In glucose-deprived conditions, ketone bodies are produced by the liver mitochondria, through the catabolism of fatty acids, and are used peripherally, as an alternative energy source. Ketones are produced in the body under normal conditions, including during pregnancy and the neonatal period, when following a ketogenic diet (KD), fasting, or exercising. Additionally, ketone synthesis is also augmented under pathological conditions, including cases of diabetic ketoacidosis (DKA), alcoholism, and several metabolic disorders. Nonetheless, diet is the main regulator of total body ketone concentrations. The KDs are mimicking the fasting state, altering the default metabolism towards the use of ketones as the primary fuel source. Recently, KD has gained recognition as a medical nutrition therapy for a plethora of metabolic conditions, including obesity and diabetes mellitus (DM). The present review aims to discuss the role of ketones, KDs, ketonemia, and ketonuria in DM, presenting all the available new evidence in a comprehensive manner.

Over 300 million patients with coronavirus disease 2019 (COVID-19) have been reported worldwide since the outbreak of the pandemic in Wuhan, Hubei Province, China. COVID-19 is induced by the acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The effect of SARS-CoV-2 infection on the male reproductive system is unclear. The aim of this review is to assess the effect of SARS-CoV-2 infection on male fertility and the impact of possible mediators, such as metabolic, oxidative and psychological stress. SARS-CoV-2 infection aggravates metabolic stress and directly or indirectly affects male fertility by reducing seminal health. In addition, SARS-CoV-2 infection leads to excessive production of reactive oxygen species (ROS) and increased psychological distress. These data suggest that SARS-CoV-2 infection reduces male fertility, possibly by means of metabolic, oxidative and psychological stress. Therefore, among other consequences, the possibility of COVID-19-induced male infertility should not be neglected.

Ceramides, a sphingolipid group that acts as a messenger in cellular differentiation, proliferation, apoptosis and senescence, have been associated with cardiovascular disease and type 2 diabetes. The evidence for an association between ceramides and gestational diabetes mellitus (GDM) is scarce. This case-control study aimed to compare women with GDM with healthy, pregnant women in terms of plasma ceramide concentrations at the time of delivery. Ninety-two pregnant women were included in this case-control study, 29 in the GDM group and 63 in the control group. All women were admitted to a tertiary academic hospital for a full-term delivery. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was applied for the quantification of four molecular ceramides, namely Cer d18:1/16:0 (Cer16:0), Cer d18:1/18:0 (Cer18:0), Cer d18:1/24:0 (Cer24:0) and Cer d18:1/24:1 (Cer24:1) in plasma samples. The raw chromatographic data obtained from the LC-MS/MS analysis were processed using Analyst SCIEX (AB Sciex Pte. Ltd., USA). In a univariate statistical analysis, Cer24:0 concentration was significantly lower in the GDM group compared with the control group (p = 0.01). The present study demonstrated lower Cer24:0 concentrations in pregnancies complicated by GDM. Further prospective studies are required to enhance the results of this study.

Gestational diabetes mellitus (GDM) is a prevalent condition impacting approximately 14% of pregnancies globally, posing significant health risks to mother and child. This review explores the role of diet, physical activity (PA), and sedentary behavior (SB) in preventing and managing GDM. Consumption of fish, fruits, vegetables, and legumes, and adherence to healthy dietary patterns, like the Mediterranean diet, are linked to lower GDM risk. Higher levels of PA and structured exercise consistently show protective effects against GDM, enhancing glucose metabolism and insulin sensitivity. Conversely, SB is a risk factor for GDM; prolonged sedentary periods detrimentally affect glucose regulation. The review emphasizes the need for a combined approach integrating healthy dietary habits, regular PA, and reduced SB to mitigate GDM risk effectively. Future research should prioritize standardized assessment methods and personalized lifestyle interventions to optimize GDM prevention strategies, ultimately informing public health guidelines and clinical recommendations for healthier pregnancies and better long-term outcomes.