Differences and associations of metabolic and vitamin D status among patients with and without sub-clinical hypothyroid dysfunction

Angiogenin Levels and Their Association with Cardiometabolic Indices Following Vitamin D Status Correction in Saudi Adults

Simple Summary

Angiogenin (ANG) is a small 123 amino acid protein which in normal growth is associated with formation of new blood vessels in a process called angiogenesis; however, the abnormal levels of this protein in blood has been associated with diseases such as cancer, neurological disorders, and cardiovascular diseases. Vitamin D deficiency and elevated levels of blood lipids have also been associated with many diseases including cardiovascular diseases. In this study, the investigators tried to evaluate the relationship between the circulating levels of ANG, vitamin D, and lipids. The model used was vitamin D supplementation of deficient Saudi adults in order to find the effect of vitamin D correction on circulating levels of ANG and blood lipids. With vitamin D supplementation, modest but non-significant elevation in ANG was observed, as well as significant increase in apolipoproteins CIII and E and significant decrease in apo B. In addition, the correlation between circulating levels of ANG and apolipoproteins especially apo E observed in this study are interesting and should be investigated more as both are linked with neurologic disorders like Alzheimer’s and Parkinson’s diseases.

Abstract

Angiogenin (ANG), a multifunctional protein known to induce blood vessel formation, is a potential biomarker for cardiovascular diseases; however, whether it is affected by vitamin D supplementation is not known. This interventional study in vitamin D-deficient Saudi adults was designed to investigate it. A total of 100 vitamin D-deficient Saudi adults aged 30–50 years were randomly selected to undergo 6-month vitamin D supplementation. Circulating levels of fasting glucose, lipids, vitamin D, apolipoproteins (AI, AII, B, CI, CII, CIII, E, and H), and ANG were measured using commercially available assays at baseline and after six months. Overall, vitamin D levels increased significantly post intervention. With this, levels of apo-CIII and apo-E significantly increased (p-values of 0.001 and 0.009, respectively) with a significant parallel decrease in apo-B (p = 0.003). ANG levels were significantly positively associated with most apolipoproteins and inversely correlated with HDL-cholesterol. Post intervention, the changes in ANG levels were positively correlated with apo-E (r = 0.32; p < 0.01 in all subjects and r = 0.40; p < 0.05 in males). Vitamin D supplementation may modestly affect ANG levels. The association observed between ANG and apo-E is worthy of further investigation since both biomarkers have been linked to neurodegenerative disorders.

Relationship Between Vitamin D and Thyroid: An Enigma

Hypothyroidism is a frequently encountered endocrine disorder in clinical practice. Besides its traditional role in bone health, vitamin D has been shown to have favorable effects in a variety of different systems due to its pleiotropic qualities and ubiquitous receptor expression. Over the years, researchers have been fascinated by the intricate molecular interplay between vitamin D and thyroid. In this regard, attempts have emerged to demonstrate the role of vitamin D in thyroid disorders. This article has reviewed the existing literature on the role of vitamin D in hypothyroidism. We explored studies discussing the physiological interactions between vitamin D and thyroid, as well as the clinical consequences, supplemental and prognostic relevancy of vitamin D in auto-immune thyroid disease (AITD) and hypothyroidism.

Vitamin D and thyroid disorders: a systematic review and Meta-analysis of observational studies

BACKGROUND

The contribution of vitamin D to thyroid disorders has received paramount attention; however, results are mixed. Hence, we designed a systematic review and meta-analysis to obtain a definitive conclusion.

METHODS

The search included PubMed, ISI Web of Science, Scopus, and Google Scholar databases up to March 2021 to collect available papers reporting the relationship between serum levels of vitamin D and thyroid disorders. The pooled effect was reported as weighted mean difference (WMD) and 95% confidence interval (CI).

RESULTS

Out of 6123 datasets, 42 were eligible to get into this systematic review and meta-analysis. Serum vitamin D was markedly lower in autoimmune thyroid diseases (AITD) (WMD - 3.1 ng/dl; 95% CI, - 5.57 to - 0.66; P = 0.013; I² = 99.9%), Hashimoto's thyroiditis (HT) (WMD - 6.05 ng/dl; 95% CI, - 8.35 to - 3.75; P < 0.001; I² = 91.0%) and hypothyroidism patients (WMD - 13.43 ng/dl; 95% CI, - 26.04 to - 0.81; P = 0.03; I² = 99.5%), but not in subjects with Graves' disease (GD) (WMD - 4.14 ng/dl; 95% CI, - 8.46 to 0.17; P = 0.06; I² = 97.5%).

CONCLUSIONS

Our findings suggested lower vitamin D levels in patients with hypothyroidism, AITD, and HT compared to healthy subjects. However, the link between serum vitamin D and GD was only significant among subjects ≥40 years old.

Correlation between Thyroid Homeostasis and Obesity in Subclinical Hypothyroidism: Community-Based Cross-Sectional Research

OBJECTIVE

It remains unknown whether obesity has an effect on the pituitary-thyroid feedback control axis in subclinical hypothyroidism (SCH). We aimed to investigate the association of thyroid homeostasis with obesity in a SCH population.

METHODS

Our study consisted of a community-based and cross-sectional study from the Epidemiological Survey of Thyroid Diseases in Fujian Province, China. A total of 193 subjects with SCH (90 males and 103 females) without a history of treatment of thyroid disease, such as surgery, radiation, and thyroid hormone or antithyroid medication, were included in the present study. Indices of obesity, including body mass index (BMI), waist circumference (WC), and waist-height ratio (WHtR) were measured.

RESULTS

Our results showed that the secretory capacity of the thyroid gland (SPINA-GT) and Jostel's thyrotropin index (TSHI) were negatively correlated with BMI, WC, and WHtR, whereas the reciprocal of the thyrotroph thyroid hormone resistance index (TTSI-1) was positively correlated with BMI (all p < 0.05). After adjustment for age, sex, smoking, iodine status, and glucolipid metabolism, the associations between TSHI, TTSI (reciprocal transformation), and BMI still persisted (all p < 0.05).

CONCLUSIONS

These results suggest that low levels of thyroid homeostasis indexes may be associated with overall obesity in SCH, rather than central adiposity.

Vitamin D Provides Benefit Based on the Proinflammatory Effects of Homocysteine in Elderly Patients With Type 2 Diabetes Mellitus

PURPOSE

It is unclear whether vitamin D provides any benefit against the pro-inflammatory effects of homocysteine in elderly patients with type 2 diabetes mellitus (T2DM).

METHODS

We compared lymphocyte counts for CD3, CD19, CD4, and CD8 subsets between elderly (age ≥65 years) T2DM patients (n = 5098) and nondiabetes control subjects (n = 20,590) based on the serum concentrations of homocysteine and total vitamin D (calcidiol + calcifediol [total vitamin D, TVD]; <20, 20-30, and >30 ng/mL).

FINDINGS

Significant variation in CD19 (P = 0.019), CD4 (P = 0.015), and CD8 (P < 0.001) were associated with serum TVD in T2DM patients with homocysteine ≤15 μmol/L, whereas CD3 (P = 0.003) and CD8 (P = 0.019) varied in control subjects with homocysteine ≤15 μmol/L. In T2DM patients with high homocysteine (>15 μmol/L) levels, significant variation based on serum TVD occurred in CD19 only (P = 0.024), whereas CD3 (P = 0.016) and CD4 (P = 0.001) varied in control subjects with high homocysteine concentrations.

IMPLICATIONS

Serum TVD influences variation in CD3, CD19, CD4, and CD8 lymphocyte subsets based on the serum homocysteine concentration in elderly T2DM patients and nondiabetic individuals with moderate to high homocysteine concentrations. The effect of TVD is partially attenuated in individuals with high homocysteine concentrations, with greater attenuation occurring in patients with T2DM. Differences in the variation of lymphocyte subsets between nondiabetes subjects with moderate homocysteine concentrations and those with high homocysteine concentrations constitute a shift from CD8-positive cells to CD4-positive cells, suggesting a change in TH1/TH2 balance based on TVD and homocysteine concentrations that is absent in diabetes cases with high homocysteine concentrations.

The role of thyroid hormone in metabolism and metabolic syndrome

Metabolic syndrome (MetS) and thyroid dysfunction are common in clinical practice. The objectives of this review are to discuss some proposed mechanisms by which thyroid dysfunctions may lead to MetS, to describe the bidirectional relationship between thyroid hormones (THs) and adiposity and finally, to resume a list of recent studies in humans that evaluated possible associations between thyroid hormone status and MetS or its clinical components. Not solely THs, but also its metabolites regulate metabolic rate, influencing adiposity. The mechanisms enrolled are related to its direct effect on adenosine triphosphate (ATP) utilization, uncoupling synthesis of ATP, mitochondrial biogenesis, and its inotropic and chronotropic effects. THs also act controlling core body temperature, appetite, and sympathetic activity. In a bidirectional way, thyroid function is affected by adiposity. Leptin is one of the hallmarks, but the pro-inflammatory cytokines and also insulin resistance impact thyroid function and perhaps its structure. MetS development and weight gain have been positively associated with thyroid-stimulating hormone (TSH) in several studies. Adverse glucose metabolism may be related to hyperthyroidism, but also to reduction of thyroid function or higher serum TSH, as do abnormal serum triglyceride levels. Hypo- and hyperthyroidism have been related to higher blood pressure (BP), that may be consequence of genomic or nongenomic action of THs on the vasculature and in the heart. In summary, the interaction between THs and components of MetS is complex and not fully understood. More longitudinal studies controlling each of all confounding variables that interact with endpoints or exposure factors are still necessary.

Expression and Clinical Significance of Serum 25-OH-D in pregnant women with SCH (Subclinical Hypothyroidism) and GDM (Gestational Diabetes Mellitus)

Objective:

To analyze the level and clinical significance of serum 25-hydroxyvitamin D (25-OH-D) levels in pregnant women with subclinical hypothyroidism (SCH) and gestational diabetes mellitus (GDM).

Method:

One hundred pregnant women of 24-28 weeks’ pregnancy with SCH combined GDM were selected into the observation group, and 100 healthy pregnant women were selected into the control group during the corresponding period. Examined the thyroid stimulating hormone (TSH), free thyroxine (FT4), 25-OH-D, serum calcium (Ca2+), fasting plasma glucose (FPG), and glycosylated hemoglobin (HbAIc) levels and thyroid peroxide antibody (TPOAb), Thyroglobulin antibody (TgAb) status. Examine and compare TSH, FT4, Ca2+, FPG, HbAIc, TPOAb, and TgAb at different levels of serum 25-OH-D in the observation group. Compared the 25-OH-D levels and the ratio of different contents of 25-OH-D of TPOAb-positive and TgAb-positive SCH pregnant women.

Result:

The levels of TSH, FPG and HbAIc in the observation group were significantly higher than those in the control group (P<0.01). Through comparison of FT4 levels between the two groups, the difference had no statistical significance (P>0.05). The levels of 25-OH-D and Ca2+ in the observation group was significantly lower than those in the control group, and the difference had statistical significance (P<0.01). Through comparison of TSH, Ca2+, FPG and HbAIc in groups with different serum 25-OH-D levels, the difference had statistical significance (P<0.01). The positive rates of TPOAb and TgAb of pregnant women in the observation group were higher than in the control group (P<0.05). The vitamin D deficiency rate of TPOAb or TgAb positive pregnant women in the observation group was higher than those in the TPOAb or TgAb negative pregnant women, the difference had statistical significance (P < 0.05).

Conclusion:

blood glucose level in pregnant women with GDM and SCH increased significantly, blood calcium level decreased significantly. This group of people are more likely to have VitD deficiency. Thyroid stimulating hormone and blood glucose levels in pregnant women are negatively correlated with VitD levels. Therefore, serum 25-OH-D level can be used as an important reference index for gestational diabetes mellitus with subclinical hypothyroidism, and it has great clinical significance to maintain it at a normal level.

The Effects of Vitamin D Supplementation on Thyroid Function in Hypothyroid Patients: A Randomized, Double-blind, Placebo-controlled Trial

BACKGROUND

Data on the effects of vitamin D supplementation on thyroid function in hypothyroid patients are scarce.

OBJECTIVE

This study was done to evaluate the effects of vitamin D supplementation on thyroid function in hypothyroid patients.

MATERIAL AND METHODS

This randomized double-blind, placebo-controlled trial was conducted on 201 hypothyroid patients aged 20-60 years old. Subjects were randomly assigned into two groups to intake either 50,000 IU vitamin D supplements (n = 102) or placebo (n = 99) weekly for 12 weeks. Markers of related with thyroid function were assessed at first and 12 weeks after the intervention.

RESULTS

After 12 weeks of intervention, compared to the placebo, vitamin D supplementation resulted in significant increases in serum 25-hydroxyvitamin D (+26.5 ± 11.6 vs. 0.0 ± 0.0 ng/mL, P < 0.001) and calcium (+0.4 ± 0.7 vs. 0.1 ± 0.6 mg/dL, P = 0.002), and a significant decrease in serum thyroid-stimulating hormone (TSH) levels (-0.4 ± 0.6 vs. +0.1 ± 2.0 μIU/mL, P = 0.02). A trend towards a greater decrease in serum parathyroid hormone (PTH) levels was observed in vitamin D group compared to placebo group (-3.8 vs. +1.9, P = 0.07). We did not observe any significant changes in serum T3, T4, alkaline phosphatase (ALP) and albumin levels following supplementation of vitamin D compared with the placebo.

CONCLUSION

Overall, the current study demonstrated that vitamin D supplementation among hypothyroid patients for 12 weeks improved serum TSH and calcium concentrations compared with the placebo, but it did not alter serum T3, T4, ALP, PTH, and albumin levels.

No Association between 25 (OH) Vitamin D Level And Hypothyroidism among Females

AIM:

The aim was to investigate serum vitamin D (25-OH) level among females with hypothyroidism.

MATERIALS AND METHODS:

A case-control study (58 in each arm) was conducted in Arar Central Hospital, Kingdom Saudi Arabia. The cases were females with hypothyroidism, and healthy females were controls. TSH, thyroid hormones: Free T3 (FT3) and Free T4 (FT4) and haemoglobin levels were measured in all participants. Serum vitamin D (25-OH) level was measured using the spectrophotometry.

RESULTS:

While there was no significant difference in the age and haemoglobin level, body mass index (BMI) was significantly higher in the cases. Compared with the controls, cases had significantly higher TSH, had significantly lower T4, and there was no significant difference in FT3 and 25 (OH) vitamin D, [16.1 (8.8-26.7) vs. 14.0 (9.5-20.3 ng/ml; P = 0.577]. Linear regression showed no association between, age, BMI, haemoglobin, TSH, FT3, FT4 and the log of 25 (OH) vitamin D levels.

CONCLUSION:

There was no significant difference in vitamin D level among females with hypothyroidism and healthy controls.

Vitamin D deficiency among subfertile women: case-control study

OBJECTIVE

The objective of the study is to compare the dietary vitamin D and calcium intake among subfertile women (cases) versus pregnant women (controls) and to determine the vitamin D levels in the subfertile and pregnant women. The study design was an observational case-control study where a total of 181 (83 previously diagnosed subfertile cases from various causes and 98 pregnant controls) women of reproductive age. A validated questionnaire was used where it focused on key indicators evaluating vitamin D-related factors. Blood was withdrawn for the measurement of serum calcium, albumin and phosphate to exclude secondary causes that might affect vitamin D level.

RESULTS

The prevalence of vitamin D deficiency was significantly higher in the subfertile group than controls (59.0% versus 40.4%; p < 0.01). Calcium supplements intake was significantly higher in controls than the subfertile group (64.6% versus 10.0%; p value < 0.001). Total dietary vitamin D intake (> 400 IU/day) was significantly higher in the controls than the subfertile group.

CONCLUSION

Vitamin D deficiency is prevalent among subfertile women. Optimization of serum calcium and vitamin D levels is encouraged.

Hypovitaminosis D and its association with lifestyle factors

OBJECTIVES

The present study was designed to determine the serum vitamin D levels and their relation with demographic features and life style factors in young adults.

METHODS

It was an analytical cross-sectional study on 88 subjects aged 18-40 years. Relevant information about physical activity, job place, duration of sun exposure, educational status and socioeconomic conditions was obtained. Serum levels of 25-OH vitamin D were measured by ELISA. Data was analyzed using SPSS 20.

RESULTS

Mean serum vitamin D level was 8.44±0.49 (Range: 1.00-21.08) ng/ml in participants. Vitamin D deficiency was found in 98.86% of the population. Mean vitamin D levels were significantly lower in females (p=0.0001), physically less active (p=0.006), indoor job holders (p=0.0001), less sun exposed (p=0.001), highly educated (p=0.020) and high socioeconomic status (p=0.007) bearing and in subjects having relatively fair skin complexion (p=0.041).

CONCLUSIONS

Serum vitamin D levels of study population were below normal and were associated with female gender, less physical activity, indoor jobs, less sun exposure, higher education and higher socioeconomic class and relatively fair skin complexion.

Vitamin D and chronic hepatitis C: effects on success rate and prevention of side effects associated with pegylated interferon-α and ribavirin

Chronic hepatitis C (CHC) is one of the most common causes of liver diseases worldwide, affecting 3% of the world population and 3 to 4 million people acquire new infection annually. Despite the recent introduction of novel antiviral drugs for the treatment of CHC, these drugs are expensive and the access to them is not an option for many patients. Hence, the traditional therapy by pegylated interferon-α (Peg-IFN-α) and ribavirin may still have a role in the clinical management of CHC especially in developing countries. However, this standard therapy is associated with several severe extra-hepatic side effects and the most common adverse events are hematological abnormalities and thyroid disorders and they could result in dose reduction and/or termination of therapy. Vitamin D has been shown to be a key regulatory element of the immune system, and its serum concentrations correlate with the severity of liver damage and the development of liver fibrosis/cirrhosis. Furthermore, supplementation with vitamin D with Peg-IFN-α based therapy for the treatment of CHC could be beneficial in increase the response rate to Peg-INF-α based therapy. Vitamin D has also been shown to regulate the thyroid functions and the process of erythropoiesis. This review appraises the data to date researching the role of vitamin D during the treatment of CHC and the potential role of vitamin D in preventing/treating Peg-IFN-α induced thyroiditis and anemia during the course of treatment.