Executive summary of the Hellenic Atherosclerosis Society guidelines for the diagnosis and treatment of dyslipidemias - 2023.

Atherosclerotic cardiovascular disease (ASCVD) remains the main cause of death worldwide, and thus its prevention, early diagnosis and treatment is of paramount importance. Dyslipidemia represents a major ASCVD risk factor that should be adequately managed at different clinical settings. 2023 guidelines of the Hellenic Atherosclerosis Society focus on the assessment of ASCVD risk, laboratory evaluation of dyslipidemias, new and emerging lipid-lowering drugs, as well as diagnosis and treatment of lipid disorders in women, the elderly and in patients with familial hypercholesterolemia, acute coronary syndromes, heart failure, stroke, chronic kidney disease, diabetes, autoimmune diseases, and non-alcoholic fatty liver disease. Statin intolerance is also discussed.

Protection against stroke with glucagon-like peptide 1 receptor agonists: a systematic review and meta-analysis.

In experimental stroke models pretreatment with the newly introduced antidiabetic agents, glucagon-like peptide 1 receptor (GLP-1R) agonists, has been shown to exert neuroprotective effects. Published evidence with regard to the effect of treatment with GLP-1R agonists on the risk of stroke was evaluated. Data from prospective randomized placebo-controlled trials up to October 2018 involving GLP-1R agonists which reported cardiovascular outcomes as primary end-points of efficacy and/or safety were meta-analysed. Five eligible multicentre randomized placebo-controlled trials (ELIXA, LEADER, SUSTAIN, EXSCEL and HARMONY) were included. The pooled analysis (n = 42 358) showed a significant reduction by 13% in the risk of total stroke from treatment with GLP-1R agonists versus placebo (risk ratio 0.87, 95% confidence interval 0.78-0.98, P = 0.021) with no significant heterogeneity between trials (Q = 4.094, P = 0.393, I2  = 2.307%). When only fatal stroke was included (this applied for the ELIXA, LEADER, EXSCEL and HARMONY trials), active treatment was associated with a non-significant reduction by 16% compared with placebo (risk ratio 0.84, 95% confidence interval 0.60-1.17, P = 0.29). The findings of this meta-analysis support the evidence from earlier experimental studies calling attention to potential 'stroke protective' effects from treatment with GLP-1R.

SGLT2 inhibitors and the kidney: Effects and mechanisms.

AIMS: Numerous clinical trials have shown that sodium glucose cotransporter 2 (SGLT2) inhibitors exert a favorable effect on the indices of renal function (albuminuria, glomerular filtration rate decline over time) and the incidence of hard renal endpoints such as renal death or time to initiation of renal replacement therapy. MATERIALS AND METHODS: In this review, we describe in detail the evidence regarding the nephroprotective mechanisms of SGLT2 inhibitors and describe the risk factors that may predispose to the development of acute kidney injury in patients receiving these drugs. RESULTS: Although the impact of these drugs on renal hemodynamics seems to represent the most important renoprotective mechanism of action, many other effects of these compounds, including beneficial effects on metabolism and blood pressure, have been proposed to contribute to the observed clinical benefit. CONCLUSIONS: SGLT2 inhibitors clearly act beneficially in terms of kidney function with many proposed mechanisms.

SGLT2 inhibitors-induced electrolyte abnormalities: An analysis of the associated mechanisms.

AIMS: Sodium-glucose co-transporter 2 (SGLT2) inhibitors are a new class of antidiabetic drugs that affect serum electrolytes levels. The aim of this review is the detailed presentation of the associated mechanisms of the SGLT2 inhibitors-induced electrolyte abnormalities. MATERIALS AND METHODS: Eligible trials and relevant articles published in PubMed (last search in July 2017) are included in the review. RESULTS: SGLT2 inhibitors induce small increases in serum concentrations of magnesium, potassium and phosphate. The small increase in serum phosphate concentration may result in reduced bone density and increased risk of bone fractures, mainly seen with canagliflozin, but recent meta-analyses did not show increased risk of bone fractures with SGLT2 inhibitors. CONCLUSION: The increases in serum electrolytes levels may play a role in the cardiovascular protection that has been recently reported with empagliflozin and canagliflozin.

Effects of evolving lipid-lowering drugs on carbohydrate metabolism.

The understanding that statins reduce but not eliminate the cardiovascular risk associated with disturbed lipid metabolism and the existence of forms of dyslipidemia that are unresponsive or only partially responsive to statins have led to the development of many novel lipid-lowering drugs. Accumulating evidence suggests that the interplay between carbohydrate and lipid metabolism is bidirectional. Thus, any intervention that affects lipid metabolism has the potential to influence the homeostasis of glucose. In this review we summarize the available data on the effects of the evolving lipid-lowering drugs on carbohydrate metabolism.

Gitelman syndrome: an analysis of the underlying pathophysiologic mechanisms of acid-base and electrolyte abnormalities.

Gitelman syndrome is the most common inherited tubular disease resulting from mutations of the SLC12A3 gene that encodes the thiazide-sensitive sodium-chloride cotransporter in the early distal convoluted tubules. The review presents the underlying pathophysiologic mechanisms of acid-base and electrolyte abnormalities observed in patients with Gitelman syndrome. The syndrome is usually characterized by hypokalemic metabolic alkalosis in combination with hypomagnesemia and hypocalciuria. Additionally, increased chloride excretion and renin/aldosterone levels, hypophosphatemia (occasionally), hyponatremia (rarely) and glucose intolerance/insulin resistance have been reported. The knowledge of the pathophysiologic mechanisms is useful for the treatment of patients with Gitelman syndrome as well as for the understanding of other tubular diseases.

Phosphate imbalance in patients with heart failure.

Patients with heart failure often exhibit electrolyte abnormalities, such as hyponatremia or hypokalemia/hyperkalemia. Although not as common as the other electrolyte disturbances observed in patients with heart failure, phosphate imbalance is also of high importance in this population. The aim of this review is to present the mechanisms of low or high phosphate serum levels in patients with heart failure and its role in the pathogenesis and progression of heart dysfunction. Hypophosphatemia in patients with heart failure may be the result of co-existing electrolyte and acid-base abnormalities, pharmacological treatments, decreased intestinal absorption or secondary to sympathetic nervous system activation and co-morbidities, such as diabetes mellitus or heavy alcohol consumption. Hypophosphatemia can affect multiple organ systems including the cardiovascular system. Depletion of phosphate can lead to ventricular arrhythmias and elimination of ATP synthesis, resulting in reversible myocardial dysfunction. Hyperphosphatemia, observed mainly in patients with chronic kidney failure, is also associated with cardiac hypertrophy, which may worsen cardiac contractility and heart failure. Studies have also shown an association of high-normal serum phosphate levels with vascular and valvular calcification. Therefore, serum phosphate imbalances may exhibit a causal role in the pathogenesis and progression of heart failure.

PCSK9 in chronic kidney disease.

PURPOSE: Chronic kidney disease (CKD) is accompanied by a number of secondary metabolic dysregulations, such as lipid abnormalities, presenting with unique characteristics. Proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitors have been introduced as the new era in the management of dyslipidemia with promising results in groups with refractory lipid abnormalities. Increasing number of studies investigate the possible association of PCSK9 levels with kidney function, especially with nephrotic range proteinuria, as well as its role as a prognostic cardiovascular risk marker in CKD. In this review, we discuss the existing evidence for PCSK9 levels in patient groups with nephrotic syndrome, non-dialysis CKD, end-stage renal disease and kidney transplantation. METHODS: Online research was conducted in MEDLINE database to identify articles investigating PCSK9 in all different aspects of CKD. References from relevant studies were screened for supplementary articles. RESULTS: Four cross-sectional studies, one secondary analysis, one publication from two independent cohort studies and one multicentre prospective cohort study assessed PCSK9 plasma levels in different subgroups of CKD patients. PCSK9 levels increase in nephrotic syndrome and have a positive correlation with proteinuria. In CKD patients, no correlation was found between PCSK9 levels and estimated GFR. Peritoneal dialysis patients have higher PCSK9 levels compared with hemodialysis and renal transplant patients as well as general population. CONCLUSION: Accumulative evidence focuses on the possible association of PCSK9 levels with kidney function. No data are available for the administration of PCSK9 inhibitors in CKD patients. Further research will optimize knowledge on the role of PCSK9 levels and PCSK9 inhibitors in CKD.

L-Carnitine/Simvastatin Reduces Lipoprotein (a) Levels Compared with Simvastatin Monotherapy: A Randomized Double-Blind Placebo-Controlled Study.

Lipoprotein (a) [Lp(a)] is an independent risk factor for cardiovascular disease. There are currently limited therapeutic options to lower Lp(a) levels. L-Carnitine has been reported to reduce Lp(a) levels. The aim of this study was to compare the effect of L-carnitine/simvastatin co-administration with that of simvastatin monotherapy on Lp(a) levels in subjects with mixed hyperlipidemia and elevated Lp(a) concentration. Subjects with levels of low-density lipoprotein cholesterol (LDL-C) >160 mg/dL, triacylglycerol (TAG) >150 mg/dL and Lp(a) >20 mg/dL were included in this study. Subjects were randomly allocated to receive L-carnitine 2 g/day plus simvastatin 20 mg/day (N = 29) or placebo plus simvastatin 20 mg/day (N = 29) for a total of 12 weeks. Lp(a) was significantly reduced in the L-carnitine/simvastatin group [-19.4%, from 52 (20-171) to 42 (15-102) mg/dL; p = 0.01], but not in the placebo/simvastatin group [-6.7%, from 56 (26-108) to 52 (27-93) mg/dL, p = NS versus baseline and p = 0.016 for the comparison between groups]. Similar significant reductions in total cholesterol, LDL-C, apolipoprotein (apo) B and TAG were observed in both groups. Co-administration of L-carnitine with simvastatin was associated with a significant, albeit modest, reduction in Lp(a) compared with simvastatin monotherapy in subjects with mixed hyperlipidemia and elevated baseline Lp(a) levels.

Dipeptidyl peptidase-4 inhibitors and protection against stroke: A systematic review and meta-analysis.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is associated with an increased risk of stroke and an unfavourable outcome following stroke. Apart from pioglitazone, glucose-lowering modalities have not been shown to protect against stroke. Nevertheless, there is evidence from experimental studies of potential neuroprotective effects with dipeptidyl peptidase (DPP)-4 inhibitors, especially if treatment starts before stroke. OBJECTIVE: To perform a meta-analysis of available evidence regarding the risk of stroke in individuals taking DPP-4 inhibitors. METHODS: All available data from prospective randomized placebo-controlled trials involving DPP-4 inhibitors in T2DM patients published up to December 2015 were considered. The included trials reported data on the incidence of stroke with a recruitment rate of at least 100 diabetes patients and a follow-up of at least 12 weeks. RESULTS: A total of 19 small randomized clinical trials (RCTs) evaluating the efficacy and safety of gliptins (n=9278), along with three multicentre prospective double-blind placebo-controlled RCTs assessing cardiovascular outcomes as the primary endpoint and involving 36,395 T2DM patients, were included in the analysis. Pooled analysis of the small RCTs showed a non-significant trend towards benefit with DPP-4 inhibitors against stroke [odds ratio (OR): 0.639, 95% confidence interval (CI): 0.336-1.212; P=0.170]. In contrast, in the analysis of RCTs reporting on cardiovascular safety, there was no difference in the risk of stroke with gliptin treatment compared with a placebo (OR: 0.996, 95% CI: 0.850-1.166; P=0.958). CONCLUSION: The promising data from experimental studies regarding cardioprotective gliptin-associated effects against stroke were not supported by available data from trials specifically looking at cardiovascular safety.

Renoprotective Effects of SGLT2 Inhibitors: Beyond Glucose Reabsorption Inhibition.

Sodium-glucose co-transporter 2 (SGLT2) inhibitors are a new class of antidiabetic drugs that inhibit glucose and sodium reabsorption at proximal tubules. These drugs may exhibit renoprotective properties, since they prevent the deterioration of the glomerular filtration rate and reduce the degree of albuminuria in patients with diabetes-associated kidney disease. In this review we consider the pathophysiologic mechanisms that have been recently implicated in the renoprotective properties of SGLT2 inhibitors. The beneficial effects of SGLT2 inhibitors on the conventional risk factors for kidney disease (such as blood pressure, hyperglycaemia, body weight and serum uric acid levels) may explain, at least in part, the observed renal-protecting properties of these compounds. However, it has been hypothesized that the most important mechanisms for this phenomenon include the reduction in the intraglomerular pressure, the changes in the local and systemic degree of activation of the renin-aldosterone-angiotensin system and a shift in renal fuel consumption towards more efficient energy substrates such as ketone bodies. The beneficial effects of SGLT2 inhibitors on various aspects of renal function make them an attractive choice in patients with (and possibly without) diabetes-associated renal impairment.

Use of intravenous fluids/solutions: a narrative review.

OBJECTIVE: Intravenous fluids are broadly categorized into colloids and crystalloids. The aim of this review is to present under a clinical point of view the characteristics of intravenous fluids that make them more or less appropriate either for maintaining hydration when enteral intake is contraindicated or for treating hypovolemia. METHODS: We considered randomized trials and meta-analyses as well as narrative reviews evaluating the effects of colloids or crystalloids in patients with hypovolemia or as maintenance fluids published in the PubMed and Cochrane databases. RESULTS: Clinical studies have not shown a greater clinical benefit of albumin solutions compared with crystalloid solutions. Furthermore, albumin and colloid solutions may impair renal function, while there is no evidence that the administration of colloids reduces the risk of death compared with resuscitation with crystalloids in patients with trauma, burns or following surgery. Among crystalloids, normal saline is associated with the development of hyperchloremia-induced impairment of kidney function and metabolic acidosis. On the other hand, the other commonly used crystalloid solution, the Ringer's Lactate, has certain indications and contraindications. These matters, along with the basic principles of the administration of potassium chloride and bicarbonate, are meticulously discussed in the review. CONCLUSIONS: Intravenous fluids should be dealt with as drugs, as they have specific clinical indications, contraindications and adverse effects.

Pharmacological management of diabetic dyslipidemia.

INTRODUCTION: Diabetes mellitus is associated with increased cardiovascular disease (CVD) risk. Areas covered: Main goal of hypolipidemic treatment in diabetic patients is low-density lipoprotein cholesterol (LDL-C) lowering with the use of statins. Addition of ezetimibe is useful in diabetic patients who cannot achieve their LDL-C target. However, many diabetic patients have increased residual CVD risk, which is mainly attributed to high triglycerides and low high-density lipoprotein (HDL-C) values. The addition of fenofibrate targets these variables and possibly reduces residual CVD risk, but a possible beneficial effect has been shown only in a pre-specified subgroup analysis in patients with high triglycerides and low HDL-C values. The newer proprotein convertase subtilisin/kexin type 9 inhibitors lower substantially LDL-C levels, but data from specifically designed trials in diabetic patients are not currently available. Although the cholesterol ester transfer protein (CETP) inhibitors have shown harmful effects or lack of efficacy in completed clinical trials, the newer CETP inhibitors have promising effects on lipid profile and carbohydrate metabolism, but their effects on CVD risk and safety profile have not been assessed. Expert commentary: Clinicians have a range of pharmacological options to reduce the CVD risk of diabetic patients.

MANAGEMENT OF ENDOCRINE DISEASE: Hypothyroidism-associated hyponatremia: mechanisms, implications and treatment.

BACKGROUND: Patients with moderate to severe hypothyroidism and mainly patients with myxedema may exhibit reduced sodium levels (<135 mmol/L). SUMMARY: The aim of this short review is the presentation of the mechanisms of hyponatremia and of the available data regarding its implications and treatment in patients with hypothyroidism. Hypothyroidism is one of the causes of hyponatremia, thus thyroid-stimulating hormone determination is mandatory during the evaluation of patients with reduced serum sodium levels. The main mechanism for the development of hyponatremia in patients with chronic hypothyroidism is the decreased capacity of free water excretion due to elevated antidiuretic hormone levels, which are mainly attributed to the hypothyroidism-induced decrease in cardiac output. However, recent data suggest that the hypothyroidism-induced hyponatremia is rather rare and probably occurs only in severe hypothyroidism and myxedema. Other possible causes and superimposed factors of hyponatremia (e.g. drugs, infections, adrenal insufficiency) should be considered in patients with mild/moderate hypothyroidism. Treatment of hypothyroidism and fluid restriction are usually adequate for the management of mild hyponatremia in patients with hypothyroidism. Patients with possible hyponatremic encephalopathy should be urgently treated according to current guidelines. CONCLUSIONS: Severe hypothyroidism may be the cause of hyponatremia. All hypothyroid patients with low serum sodium levels should be evaluated for other causes and superimposed factors of hyponatremia and treated accordingly.

A Genetic Biomarker of Oxidative Stress, the Paraoxonase-1 Q192R Gene Variant, Associates with Cardiomyopathy in CKD: A Longitudinal Study.

Background. Oxidative stress is a hallmark of CKD and this alteration is strongly implicated in LV hypertrophy and in LV dysfunction. Methods and Patients. We resorted to the strongest genetic biomarker of paraoxonase-1 (PON1) activity, the Q192R variant in the PON1 gene, to unbiasedly assess (Mendelian randomization) the cross-sectional and longitudinal association of this gene-variant with LV mass and function in 206 CKD patients with a 3-year follow-up. Results. The R allele of Q192R polymorphism associated with oxidative stress as assessed by plasma 8-isoPGF2α (P = 0.03) and was dose-dependently related in a direct fashion to LVMI (QQ: 131.4 ± 42.6 g/m(2); RQ: 147.7 ± 51.1 g/m(2); RR: 167.3 ± 41.9 g/m(2); P = 0.001) and in an inverse fashion to systolic function (LV Ejection Fraction) (QQ: 79 ± 12%; RQ: 69 ± 9%; RR: 65 ± 10% P = 0.002). On longitudinal observation, this gene variant associated with the evolution of the same echocardiographic indicators [LVMI: 13.40 g/m(2) per risk allele, P = 0.005; LVEF: -2.96% per risk allele, P = 0.001]. Multivariate analyses did not modify these associations. Conclusion. In CKD patients, the R allele of the Q192R variant in the PON1 gene is dose-dependently related to the severity of LVH and LV dysfunction and associates with the longitudinal evolution of these cardiac alterations. These results are compatible with the hypothesis that oxidative stress is implicated in cardiomyopathy in CKD patients.

Hyponatremia in patients with liver diseases: not just a cirrhosis-induced hemodynamic compromise.

Hyponatremia (Na(+) <135 mmol/l) is the most common electrolyte disorder. Cirrhosis represents a rather frequent cause of hyponatremia mainly due to systemic and splanchnic vasodilation resulting in decreased effective arterial blood volume, which leads to excessive non-osmotic secretion of antidiuretic hormone. However, hyponatremia of multifactorial origin may be seen in patients with liver diseases. The review focuses on the factors and pathogenetic mechanisms of decreased sodium levels other than the hemodynamic compromise of cirrhosis in patients with liver diseases. The mechanisms and causal or contributing role of pseudohyponatremia, hyperglycemia, infections, drugs and toxins as well as of endocrine disorders, renal failure and cardiac disease in patients with liver disease are meticulously discussed. Hyponatremia of multifactorial origin is frequently observed in patients with liver diseases, and special efforts should be made to delineate the underlying causative and precipitating factors as well as the risk factors of the osmotic demyelination syndrome in order to properly manage this serious electrolyte disorder and avoid treatment pitfalls.

Cholesteryl ester transfer protein inhibitors: challenges and perspectives.

INTRODUCTION: Cholesteryl ester transfer protein (CETP) inhibitors substantially increase the concentration of high-density lipoprotein cholesterol (HDL-C), which may have a possible beneficial effect for cardiovascular disease risk reduction. AREAS COVERED: Current data regarding the effects of CETP inhibitors on cardiovascular disease risk and possible mechanisms for their effects and safety are presented in this review. Expert commentary: The first CETP inhibitor, torcetrapib, was discontinued because of increased off-target adverse effects (increased serum aldosterone and blood pressure levels). The development program of dalcetrapib and evacetrapib, which were not associated with increased blood pressure, was terminated due to futility (insufficient efficacy) concerning cardiovascular outcomes. Although the failure of torcetrapib has been attributed to specific off-target effects, there are some common characteristics between CETP inhibitors pointing to the possibility that certain adverse effects may be class-specific. The newer CETP inhibitors anacetrapib and TA-8995 have promising effects on lipid profile and metabolism (increase of HDL-C and reduction of both low-density lipoprotein cholesterol and lipoprotein (a) levels), but their cardiovascular effects and safety profile have not yet been confirmed in large outcome trials.

Pitavastatin and carbohydrate metabolism: what is the evidence?

Statins are the cornerstone of hypolipidemic treatment but recently have been associated with increased risk of developing diabetes mellitus. However, the risk of incident diabetes is not the same among statins. Pitavastatin lowers low-density lipoprotein cholesterol and increases high-density lipoprotein cholesterol but also seems to be neutral in terms of risk of incident diabetes. Clinical and experimental evidence shows that pitavastatin increases adiponectin levels and reduces oxidative stress, effects that seem to be implicated in the beneficial effect of the drug on carbohydrate metabolism variables. Pitavastatin is a useful hypolipidemic drug, which is promising for patients with increased diabetes risk or established diabetes.