The basic principles of diet therapy in the treatment of patients with associated heart and kidney diseases

The relationship between chronic kidney disease (CKD) and cardiovascular disease (CVD) is extensively documented in the literature. Patients with CKD exhibit an elevated cardiovascular risk, often presenting edema, imbalance in electrolytes, proteins, lipoproteins, hormones (including vitamin D, parathormone, renin-angiotensin-aldosterone system), enzymes, growth factors, cytokines, endothelial dysfunction, inflammation, oxidative stress, insulin resistance, and anemia, leading to cardiovascular remodeling. This results in hypertension, arteriosclerosis, arterial and cardiac valve calcifications, coronary artery disease, cerebrovascular diseases, systolic and diastolic dysfunction, myocardial fibrosis, arrhythmias, heart failure, and sudden cardiac death. Conversely, hypertension, arteriosclerosis, and heart failure damage kidney function. Both CKD and CVD share common risk factors, including obesity, diabetes, dyslipidemia, and smoking. Diet therapy plays an essential role in the prevention and treatment of CVD, CKD, and their mutual risk factors. The specificity of diet therapy in patients with joint CVD and CKD is that renal failure requires some restrictions (e.g., for protein intake, phosphate, potassium, and acid load) possibly contradicting some nutritional recommendations for the prevention and treatment of CVD and associated risk factors. The balance in achieving the dietary goals for both conditions, with close monitoring of biochemical indicators and nutritional status, requires a systematic and individualized dietary approach. Additionally, the patient’s condition can progressively change, requiring constant monitoring and adaptation of dietary advice. Unfortunately, the current scientific literature does not allow appropriate assessing the effectiveness of various dietary strategies, due to limited and low-quality scientific evidence. This article summarizes the latest dietary recommendations for patients with joint CKD and CVD.