Urolithiasis and metabolic syndrome. Pathophysiology of stone formation

The review is devoted to the analysis of modern literature on the relationship between metabolic syndrome and urolithiasis. Epidemiological data on the prevalence of metabolic syndrome and urolithiasis are presented, which indicate a more frequent development of urolithiasis in people with metabolic syndrome. This reveals the relationship between the incidence of urolithiasis and the severity of the metabolic syndrome: with an increase in the number of components of the metabolic syndrome, the incidence of urolithiasis increases. Features of the pathogenesis of formation of stones of different composition in patients with metabolic syndrome are analyzed. In the formation of uric acid stones, most often detected in the metabolic syndrome, the main role is played by the increase in uric acid excretion as a result of metabolic disorders and urinary acidification caused by a violation of the secretion of ammonium ions in urine with a general increase in the production of acids. These disorders are associated with insulin resistance, which is present in patients with metabolic syndrome. Rarely in patients with metabolic syndrome, calcium oxalate urolithiasis develops. The formation of these stones is also associated with insulin resistance accompanied by dyslipidemia, which leads to the accumulation of lipid metabolism products in the kidney tissue and its local damage by products of oxidative stress followed by calcification and the formation of Randall plaques, which catalyze the crystallization of calcium and oxalate salts. The initiator of stone formation can also serve as aggregates from uric acid. Accumulation of data on the pathogenesis of nephrolithiasis development allows us to consider urolithiasis as a new component of the metabolic syndrome. The detection of kidney stones can be considered as a renal manifestation of the metabolic syndrome, and its presence must be taken into account in patients with the so-called idiopathic nephrolithiasis.