Effect of 9 months of vitamin D supplementation on arterial stiffness and blood pressure in Graves' disease: a randomized clinical trial

Changes in bone density and microarchitecture following treatment of Graves' disease and the effects of vitamin D supplementation. A randomized clinical trial

Thyrotoxicosis leads to loss of bone mass. Vitamin D is important to bone health. In this randomized, placebo-controlled trial, we showed that bone restoration did not improve when adding vitamin D supplementation to standard care of Graves' disease thyrotoxicosis. Bone density and microarchitecture improved markedly with treatment of thyrotoxicosis.

PURPOSE

Vitamin D is important to skeletal health and ensuring a replete vitamin D status is recommended. In thyrotoxicosis, bone turnover is increased and bone mass density (BMD) reduced. We examined whether vitamin D supplementation improves bone recovery in thyrotoxicosis caused by Graves' disease (GD).

METHODS

Using a double-blinded design, hyperthyroid patients with GD were randomized to vitamin D3 70 µg/day (2800 IU) or similar placebo as add-on to antithyroid drugs (ATD). At baseline and 9 months, we measured BMD and bone architecture using DXA and high resolution peripheral quantitative computerized tomography. Bone turnover markers (BTM) were measured at 3 months also. Effect of vitamin D versus placebo and the response to ATD treatment were analyzed using linear mixed modelling.

RESULTS

Eighty-six GD patients were included (age 41 ± 14 years, 86% females). Compared to placebo, vitamin D3 did not improve BMD or microarchitecture. In response to ATD, BMD increased in the hip by 2% (95%CI: 1-4%). Cortical porosity decreased in tibia (- 7% [95%CI: - 12 to - 2%]) and radius [- 14% [95%CI: - 24 to - 3%]), and trabecular thickness increased (tibia (5% [95%CI: 2 - 9%]) and radius (4% [95%CI: 1-7%]). Changes in BTM, but not thyroid hormones, were associated with changes in BMD by DXA and with changes in the cortical compartment.

CONCLUSION

In newly diagnosed GD, 9 months of high dose vitamin D3 supplementation does not offer benefit by improving skeletal health. Treatment of thyrotoxicosis is associated with the recovery of BMD and microarchitecture.

CLINICALTRIAL

GOV IDENTIFIER

NCT02384668.

Genome-wide association study of maternal plasma metabolites during pregnancy

Metabolites are key indicators of health and therapeutic targets, but their genetic underpinnings during pregnancy-a critical period for human reproduction-are largely unexplored. Using genetic data from non-invasive prenatal testing, we performed a genome-wide association study on 84 metabolites, including 37 amino acids, 24 elements, 13 hormones, and 10 vitamins, involving 34,394 pregnant Chinese women, with sample sizes ranging from 6,394 to 13,392 for specific metabolites. We identified 53 metabolite-gene associations, 23 of which are novel. Significant differences in genetic effects between pregnant and non-pregnant women were observed for 16.7%-100% of these associations, indicating gene-environment interactions. Additionally, 50.94% of genetic associations exhibited pleiotropy among metabolites and between six metabolites and eight pregnancy phenotypes. Mendelian randomization revealed potential causal relationships between seven maternal metabolites and 15 human traits and diseases. These findings provide new insights into the genetic basis of maternal plasma metabolites during pregnancy.

A Mendelian randomization study of the effect of serum 25-hydroxyvitamin D levels on autoimmune thyroid disease

Objective

The influence of vitamin D on autoimmune thyroid disease (AITD) remains a subject of ongoing debate. This study employs Mendelian randomization (MR) to investigate the causal correlations of serum 25-hydroxyvitamin D (25[OH]D) levels with autoimmune thyroiditis (AIT), autoimmune hyperthyroidism (AIH), and Graves disease (GD).

Methods

Data on single nucleotide polymorphisms related to serum 25(OH)D levels, AIT, AIH, and GD were sourced from UK Biobank and FinnGen. Inverse variance weighted, MR-Egger, and weighted median were employed to test the exposure-outcome causal relationship. Assessments of horizontal pleiotropy, heterogeneity, and stability were performed using the MR-Egger intercept, Cochran's Q test, and leave-one-out sensitivity analysis, respectively.

Results

The results of MR analysis showed increased serum 25(OH)D levels was associated with a reduced risk of AIT (OR 0.499, 95% CI 0.289 to 0.860, p = 0.012) but not causal associated with AIH (OR 0.935, 95% CI 0.695 to 1.256, p = 0.654) and GD (OR 0.813, 95% CI 0.635 to 1.040, p = 0.100). Intercept analysis showed no horizontal pleiotropy (p > 0.05), and Cochran's Q test showed no heterogeneity (p > 0.05). Sensitivity analysis suggested that these results were robust.

Conclusion

An increased serum 25(OH)D level is associated with AIT risk reduction but unrelated to AIH and GD. This finding suggests that vitamin D supplementation can be valuable for preventing and treating AIT.

Effect of Vitamin D Supplementation on Graves' Disease: The DAGMAR Trial

Objective: Treatment options in Graves' disease (GD) are limited and do not target the underlying autoimmunity, and relapse rates following a course of antithyroid drug (ATD) reach 50%. Previous research has shown promising results for a role of vitamin D in GD. We aimed to investigate whether vitamin D reduces failure to enter and sustain remission in patients with GD treated with ATD. Design: A multicenter, double-blinded, randomized placebo-controlled trial comparing vitamin D 70 mcg once daily (2800 IU) or placebo. The intervention was given first as add-on to ATD treatment, maximally 24 months, and then for 12 months after ATD cessation. Inclusion period was from 2015 to 2017 and study completion by December 2020. Patients included were adults with a first-time diagnosis of GD treated with ATD. Exclusion criteria included pregnancy and glucocorticoid treatment. The primary endpoint was failure to enter and sustain remission defined as relapse of hyperthyroidism within 12 months after ATD cessation, inability to stop ATD within 24 months, or radioiodine treatment or thyroidectomy. Two hundred seventy-eight patients were included in the study, and 4 patients withdrew consent. No adverse effects were found. Results: Participants were aged 44 ± 14 years at enrollment and 79% were female. The risk of failure to enter and sustain remission was 42% [95% confidence interval (CI) 33-50%] in the vitamin D group and 32% [CI 24-40%] in the placebo group corresponding to a relative risk of 1.30 [CI 0.95-1.78]. Conclusions: Vitamin D supplementation did not improve the treatment of GD in patients with normal or insufficient vitamin D status. Thus, supplementation with high-dose vitamin D cannot be recommended for GD. Study registration: ClinicalTrials.gov NCT02384668.

Assessment of the reporting quality of randomised controlled trials for vitamin D supplementation in autoimmune thyroid disorders based on the CONSORT statement

BACKGROUND-PURPOSE

Randomized controlled trials (RCTs) are the cornerstone of evidence-based medicine, yet their quality is often suboptimal. The Consolidated Standards of Reporting Trials (CONSORT) statement is a list of advice to upgrade the quality of RCTs. The aim of this study was the assessment of the quality of RCTs for vitamin D supplements in thyroid autoimmunity according to the revised CONSORT 2010 checklist.

METHODS

Databases were searched for RCTs involving patients with autoimmune thyroid disorders (AITDs) who received vitamin D supplements published from 2011 to 2021. A list of 37-items was used and adherence ≥75% was considered of optimal quality. The primary outcome was the mean CONSORT adherence of studies. Secondary outcomes were the estimation of compliance per CONSORT item and the examination for possible determinants of the reporting quality.

RESULTS

Thirteen eligible trials were finally included. The mean compliance was 61.15% ± 14.86%. Only threeof the studies (23%) achieved a good reporting quality (≥75%), while ten (77%) were presented with inadequate reporting (<75%). Randomization and blinding were mainly poorly reported. Impact Factor (IF) of journal was associated with the reporting quality in the univariate analysis [p = 0.033, OR = 1.65, 95%CI = (1316, 1773)]. Sample size (p = 0.067), number of authors (p = 0.118) and number of citations (p = 0.125) were marginally not significant. None of the factors showed significant results in multivariate analysis. Reporting quality and IF were strongly positively correlated [Pearson's r = 0.740, p = 0.04].

CONCLUSION

This study shows that mean CONSORT adherence of RCTs for Vitamin D supplementation in AITDs is moderate, reflecting that study quality and transparency could be improved with better adherence to CONSORT rules.

Vitamin D, Thyroid Hormones and Cardiovascular Risk: Exploring the Components of This Novel Disease Triangle

The role of thyroid hormones (THs) in the cardiovascular (CV) system, through several direct and indirect effects is recognized. Even very small modification in TH levels (as those observed in subclinical hypothyroidism or hyperthyroidism, and low triiodothyronine syndrome) may adversely affect the CV system, whereas thyroid hormones benefit the CV system and improve the prognosis. There is also evidence of vitamin D effects on cardiometabolic disease (e.g., through modulation of endothelial and smooth muscle cell activity, renin-angiotensin-aldosterone system, nitric oxide, oxidative stress, and inflammatory response), as well as an association between vitamin D [25(OH)D] deficiency and autoimmune thyroid diseases or cancer, and a relationship between vitamin D concentration and titers of antibodies and thyroid autoimmunity replacement. Interestingly, experimental data indicate a direct effect of vitamin D on Type 2 deiodinase expression causing subsequential peripheral conversion of T4 into T3. However, the functional links among THs, vitamin D and the cardiovascular system, and clinical effects of coexisting abnormalities in this new troublesome triad, have not yet been reviewed. The main aim of this review is to discuss pathophysiology of this relationship, proposing new mechanistic insights involving vitamin D in the modulation of cardiometabolic disease and thyroid profile.

Sex and body mass index dependent associations between serum 25-hydroxyvitamin D and pulse pressure in middle-aged and older US adults

High pulse pressure (PP) is a valid indicator of arterial stiffness. Many studies have reported that vitamin D concentration is inversely associated with vascular stiffening. This association may differ depending on sex and body mass index (BMI). This study investigated the associations between vitamin D and PP and evaluated whether these associations differ according to sex and BMI, using data for individuals aged ≥ 50 years from the National Health and Nutrition Examination Survey (NHANES) 2007-2010. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were used as biomarkers of vitamin D levels. High PP was defined as ≥ 60 mmHg. Total 25(OH)D concentrations were dose-dependently associated with lower odds ratios (ORs) for high PP (p-trend = 0.01), after controlling for sociodemographic, behavioral, and dietary factors. When stratified by sex, there was a dose-dependent association between total 25(OH)D concentrations and lower risk of high PP (p-trend < 0.001) in females, but not in males. When stratified by BMI, there was a dose-dependent association between total 25(OH)D concentrations and lower risk of high PP (p-trend < 0.001) in non-overweight subjects, but not in overweight subjects. Improving the vitamin D status could delay elevation of PP and vascular stiffening in female and non-overweight subjects.

Vitamin D and Autoimmune Thyroid Disease-Cause, Consequence, or a Vicious Cycle?

Vitamin D is a steroid hormone traditionally connected to phosphocalcium metabolism. The discovery of pleiotropic expression of its receptor and of the enzymes involved in its metabolism has led to the exploration of the other roles of this vitamin. The influence of vitamin D on autoimmune disease-namely, on autoimmune thyroid disease-has been widely studied. Most of the existing data support a relationship between vitamin D deficiency and a greater tendency for development and/or higher titers of antibodies linked to Hashimoto's thyroiditis, Graves' disease, and/or postpartum thyroiditis. However, there have also been some reports contradicting such relationships, thus making it difficult to establish a unanimous conclusion. Even if the existence of an association between vitamin D and autoimmune thyroid disease is assumed, it is still unclear whether it reflects a pathological mechanism, a causal relationship, or a consequence of the autoimmune process. The relationship between vitamin D's polymorphisms and this group of diseases has also been the subject of study, often with divergent results. This text presents a review of the recent literature on the relationship between vitamin D and autoimmune thyroid disease, providing an analysis of the likely involved mechanisms. Our thesis is that, due to its immunoregulatory role, vitamin D plays a minor role in conjunction with myriad other factors. In some cases, a vicious cycle is generated, thus contributing to the deficiency and aggravating the autoimmune process.

Effects of Supplemental Vitamin D on Muscle Performance and Quality of Life in Graves' Disease: A Randomized Clinical Trial

Background: Vitamin D deficiency has been proposed to have a role in the development and course of Graves' disease (GD). Muscle weakness and quality of life (QoL) impairments are shared features of GD and vitamin D deficiency. We aimed at investigating whether vitamin D supplementation would improve restoration of muscle performance and thyroid-related QoL in GD and at describing the effect of anti-thyroid medication (ATD) on these outcomes. Methods: In a double-blinded clinical trial, hyperthyroid patients with a first-time diagnosis of GD were randomized to vitamin D 70 μg (2800 IU)/day or matching placebo as add-on to standard ATD. At baseline and after 3 and 9 months of intervention, we assessed isometric muscle strength, muscle function tests, postural stability, body composition, and QoL-impairment by using the ThyPRO questionnaire. Linear mixed modeling was used to analyze between-group differences. (The DAGMAR study clinicaltrials.gov ID NCT02384668). Results: Nine months of vitamin D supplementation caused an attenuation of muscle strength increment in all muscle measures investigated, significant at knee extension 60° where the increase was 24% lower (p = 0.04) in the vitamin D group compared with placebo. Compared with placebo, vitamin D supplementation tended to reduce gain of lean body mass (-24%, p = 0.08). Vitamin D supplementation significantly impeded alleviation of Composite QoL and the same trend was observed for the Overall QoL-Impact and Impaired Daily Life scales. In response to ATD, all measures improved significantly. The increase in muscle strength ranged from 25% to 40% (p_all < 0.001), and increment of lean body mass was 10% (p < 0.001). Large changes were observed in all QoL scales. Conclusions: Nine months of vitamin D supplementation caused unfavorable effects on restoration of muscle performance. In contrast, ATD treatment was associated with marked improvement in all measures of muscle performance and thyroid-related QoL. In patients with newly diagnosed GD, high-dose vitamin D supplementation should not be recommended to improve muscle function, but ATD is of major importance to alleviate muscle impairment.

Arterial Stiffness and Blood Pressure in Patients Newly Diagnosed with Graves' Disease Compared with Euthyroid Controls

INTRODUCTION AND OBJECTIVE

The excess cardiovascular morbidity and mortality in hyperthyroidism and Graves' disease (GD) is inadequately understood. We aimed to elucidate whether well-established cardiovascular risk factors such as arterial stiffness in terms of pulse wave velocity (PWV) and blood pressure differ in GD and controls.

METHODS

This was a cross-sectional study comparing 55 hyperthyroid patients with newly diagnosed GD and 55 euthyroid, population-based controls matched for age, sex and menopausal status. PWV and blood pressure were measured in office (SphygmoCor Xcel) and 24-h ambulatory settings (Arteriograph). Differences between groups were assessed using adjusted linear regression analysis.

RESULTS

Compared to controls, GD patients showed higher PWV in the 24-h but not in the office setting with an adjusted 24-h PWV difference of 1.0 (95% CI: 0.6-1.5) m/s. PWV was higher in GD at both day and night, and nightly PWV dipping was lower (-5.5, 95% CI: -10.4 to -0.6%). Furthermore, central and brachial pulse pressure was significantly higher in both the office and 24-h setting, whereas nightly central pulse pressure dipping was significantly lower in GD (-5.4, 95% CI: -10.5 to -0.2%). Mean arterial pressure did not differ between the groups.

CONCLUSIONS

Despite comparable blood pressure, GD is associated with a higher 24-h PWV that was not detected in the office setting. Pulse pressure was higher in GD, whereas mean arterial pressure did not differ between the groups. Longitudinal studies should pursue whether higher PWV might be a piece to the puzzle of understanding the increased risk of cardiovascular disease in hyperthyroidism and GD.