triiodothyronine--reverse and Myocardial-Infarction

Serum levels of T4, T3 rT3 and resin T3 uptake were followed for 5 days in 40 patients with acute myocardial infarction (AMI) allocated to early treatment either with alprenolol or placebo. There was a significant fall in T3 (P less than 0.05) and an increase in rT3 (P less than 0.05) without any significant difference between the alprenolol - (n = 19) and placebo - (n = 21) treated groups. The risk of missing a further 20% change in se-T3 and se-rT3 after alprenolol compared to placebo treatment (beta) was less than 0.10 and less than 0.50, respectively. In patients with a severe clinical course, the fall in T3 and increase in rT3 was significantly greater than in patients without complications. No change in T4 was observed either with respect to the clinical course nor following alprenolol. The data suggest that alprenolol can be given in the acute phase of myocardial infarction without causing any additional disturbance in the serum levels of T3 and T4.

Topics: Adrenergic beta-Antagonists; Aged; Alprenolol; Female; Humans; Male; Middle Aged; Myocardial Infarction; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse

After treatment with alprenolol for 1 year, serum 3,3',5'-triiodothyronine (rT3) was significantly increased (P less than 0.01) in a group (n = 20) of euthyroid subjects compared to a control group (n = 20) given placebo. All subjects had definite or suspected myocardial infarction one year previously. Serum thyroxine (T4), free T3 index (FT4I), serum 3,5,3'-triiodothyronine, (T3) and free T3 index (FT3I) were not significantly different in the two groups. Alprenolol and placebo were gradually withdrawn over 14 days. On the first day after withdrawal a significant decrease in serum rT3 in the alprenolol treated group was the only change observed. Fourteen days after withdrawal a significant fall in serum T4, FT4I, rT3 and a rise in serum T3 and FT3I was found in the alprenolol treated group. Six months after withdrawal the only further change observed in the alprenolol treated group was an increase in T3 and FT3I. No changes occurred in the placebo treated group in any of the hormones studied. The results are consistent with a direct effect of long-term alprenolol treatment on the peripheral levels of serum T4, T3 and rT3 in euthyroid subjects. The changes in the thyroid hormones after withdrawal further indicate withdrawal of a permanent inhibition of 5'deiodinase during long-term treatment with alprenolol in euthyroid subjects.

Topics: Adult; Aged; Alprenolol; Clinical Trials as Topic; Double-Blind Method; Female; Humans; Male; Middle Aged; Myocardial Infarction; Thyroxine; Time Factors; Triiodothyronine; Triiodothyronine, Reverse

In severe illness of any cause, down-regulation of the thyroid hormone system may occur. How this affects patients with acute myocardial infarction (AMI) is largely unknown.. To investigate changes in serum levels of the thyroid hormones during AMI and their association with cardiac function and outcome.. Forty-seven consecutive euthyroid patients with AMI were studied prospectively during the first 5 days and again 6 and 12 weeks later. Time from pain onset was used in all analyses.. The thyroid hormone system was rapidly down-regulated with maximal changes 24 to 36 hours after onset of symptoms. The mean level of the hormone total triiodothyronine (T3) decreased 19% (P =.02), the inactive metabolite reverse T3 (rT3) levels increased 22% (P =.01), and thyrotropin levels declined 51% (P<.001) between the first 6-hour and the 24- to 36-hour period. The prohormone free thyroxine was largely unchanged. Patients with poor heart function or more intense inflammatory reaction showed more pronounced down-regulation of the thyroid system. No correlation was found with cardiac enzymes. Patients with prior angina pectoris had lower T(3) levels in early samples, smaller infarctions, and higher levels of C-reactive protein and the proinflammatory cytokine interleukin 6 on admittance. Peak levels of interleukin 6 correlated negatively with T3 (P =.005) and positively with rT3 (P<.05), suggesting that down-regulation before AMI may be cardioprotective. However, mortality was high among patients with the most pronounced thyroid level depression, indicating that down-regulation after AMI may be maladaptive.. The thyroid hormone system is rapidly down-regulated in AMI. This may be beneficial during acute ischemia. Patients with angina had higher levels of interleukin 6 and C-reactive protein and more depressed thyroid hormone system in early samples. Thyroid level depression in patients with angina may possibly have been present before the infarction process started. This novel finding needs further evaluation in large studies to sort out cause-and-effect relationships.

Topics: Adult; Aged; Aged, 80 and over; Angina Pectoris; Biomarkers; Case-Control Studies; Down-Regulation; Female; Humans; Male; Middle Aged; Myocardial Infarction; Risk Factors; Severity of Illness Index; Thyroid Hormones; Thyrotropin; Thyroxine; Time Factors; Triiodothyronine; Triiodothyronine, Reverse; Ventricular Function

The thyroid hormone system may be downregulated temporarily in patients who are severely ill. This "euthyroid sick syndrome" may be an adaptive response to conserve energy. However, thyroid hormone also has beneficial effects on the cardiovascular system, such as improving cardiac function, reducing systemic vascular resistance, and lowering serum cholesterol levels. We investigated whether thyroid hormone levels obtained at the time of myocardial infarction are associated with subsequent mortality.. Serum levels of thyroid hormones (triiodothyronine [T3], reverse T3, free thyroxine [T4], and thyroid-stimulating hormone) were measured in 331 consecutive patients with acute myocardial infarction (mean age [+/- SD], 68 +/- 12 years), from samples obtained at the time of admission.. Fifty-three patients (16%) died within 1 year. Ten percent (16 of 165) of patients with reverse T3 levels (an inactive metabolite) >0.41 nmol/L (the median value) died within the first week after myocardial infarction, compared with none of the 166 patients with lower levels (P <0.0004). After 1 year, the corresponding figures were 24% (40 of 165) versus 7.8% (13 of 166; P <0.0001). Reverse T3 levels >0.41 nmol/L were associated with an increased risk of 1-year mortality (hazard ratio = 3.0; 95% confidence interval: 1.4 to 6.3; P = 0.005), independent of age, previous myocardial infarction, prior angina, heart failure, serum creatinine level, and peak serum creatine kinase-MB fraction levels.. Determination of reverse T3 levels may be a valuable and simple aid to improve identification of patients with myocardial infarction who are at high risk of subsequent mortality.

Topics: Aged; Biomarkers; Female; Humans; Male; Multivariate Analysis; Myocardial Infarction; Prognosis; Proportional Hazards Models; Survival Analysis; Sweden; Triiodothyronine, Reverse

Topics: Adult; Aged; Female; Humans; Male; Middle Aged; Myocardial Infarction; Prognosis; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse

It has been reported that there is a decrease in the serum concentration of thyroid hormones in non-thyroidal illness. In the present study we made serial measurements of serum concentration of thyroid hormones [triiodothyronine (T3), thyroxine (T4), free triiodothyronine (FT3), free thyroxine (FT4), reverse triiodothyronine (rT3)], thyroid stimulating hormone (TSH) and thyroxine binding globulin (TBG) in 10 patients with acute myocardial infarction (AMI, Grade I, according to the classification of Killip & Forrester) during 14 days after onset. In the early phase of AMI, serum T3, T4, FT3 and FT4 levels decreased while rT3 increased. TSH and TBG levels, however, were unchanged. In the patients with a high peak creatine phosphokinase activity (greater than or equal to 400 mU/ml), the decrease in thyroid hormone and increase in serum rT3 levels were greater than in patients with a low peak value (less than 400 mU/ml), suggesting a correlation between severity of AMI and changes in serum thyroid hormone levels. Especially, serum FT3 levels fell below the lower limit of controls within 14 days, with the lowest levels and the rT3 peak on the third day after onset. These data suggest that in AMI peripheral conversion of T4 favours rT3 production and that low levels of serum FT3 and T3 protect the infarcted heart muscle against thyroid hormone action.

Topics: Aged; Alpha-Globulins; Humans; Middle Aged; Myocardial Infarction; Thyroid Hormones; Thyrotropin; Thyroxine; Thyroxine-Binding Proteins; Triiodothyronine; Triiodothyronine, Reverse

In patients with severely acute diseases, a special relationship of thyroidal hormones with decreased T3 and increased rT3 levels is known, the so-called low T3 syndrome. The aim of this study was to elucidate the involvement of the hypothalamo-pituitary thyroid axis, the pituitary-gonadal axis, the altered hepatic function, the plasma proteins in the low T3 syndrome, and the evaluation of these parameters for prognosis in patients with acute myocardial infarction. Thirty-one patients (29 male, 2 female) with AMI entered the study for the determination of hypothalamo-pituitary thyroid axis and the plasma proteins. Besides routine laboratory determinations, TRH, TSH, T4, T3, rT3, CHE, albumin, total protein, TBG, and estradiol concentrations in plasma were measured daily for 5 days after AMI using immunological and other methods. Twelve male patients with AMI entered the study for the determination of pituitary-gonadal axis; the T3, rT3, estradiol, testosterone, FSH, and LH concentrations in serum were determined using immunological methods. We found that T3 and T4 decreased significantly to a minimum on the first and the second day, respectively, after admission and increased in the course of the observation period. In contrast, rT3 was elevated significantly within the first 2 days and decreased later. TSH and TRH decreased in the first 2 days and increased in the following days. CHE, albumin, and total protein levels significantly showed a minimum on day 4 and TBG significantly showed a minimum on the second day after AMI and increased to day 4.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Blood Proteins; Estradiol; Euthyroid Sick Syndromes; Female; Follicle Stimulating Hormone; Gonadotropins, Pituitary; Humans; Luteinizing Hormone; Male; Middle Aged; Myocardial Infarction; Testosterone; Thyroid Hormones; Thyrotropin; Thyrotropin-Releasing Hormone; Thyroxine; Thyroxine-Binding Proteins; Triiodothyronine; Triiodothyronine, Reverse

Topics: Aged; Aged, 80 and over; Aspartate Aminotransferases; Female; Humans; Male; Middle Aged; Myocardial Infarction; Prognosis; Thyroid Hormones; Thyrotropin; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse

We have studied with seriated controls for a period of 9 days 18 patients admitted to our hospital for acute myocardial infarction (AMI). Slight, but non significant variations in thyroidal hormone pattern were observed: slight decrease of T3 and T4 levels, increase of reverse T3 on day 3, low free T4 levels, slight increase of TSH levels until the 3rd day. However, hormonal pattern was clearly different in patients who presented a clinical improvement (group 1a) and in patients who died for AMI (group 1b). In fact, a significant TSH increase was recorded in patients of group 1a; on the contrary, a significant decrease of TSH, T4 and free T4 concentrations was observed for subjects of group 1b, suggesting an inadequate response of pituitary-thyroid axis. In conclusion, the evaluation of thyroid hormones and thyrotropin levels can be of clinical usefulness in the management of patients with AMI. The decrease of plasma T4 and free T4 concentrations, accompanied with low TSH levels, can be associated with unfavorable course of the disease and therefore can be considered a bad prognostic sign.

Topics: Adult; Aged; Female; Humans; Male; Middle Aged; Myocardial Infarction; Pituitary Gland; Thyroid Hormones; Thyrotropin; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse

Subjects followed serially after acute myocardial infarction demonstrated a rapid and sustained fall in serum total tri-iodothyronine (T3) concentration and a rise in reverse tri-iodothyronine (rT3) concentration. There was a transient fall in total thyroxine (T4) concentration. Thyroxine binding globulin (TBG) levels were unchanged after acute myocardial infarction but prolonged falls were observed in thyroxine binding prealbumin (TBPA) and albumin concentrations. In contrast to the fall in total T4, both measured and calculated free T4 concentrations were unchanged but measured and calculated free T3 concentrations fell as did total T3. Despite the observed fall in T3, basal thyrotrophin (TSH) concentrations did not rise. The reduction in circulating T3 levels after acute myocardial infarction suggests that a hypothyroid state exists. Until tissue thyroid status can be assessed directly, however, this conclusion must remain in doubt.

Topics: Acute Disease; Female; Humans; Male; Middle Aged; Myocardial Infarction; Prealbumin; Thyroid Hormones; Thyrotropin; Thyroxine; Thyroxine-Binding Proteins; Time Factors; Triiodothyronine; Triiodothyronine, Reverse

Thyroid hormones and cortisol levels were serially measured over seven mornings and evenings in 23 consecutive patients with acute myocardial infarction (AMI) or acute coronary insufficiency (ACI). The patients were divided into two groups, high level cortisol (HLC) and low level cortisol (LLC) groups, according to mean morning and evening cortisol levels. The transient increase in plasma rT3, decrease in T3 and TSH was significantly greater in the HLC group. A diurnal variation in cortisol levels was observed in the LLC group 48 h and in the HLC group 72 h after admission. Taking the 23 patients together, no significant correlation was observed between infarct size (peak CPK levels) and the altered rT3, T4 or TSH levels. However, a significant correlation was obtained between the maximal change in T3, rT3 or TSH and the mean cortisol levels preceding these alterations, as well as between cortisol levels and infarct size. It is suggested that cortisol rather than infarct size may be the dominant factor involved in the alteration of thyroidal levels in AMI patients.

Topics: Adult; Aged; Circadian Rhythm; Female; Humans; Hydrocortisone; Male; Middle Aged; Myocardial Infarction; Thyrotropin; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse

Topics: Adult; Creatine Kinase; Female; Humans; Iodide Peroxidase; Male; Middle Aged; Myocardial Infarction; Triiodothyronine; Triiodothyronine, Reverse

Thyroid hormones were serially measured over a 2-week period in thirty-four consecutive patients with acute myocardial infarction (AMI). A transient increase in plasma rT3 and a decrease in plasma T3 was found, with the maximum changes occurring on the third day after the onset of AMI. The changes in plasma rT3 and T3 were greater in the seventeen patients with a complicated AMI (mean peak SGOT 145 mu/l) than in the seventeen patients with an uncomplicated AMI (mean peak SGOT 79 mu/l). A correlation was found between infarct size (as estimated by the peak SGOT value) and the following indices: delta r T3, delta T3, highest rT3/t3 and highest rT3/T4 ratios. A transient increase in plasma TSH (peak on days 4 and 5) and in plasma T4 and FT4 index (peak on days 6 and 7) was also observed, whereas T3 resin uptake (T3U) decreased. These findings suggest that the following sequence of events occurs in thyroid hormone metabolism during AMI: (1) inhibition of the 5'-deiodination of T4, resulting in increased plasma rT3 and decreased plasma T3 values, and in a lower metabolic clearance of T4. (2) Increased secretion of TSH (provoked by the lower T3 levels) resulting in increased thyroidal secretion of T4 and T3, which is then switched off by the negative feedback of thyroid hormones on the pituitary.

Topics: Acute Disease; Aged; Aspartate Aminotransferases; Female; Humans; Male; Middle Aged; Myocardial Infarction; Prospective Studies; Thyrotropin; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse

Topics: Aged; Female; Humans; Male; Middle Aged; Myocardial Infarction; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse

Topics: Aged; Diiodothyronines; Female; Humans; Male; Middle Aged; Myocardial Infarction; Propranolol; Thyronines; Triiodothyronine; Triiodothyronine, Reverse

In 21 males (age 50-78 yrs) without endocrine diseases, plasma thyroxine, triiodothyronine, reverse-triiodothyronine and TSH were determined by specific RIAs in the early stage of an acute myocardial infarction. Blood was taken every 4 hours up to 43 hours after admission. The patients were separated in 2 groups, depending on the severity of the infarction (group A with 11 patients = severe infarction; group B with 10 patients = not severe infarction). 25 healthy men served as an aged-matched control group (age 56-83 yrs). Thyroxine in all patients (group A and B together) did not show essential fluctuations during the 43 hours of observation. The mean values were elevated, the individual values were predominantly in the normal range. There were no significant differences between the groups A and B. As well in the total-patients group as in the groups A and B already on admission, T3 was diminished and went on falling during the 43 hours. From 35 hours after admission, T3 was significantly decreased in group A compared to group B. On admission, rT3 was elevated in both the total-patients group and group A and B; it reached its maximum after 19 hours. Group A showed from 7 hours after admission a tendency more increased levels compared to group B. In all cases (total-patients group, group A and B) TSH levels were constant within the normal range during the whole time. The results suggest that in the early stage of myocardial infarction an important alteration in the thyroxine metabolism with enhancement of the inactive reverse-triiodothyronine production occurs very quickly. Moreover, the results show that this alteration may depend on the severity of myocardial infarction. Hypothyreoidism can be excluded because of the normal or elevated thyroxine values and the normal TSH levels.

Topics: Aged; Humans; Male; Middle Aged; Myocardial Infarction; Thyroid Hormones; Thyrotropin; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse

A study was performed to elucidate whether endogenous cortisol, as previously suggested, could be responsible for the decreased T3 levels seen in euthyroid patients with acute myocardial infarction. Levels of these hormones as well as levels of T4 and reverse-T3 were monitored in 31 consecutive patients admitted to the Coronary Care Unit with symptoms of precordial pain or with acute arrhythmias. Sixteen of the patients had proven myocardial infarction, the remaining 15 were used as a control group. The results demonstrated that a reduction of T3 levels was seen in the infarction group without evidence of a statistically significant difference between the daily mean cortisol levels. No significant difference could be observed in T4 or reverse-T3 levels in the two groups or in T3 levels in the control group. It is concluded that the decrease in T3 levels is not a consequence of the increased levels of endogenous cortisol.

Topics: Acute Disease; Adult; Aged; Female; Humans; Hydrocortisone; Male; Middle Aged; Myocardial Infarction; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse