Kidney stones diseases and glycaemic statuses: focus on the latest clinical evidences

Diabetes and obesity are already recognized as potential risk factors for nephrolithiasis, especially for uric acid stones. Insulin resistance and hyperinsulinemia actively contribute to impaired ability to excrete an acid load and altered ammonium production, leading to a lower urinary pH compared to non-diabetic controls. All these electrolytic disorders play an important role in stone formation and aggregation, especially in uric acid stones. There are still missing points in scientific evidence if the increased risk in stone formation is already existing even in the prediabetic statuses (isolated impaired glucose tolerance, isolated impaired fasting glucose, and associated impaired glucose tolerance/impaired fasting glucose) as well as it is worth to consider the same level of risk. Urolithiasis is the most frequent urological cause of hospitalization in diabetic patients and its cost is usually higher compared to non-diabetic patients, but less is known in others altered glycaemic diseases. The aim of this review article is to focus on the association between stone formation and altered glycaemic statuses, beyond the already known link between nephrolithiasis and diabetes mellitus.