The Effect of Simvastatin on Lymphocyte Secretory Function in Patients With Impaired Fasting Glucose

A systematic review and meta-analysis of the effect of statin treatment on sVCAM-1 and sICAM-1

BACKGROUND AND AIMS

Statins might prevent cell adhesion to the endothelium, a key step in atherosclerosis. We conducted a systematic review and meta-analysis of the effect of statins on soluble vascular (sVCAM-1) and intercellular (sICAM-1) adhesion molecule 1.

METHODS

A systematic literature search was conducted in PubMed, Web of Science, and Scopus, from inception to July 2021. Risk of bias and certainty of evidence were assessed using the Joanna Briggs Institute Critical Appraisal Checklist for analytical studies and GRADE, respectively.

RESULTS

Statins significantly reduced both sVCAM-1 (standard mean difference, SMD=-0.28, 95% CI -0.44 to -0.12, p=0.001; 46 treatment arms; low certainty of evidence) and sICAM-1 (SMD=-0.75, 95% CI -1.00 to -0.50, p<0.001; 61 treatment arms; moderate certainty of evidence) concentrations. In sensitivity analysis, the SMD values were not modified when individual studies were sequentially removed. There were significant associations between SMD and publication year and, for sICAM-1, statin-induced changes in HDL-cholesterol. In subgroup analysis, the lowering effect was significant with liphophilic, but not hydrophilic, statins, and similar, for sICAM-1, in participants with or without clinically overt atherosclerosis.

CONCLUSIONS

Statins significantly lower sVCAM-1/sICAM-1. Prospective studies are required to determine whether this mediates their atheroprotective effects (PROSPERO registration number: CRD42021276825).

The effect of statin therapy on thyroid autoimmunity in patients with Hashimoto's thyroiditis: A pilot study

BACKGROUND

Statins have been found to exert antiinflammatory and immunomodulatory properties. The aim of this study was to compare the effects of intensive and less aggressive statin treatment on thyroid autoimmunity and hypothalamic-pituitary-thyroid axis activity in patients with Hashimoto's thyroiditis.

METHODS

The study included 38 adult women with Hashimoto's thyroiditis, who required statin therapy and were allocated into one of two groups. Patients at very high cardiovascular risk (n=16) received intensive statin treatment (rosuvastatin 20-40mg daily), while patients at moderate or moderately high cardiovascular risk (n=22) were treated with simvastatin (20-40mg daily) for the following 6 months. Serum levels of thyrotropin, total and free thyroid hormones, and high-sensitivity C-reactive protein (hsCRP), as well as titers of thyroid peroxidase and thyroglobulin antibodies were measured at the beginning and at the end of the study.

RESULTS

Thirty-six individuals completed the study and were included in the final analyses. Apart from improving plasma lipids and reducing circulating levels of hsCRP, intensive, but not less aggressive, statin therapy reduced thyroid peroxidase and thyroglobulin antibody titers, as well as tended to reduce circulating levels of thyrotropin. The effect of intensive statin therapy on thyroid antibody titers was lipid-independent but correlated with treatment-induced changes in thyrotropin and hsCRP.

CONCLUSIONS

Although 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors are able to reduce thyroid autoimmunity in women with Hashimoto's thyroiditis, intensive statin therapy is required to produce this effect.

The effect of testosterone on cardiometabolic risk factors in atorvastatin-treated men with late-onset hypogonadism

BACKGROUND

By reducing LDL cholesterol levels, statins may decrease androgen production. This study was aimed at investigating whether testosterone treatment has an impact on cardiometabolic risk factors in statin-treated men with late-onset hypogonadism (LOH).

METHODS

The study included 31 men with LOH who had been treated for at least 6 months with atorvastatin (20-40mg daily). On the basis of patient preference, atorvastatin-treated patients were divided into two matched groups of patients: receiving intramuscular testosterone enanthate (100mg weekly, n=16) and not treated with this hormone (n=15). Plasma lipids, glucose homeostasis markers, as well as plasma levels of androgens, uric acid, high-sensitivity C-reactive protein (hsCRP), homocysteine, and fibrinogen were assessed before and after 4 months of therapy.

RESULTS

Compared with the control age-, weight, and lipid-matched statin-naïve subjects with LOH (n=12), atorvastatin-treated patients were characterized by decreased levels of testosterone, hsCRP, and homocysteine. In patients not receiving testosterone therapy, plasma lipids, glucose homeostasis markers, as well as plasma levels of the investigated risk factors remained at the similar levels throughout the whole period of atorvastatin treatment. In atorvastatin-naïve patients, testosterone increased its plasma levels and decreased HDL cholesterol. Apart from an increase in testosterone levels, if administered to atorvastatin-treated subjects with LOH, testosterone reduced plasma levels of LDL cholesterol, uric acid, hsCRP, homocysteine, and fibrinogen, as well as improved insulin sensitivity.

CONCLUSIONS

Our study may suggest the clinical benefits associated with combination therapy with a statin and testosterone in elderly men with LOH.

Lymphocyte-suppressing action of simvastatin in patients with isolated hypertriglyceridemia

BACKGROUND

No previous study examined whether statins affect lymphocyte cytokine release in patients with isolated hypertriglyceridemia.

METHODS

The study included 46 patients with elevated triglyceride levels and peripheral artery stenosis, randomly assigned to receive simvastatin or placebo. Plasma lipids, glucose homeostasis markers, plasma C-reactive protein and lymphocyte cytokine release were measured at baseline and at the end of the treatment.

RESULTS

Ninety-day simvastatin treatment reduced lymphocyte release of TNF-α, interleukin-2 and interferon-γ, which was accompanied by a decrease in plasma C-reactive protein.

CONCLUSION

The obtained results suggest that statins produce lymphocyte-suppressing and systemic anti-inflammatory effects in patients with isolated hypertriglyceridemia.

The effect of ezetimibe, administered alone or in combination with simvastatin, on lymphocyte cytokine release in patients with elevated cholesterol levels

OBJECTIVE

Studies assessing the extra-lipid effects of ezetimibe have provided contrasting results. In the present study, we compared the effects of ezetimibe and simvastatin, administered alone or in combination, on the secretory function of human lymphocytes, systemic inflammation and endothelial function in subjects with elevated cholesterol levels.

METHODS

A prospective study involving a group of 178 ambulatory patients with isolated hypercholesterolaemia who were randomly assigned in a double-blind fashion to 90days of treatment with ezetimibe (10mg), simvastatin (40mg), ezetimibe (10mg) plus simvastatin (4mg) or placebo. A total of 170 patients completed the study.

MAIN OUTCOME MEASURES

Lymphocyte cytokine release and plasma levels of high-sensitivity C-reactive protein (hsCRP) and intercellular adhesion molecule 1 (ICAM-1).

RESULTS

Although both drugs reduced lymphocyte release of tumour necrosis factor-α, interferon-γ and interleukin-2 in a lipid-independent manner, only the effect of simvastatin was statistically significant (P<0.001). This lymphocyte-suppressing effect, which was accompanied by a decrease in plasma levels of hsCRP and ICAM-1 (P<0.001), was strongest in patients receiving both simvastatin and ezetimibe. There were no differences in lymphocyte-suppressing, systemic anti-inflammatory and endothelial protective effects of simvastatin between insulin-resistant and insulin-sensitive subjects, whereas the effects of ezetimibe and the combined treatment were greater in the former group of patients (P<0.01 and P<0.001, respectively).

CONCLUSIONS

The results of this study indicate that simvastatin is superior to ezetimibe in producing lymphocyte-suppressing, systemic anti-inflammatory and endothelial protective effects in patients with elevated cholesterol levels. Hypercholesterolaemic patients with high cardiovascular risk may receive the greatest benefits from concomitant treatment with a statin and ezetimibe.