Impact of Macroprolactinemia on Cardiometabolic Effects of Atorvastatin in Women With Hypercholesterolemia

Effect of statin treatment on homocysteine concentrations: an updated systematic review and meta-analysis with meta-regression

BACKGROUND AND AIMS

Statins might exert atheroprotective effects through lowering the pro-atherogenic amino acid homocysteine. We conducted an updated systematic review and meta-analysis of the effect of statins on circulating homocysteine.

METHODS

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

RESULTS

In 61 treatment arms in 2,218 patients (mean age 55 years, 52% males), statins significantly reduced homocysteine concentrations (weighted mean difference, WMD = -2.46 µmol/L, 95% CI -3.17 to -1.75 µmol/L, p < 0.001; high certainty of evidence). Similar results were observed in a subgroup of 10 randomized placebo-controlled studies (WMD = -2.45 µmol/L, 95% CI -4.43 to -0.47 µmol/L, p = 0.015). The extreme heterogeneity observed was virtually removed in a subgroup of 10 studies using fluorescence polarization immunoassay for homocysteine measurement. There was no publication bias. In sensitivity analysis, the pooled WMD values were not modified when individual studies were sequentially removed. In meta-regression, the WMD was significantly associated with proportion of males and publication year.

CONCLUSIONS

Statins significantly lower homocysteine concentrations.

The interplay between prolactin and cardiovascular disease

Hyperprolactinemia can be caused by several conditions and its effects on the hypothalamic-pituitary-gonadal axis are understood in more detail. Nevertheless, in recent decades, other metabolic effects have been studied and data pointed to a potential increased cardiovascular disease (CVD) risk. A recent study showed a decrease in total and LDL- cholesterol only in men with prolactinoma treated with dopamine agonists (DA) supporting the previous results of a population study with increased CVD risk in men harboring prolactinoma. However, other population studies did not find a correlation between prolactin (PRL) levels and CVD risk or mortality. There is also data pointing to an increase in high-density lipoprotein levels, and decreases in triglycerides, carotid-intima-media thickness, C-reactive protein, and homocysteine levels in patients with prolactinoma on DA treatment. PRL was also implicated in endothelial dysfunction in pre and postmenopausal women. Withdrawal of DA resulted in negative changes in vascular parameters and an increase in plasma fibrinogen. It has been shown that PRL levels were positively correlated with blood pressure and inversely correlated with dilatation of the brachial artery and insulin sensitivity, increased homocysteine levels, and elevated D-dimer levels. Regarding possible mechanisms for the association between hyperprolactinemia and CVD risk, they include a possible direct effect of PRL, hypogonadism, and even effects of DA treatment, independently of changes in PRL levels. In conclusion, hyperprolactinemia seems to be associated with impaired endothelial function and DA treatment could improve CVD risk. More studies evaluating CVD risk in hyperprolactinemic patients are important to define a potential indication of treatment beyond hypogonadism.

The impact of hypotestosteronemia on cardiometabolic effects of atorvastatin in men with hypercholesterolemia: a pilot study

BACKGROUND

Hypothyroidism, hyperprolactinemia, macroprolactinemia and low vitamin D status were found to impair pleiotropic effects of hypolipidemic agents. The aim of the current study was to investigate whether cardiometabolic effects of atorvastatin in men are determined by endogenous testosterone.

METHODS

We studied three groups of men matched for age, BMI, plasma lipids and blood pressure: 19 untreated subjects with low testosterone levels (group A), 19 normotestosteronemic men receiving testosterone preparations (group B) and 21 untreated men with testosterone levels within the reference range (group C). Because of coexistent hypercholesterolemia, all subjects were managed with atorvastatin (40 mg daily) for 6 months. Glucose homeostasis markers, plasma lipids, as well as circulating levels of testosterone, uric acid, high-sensitivity C-reactive protein (hsCRP), fibrinogen, homocysteine and 25-hydroxyvitamin D were determined at the beginning and at the end of the study.

RESULTS

At baseline, group A was more insulin-resistant and was characterized by higher levels of hsCRP, fibrinogen and homocysteine, and lower levels of 25-hydroxyvitamin D than the remaining groups of patients. Despite reducing total and low-density lipoprotein cholesterol and hsCRP levels in all treatment groups, this effect was stronger in groups B and C than in group A. In groups B and C, atorvastatin use was also associated with a decrease in uric acid, fibrinogen and homocysteine concentrations and with an increase in 25-hydroxyvitamin D levels. In group A, but not in the remaining groups, the drug decreased insulin sensitivity.

CONCLUSION

The obtained results suggest that untreated hypotestosteronemia may attenuate cardiometabolic effects of atorvastatin in men.

The impact of vitamin D status on cardiometabolic effects of fenofibrate in women with atherogenic dyslipidemia

Vitamin D deficiency is a risk factor for cardiometabolic disease. The aim of this study was to determine the role of vitamin D status in the impact of fenofibrate on plasma levels of cardiometabolic risk factors. The study population (n = 61) consisted of three matched groups of women with atherogenic dyslipidaemia: vitamin D-naïve women with vitamin D insufficiency (group A), women receiving vitamin D preparations because of vitamin D deficiency (group B), as well as vitamin D-naïve women with normal vitamin D status (group C), who were treated with micronized fenofibrate (200 mg daily). Glucose homeostasis markers, plasma lipids, as well as plasma levels of 25-hydroxyvitamin D, uric acid, high-sensitivity C-reactive protein (hsCRP), fibrinogen and homocysteine were determined at the beginning of the study and 6 months later. At entry, group A was characterized by lower levels of 25-hydroxyvitamin D, reduced insulin sensitivity and higher concentrations of uric acid, hsCRP, fibrinogen and homocysteine. Apart from a weaker effect on HDL-cholesterol and triglycerides in group A, there were no differences between the treatment arms in the effect of fenofibrate on plasma lipids. However, only in groups B and C the drug improved insulin sensitivity and reduced circulating levels of uric acid and hsCRP, as well as increased levels of 25-hydroxyvitamin D and these effects correlated with the degree of improvement in insulin sensitivity. Treatment-induced increase in homocysteine was observed only in group A. The results of the study indicate that cardiometabolic effects of fibrates may depend on the vitamin D status of patients.