Serum immunoglobulins and biomarkers of dementia:a population-based study

Background: Inflammation plays a key role in the development of dementia, but its link to early biomarkers, particularly those in plasma or neuroimaging, remains elusive. This study aimed to investigate the association between serum immunoglobulins and biomarkers of dementia. Methods: Between 1997 and 2009, serum immunoglobulins (IgA, IgG and IgM) were measured in dementia-free participants of the population-based Rotterdam Study. A random subset of participants had assessment of biomarkers in plasma (total tau (t-tau), neurofilament light chain (NfL), amyloid-β40 (Aβ-40), amyloid-β42 (Aβ-42), while another subset of participants underwent neuroimaging to quantify brain volume, white matter structural integrity and markers of cerebral small vessel disease. Linear regression models were constructed to determine cross-sectional associations between IgA, IgG, IgM and biomarkers of dementia, with adjustment for potential confounders. Multiple testing correction was applied using the false discovery rate. As a sensitivity analysis, we re-ran the models for participants within the reference range of immunoglobulins, excluding those using immunomodulating drugs, and conducted a stratified analysis by APOE-ε4 carriership and sex. Results: Of 8,768 participants with serum immunoglobulins, 3,455 participants (65.8 years [interquartile range (IQR): 61.5–72.0], 57.2% female) had plasma biomarkers available and 3,139 participants (57.4 years [IQR: 52.7–60.7], 54.4% female) had neuroimaging data. Overall, no associations between serum immunoglobulins and biomarkers of dementia remained significant after correction for multiple testing. However, several suggestive associations were noted: higher serum IgA levels concurred with lower plasma levels of Aβ-42 (standardized adjusted mean difference: -0.015 [95% confidence interval (CI): -0.029−-0.002], p = 2.8 × 10–2), and a lower total brain volume, mainly driven by less gray matter (-0.027 [-0.046−-0.008], p = 6.0 × 10–3) and more white matter hyperintensities (0.047 [0.016 – 0.077], p = 3.0 × 10–3). In sensitivity analyses, higher IgM was linked to lower t-tau, Aβ-40, and Aβ-42, but also a loss of white matter microstructural integrity. Stratified analyses indicate that these associations potentially differ between carriers and non-carriers of the APOE-ε4 allele and men and women. Conclusions: While associations between serum immunoglobulins and early markers of dementia could not be established in this population-based sample, it may be valuable to consider factors such as APOE-ε4 allele carriership and sex in future investigations.</p

Preferences of patients, clinicians, and healthy controls for the management of a Bethesda III thyroid nodule

Background: Active surveillance is propagated as an alternative for hemithyroidectomy in the management of Bethesda III thyroid nodules. Methods: A cross-sectional survey questioned respondents on their willingness to accept risks related to active surveillance and hemithyroidectomy. Results: In case of active surveillance, respondents (129 patients, 46 clinicians, and 66 healthy controls) were willing to accept a risk of 10%–15% for thyroid cancer and 15% for needing more extensive surgery in the future. Respondents were willing to accept a risk of 22.5%–30% for hypothyroidism after hemithyroidectomy. Patients and controls were willing to accept a higher risk on permanent voice changes compared with clinicians (10% vs. 3%, p < 0.001). Conclusion: Real-life risks associated which active surveillance and hemithyroidectomy for Bethesda III nodules are equivalent or less than the risks people are willing to accept. Clinicians accepted less risk for permanent voice changes

Clinical considerations for the treatment of secondary differentiated thyroid carcinoma in childhood cancer survivors

The incidence of differentiated thyroid carcinoma (DTC) has increased rapidly over the past several years. Thus far, the only conclusively established risk factor for developing DTC is exposure to ionizing radiation, especially when the exposure occurs in childhood. Since the number of childhood cancer survivors (CCS) is increasing due to improvements in treatment and supportive care, the number of patients who will develop DTC after surviving childhood cancer (secondary thyroid cancer) is also expected to rise. Currently, there are no recommendations for management of thyroid cancer specifically for patients who develop DTC as a consequence of cancer therapy during childhood. Since complications or late effects from prior cancer treatment may elevate the risk of toxicity from DTC therapy, the medical history of CCS should be considered carefully in choosing DTC treatment. In this paper, we emphasize how the occurrence and treatment of the initial childhood malignancy affects the medical and psychosocial factors that will play a role in the diagnosis and treatment of a secondary DTC. We present considerations for clinicians to use in the management of patients with secondary DTC, based on the available evidence combined with experience -based opinions of the authors

Incorporating Baseline Outcome Data in Individual Participant Data Meta-Analysis of Non-randomized Studies.

Background In non-randomized studies (NRSs) where a continuous outcome variable (e.g., depressive symptoms) is assessed at baseline and follow-up, it is common to observe imbalance of the baseline values between the treatment/exposure group and control group. This may bias the study and consequently a meta-analysis (MA) estimate. These estimates may differ across statistical methods used to deal with this issue. Analysis of individual participant data (IPD) allows standardization of methods across studies. We aimed to identify methods used in published IPD-MAs of NRSs for continuous outcomes, and to compare different methods to account for baseline values of outcome variables in IPD-MA of NRSs using two empirical examples from the Thyroid Studies Collaboration (TSC). Methods For the first aim we systematically searched in MEDLINE, EMBASE, and Cochrane from inception to February 2021 to identify published IPD-MAs of NRSs that adjusted for baseline outcome measures in the analysis of continuous outcomes. For the second aim, we applied analysis of covariance (ANCOVA), change score, propensity score and the naïve approach (ignores the baseline outcome data) in IPD-MA from NRSs on the association between subclinical hyperthyroidism and depressive symptoms and renal function. We estimated the study and meta-analytic mean difference (MD) and relative standard error (SE). We used both fixed- and random-effects MA. Results Ten of 18 (56%) of the included studies used the change score method, seven (39%) studies used ANCOVA and one the propensity score (5%). The study estimates were similar across the methods in studies in which groups were balanced at baseline with regard to outcome variables but differed in studies with baseline imbalance. In our empirical examples, ANCOVA and change score showed study results on the same direction, not the propensity score. In our applications, ANCOVA provided more precise estimates, both at study and meta-analytical level, in comparison to other methods. Heterogeneity was higher when change score was used as outcome, moderate for ANCOVA and null with the propensity score. Conclusion ANCOVA provided the most precise estimates at both study and meta-analytic level and thus seems preferable in the meta-analysis of IPD from non-randomized studies. For the studies that were well-balanced between groups, change score, and ANCOVA performed similarly

Serum microRNA profiles in athyroid patients on and off levothyroxine therapy

BackgroundLevothyroxine replacement treatment in hypothyroidism is unable to restore physiological thyroxine and triiodothyronine concentrations in serum and tissues completely. Normal serum thyroid stimulating hormone (TSH) concentrations reflect only pituitary euthyroidism and, therefore, novel biomarkers representing tissue-specific thyroid state are needed. MicroRNAs (miRNAs), small non-coding regulatory RNAs, exhibit tissue-specific expression patterns and can be detectable in serum. Previous studies have demonstrated differential expression of (precursors of) miRNAs in tissues under the influence of thyroid hormone.ObjectiveTo study if serum miRNA profiles are changed in different thyroid states.Design and methodsWe studied 13 athyroid patients (6 males) during TSH suppressive therapy and after 4 weeks of thyroid hormone withdrawal. A magnetic bead capture system was used to isolate 384 defined miRNAs from serum. Subsequently, the TaqMan Array Card 3.0 platform was used for profiling after individual target amplification.ResultsMean age of the subjects was 44.0 years (range 20-61 years). Median TSH levels were 88.9 mU/I during levothyroxine withdrawal and 0.006 mU/I during LT4 treatment with a median dosage of 2.1 fag/kg. After normalization to allow inter-sample analysis, a paired analysis did not demonstrate a significant difference in expression of any of the 384 miRNAs analyzed on and off LT4 treatment.ConclusionAlthough we previously showed an up-regulation of pri-miRNAs 133b and 206 in hypothyroid state in skeletal muscle, the present study does not supply evidence that thyroid state also affects serum miRNAs in humans

Bone Mineral Density in Adult Survivors of Pediatric Differentiated Thyroid Carcinoma:A Longitudinal Follow-Up Study

Background: Survivors of pediatric differentiated thyroid carcinoma (DTC) receive thyrotropin-suppressive therapy to minimize disease recurrence. However, knowledge about long-term effects of subclinical hyperthyroidism on bone mineral density (BMD) in pediatric DTC survivors is scarce, as is the information regarding long-term consequences of permanent hypoparathyroidism on BMD. We evaluated BMD in pediatric DTC survivors and investigated if BMD was affected by subclinical hyperthyroidism and/or permanent hypoparathyroidism during long-term follow-up. Methods: In this nationwide longitudinal study, we determined BMD in the lumbar spine and femur by dual energy X-ray absorptiometry in 65 pediatric DTC survivors. Measurements were repeated after minimal 5 years of follow-up in 46 pediatric DTC survivors. BMD results were evaluated according to the recommendations of the International Society for Clinical Densitometry (ISCD) and WHO. At both visits, we determined biochemical parameters and markers of bone resorption (C-terminal telopeptide of type I collagen [β-CTX]) and formation (N-propeptide of type I collagen [PINP] and osteocalcin). Results: First and second BMD measurements were done after a median follow-up of 17.0 (interquartile range [IQR] 8.0-25.0) and 23.5 (IQR 14.0-30.0) years after diagnosis, respectively. Median age at diagnosis was 15 years (IQR 13.0-17.0). Twenty-nine percent of the survivors had subclinical hyperthyroidism. In most survivors, BMD T-and Z-scores were within the reference range during both BMD evaluations. However, after 23.5 years of follow-up, a low BMD was found in 13.0%. In the 13 survivors with permanent hypoparathyroidism, BMD values did not differ after 5 years of follow-up compared with baseline values or in comparison with the 33 survivors without permanent hypoparathyroidism. During follow-up, turnover markers β-CTX and PINP remained stable. Conclusions: This longitudinal study of pediatric DTC survivors demonstrated normal and stable median lumbar spine and femur BMD values after a median time of 17 and 23.5 years after diagnosis. However, compared with controls, a lower BMD was still found in 13.0% after prolonged follow-up despite intensive follow-up. Based on the studied follow-up period, these data do not provide convincing evidence in support of standard monitoring of bone mass among DTC survivors, but may be restricted to individual cases at low frequency. Trial Registration: This follow-up study was registered in The Netherlands Trial Register under no. NL3280 (www.trialregister.nl/trial/3280)

Thyroid function tests in the reference range and fracture: individual participant analysis of prospective cohorts.

Context Hyperthyroidism is associated with increased fracture risk, but it is not clear if lower TSH and higher free thyroxine (FT4) in euthyroid individuals are associated with fracture risk. Objective To evaluate the association of TSH and FT4 with incident fractures in euthyroid individuals. Design Individual participant data analysis. Setting Thirteen prospective cohort studies with baseline examinations between 1981 and 2002. Participants Adults with baseline TSH 0.45-4.49 mIU/L. Main Outcome Measures Primary outcome was incident hip fracture. Secondary outcomes were any, non-vertebral, and vertebral fractures. Results were presented as hazard ratios (HR) with 95% confidence interval (CI) adjusted for age and sex. For clinical relevance, we studied TSH according to five categories: 0.45-0.99mIU/L; 1.00-1.49mIU/L; 1.50-2.49mIU/L; 2.50-3.49mIU/L; 3.50-4.49mIU/L (reference). FT4 was assessed as study-specific standard deviation increase, because assays varied between cohorts. Results During 659,059 person-years, 2,565/56,835 participants had hip fracture (4.5%; 12 studies with data on hip fracture). The pooled adjusted HR (95% CI) for hip fracture was 1.25 (1.05-1.49) for TSH 0.45-0.99mIU/L, 1.19 (1.01-1.41) for TSH 1.00-1.49mIU/L, 1.09 (0.93-1.28) for TSH 1.50-2.49mIU/L, and 1.12 (0.94-1.33) for TSH 2.50-3.49mIU/L (P for trend = 0.004). Hip fracture was also associated with FT4 (HR [95%CI] 1.22 [1.11-1.35] per one standard deviation increase in FT4). FT4 only was associated with any and non-vertebral fracture. Results remained similar in sensitivity analyses. Conclusions Among euthyroid adults, lower TSH and higher FT4 are associated with an increased risk of hip fracture. These findings may help refine the definition of optimal ranges of thyroid function tests

Selenium status is positively associated with bone mineral density in healthy aging European men

Objective It is still a matter of debate if subtle changes in selenium (Se) status affect thyroid function tests (TFTs) and bone mineral density (BMD). This is particularly relevant for the elderly, whose nutritional status is more vulnerable. Design and Methods We investigated Se status in a cohort of 387 healthy elderly men (median age 77 yrs; inter quartile range 75-80 yrs) in relation to TFTs and BMD. Se status was determined by measuring both plasma selenoprotein P (SePP) and Se. Results The overall Se status in our population was low normal with only 0.5% (2/387) of subjects meeting the criteria for Se deficiency. SePP and Se levels were not associated with thyroid stimulating hormone (TSH), free thyroxine (FT4), thyroxine (T4), triiodothyronine (T3) or reverse triiodothyronine (rT3) levels. The T3/T4 and T3/rT3 ratios, reflecting peripheral metabolism of thyroid hormone, were not associated with Se status either. SePP and Se were positively associated with total BMD and femoral trochanter BMD. Se, but not SePP, was positively associated with femoral neck and ward's BMD. Multivariate linear analyses showed that these associations remain statistically significant in a model including TSH, FT4, body mass index, physical performance score, age, smoking, diabetes mellitus and number of medication use. Conclusion Our study demonstrates that Se status, within the normal European marginally supplied range, is positively associated with BMD in healthy aging men, independent of thyroid function. Thyroid function tests appear unaffected by Se status in this population