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.

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.

Effects of 12 months of treatment with disease-modifying anti-rheumatic drugs on low and high density lipoprotein subclass distribution in patients with early rheumatoid arthritis: a pilot study.

OBJECTIVES: Patients with rheumatoid arthritis (RA) have increased cardiovascular risk. The aim of the present study was the assessment of low density lipoprotein (LDL) and high density lipoprotein (HDL) subclass distribution in patients with early RA (ERA, n = 30) compared with age- and sex-matched healthy subjects (n = 30), as well the effect of treatment for 12 months with the disease-modifying anti-rheumatic drugs (DMARDs) methotrexate and prednisone in this distribution. METHOD: LDL and HDL subclass distribution was determined using a polyacrylamide gel-tube electrophoresis method. RESULTS: ERA patients exhibited increased levels of inflammatory markers and high disease activity score. ERA patients had higher serum levels of total cholesterol (TC), LDL cholesterol (LDL-C), and triglycerides (TG) whereas their serum HDL cholesterol (HDL-C) levels were significantly lower compared with controls. ERA patients exhibited significantly higher plasma levels of small dense LDL-C (sdLDL-C), leading to a significantly decreased mean LDL diameter. ERA patients had significantly decreased small HDL particles (HDL-3) concentration whereas serum levels of large HDL particles (HDL-2) did not differ compared with controls. Treatment with DMARDs resulted in a significant decrease in inflammatory markers and disease activity, along with a significant increase in HDL-C serum levels. The concentration of sdLDL-C did not change significantly during treatment. We observed a significant increase in the levels of large HDL-2 whereas the concentration of small HDL-3 did not significantly change. CONCLUSIONS: Patients with ERA have increased sdLDL-C levels and decreased HDL-C levels because of decreased concentration of the small HDL-3 subclass. The administration of DMARDs induced a significant increase in HDL-C levels, which was attributed to the increase in large HDL-2 serum concentration.

Increased plasma visfatin concentration is a marker of an atherogenic metabolic profile.

BACKGROUND AND AIMS: Visfatin is associated with atherosclerosis-related diseases. We assessed in non-diabetic individuals the association of plasma visfatin levels with cardiovascular disease (CVD) risk and the atherosclerosis-related metabolic variables. METHODS AND RESULTS: When study population (n = 179, age 49 ± 11 years) was divided according to visfatin tertiles, the 10-year CVD Framingham risk scores were significantly increased in the top visfatin tertile. We observed a positive association between visfatin tertiles with waist circumference and blood pressure, as well as with total cholesterol and triglyceride levels, but not with apolipoprotein C-III, fibrinogen or pre-beta1 high density lipoprotein (HDL). The percentage of large HDL subclasses was significantly lower and the percentage of small HDL subclasses over the HDL-C concentration was significantly higher in the top visfatin tertile compared with the other tertiles. The atherogenic small dense low density lipoprotein subclasses (sdLDL-C) were significantly increased in the top visfatin tertile compared with the lower tertiles. High sensitivity C-reactive protein (hsCRP) concentration was significantly increased in the top visfatin tertile compared with the lower tertiles. Although age and sex distribution did not differ between visfatin tertiles, the simultaneous adjustment for these parameters attenuated the significance of the differences observed in sdLDL-C and hsCRP levels. Similarly, after adjustment for hsCRP or waist circumference, only triglycerides and blood pressure levels, as well as the distribution of HDL subclasses, remained significantly different between visfatin tertiles. CONCLUSIONS: Our results support a role for visfatin in the detection of subjects with many metabolic abnormalities, which result in increased CVD risk.

Effect of rosuvastatin monotherapy or in combination with fenofibrate or ω-3 fatty acids on lipoprotein subfraction profile in patients with mixed dyslipidaemia and metabolic syndrome.

BACKGROUND: Raised triglycerides (TG), decreased high-density lipoprotein cholesterol (HDL-C) levels and a predominance of small dense low density lipoproteins (sdLDL) are characteristics of the metabolic syndrome (MetS). OBJECTIVE: To compare the effect of high-dose rosuvastatin monotherapy with moderate dosing combined with fenofibrate or ω-3 fatty acids on the lipoprotein subfraction profile in patients with mixed dyslipidaemia and MetS. METHODS: We previously randomised patients with low-density lipoprotein cholesterol (LDL-C) > 160 and TG > 200 mg/dl to rosuvastatin monotherapy 40 mg/day (R group, n = 30) or rosuvastatin 10 mg/day combined with fenofibrate 200 mg/day (RF group, n = 30) or ω-3 fatty acids 2 g/day (Rω group, n = 30). In the present study, only patients with MetS were included (24, 23 and 24 in the R, RF and Rω groups respectively). At baseline and after 12 weeks of treatment, the lipoprotein subfraction profile was determined by polyacrylamide 3% gel electrophoresis. RESULTS: The mean LDL size was significantly increased in all groups. This change was more prominent with RF than with other treatments in parallel with its greater hypotriglyceridemic capacity (p < 0.05 compared with R and Rω). A decrease in insulin resistance by RF was also noted. Only RF significantly raised HDL-C levels (by 7.7%, p < 0.05) by increasing the cholesterol of small HDL particles. The cholesterol of larger HDL subclasses was significantly increased by R and Rω. CONCLUSIONS: All regimens increased mean LDL size; RF was the most effective. A differential effect of treatments was noted on the HDL subfraction profile.

High doses of rosuvastatin are superior to low doses of rosuvastatin plus fenofibrate or n-3 fatty acids in mixed dyslipidemia.

The aim of the study was to compare the efficacy of high-dose rosuvastatin, low-dose rosuvastatin plus fenofibrate and low-dose rosuvastatin plus omega-3 fatty acids with regard to the lipid profile in patients with mixed hyperlipidemia. The primary endpoint was changes in non-high density lipoprotein-cholesterol (non-HDL-C) levels. Study participants were randomly allocated to receive rosuvastatin 40 mg (n = 30, R group), rosuvastatin 10 mg plus fenofibrate 200 mg (n = 30, RF group) or rosuvastatin 10 mg plus n-3 fatty acids 2 g (n = 30, RN group). Non-HDL-C levels were reduced in all groups: in R group by 54%, in RF group by 42% and in RN group by 42%. Significant reductions in total cholesterol (TC), low density lipoprotein (LDL)-C and triglyceride levels were observed in all groups. The reductions in total and LDL-C were greatest in the R group while a more pronounced reduction of triglycerides in the RF group compared with that in the R and the RN group was observed. HDL-C levels were significantly increased only in the RF group. In conclusion, high doses of rosuvastatin and small doses of rosuvastatin plus either fenofibrate or n-3 fatty acids exhibit favorable effects on both LDL-C and non-HDL-C levels. However, rosuvastatin monotherapy more potently reduces these parameters. The combination of rosuvastatin plus fenofibrate leads to a greater decrease in triglyceride levels and a greater increase in HDL-C levels compared with the other two treatments. While awaiting the results of ongoing trials high doses of rosuvastatin may represent the treatment of choice in individuals with mixed dyslipidemia.

Cola-induced hypokalaemia: pathophysiological mechanisms and clinical implications.

BACKGROUND/AIMS: The consumption of soft drinks has increased considerably during the last decades. Among them, the cola-based preparations are possibly the refreshments with the largest sales worldwide. In addition to the possible detrimental effects of moderate, chronic cola consumption, it has been proposed that the consumption of large amounts of cola-based soft drinks may result in severe hypokalaemia. METHODS: In this review, we discuss the clinical significance of these disturbances and summarise the pathophysiological mechanism that may underlie the development of this rare, but potentially severe, side effect. RESULTS/CONCLUSION: Several lines of evidence suggest that the chronic consumption of large amounts of cola soft drinks may adversely affect potassium homeostasis and result in potentially severe conditions such as hypokalaemic myopathy.

Pleiotropic effects of fenofibrate.

Fenofibrate represents the most commonly used fibric acid derivative. The drug exerts its metabolic effects by modulating the expression of several genes involved in lipoprotein metabolism. In addition, numerous studies suggest that fenofibrate may also affect the progression of the atherosclerotic process by several lipid-independent mechanisms. This review considers the clinical pharmacology of fenofibrate and the current evidence on the pleiotropic effects of this fibric acid derivative.

Alterations in the high density lipoprotein phenotype and HDL-associated enzymes in subjects with metabolic syndrome.

Patients with metabolic syndrome (MetS) usually have low high density lipoprotein cholesterol (HDL-C) levels. We determined the HDL distribution profile as well as the HDL-related lipoprotein associated phospholipase A(2) (HDL-LpPLA(2)) and paraoxonase-1 (PON1) activities in subjects with MetS (n = 189) but otherwise healthy. Age and sex-matched individuals (n = 166) without MetS served as controls. The lower HDL-C concentration in MetS patients was due to a reduction in both large and small HDL subclasses (P < 0.001 and P < 0.05, respectively). As the number of MetS components increased, the HDL phenotype comprised of a greater percentage of small HDL-3 and less large HDL-2 subclasses, resulting in a decreased HDL-2/HDL-3 ratio (P < 0.001 for all trends). Multivariate analysis revealed that HDL-2 levels and the HDL-2/HDL-3 ratio significantly and independently correlated with HDL-C (positively) and TG (negatively) levels. HDL-3 concentration significantly and independently positively correlated with HDL-C and TG levels. HDL-LpPLA(2) activity was decreased in MetS patients (P < 0.01), a phenomenon that may contribute to the defective antiatherogenic activity of HDL in MetS. PON1 activity did not differ between groups. We conclude that MetS, in addition to the decrease in HDL-C concentration, is associated with alterations in the HDL phenotype, which is comprised of a greater percentage of small HDL subclasses. Furthermore, HDL-LpPLA(2) activity is decreased in MetS patients.