scholarly journals T3:T4 Ratio Can Distinguish Between Adaptive Changes and True Subclinical Hypothyroidism in Older Adults

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 229-229
Author(s):  
Enoch Abbey ◽  
John McGready ◽  
Eleanor Simonsick ◽  
Jennifer Mammen
Keyword(s):  
Older Adults ◽  
Thyroid Hormone ◽  
Clinical Decision Making ◽  
Hormone Replacement ◽  
Primary Hypothyroidism ◽  
Free T4 ◽  
Cross Sectional ◽  
Adaptive Changes ◽  
C Statistic ◽  
Central Adaptation

Abstract Because of heterogeneity in hormonal aging,1 we believe isolated elevated TSH is insufficient to drive clinical decision making for thyroid hormone replacement in older adults. We performed a cross-sectional study involving 63 older adult participants of the BLSA in order to assess the diagnostic value of individual hormone levels or free T3: free T4 ratio for differentiating thyroid-aging phenotypes. We defined two phenotypic groups, central adaptation and primary hypothyroidism, both with a rising TSH and with a rising or falling FT4 respectively. Fifty-four percent of study participants were male, the average age was 78.8 years, and 66.7% had the primary hypothyroidism phenotype. The unadjusted odds ratio of having the central adaptation phenotype is 23.40 (95% CI 3.66-149.73) for every unit increase in the FT3:FT4 ratio. The ROC curve had a C-statistic of 0.815. Similarly, FT4 alone distinguished the phenotypes with a C-statistic of 0.864. In contrast, TSH and FT3 were not predictive (C-statistic of 0.617, and 0.479 respectively). When the analysis is limited to the 24 individuals with elevated TSH, the ratio remains predictive (0.839). Both the higher FT4 and the lower ratio found in individuals with adaptive changes are consistent with a physiology similar to the adaptations seen in acute illness. This supports the hypothesis that elevated TSH can represent a response to stressors with aging and doesn’t always warrant treatment with thyroid hormone. Our findings suggest that full thyroid function panel can be used to make better diagnostic decisions in older adults.

scholarly journals Free Triiodothyronine Has a Distinct Circadian Rhythm That Is Delayed but Parallels Thyrotropin Levels

2008 ◽  
Vol 93 (6) ◽  
pp. 2300-2306 ◽  
Author(s):  
W. Russell ◽  
R. F. Harrison ◽  
N. Smith ◽  
K. Darzy ◽  
S. Shalet ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Thyroid Hormone ◽  
Cross Correlation ◽  
Hormone Replacement ◽  
Cross Sectional Study ◽  
University Hospital ◽  
Free Triiodothyronine ◽  
Free T4 ◽  
Cross Sectional ◽  
Thyroid Hormone Replacement

Abstract Context: TSH is known to have a circadian rhythm, but the relationship between this and any rhythm in T4 and T3 has not been clearly demonstrated. Objective: With a view to optimizing thyroid hormone replacement therapy, we have used modern assays for free T4 (FT4) and free T3 (FT3) to investigate circadian rhythmicity. Setting: The study was performed at a university hospital. Design and Subjects: This was a cross-sectional study in 33 healthy individuals with 24-h blood sampling (TSH in 33 and FT4 and FT3 in 29 individuals) and cosinor analysis. Results: Of the individuals, 100% showed a sinusoidal signal in TSH, for FT4 76%, and for FT3 86% (P < 0.05). For FT4 and FT3, the amplitude was low. For TSH the acrophase occurred at a clock time of 0240 h, and for FT3 approximately 90 minutes later at 0404 h. The group cosinor model predicts that TSH hormone levels remain above the mesor between 2020 and 0820 h, and for FT3 from 2200–1000 h. Cross correlation of FT3 with TSH showed that the peak correlation occurred with a delay of 0.5–2.5 h. When time-adjusted profiles of TSH and FT3 were compared, there was a strong correlation between FT3 and TSH levels (ρ = 0.80; P < 0.0001). In contrast, cross correlation revealed no temporal relationship between FT4 and TSH. Conclusions: FT3 shows a circadian rhythm with a periodicity that lags behind TSH, suggesting that the periodic rhythm of FT3 is due to the proportion of T3 derived from the thyroid. Optimizing thyroid hormone replacement may need to take these rhythms into account.

Twice-Weekly Dosing for Thyroxine Replacement in Elderly Patients with Primary Hypothyroidism

1994 ◽  
Vol 22 (5) ◽  
pp. 273-277 ◽  
Author(s):  
J Taylor ◽  
B O Williams ◽  
J Frater ◽  
D J Stott ◽  
J Connell
Keyword(s):  
Thyroid Hormone ◽  
Elderly Patients ◽  
Hormone Replacement ◽  
Systolic Time Intervals ◽  
Serum Levels ◽  
Primary Hypothyroidism ◽  
Time Intervals ◽  
Thyroxine Therapy ◽  
Total Triiodothyronine ◽  
Systolic Time

Seven female patients (mean age 86 years) with proven biochemical primary hypothyroidism were enrolled in a single-blind randomized crossover study, of standard daily versus twice-weekly thyroxine therapy, with each phase of one month's duration. The median daily dose of thyroxine was 100 μg (range 75 – 100 μg). Serum levels of thyroid hormones and thyrotrophin were very similar during twice-weekly thyroxine therapy to those during daily therapy and there were no statistically significant differences between trough and peak serum total triiodothyronine, free thyroxine, or thyrotrophin levels or systolic time intervals during twice-weekly thyroxine. Administration of thyroxine twice-weekly to elderly patients with primary hypothyroidism gives effective biochemical thyroid hormone replacement, with no evidence from the systolic time intervals of tissue thyrotoxicosis at expected peak thyroid hormone concentrations. Supervised twice-weekly thyroxine should be considered in patients with primary hypothyroidism who comply poorly with daily dosing.

scholarly journals Thyroid hormone profile and PELOD score in children with sepsis

2014 ◽  
Vol 54 (4) ◽  
pp. 245
Author(s):  
Agung G. Tanurahardja ◽  
Antonius H. Pudjiadi ◽  
Pramita G. Dwipoerwantoro ◽  
Aman Pulungan
Keyword(s):  
Thyroid Hormone ◽  
Pediatric Intensive Care ◽  
Cross Sectional Study ◽  
Free T4 ◽  
Cross Sectional ◽  
Risk Of Death ◽  
Hormone Profile ◽  
Low T3 ◽  
Hormonal Dysfunction ◽  
Pelod Score

Background Thyroid hormonal dysfunction, also known aseuthyroid sick syndrome or nonthyroidal illness, can be seenin sepsis. There have been few studies on thyroid hormonedysfunction in septic children, as well as on a relationshipbetween their thyroid hormone profiles and pediatric logisticorgan dysfunction (PELOD) scores. Procakitonin (PCT) is oneof the sepsis biomarker.Objective To evaluate the thyroid hormone profile in childrenwith sepsis as well as to assess for a correlation between the thyroidlevels and PELOD scores, PCT levels, and patient outcomes.Methods This cross-sectional study included children aged 1- 18years admitted to the pediatric intensive care unit (PICU) with aprimary diagnosis of sepsis. PELOD scores and thyroid hormonallevels were assessed once during the first 24 hours after PICUadmission.Results Thirty subjects were included in the study. The medianvalues ofT3, free T4, and TSH were 45 (range 17 -133) ng/dL,0.81 (range 0.3-1.57) ng/dL, and 1.36 (range 0.05-7.78) μIU/L,respectively. The T3, free T4, and TSH levels were decreased in97%, 50% and 40% of the subjects. There were no significantdifferences between low and normal to high TSH with regards tothe PELOD score (P=0.218), PCT level (P=0.694), or patientoutcomes (P=0.55). The risk of death increased by 15 timesamong the subjects with PELOD score ~20 compared to thosewith PELOD score <20 (OR 15; 95%CI: 1.535 to 146.545;P=0.012).Conclusion Thyroid hormones are decreased in septic childrenwith the majority having low T3. A high PELOD score is stronglycorrelated with mortality and can be used as a prognostic parameterfor septic children in the PICU, but there is no correlation withdecreased TSH.

scholarly journals Effect of Adequate Thyroid Hormone Replacement on the Hypothalamo-Pituitary-Gonadal Axis in Premenopausal Women with Primary Hypothyroidism

2019 ◽  
Vol 8 (3) ◽  
pp. 152-158
Author(s):  
Bharath Bachimanchi ◽  
Suresh Vaikkakara ◽  
Alok Sachan ◽  
Ganji Praveen Kumar ◽  
Ashok Venkatanarasu ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Hormone Replacement ◽  
Premenopausal Women ◽  
Primary Hypothyroidism ◽  
Thyroid Hormone Replacement

scholarly journals Treated hypothyroidism, cognitive function, and depressed mood in old age: the Rancho Bernardo Study

2009 ◽  
Vol 161 (6) ◽  
pp. 917-921 ◽  
Author(s):  
Caroline K Kramer ◽  
Denise von Mühlen ◽  
Donna Kritz-Silverstein ◽  
Elizabeth Barrett-Connor
Keyword(s):  
Older Adults ◽  
Cognitive Function ◽  
Thyroid Hormone ◽  
Old Age ◽  
Depressed Mood ◽  
Medication Use ◽  
Antidepressant Medication ◽  
Primary Hypothyroidism ◽  
Overt Hypothyroidism

ObjectiveOvert hypothyroidism is associated with cognitive impairment, which can be reversed if treated early and appropriately. We compared cognitive function (CF) of euthyroid older adults with those who had long-term treated hypothyroidism.MethodsBetween 1999 and 2003, the CF of 885 euthyroid and 149 hypothyroid-treated older adults (primary hypothyroidism after surgery or autoimmune thyroid disease) was assessed using three standardized CF tests: the modified mini-mental state examination, Trails B, and verbal fluency. Depressed mood was assessed using the Beck Depression Inventory (BDI). Only participants with thyroid stimulating hormone (TSH) in the normal range were included.ResultsThe treated hypothyroid group had been treated with l-thyroxine for an average of 20 years. Those with treated hypothyroidism were older than the euthyroid group (76.1±9.6 vs 73.6±10.2 years, P=0.005) and were much more often women (81.6 vs 54.8%, P<0.001). TSH levels were similar between groups (median interquartile range=1.57 (1.19) vs 1.54 (1.59) mIU/l, P=0.81). Compared to euthyroid, the treated hypothyroidism group had more frequent antidepressant medication use (19.5 vs 8.5%, P<0.001) but similar BDI scores. Performance on the three CF tests did not differ by thyroid hormone treatment. Results were not changed after adjustment for age, sex, antidepressant medication use, exercise, and total cholesterol.ConclusionLong-term treated hypothyroidism is not associated with impaired CF or depressed mood in old age. The lack of association with CF is reassuring with regard to long-term use of thyroid hormone therapy.

scholarly journals SUN-281 Pituitary Hyperplasia Secondary to Uncontrolled Primary Hypothyroidism

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Jessica Lee Betancourt
Keyword(s):  
Pituitary Gland ◽  
Early Recognition ◽  
Hormone Replacement ◽  
Primary Hypothyroidism ◽  
Laboratory Evaluation ◽  
Complete Regression ◽  
Pituitary Macroadenoma ◽  
Free T4 ◽  
Pituitary Hyperplasia ◽  
Patient Reported

Abstract Background: There are several recognized causes of hyperplasia of the pituitary gland. These may present as sellar masses and be misdiagnosed as pituitary adenomas. Pituitary hyperplasia can occur in the presence of long standing primary hypothyroidism due to the loss of negative feedback caused by decreased secretion of thyroxine (T4) and triiodothyronine (T3) by the thyroid gland, leading to excessive thyrotropin releasing hormone (TRH) production by the hypothalamus causing Thyrotroph pituitary hyperplasia Clinical case: 51 y/o female with a past medical history that includes anxiety & depression, obesity, pre-diabetes and uncontrolled hypothyroidism due to Hashimoto’s, presented to the Endocrinology clinic for recent diagnosis of pituitary macroadenoma. Patient reported tiredness, decrease energy, myalgias, weight gain, abnormal menstrual periods and frontal headaches. On physical exam, she had a body mass index of 37.39kg/m2, blood pressure of 130/85mmHg, heart rate of 91 bpm. There was no thyromegaly noted on exam. No abdominal striae was noted. Overall, exam was unremarkable. Her neurological exam was normal and there were no obvious visual field deficits. Initial laboratory tests revealed a thyroid stimulating hormone (TSH) &gt;150 uIU/mL (0.46–4.7 uIU/mL), free T4 0.3 ng/dL (0.7–1.3 ng/dL) and positive TPO antibodies. Other endocrine work up including ACTH, cortisol, prolactin, FSH, LH and IGF-1, were normal. An MRI of the pituitary revealed a heterogeneous enhancing mass replacing the pituitary gland in the sella that measured 16 x 17 x 11 mm. She was evaluated by Neurosurgery, for presumed diagnosis of pituitary macroadenoma. However, prompt recognition of uncontrolled primary hypothyroidism causing pituitary hyperplasia lead to medical management, first. She was started on weight based (1.6mcg/kg/day) levothyroxine at 175 mcg per day. Six weeks after thyroid replacement therapy laboratory evaluation showed improvement in thyroid function test with a TSH of 0.8mIU/mL, free T4 2.8ng/dL and total T3 307ng/dL. A repeat MRI of the pituitary showed decrease in size of the pituitary gland measuring 15 x 4 x 10 mm. Conclusion: This case illustrates the importance of early recognition of uncontrolled primary hypothyroidism during the evaluation of a pituitary mass. Complete regression of this pituitary gland abnormality can be achieved with thyroid hormone replacement avoiding the irreversible consequences of inappropriate pituitary surgery.

Abstract P266: Prevalence and Risk Factors of Thyroid Dysfunction in Older Adults in the Community

Circulation ◽  
2018 ◽  
Vol 137 (suppl_1) ◽  
Author(s):  
Nermin Diab ◽  
Natalie Daya ◽  
Stephen P Juraschek ◽  
Seth Martin ◽  
John W McEvoy ◽  
...  
Keyword(s):  
Risk Factors ◽  
Older Adults ◽  
Cardiovascular Risk ◽  
Thyroid Hormone ◽  
Thyroid Dysfunction ◽  
Thyroid Peroxidase ◽  
Age Group ◽  
Cross Sectional ◽  
Hormone Levels ◽  
Thyroid Hormone Levels

Context: Prevalence estimates and evidence informing treatment targets for thyroid dysfunction largely come from studies of middle-aged adults. There are limited data on the prevalence of thyroid dysfunction in older populations. Objective: To determine the prevalence of thyroid dysfunction and risk factors for abnormal thyroid tests in older adults. Methods: We conducted a cross-sectional analysis of data from participants aged 65 or older in the Atherosclerosis Risk in Communities (ARIC) study who attended visit 5 in 2011-2013. We measured serum concentrations of triiodothyronine (T3), free thyroxine (FT4), thyroid peroxidase antibody (Anti-TPO), and thyroid stimulating hormone (TSH) in 5,392 participants. We used multivariable linear and logistic regression to assess associations of demographic and clinical risk factors with thyroid hormone levels. Results: In this population of older adults (mean age 76; 56% women and 22% black), the prevalence of thyroid dysfunction was up to 25% when accounting for treated and untreated thyroid dysfunction categories. 15.6% reported use of medication for thyroid dysfunction. Among those not being treated, the prevalence of overt chemical hypothyroidism was 6.0% and subclinical hypothyroidism was 0.82%. Overt chemical hyperthyroidism and subclinical hyperthyroidism affected 0.26% and 0.78% of the population, respectively. Multivariable adjusted cardiovascular risk factor associations for TSH, FT4 and T3 levels are presented in Table . Men were less likely to be anti-TPO positive compared to women (OR=0.59, CI: 0.47,0.75, P<0.001). Conclusions: There is a high prevalence of thyroid dysfunction in this older, community-based population. Prevalence of thyroid dysfunction and thyroid hormone levels vary with sex, race, age group and multiple cardiovascular risk factors. Accounting for these associations in the clinical setting might prove useful in improving thyroid function assessment in this age group.

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