Statin Use and Benefits of Thyroid Function: A Retrospective Cohort Study

The non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) is associated with thyroid hormones and thyroid hormone sensitivity indices: a cross-sectional study

BACKGROUND

Lipids and thyroid hormones (TH) are closely interrelated. However, previous studies have not mentioned the linkage encompassing the non-high-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio (NHHR) alongside TH level, as well as sensitivity indices.

METHODS

This cross-sectional study leverages expansive datasets from the National Health and Nutrition Examination Survey (NHANES) spanning 2007 to 2012. Weighted multivariate linear regression, smoothed curve fitting and sensitivity analyses were used to investigate the associations of the NHHR with the thyroid. Subgroup analyses and interaction tests were conducted to determine the robustness of the findings across diverse segments of the population, ensuring the consistency and generalizability of the observed associations.

RESULTS

The NHHR was significantly positively correlated with free triiodothyronine (FT3) levels, thyroid-stimulating hormone (TSH) levels, the FT3 to FT4 ratio (FT3/FT4), and the quantile-based thyroid feedback index for FT3 (TFQIFT3) and negatively correlated with free thyroxin (FT4) levels [0.17(0.07-0.27), P = 0.001; 0.60 (0.03-1.17), P = 0.040; 0.06 (0.04-0.08), P < 0.0001; 0.23 (0.16-0.30), P < 0.0001; and -0.65 (-1.05--0.24), P = 0.002]. Smoothed curve fitting revealed nonlinear correlations of the NHHR with thyroid function and thyroid hormone sensitivity indices. In subgroup analyses, interaction tests, and smoothed curve fitting analyses, different populations presented largely consistent statistical differences.

CONCLUSION

Among American adults, the NHHR was significantly positively correlated with FT3 levels, TSH levels, the FT3/FT4 and the TFQIFT3. Conversely, a negative association was noted between the NHHR and FT4 levels.

Lipid Metabolism in Pregnancy Women with Hypothyroidism and Potential Influence on Pregnancy Outcome

Thyroid hormone (TH) is essential for maintaining normal physiological processes during pregnancy, including the metabolism of energy materials in both the mother and fetus and the growth and development of fetal bone and nervous system. TH can act on the liver, fat, and other tissues and organs to participate in lipid synthesis and breakdown through multiple pathways. Consequently, abnormal thyroid function is often accompanied by lipid metabolism disorders. Both clinical and subclinical hypothyroidism, as well as dyslipidemia during pregnancy, have been shown to be associated with an increased risk of multiple adverse pregnancy outcomes. Recently, there has been an increased interest in studying the alteration of lipidomic and hypothyroidism (both clinical and subclinical hypothyroidism) during pregnancy. Studies have suggested that altered lipid molecules might be used as potential biomarker and associated with adverse maternal and neonatal outcome. Thus, we summarized the associations between lipid metabolism and clinical or subclinical hypothyroidism during pregnancy in this review. Then, we discussed the underlying mechanisms of thyroid dysfunction and lipid metabolism. In addition, we reviewed the possible effect of dyslipidemia on pregnancy and neonatal outcome. However, the relationship between hypothyroidism during pregnancy and changes in the lipid profile and how to intervene in the occurrence and development of adverse pregnancy outcomes require further study.

Effects of statin use on serum creatinine phosphokinase levels in normal thyroid function

BACKGROUND/AIMS

Statins are common lipid-lowering agents used in dyslipidemia. However, they increase serum creatinine phosphokinase (CPK) levels. Currently, there are no studies on the effect of thyroid-stimulating hormone (TSH) levels on CPK levels after statin administration. Therefore, this study aimed to investigate CPK level alterations after statin administration according to TSH quartiles in participants with euthyroidism.

METHODS

This retrospective analysis included 25,047 patients with euthyroidism. CPK levels were measured before and 6 months after statin administration. Normal TSH levels were divided into four quartiles, and the CPK levels and proportions of patients with normal CPK levels after statin administration for each TSH quartile were evaluated.

RESULTS

The baseline CPK level was significantly higher in the lowest TSH quartile (Q1) compared to the other quartiles but decreased after statin administration. Thus, the difference between the CPK levels and the other quartile groups was not significant. The proportion of patients with normal CPK levels was also significantly lowest in Q1 before statin administration; however, no significant difference was noted in the ratio among each group after statin administration. These findings were consistent with the findings of the analysis according to statin intensity.

CONCLUSION

In patients in the lowest TSH quartile of the normal TSH range, the CPK level decreased, and the proportion of normal CPK levels increased significantly after statin administration. However, similar changes were not observed in other TSH quartiles. Therefore, further studies are required to mechanistically confirm these conclusions.

Shared genetic links between hypothyroidism and psychiatric disorders: evidence from a comprehensive genetic analysis

Background

Epidemiologic studies have suggested co-morbidity between hypothyroidism and psychiatric disorders. However, the shared genetic etiology and causal relationship between them remain currently unclear.

Methods

We assessed the genetic correlations between hypothyroidism and psychiatric disorders [anxiety disorders (ANX), schizophrenia (SCZ), major depressive disorder (MDD), and bipolar disorder (BIP)] using summary association statistics from genome-wide association studies (GWAS). Two disease-associated pleiotropic risk loci and genes were identified, and pathway enrichment, tissue enrichment, and other analyses were performed to determine their specific functions. Furthermore, we explored the causal relationship between them through Mendelian randomization (MR) analysis.

Results

We found significant genetic correlations between hypothyroidism with ANX, SCZ, and MDD, both in the Linkage disequilibrium score regression (LDSC) approach and the high-definition likelihood (HDL) approach. Meanwhile, the strongest correlation was observed between hypothyroidism and MDD (LDSC: rg=0.264, P=7.35×10-12; HDL: rg=0.304, P=4.14×10-17). We also determined a significant genetic correlation between MDD with free thyroxine (FT4) and thyroid-stimulating hormone (TSH) levels. A total of 30 pleiotropic risk loci were identified between hypothyroidism and psychiatric disorders, of which the 15q14 locus was identified in both ANX and SCZ (P values are 6.59×10-11 and 2.10×10-12, respectively) and the 6p22.1 locus was identified in both MDD and SCZ (P values are 1.05×10-8 and 5.75×10-14, respectively). Sixteen pleiotropic risk loci were identified between MDD and indicators of thyroid function, of which, four loci associated with MDD (1p32.3, 6p22.1, 10q21.1, 11q13.4) were identified in both FT4 normal level and Hypothyroidism. Further, 79 pleiotropic genes were identified using Magma gene analysis (P<0.05/18776 = 2.66×10-6). Tissue-specific enrichment analysis revealed that these genes were highly enriched into six brain-related tissues. The pathway analysis mainly involved nucleosome assembly and lipoprotein particles. Finally, our two-sample MR analysis showed a significant causal effect of MDD on the increased risk of hypothyroidism, and BIP may reduce TSH normal levels.

Conclusions

Our findings not only provided evidence of a shared genetic etiology between hypothyroidism and psychiatric disorders, but also provided insights into the causal relationships and biological mechanisms that underlie their relationship. These findings contribute to a better understanding of the pleiotropy between hypothyroidism and psychiatric disorders, while having important implications for intervention and treatment goals for these disorders.

A mediation analysis of the role of total free fatty acids on pertinence of gut microbiota composition and cognitive function in late life depression

BACKGROUND

Extensive evidence demonstrates correlations among gut microbiota, lipid metabolism and cognitive function. However, there is still a lack of researches in the field of late-life depression (LLD). This research targeted at investigating the relationship among gut microbiota, lipid metabolism indexes, such as total free fatty acids (FFAs), and cognitive functions in LLD.

METHODS

Twenty-nine LLD patients from the Cognitive Outcome Cohort Study of Depression in Elderly were included. Cognitive functions were estimated through the Chinese version of Montreal Cognitive Assessment (MoCA). Blood samples were collected to evaluate serum lipid metabolism parameters. Fecal samples were evaluated for gut microbiota determination via 16S rRNA sequencing. Spearman correlation, linear regression and mediation analysis were utilized to explore relationship among gut microbiota, lipid metabolism and cognitive function in LLD patients.

RESULTS

Spearman correlation analysis revealed significant correlations among Akkermansia abundance, total Free Fatty Acids (FFAs) and MoCA scores (P < 0.05). Multiple regression indicated Akkermansia and total FFAs significantly predicted MoCA scores (P < 0.05). Mediation analysis demonstrated that the correlation between decreased Akkermansia relative abundance and cognitive decline in LLD patients was partially mediated by total FFAs (Bootstrap 95%CI: 0.023-0.557), accounting for 43.0% of the relative effect.

CONCLUSION

These findings suggested a significant relationship between cognitive functions in LLD and Akkermansia, as well as total FFAs. Total FFAs partially mediated the relationship between Akkermansia and cognitive functions. These results contributed to understanding the gut microbial-host lipid metabolism axis in the cognitive function of LLD.

Genetic insights into repurposing statins for hyperthyroidism prevention: a drug-target Mendelian randomization study

Background

Current therapeutic measures for thyroid dysfunction are limited and often accompanied by adverse effects. The use of lipid-lowering drugs like statins has recently been associated with lower thyroid eye diseases risk.

Objective

To investigate the implications of genetically proxied lipid-lowering drugs on thyroid dysfunction.

Methods

In this drug-target Mendelian randomization (MR) study, we utilized genetic variants within drug target genes associated with low-density lipoprotein (LDL) or triglyceride (TG), derived from a genome-wide association study (GWAS) meta-analysis (N ≤ 188,577), to simulate lifelong drug interventions. Genetic summary statistics for thyroid dysfunction outcomes were retrieved from GWAS datasets of Thyroid Omics Consortium (N ≤ 54,288) and UK Biobank (N = 484,598). Inverse-variance-weighted MR (IVW-MR) method was performed as primary analysis, followed by validation in colocalization analysis. A subsequent two-step MR analysis was conducted to identify biomarkers mediating the identified drug-outcome association.

Results

In IVW-MR analysis, genetic mimicry of 3-hydroxy-3-methylglutarylcoenzyme reductase (HMGCR) inhibitors (e.g. statins) was significantly associated with lower risk of hyperthyroidism in two independent datasets (OR1, 0.417 per 1-mmol/L lower in LDL-C; 95% CI 0.262 to 0.664; P1 = 2.262 × 10-4; OR2 0.996; 95% CI 0.993-0.998; P2 = 0.002). Two-step MR analysis revealed eighteen biomarkers linked to genetic mimicry of HMGCR inhibition, and identified insulin-like growth factor 1 (IGF-1) levels mediating 2.108% of the negative causal relationship between HMGCR inhibition and hyperthyroidism.

Conclusion

This study supports HMGCR inhibition as a promising therapeutic strategy for hyperthyroidism and suggests its underlying mechanisms may extend beyond lipid metabolism. Further investigations through laboratory studies and clinical trials are necessary to confirm and elucidate these findings.

Rosuvastatin potentiates the thyrotropin-lowering effect of metformin in men with non-autoimmune subclinical hypothyroidism and prediabetes

WHAT IS KNOWN AND OBJECTIVE

Metformin treatment decreases thyrotropin levels in individuals with hypothyroidism and this effect seems to be mediated by the 5'-adenosine monophosphate-activated protein kinase pathway in the pituitary. The activity of this pathway is also stimulated by statins. The current study was aimed at investigating whether the impact of metformin on hypothalamic-pituitary-thyroid axis activity is affected by statin use.

METHODS

The study included three matched groups of men with non-autoimmune hypothyroidism and prediabetes: patients treated for at least 6 months with high-intensity rosuvastatin therapy (20-40 mg daily) [groups A (n = 24) and C (n = 19)] and men not receiving statin therapy [group B (n = 24)]. Over the entire study period (6 months), groups A and B received metformin (2.55-3 g daily). Moreover, groups A and C continued rosuvastatin therapy. The lipid profile, glucose homeostasis markers, and plasma concentrations of thyrotropin, total and free thyroid hormones, prolactin, FSH, LH, ACTH and insulin-like growth factor-1 were determined at baseline and 6 months later.

RESULTS AND DISCUSSION

Fifty-nine patients completed the study. There were differences between groups A and C and group B in baseline values of total cholesterol, LDL-cholesterol, gonadotropins and ACTH. Although observed in both groups of metformin-treated patients, the effect on thyrotropin levels was more pronounced in group A than in group B. The impact on fasting glucose and insulin sensitivity was stronger in group B than group A. In turn, only in group A metformin tended to reduce gonadotropin levels. There were no differences between follow-up and baseline values of lipids, total and free thyroid hormones, prolactin, ACTH and insulin-like growth factor-1 in both these groups. In group C, all assessed variables remained at a similar level.

WHAT IS NEW AND CONCLUSION

The results of the current study suggest that rosuvastatin potentiates the inhibitory effect of metformin on thyrotrope secretory function.

Statin Use and the Risk of Prostate Cancer Biochemical Recurrence Following Definitive Therapy: A Systematic Review and Meta-Analysis of Cohort Studies

Background

Numerous studies have reported the role of statins on biochemical recurrence (BCR) among patients with prostate cancer (PCa) after definite treatment. However, the conclusions of these studies are contradictory. We aimed to determine the effect of statins on BCR of PCa using a systematic review and meta-analysis.

Methods

We searched PubMed (Medline) and other databases for cohort studies evaluating the effect of statins on the BCR of patients with PCa between January 1, 2000, and December 31, 2021. The random effects (RE) model and quality effects (QE) model were used to calculate the pooled hazard ratio (pHR) and pooled risk ratio (pRR) and their 95% confidence interval (95% CI).

Results

A total of 33 cohort studies were finally selected and included in this systematic review and meta-analysis. Statin use was significantly associated with a 14% reduction in the HR of BCR (pHR: 0.86, 95% CI: 0.78 to 0.95, I² = 64%, random effects model, 31 studies) and a 26% reduction in the RR of BCR (pRR: 0.74, 95% CI: 0.57 to 0.94, 24,591 patients, I² = 88%, random effects model, 15 studies) among patients with PCa. The subgroup analyses showed that statins could result in 22% reduction in the HR of BCR (pHR: 0.78, 95% CI: 0.61 to 0.98, I² = 57%, random effects model) among patients accepting radiotherapy (RT).

Conclusions

Our study suggests that statins have a unique role in the reduction of BCR in patients with PCa after definite treatment, especially RT. In the future, more clinical trials and in vitro and animal experiments are needed to further verify the effects of statins in PCa and the potential mechanisms.

Effects of Antihypertensive Drugs on Thyroid Function in Type 2 Diabetes Patients With Euthyroidism

Objective: There is little literature about whether antihypertensive drugs would affect thyroid function in patients with euthyroid type 2 diabetes, which was significant in maintaining a proper balance of thyroid function. A retrospective cohort study was conducted to evaluate the influence of antihypertensive drugs on thyroid function in patients with type 2 diabetes with euthyroidism. Design and Methods: The study involved dividing 698 patients with antihypertensive monotherapy into five groups according to the antihypertensive drugs they were treated with. Antihypertensive drugs included in this study were β-blockers, angiotensin-converting enzyme inhibitors (ACEI), angiotensin receptor blockers (ARB), and calcium channel blockers (CCB). The clinical data and thyroid function level between or within groups were compared. Multiple logistic regression analysis was conducted to evaluate the association of antihypertensive drugs with thyroid function level. Results: Selective β₁- adrenergic receptor blockers treatment was related to thyroid-stimulating hormone (TSH), increasing in patients with diabetes and euthyroidism as shown by multiple logistic regression analysis. The association existed after adjustment for confounding factors. No significant influence on thyroid function was found among other antihypertensive drugs. Conclusion: These data show the TSH-lifting effect of selective β₁-adrenergic receptor blockers in patients with type 2 diabetes with euthyroidism.

Cholesterol-induced toxicity: An integrated view of the role of cholesterol in multiple diseases

High levels of cholesterol are generally considered to be associated with atherosclerosis. In the past two decades, however, a number of studies have shown that excess cholesterol accumulation in various tissues and organs plays a critical role in the pathogenesis of multiple diseases. Here, we summarize the effects of excess cholesterol on disease pathogenesis, including liver diseases, diabetes, chronic kidney disease, Alzheimer's disease, osteoporosis, osteoarthritis, pituitary-thyroid axis dysfunction, immune disorders, and COVID-19, while proposing that excess cholesterol-induced toxicity is ubiquitous. We believe this concept will help broaden the appreciation of the toxic effect of excess cholesterol, and thus potentially expand the therapeutic use of cholesterol-lowering medications.