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Association between change in serum bicarbonate and change in thyroid hormone levels in patients receiving conventional or more frequent maintenance haemodialysis.
Molfino, A, Beck, GJ, Li, M, Lo, JC, Kaysen, GA, ,
Nephrology (Carlton, Vic.). 2019;(1):81-87
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Abstract
AIM: Correction of metabolic acidosis in patients with chronic kidney disease has been associated with improvement in thyroid function. We examined whether changes in bicarbonate were associated with changes in thyroid function in patients with end-stage renal disease receiving conventional or more frequent haemodialysis. METHODS In the Frequent Hemodialysis Network Trials, the relationship between changes in serum bicarbonate, free triiodothyronine (FT3) and free thyroxine (FT4) was examined among 147 and 48 patients with endogenous thyroid function who received conventional (3×/week) or more frequent (6×/week) haemodialysis (Daily Trial) or who received conventional or more frequent nocturnal haemodialysis (Nocturnal Trial). Equilibrated normalized protein catabolic rate (enPCR) was examined to account for nutritional factors affecting both acid load and thyroid function. RESULTS Increasing dialysis frequency was associated with increased bicarbonate level. Baseline bicarbonate level was not associated with baseline FT3 and FT4. Change in bicarbonate level was not associated with changes in FT3 and FT4 in the Daily Trial nor for FT4 in the Nocturnal Trial (r ≤ 0.14, P > 0.21). While, a significant correlation between change in serum bicarbonate and change in FT3 (r = 0.44, P = 0.02) was observed in the Nocturnal Trial; findings were no longer significant after adjusting for change in enPCR (r = 0.37, P = 0.08). For participants with baseline bicarbonate <23 mmol/L, no association between change in bicarbonate and change in thyroid indices were seen in the Daily Trial; for the Nocturnal Trial, findings were also not significant for change in FT3 and the association between change in bicarbonate and change in FT4 (r = 0.54, P = 0.03) was no longer significant after adjusting for enPCR (r = 0.45, P = 0.11). CONCLUSION Changes in bicarbonate were not associated with changes in thyroid hormone levels after adjusting for enPCR, as a marker of nutritional status. Future studies should examine whether improvement in acid base status improves thyroid function in haemodialysis patients with evidence of thyroid hypofunction.
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Trend of lipid and thyroid function tests in adults without overt thyroid diseases: A cohort from Tehran thyroid study.
Ahi, S, Amouzegar, A, Gharibzadeh, S, Delshad, H, Tohidi, M, Azizi, F
PloS one. 2019;(5):e0216389
Abstract
CONTEXT While the role of overt hypothyroidism in lipid disorders is clear, the association between dyslipidemia and subclinical thyroid diseases remains unclarified. OBJECTIVE To examine lipid trends based on thyroid function over a 10-year period. DESIGN This is a prospective population based cohort study. SETTING General community. PARTICIPANTS 2383 euthyroid participants, as well as those with subclinical thyroid diseases, in all residents of district 13 of Tehran were examined. Subjects who were on levothyroxine, anti-hyperthyroid drugs, and glucocorticoids, those with a history of thyroid surgery or RAI and pregnant women were excluded. MAIN OUTCOME MEASURES Lipid trends in Model 1 were adjusted for age and follow up duration, and in Model 2 gender-specific multivariate adjustments were performed for thyroid status, diabetes mellitus, smoking status, education, BMI, lipid lowering medications, age and follow up duration by using generalized estimating equations. RESULTS In every four years of assessments, there were significant decreases in levels of all lipid parameters (all Ps <0.001) except for HDL-C, in which a decrescendo-crescendo trend was observed. The results did not change after adjusting for thyroid status, consumption of lipid lowering drugs during the follow-up period, or other variables. There were significant decreases in the prevalence of hypercholesterolemia and hypertriglyceridemia (all Ps <0.001) during the follow-up period. CONCLUSION During a 10 year follow-up, decrescendo trends were observed in levels of total cholesterol, triglycerides, which were not be accounted for by the consumption of lipid lowering drugs and thyroid status.
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Effect of timing of levothyroxine administration on the treatment of hypothyroidism: a three-period crossover randomized study.
Skelin, M, Lucijanić, T, Liberati-Čizmek, AM, Klobučar, SM, Lucijanić, M, Jakupović, L, Bakula, M, Lončar, JV, Marušić, S, Matić, T, et al
Endocrine. 2018;(2):432-439
Abstract
AIM: Hypothyroidism is a common clinical problem that is successfully treated with hormone substitutes in the form of levothyroxine (LT4). LT4 is a drug with a narrow therapeutic index and is usually administered by strict rules, standardly at least half an hour before breakfast. The aim of this study was to investigate a possible effect of different timings of administration on thyroid function status and lipid profile. METHODS The study included patients with the diagnosis of primary hypothyroidism, which were using a stable dose of levothyroxine. They were randomized into three different groups regarding the timing of LT4 administration in a crossover fashion. Each timing regimen lasted for at least 8 weeks; timing regimen A-half an hour before breakfast; timing regimen B-an hour before the main meal of the day; timing regimen C-at bedtime (minimally 2 h after dinner). The hormones (TSH, fT3, fT4) and lipid profile (triglycerides, HDL-, LDL-, and total cholesterol) were measured before the study, at the beginning of every timing regimen and at the end of the study. RESULTS Altogether, 84 patients finished the study. Different timings of LT4 administration were non-inferior in comparison to the standard one and between each other. Median differences in TSH level between baseline and timing regimens were: baseline vs. A = -0.017 95% C.I. (-0.400-0.192); baseline vs. B = -0.325 95% C.I. (-0.562-0.023); baseline vs. C = -0.260 95% C.I. (-0.475-0.000). There were no statistically significant differences in either TSH, fT4, or fT3 when compared between all three timing regimens of LT4 administration and the baseline. There were no statistically significant differences in any of the lipid profile parameters (triglycerides, HDL-, LDL-, and total cholesterol) when compared between all three timing regimens of LT4 administration and the baseline. CONCLUSION The three investigated timing regimens of LT4 administration were equally efficient and offer additional options regarding the treatment individualization.
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Free Thyroxine During Early Pregnancy and Risk for Gestational Diabetes.
Haddow, JE, Craig, WY, Neveux, LM, Palomaki, GE, Lambert-Messerlian, G, Malone, FD, D'Alton, ME, ,
PloS one. 2016;(2):e0149065
Abstract
Several studies have now reported associations between gestational diabetes mellitus (GDM) and low free thyroxine (fT4) during the second and third trimesters, but not in the first trimester. The present study further examines relationships between low fT4, maternal weight, and GDM among women in the FaSTER (First and Second Trimester Evaluation of Risk) trial, in an effort to determine the extent to which thyroid hormones might contribute to causality. The FaSTER cohort includes 9351 singleton, euthyroid women; 272 of these women were subsequently classified as having GDM. Thyrotropin (TSH), fT4, and thyroid antibodies were measured at 11-14 weeks' gestation (first trimester) and 15-18.9 weeks' gestation (second trimester). An earlier report of this cohort documented an inverse relationship between fT4 in the second trimester and maternal weight. In the current analysis, women with GDM were significantly older (32 vs. 28 years) and weighed more (75 vs. 64.5 kg). Maternal weight and age (but not TSH) were significantly associated univariately with fT4 (dependent variable), in the order listed. Second trimester fT4 odds ratios (OR) for GDM were 2.06 [95% CI 1.37-3.09] (unadjusted); and 1.89 [95% CI 1.26-2.84] (adjusted). First trimester odds ratios were not significant: OR 1.45 [95%CI 0.97-2.16] (unadjusted) and 1.11 [95% CI 0.74-1.62] (adjusted). The second trimester fT4/GDM relationship thus appeared to strengthen as gestation progressed. In FaSTER, high maternal weight was associated with both low fT4 and a higher GDM rate in the second trimester. Peripheral deiodinase activity is known to increase with high caloric intake (represented by high weight). We speculate that weight-related low fT4 (the metabolically inactive prohormone) is a marker for deiodinase activity, serving as a substrate for conversion of fT4 to free triiodothyronine (fT3), the active hormone responsible for glucose-related metabolic activity.
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Changes in hormone and lipid levels in male patients with focal seizures when switched from carbamazepine to lacosamide as adjunctive treatment to levetiracetam: A small phase IIIb, prospective, multicenter, open-label trial.
Elger, CE, Rademacher, M, Brandt, C, Elmoufti, S, Dedeken, P, Eckhardt, K, Tennigkeit, F, De Backer, M
Epilepsy & behavior : E&B. 2016;:1-5
Abstract
Treatment with enzyme-inducing antiepileptic drugs (AEDs) such as carbamazepine (CBZ) can lead to changes in reproductive, endocrine, and lipid parameters, resulting in clinical symptoms for some patients. Previous studies indicate that these changes can be reversed by switching to a nonenzyme-inducing AED. Lacosamide is a newer-generation AED, not known to induce or strongly inhibit cytochrome P450 (CYP450) enzymes. In this phase IIIb, prospective, multicenter, open-label, single-arm trial (NCT01375374), the serum concentrations of CYP-related reproductive hormones, thyroid hormones, and lipids were assessed in otherwise healthy male patients with focal seizures (N=11), before and after a switch from CBZ (600-1200mg/day at baseline) to lacosamide (target dose: 400mg/day by the end of titration) as adjunctive treatment to the nonenzyme-inducing AED levetiracetam (LEV, stable dosage of >1000mg/day throughout). Cross titration took place over 4weeks, followed by an 8-week maintenance period. Serum measurements were conducted at baseline and at the end of maintenance. The median serum sex-hormone-binding globulin (SHBG) concentration was towards the higher end of the normal range at baseline and decreased following the switch (61.7 to 47.5nmol/L, N=10, p=0.027 by Wilcoxon signed-rank test). Free androgen index (100×testosterone/SHBG) and free thyroxine serum concentration increased (25.4 to 36.4 and 13.0 to 14.9pmol/L, respectively, both N=10 and p=0.002). At baseline, the median progesterone serum concentration was below the normal range (0.7nmol/L), whereas median cholesterol and low-density lipoprotein concentrations were above the normal range (5.5 and 3.6mmol/L, respectively). By the end of maintenance, all measured parameters were within the normal range. The safety and tolerability profile of lacosamide was consistent with that observed in previous studies. Furthermore, antiseizure efficacy appeared to be maintained, suggesting that deinduction of CYP enzymes following a switch from CBZ to lacosamide as adjunctive therapy to LEV is feasible within 8weeks and is associated with normalization of serum parameters.
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Reduction of thyroid nodule volume by levothyroxine and iodine alone and in combination: a randomized, placebo-controlled trial.
Grussendorf, M, Reiners, C, Paschke, R, Wegscheider, K, ,
The Journal of clinical endocrinology and metabolism. 2011;(9):2786-95
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Abstract
CONTEXT Nodular goiter is common worldwide, but there is still debate over the medical treatment. OBJECTIVE The objective of the study was the measurement of the effect of a treatment with (nonsuppressive) T(4), iodine, or a combination of both compared with placebo on volume of thyroid nodules and thyroid. DESIGN This was a multicenter, randomized, double-blind trial in patients with nodular goiter in Germany [LISA (Levothyroxin und Iodid in der Strumatherapie Als Mono-oder Kombinationstherapie) trial]. SETTING The study was conducted in outpatient clinics in university hospitals and regional hospitals and private practices. PARTICIPANTS One thousand twenty-four consecutively screened and centrally randomized euthyroid patients aged 18-65 yr with one or more thyroid nodules (minimal diameter 10 mm) participated in the study. INTERVENTION Intervention included placebo, iodine (I), T(4), or T(4)+I for 1 yr. T(4) doses were adapted for a TSH target range of 0.2-0.8 mU/liter. OUTCOME MEASURES The primary end point was percent volume reduction of all nodules measured by ultrasound, and the main secondary end point was a change in goiter volume. RESULTS Nodule volume reductions were -17.3% [95% confidence interval (CI) -24.8/-9.0%, P < 0.001] in the T(4)+I group, -7.3% (95% CI -15.0/+1.2%, P = 0.201) in the T(4) group, and -4.0% (95% CI -11.4/+4.2%, P = 0.328) in the I group as compared with placebo. In direct comparison, the T(4)+I therapy was significantly superior to T(4) (P = 0.018) or I (P = 0.003). Thyroid volume reductions were -7.9% (95% CI -11.8/-3.9%, P < 0.001), -5.2% (95% CI -8.7/-1.6%, P = 0.024) and -2.5% (95% CI -6.2/+1.4%, P = 0.207), respectively. The T(4)+I therapy was significantly superior to I (P = 0.034) but not to T(4) (P = 0.190). CONCLUSION In a region with a sufficient iodine supply, a 1-yr therapy with a combination of I and T(4) with incomplete suppression of thyrotropin reduced thyroid nodule volume further than either component alone or placebo.
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Relapse of Graves' disease after successful outcome of antithyroid drug therapy: results of a prospective randomized study on the use of levothyroxine.
Hoermann, R, Quadbeck, B, Roggenbuck, U, Szabolcs, I, Pfeilschifter, J, Meng, W, Reschke, K, Hackenberg, K, Dettmann, J, Prehn, B, et al
Thyroid : official journal of the American Thyroid Association. 2002;(12):1119-28
Abstract
Antithyroid drugs are effective in restoring euthyroidism in Graves' disease, but many patients experience relapse after withdrawal. Prevention of recurrence would therefore be a desirable goal. In a prospective study, patients with successful outcome of 12 to 15 months antithyroid drug therapy were stratified for risk factors and randomly assigned to receive levothyroxine in a variable thyrotropin (TSH)-suppressive dose for 2 years or no treatment. The levothyroxine group was randomized to continue or discontinue levothyroxine after 1 year. End points included relapse of overt hyperthyroidism. Of 346 patients with Graves' disease enrolled 225 were euthyroid 4 weeks after antithyroid drug withdrawal and were randomly assigned to receive levothyroxine (114 patients) or no treatment (controls, 111 patients). Of those not randomized, 39 patients showed early relapse within 4 weeks, 61 endogenous TSH suppression, 7 TSH elevation, and 14 had to be excluded. Dropout rate during the study were 13.3%. Kaplan-Meier analyses showed relapse rates to be similar in the levothyroxine group (20% after 1 year, 32% after 2 years) and the randomized controls (18%, 24%), whereas relapses were significantly more frequent in the follow-up group of patients with endogenously suppressed TSH (33%, 49%). Levothyroxine therapy did not influence TSH-receptor antibody, nor did it reduce goiter size. The best prognostic marker available was basal TSH determined 4 weeks after withdrawal of antithyroid drugs (posttreatment TSH). The study demonstrates that levothyroxine does not prevent relapse of hyperthyroidism after successful restoration of euthyroid function by antithyroid drugs and characterizes posttreatment TSH as a main prognostic marker.