Hyperthyroidism after cholecystography

Review of oral cholecystographic agents for the management of hyperthyroidism

OBJECTIVE

Although the use of oral cholecystographic agents (OCAs) had declined due to limited availability, there is literature to suggest it is an effective medication for thyrotoxicosis in appropriate clinical situations.

METHODS

The authors performed a PubMed search and systematically reviewed all the English written case reports, original studies and reviews from 1953 to 2012. Additional information was supplemented from available online pharmacologic databases.

RESULTS

The off-label use of OCAs was reviewed for the management of neonatal and adult Graves' disease, subacute thyroiditis, amiodarone-induced thyroiditis (AIT), exogenous hyperthyroidism, toxic multinodular goiter (TMNG), thyrotropinoma, thyrotoxicosis during pregnancy, rapid pre-operative control of hyperthyroidism, and thyroid storm. Adverse effects were also reviewed.

CONCLUSION

OCAs generally are effective agents in treating thyrotoxicosis in the etiologies reviewed. OCAs are clinically relevant in patients who require rapid control, such as in the pre-operative state or patient who cannot tolerate a thyrotoxicosis state. OCA may also be beneficial in situations where other anti-thyroidal medication would be hazardous or ineffective, such as thionamide allergy or exogenous thyrotoxicosis. Given concern for long-term relapse, OCAs should be considered a short-term bridge to definitive therapy. OCAs are limited in TMNG and should be second line after glucocorticoids in AIT II. OCAs do not preclude the use of radioactive iodine, which can be performed one week after OCA therapy.

The use of oral radiographic contrast agents in the management of hyperthyroidism

Oral iodinated radiographic contrast agents such as ipodate and iopanoic acid form an important part of the armamentarium used to treat hyperthyroidism. They rapidly and dramatically reduce serum triiodothyronine (T3) levels by inhibiting conversion of thyroxine (T4) to T3 in the periphery and by blocking secretion from the thyroid. Potential risks from the large iodine load resulting from their use limit their widespread applicability. In addition, they are ineffective when used alone on a long-term basis. However, these agents may be especially useful in treating thyrotoxic patients preoperatively, in neonatal Graves' disease, in massive levothyroxine ingestion, and when other conventional antithyroid drugs are unsuccessful or contraindicated.

Epidemiology of low cholesterol levels in older adults. The Cardiovascular Health Study

BACKGROUND

Low cholesterol levels have been associated with increased mortality from stroke, cancer, and other noncardiovascular diseases, but the reasons for this association remain unclear. One explanation is that persons with low cholesterol levels have early or occult disease that eventually leads to their deaths.

METHODS AND RESULTS

This possibility was explored in 2,091 men and 2,714 women 65-100 years old in the Cardiovascular Health Study, a multicenter observational study of risk factors for heart disease and stroke in older adults. Cholesterol levels < or = 160 mg/dL were present in 11.6% of men and 3.7% of women and increased in prevalence with age. After adjustment for age, total cholesterol levels in this range were associated with a twofold increased prevalence of treated diabetes in men and women and with a twofold increased prevalence of cancer diagnosed in the preceding 5 years in women only. Low cholesterol was also associated with lower levels of hemoglobin, albumin, and factor VII, suggesting a link with hepatic synthetic function. On multivariate analysis, factors most strongly associated with low cholesterol levels in men and women were decreased factor VII levels, decreased albumin, and diabetes.

CONCLUSIONS

Cross-sectional associations with low cholesterol levels differ by sex and suggest poorer health by some measures. The observed relations with treated diabetes and impaired hepatic synthetic function should be examined for risk of mortality in longitudinal data from this and other observational studies.

Characteristics and outcomes of hospitalized older patients who develop hypocholesterolemia

OBJECTIVES

This research project was undertaken to determine the clinical characteristics, lipoprotein abnormalities, and outcomes of older hospitalized patients who develop hypocholesterolemia.

METHODS

The project had two parts: (1) a retrospective, case-control study of 50 hospitalized patients greater than or equal to 65 years old whose serum cholesterol was normal on admission (greater than or equal to 160 mg/dL) and fell to less than or equal to 120 mg/dL during hospitalization; (2) a laboratory study of lipoproteins in 17 hospitalized patients greater than or equal to 65 years old whose cholesterol was normal on admission but fell to less than or equal to 120 mg/dL during hospitalization.

RESULTS

Case-control Study--Nine percent of patients greater than or equal to 65 years old developed hypocholesterolemia while in the hospital, and these patients were more likely than controls to have undergone surgery and to have nothing by mouth for 5 days or longer. Cases had a longer length of stay, more complications, and were slightly more likely to die in the hospital than controls. LABORATORY STUDY--Hypocholesterolemic patients had low concentrations of all lipoproteins (VLDL, LDL, HDL), and the LDL and HDL were enriched in triglyceride and depleted of cholesterol ester.

CONCLUSION

Acquired hypocholesterolemia is a common finding in hospitalized older patients and is associated with poor outcomes. Patients who became hypocholesterolemic in the hospital had both a low concentration of lipoprotein particles and abnormalities in lipoprotein particle composition.

Prognostic significance of serum cholesterol in nursing home men

Serum cholesterol was measured in 129 men (average age 70.6; range 41-96) of a Veterans Administration Nursing Home, and was correlated with other items in an extensive clinical data base. Serum cholesterol was less than 150 mg/dl in 13% of the subjects, and was less than 160 mg/dl in 18%. Cholesterol greater than 280 mg/dl occurred in 8%. Serum cholesterol varied directly (p less than 0.02) with: body weight, serum albumin, serum total protein, serum sodium, ability to walk, and ability to feed oneself; and indirectly (p less than 0.02) with death rate, degree of functional dependence, and serum SGOT and LDH. Nursing home men with cholesterol less than 150 mg/dl had a death rate of 63% during the 14 months after the cholesterol analysis, compared to a death rate of 9% in men with cholesterol greater than 150 mg/dl (p less than 0.05). Death rate during the year after the analysis was 52% if cholesterol was below 160 mg/dl, compared to 7% if it was above this threshold (p less than 0.05).

Relation of serum albumin concentration to death rate in nursing home men

Serum albumin was measured in 126 men (average age 70.6; range 40 to 96) of a Veterans Administration Nursing Home, and was correlated with other items in an extensive clinical data base, including death or survival during the year after the analysis. The reason for institutionalization was chronic neurologic disease or other disabling physical condition in 63 men (group A), and psychiatric disorder in 63 men (group B). In group A, the proportions of men with albumin less than 3.5, 3.5-4.0, and greater than 4.0 g/dl were 6%, 37%, and 57%, respectively. In this group, the serum albumin level was significantly (p less than 0.05) correlated with death rate, hemoglobin, hematocrit, serum cholesterol, and serum lactic dehydrogenase. The death rate in group A during the year after the albumin analysis was 25%. For the patients with albumin level less than 3.5, 3.5-4.0, and greater than 4.0 g/dl, the death rates were 50%, 43%, and 11% respectively (p less than 0.01 for comparison of the former two groups with the latter). The subgroup with albumin 3.5-4.0 g/dl represented only 37% of the men in group A, but accounted for 63% of the group's deaths. In group B, serum albumin level was not significantly correlated with any other clinical variable. Death rate during the year after the albumin analysis was only 2% in group B, and did not correlate with the albumin level. These data indicate that, in nonpsychiatric Nursing Home men, the desirable level for the serum albumin concentration is higher than 3.5 g/dl.

Thyrotoxicosis induced by amiodarone, a new efficient antiarrhythmic drug with high iodine content

Amiodarone is an antiarrhythmic agent with high iodine content. Ten patients treated with amiodarone developed thyrotoxicosis. I131 uptakes were negligible, and TT3 levels low in relation to TT4 levels, and sometimes even normal. Cessation of amiodarone caused thyroid functions to return to normal in one to five months, unrelated to propylthiouracil treatment. Eight of the patients had normal thyroid glands on radioscan or palpation. All patients tested had normal TRH tests. Thyrotoxicosis is a relatively common complication of amiodarone treatment, probably caused by its high iodine content. It is possible in apparently normal thyroid glands, suggesting failure of the homeostatic mechanisms controlling thyroid synthesis and release in these patients. Amiodarone is very efficient in controlling tachyarrhythmias and angina pectoris, situations in which thyrotoxicosis is dangerous. Thyroid function tests should therefore be drawn periodically, and the complication considered whenever tachyarrhythmias worsen on treatment with amiodarone.

Iodothyronine and thyrotropin concentrations after iodoamide administration for angiographic studies

In order to study the effect of iodoamide (a contrast medium widely used for urographic and arteriographic studies) on thyroid function, seventeen subjects were studied before and after arteriographic examinations employing this contrast compound. Serum concentrations of T4, T3, rT3 and TSH were not modified during the observation period by the administration of iodoamide. This finding is in contrast with the observation that iopanoic acid and ipodate, used for cholecystographic examinations, can reduce the serum concentrations of T4 and T3 with a concomitant increase in rT3. Therefore, iodoamide is not useful in the treatment of hyperthyroidism.

Iodine treatment of iodine-induced thyrotoxicosis

A 62-year-old female who had received prolonged iodine therapy for asthma presented with severe thyrotoxicosis and severe asthma. Her history, elevated serum thyroxine and triiodothyronine, low 131I uptake, and elevated intrathyroidal iodine content by fluorescent scan were most consistent wiht a diagnosis of iodine-induced thyrotoxicosis (IITT). The clinical course of her thyrotoxicosis was protracted, and in spite of its etiologic role in the precipitaton of thyrotoxicosos, iodine was therapeutically efficacious, although combined treatment with methimazole was required to ultimately restore euthyroidism. Therapy with lithium was also employed but appeared to be only transiently effective and combined no additional decrement in serum T4 than that seen with iodine alone. The case exemplifies the heterogeneity of what is considered "iodine-induced" thyrotoxicosis, the complexities inherent in establishing a diagnosis of IITT, and the use of other rapid acting pharmacologic agents in IITT when beta blockade is contraindicated by asthma.

Thyroid, renal, and hepatic function tests following cholecystography with high-dose contrast agents

Serum biochemical tests were observed for about three weeks following oral cholecystography with fractionated high doses (6 g) of iopanoic acid (Telepaque) or sodium ipodate (Biloptin) in 24 and 29 patients, respectively. Both agents produced similar effects. No significant changes were seen in renal or hepatic function except for a mild increase in bilirubin on day 22. Serum urate decreased 10% on day 4, but the change was not significant. On days 4 and 11, there were significant increases in thyroid-stimulating hormone, thyroxine and free thyroxine index, and a moderate fall in triiodothyronine. Reverse triiodothyronine increased sharply on day 4. The pattern of changes observed suggests that these contrasts interfere with the extrathyroidal deiodination of iodothyronines. The temporary rise in thyroxine and free thyroxine index exceeded reference ranges in about half of all subjects, but they remained clinically euthyroid. Thyroid function tests should be interpreted with caution within three weeks of cholecystography.