregnancy and lactation.

The hypothalamic-pituitary-thyroid axis in patients with schizophrenia

Serum concentrations of thyroxine (T(4)), triiodothyronine (T(3)), reverse triiodothyronine (rT(3)) and thyrotropine (TSH) were measured in 31 acutely ill in-patients with schizophrenia before and after four weeks of treatment with the phenothiazine derivative perazine. The serum levels of all the above hormones were also determined in 19 schizophrenic patients in remission who were receiving no medication, 20 schizophrenic patients in remission taking neuroleptic drugs, and 24 patients with residual-type schizophrenia. The serum levels of T(4) of acutely ill schizophrenic patients were elevated, while those of T(3), rT(3) and TSH were normal. Their T(4) levels showed a positive correlation with the severity of illness and the degree of clinical response to neuroleptic treatment. There was a significant fall in serum concentrations of T(4) and rT(3) during four weeks of drug treatment and the decrease was significantly correlated to clinical response. No abnormalities in the serum concentrations of any of the hormones measured were found in schizophrenic patients in remission or in residual-type schizophrenia. In conclusion, our results indicate that the elevated serum levels of T(4) may be specific for acutely ill schizophrenic patients and that neuroleptic medication may affect thyroid hormone metabolism, this interaction being involved in the mechanism of action of these drugs.

Effects of chronic mild stress (CMS) on thyroid hormone function in two rat strains

This work was carried out to assess the effects of chronic mild stress (CMS) on thyroid function. The CMS model produced an anhedonic effect (reduced preference to sucrose) in Sprague-Dawley and Wistar rats and this effect was reversed by imipramine (IMI) treatment. The effects of CMS on thyroid function were assessed by measuring tT4 (total Thyroxine), tT3 (total Triiodothyronine), TSH (Thyroid Stimulating Hormone) and fT4 (free Thyroxine) serum levels with appropriate immunoassays. CMS increased tT4 and tT3 serum levels in Sprague-Dawley and Wistar rats, but not TSH and fT4 serum levels. Imipramine (IMI) treatment normalized tT4 values. Albumin which binds a fraction of peripheral tT4 and tT3 was also significantly increased in response to CMS, possibly contributing to tT4 and tT3 elevations. The above findings suggest an impact of CMS on thyroid function, especially in tT4 values the changes being reversed with IMI treatment.

Chronic ethanol drinking and food deprivation affect rat hypothalamic-pituitary-thyroid axis and TRH in septum

Because chronic ethanol ingestion may perturb thyroid function, we evaluated the effect of 4-wk of oral 10% ethanol ingestion on the hypothalamic-pituitary-thyroid (HPT) axis and septal thyrotropin-releasing hormone (TRH) in 200-g male Wistar rats. Animals were divided into three groups: absolute control receiving tap water and food ad libitum; ethanol group receiving food ad libitum and 10% ethanol as the sole source of drinking fluid; pair-fed group receiving tap water and an amount of food corresponding to the consumption of ethanol group. After 4-wk of treatment, the body weight of the ethanol group was 7% and of the pair-fed rats 19% lower than that of the absolute controls. Both chronic ethanol treatment and food deprivation produced a decrease in plasma thyroid-stimulating hormone (TSH). Pair-fed rats also had a lower plasma T3. Type I iodothyronine 5'-deiodinase activity in the liver was increased in the pair-fed and even more in the ethanol-treated group. The content and secretion in vitro of TRH from the hypothalamic paraventricular nucleus and median eminence were unchanged. TRH content in the septum was increased in both the ethanol and pair-fed groups. TRH secretion from the septum in vitro was lower in the pair-fed, but unchanged in the ethanol group. These data suggest that 4-wk of peroral ethanol intake affects thyroid function mostly at the extrahypothalamic level and that there is a contribution of concomitant food deprivation. Both ethanol treatment and food deprivation increased TRH content in the septum.

Serum levels of thyroid hormones as biological markers in a Swedish forensic psychiatric population

BACKGROUND

In a Swedish study, delinquent boys had high serum levels of triiodothyronine (T3). Furthermore, former delinquents, followed up after about 30 years, had T3 levels significantly related to repeated criminality. The aim of the present study was to shed further light on the relationship between the thyroid hormones and specific behaviors and personality characteristics.

METHODS

Serum levels of T3 and free thyroxine (FT4) were measured in 61 nonpsychotic male subjects at forensic psychiatric examinations and 66 normal controls. Psychopathy was determined by means of the Psychopathy Checklist-Revised (PCL-R) and DSM-III-R, DSM-IV, and ICD-10 diagnoses.

RESULTS

The study population had high T3 and low FT4 values. Elevated T3 levels were related to type II alcoholism, Cluster B personality disorders, psychopathy as measured by the PCL-R, criminality, a diagnosis of a DSM-IV antisocial disorder, and an ICD-10 dissocial disorder. Serum levels of FT4 were negatively related to the same disorders and personality traits.

CONCLUSIONS

The results indicate an intimate relationship between T3 and FT4, and abuse and antisocial behavior. They emphasize the importance of further studies on T3 as a biological marker for abuse, social deviance, and repeated violent behavior.

Hormone-specific alterations of T4, T3, and reverse T3 metabolism with recent ethanol abstinence in humans

Effects of recent alcoholic withdrawal on thyroxine (T4), 3,5,3'-triiodothyronine (T3), and reverse T3 (rT3) metabolism were determined by serum tracer kinetic studies in recently abstinent alcoholics without overt hepatocellular injury or caloric deprivation. Data were compared with those of normal subjects using a three-pool model, with rapidly and slowly equilibrating pools exchanging with serum. Significant differences included 1) reduced serum total rT3 levels (to 69% of normal) and rT3 degradation rates (to 61%); 2) increased rT3 binding in rapidly (to 557%) but reduced binding in slowly (to 13%) equilibrating tissues, with opposite effects on rT3 fractional transfer rates to serum from rapidly (to 7.5%) and slowly equilibrating sites (to 669%); 3) increased T4 fractional transfer rates from serum to rapidly equilibrating tissues (to 122%); and 4) increased T4 binding to both rapidly (to 195%) and slowly (to 190%) equilibrating tissues. T3 kinetics were not significantly altered. Thus recently abstinent alcoholics have hormone-specific alterations of T4, T3, and rT3 transfer, distribution, and metabolism distinct from other nonthyroidal illnesses or caloric deprivation. Furthermore, these data indicate separate transfer processes for T4, T3, and rT3 from serum to tissue sites and hormone-specific tissue binding characteristics in humans in vivo.

Chronic ethanol treatment reduces the responsiveness of the hypothalamic-pituitary-thyroid axis to central stimulation

The hypothalamic-pituitary-thyroid (HPT) axis functions abnormally in man and animals chronically exposed to ethanol. The most consistent observation in humans is that the thyrotropin response to thyrotropin-releasing hormone (TRH) is blunted. We have tested the hypothesis that chronic ethanol treatment in rats leads to a diminished responsiveness of the hypothalamus to central stimulation. Animals were maintained on 1 of 3 diets for 4 weeks: (1) laboratory chow and water provided ad libitum (chow-fed), (2) Sustacal chocolate liquid diet with vitamin mixture containing 5% (w/v) ethanol provided ad libitum (ethanol), or (3) Sustacal chocolate liquid diet with vitamin mixture containing sucrose substituted isocalorically (35%) for ethanol and provided in amounts matched to a weight-paired, ethanol-treated animal (pair-fed). At the end of 4 weeks, the animals were evaluated for their response to a single injection of ethanol (3 g/kg, ip) and/or exposure to 5 degrees C. Chronic ethanol treatment produced an increase in TRH mRNA in neurons of the paraventricular nucleus and fully blocked the thyrotropic response to cold exposure. However, chronic ethanol-treated animals did not exhibit altered basal levels of triiodothyronine or thyrotropin, nor did they have an altered response to a single injection of ethanol. These data demonstrate that chronic alcohol exposure alters functioning of the hypothalamic-pituitary-thyroid axis at least in part by affecting TRH neurons of the paraventricular nucleus.

Long-term observation of the hypothalamic-pituitary-thyroid (HPT) axis in alcohol-dependent patients

Thyroid hormone levels and thyrotrophin (TSH) were measured in 45 alcohol-dependent patients before detoxification and 8 days, 3 months and 6 months after detoxification, and compared to levels in healthy controls. Before detoxification, levels of thyroxine (T4) and thyroxine-binding globulin (TBG) were significantly reduced in patients compared with healthy controls, while triiodothyronine (T3), reverse T3, and TSH levels did not differ from those in healthy controls. During the entire observation period, free T4 (fT4) and free T3 (fT3) levels were slightly elevated compared with those in healthy controls. T4 and TBG levels increased significantly during the first week of abstinence. Severity of withdrawal symptoms was negatively correlated with the total T4 levels after 8 days of abstinence. Three months after detoxification, relapsers displayed significantly lower T4 and TBG levels compared with abstinent patients. The increase in T3 levels was most pronounced between 8 days and 3 months of abstinence in both relapsing and abstinent patients. Six months after detoxification, only abstinent patients could be assessed, and they displayed increased TBG and T3 levels compared to healthy controls. Our findings suggest a different time-course for T3 and T4 levels after detoxification in alcohol-dependent patients, and indicate that T4 levels after detoxification interact with withdrawal symptoms.

Hypothalamic-pituitary-gonadal axis, prolactin, and cortisol in alcoholics during withdrawal and after three weeks of abstinence: comparison with healthy control subjects

Serum concentrations of luteinizing hormone, follicle-stimulating hormone, testosterone, androstenedione, estradiol, sex hormone-binding globulin, cortisol, and prolactin were measured in 12 male chronic alcoholics once during withdrawal and once after 21 days of abstinence. The results were compared with those of 14 healthy volunteers. During withdrawal, luteinizing hormone, estradiol, and cortisol levels were significantly enhanced. Estradiol and cortisol concentrations fell significantly during abstinence, whereas luteinizing hormone concentrations remained elevated. The results may be interpreted as follows: the well-known inhibitory effect of alcohol on the biosynthesis of testosterone may have led to a compensatory increase in luteinizing hormone secretion, so that normal serum concentrations of testosterone were maintained. On the other hand, peripheral conversion from androstenedione to estradiol via aromatase pathways seemed to be enhanced in chronic alcoholics, at least during withdrawal. Whether this marked increase in estradiol concentrations is implicated in different clinical and psychological symptoms seen in chronic alcoholics remains to be investigated.