Hypolipidemic Drugs and Diabetes Mellitus-Mechanisms and Data From Genetic Trials.

Clinical trials and meta-analyses have shown that statins can dose dependently increase the incidence of new-onset diabetes mellitus (DM) especially in patients with underlying abnormalities of carbohydrate homeostasis. Mendelian randomization studies support these findings since genetic variants in the gene encoding the target of statins, the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase, are associated with increased incidence of new-onset DM, suggesting that the so-called diabetogenic effect of statins is an "on-target effect" possibly related to their main mechanism of action, that is the increased low-density lipoprotein (LDL) receptor expression. Additionally, Mendelian randomization studies have shown that genetic variants as proxies of other drugs that increase LDL receptor expression (ezetimibe and proprotein convertase subtilisin/kexin type 9 [PCSK9] inhibitors) also increase the risk of new-onset DM. This concept is supported by the fact of decreased DM prevalence in patients with familial hypercholesterolemia who have decreased LDL receptor expression. In contrast, hypolipidemic drugs, such as the cholesteryl ester transfer protein inhibitors, that decrease LDL cholesterol without directly interfering with the LDL receptor expression do not seem to detrimentally affect carbohydrate homeostasis. However, the clinical trials of ezetimibe and PCSK9 inhibitors have not shown an increased DM risk, possibly suggesting that other potential non-well-defined "off-target effects" of hypolipidemic drugs may affect carbohydrate homeostasis. Thus, the long-term effect of hypolipidemic drugs on DM risk depends not only on their final mechanism of hypolipidemic action but also on other "on-target" and "off-target" effects of these drugs.

Acid-base and electrolyte disorders associated with the use of antidiabetic drugs.

INTRODUCTION: The use of antidiabetic drugs is expected to substantially increase since diabetes mellitus incidence rises. Currently used antidiabetic drugs have a positive safety profile, but they are associated with certain acid-base and electrolyte abnormalities. The aim of the review is to present the current data regarding the antidiabetic drugs-associated acid-base and electrolyte abnormalities. Areas covered: Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been linked with the scarce, but serious, complication of euglycemic diabetic ketoacidosis, as well as with an increase in serum potassium, magnesium and phosphorus levels. Metformin use has been associated with the development of lactic acidosis, although many studies have doubt the direct link with this serious complication. Additionally, metformin in some studies has been linked with a decrease in serum magnesium levels. Insulin administration is associated with a reduction in serum potassium, magnesium and phosphorus concentration, along with reduced renal magnesium excretion. Pioglitazone is associated with an increase in serum magnesium levels. Current data regarding the pathophysiological mechanisms, precipitants, risk factors and presentation of the above abnormalities are discussed in the present review. Expert opinion: Clinicians should choose appropriately between antidiabetic drugs based not only on their hypoglycemic efficacy and effects on cardiovascular risk but also based on the patient's specific risk to develop acid-base or electrolyte derangements.

Sitosterolemia: A multifaceted metabolic disorder with important clinical consequences.

Sitosterolemia is a metabolic disorder characterized by increased intestinal absorption and tissue accumulation of phytosterols. Although sitosterolemia is considered a rare disease, its prevalence may be significantly higher than initially thought. Indeed, accumulating evidence suggests that patients with unexplained hematologic abnormalities or premature cardiovascular disease in the absence of classic risk factors may exhibit disordered phytosterol metabolism. In this review, we present a patient with sitosterolemia, describe the pathophysiology and the clinical picture of this disorder, and discuss the clinical value of phytosterol supplementation in patients with primary dyslipidemias.