HDL Cholesterol

Patients who receive maintenance hemodialysis have a very high risk of cardiovascular disease, and standard cholesterol-lowering treatments such as statins have not been shown to reduce cardiovascular events in this group. A recent clinical trial (PISCES) found that high-dose omega-3 fatty acids (fish oil) reduced cardiovascular events in hemodialysis patients, but the reason for this benefit is not understood. One possible explanation is that, in kidney failure, high-density lipoprotein (HDL) no longer works normally. This study investigates whether omega-3 fatty acid supplementation improves the function of HDL in people on maintenance hemodialysis. Forty adults on maintenance hemodialysis will take part. Each participant receives fish oil (4 g per day) for 8 weeks and also has an 8-week period without supplementation; participants are randomly assigned to the order of these two periods (crossover design), for a total of 16 weeks each. The main measure is cholesterol efflux capacity, a laboratory test of how well HDL removes cholesterol from cells. The study also examines other markers of HDL quality. This is an exploratory, mechanistic study. Its aim is to determine whether omega-3 fatty acids change HDL function and to inform the design of larger future trials.

This pilot study aims to explore the potential benefits of consuming Greek bottarga (grey mullet fish roe) in individuals with at least one metabolic abnormality (low HDL cholesterol, high LDL cholesterol, high triglycerides, obesity, or HbA1c ≥ 5.7%) or a diagnosis of diabetes. Before initiating the crossover randomized controlled trial (RCT), the investigators will conduct a preliminary dose-testing study in five adults with at least one metabolic abnormality. Participants will undergo clinical assessments before and after the dietary intervention to evaluate changes in metabolic health markers. Following this phase, the investigators will proceed with a randomized, controlled crossover trial involving 20 eligible adult participants. This main study phase will compare the metabolic effects of daily bottarga supplementation with those of a calorically matched dairy product over an 8-week intervention period, with a 2-week washout period between interventions. The investigators anticipate that bottarga supplementation will improve lipid profiles, inflammation markers, and insulin resistance, thereby supporting the potential use of sustainable blue foods as part of a healthy diet.