Association of Adherence to The Mediterranean Diet with Urinary Factors Favoring Renal Lithiasis: Cross-Sectional Study of Overweight Individuals with Metabolic Syndrome

Abstract

Our purpose was to study the relationship of adherence to the Mediterranean diet (MedDiet) with urinary factors that favor the formation of renal calcium and uric acid stones in overweight and obese participants who had metabolic syndrome. This cross-sectional study examined 267 participants. A well-known MedDiet score (range 0–9) was calculated for each patient, and patients were then categorized has having low (≤3), medium (4–5), or high (≥6) adherence to the MedDiet. Baseline characteristics and urinary parameters were also analyzed. High calcium salt urinary crystallization risk (CaUCR) and high uric acid urinary crystallization risk (UrUCR) were calculated from urinary parameters using pre-defined criteria. More than half of patients with MedDiet scores ≤3 had high UrUCR (55.4%) and high CaUCR (53.8%). In contrast, fewer patients with high adherence (≥6) to the MedDiet had high UrUCR (41.2%) and high CaUCR (29.4%). Relative to those with low adherence, individuals with high adherence had a prevalence ratio (PR) of 0.77 for a high UrUCR (95% CI: 0.46–1.12; p for trend: 0.069) and a PR of 0.51 for a high CaUCR (95% CI: 0.26–0.87; p for trend: 0.012) after adjusting for age, sex, body mass index, type 2 diabetes, and total energy intake. Our findings indicate that greater adherence to the MedDiet was associated with a reduced CaUCR and a reduced UrUCR. This suggests that adequate dietary management using the MedDiet patterns may prevent or reduce the incidence and recurrence of calcium salt and uric acid renal stones.

The Relationship between Modern Fad Diets and Kidney Stone Disease: A Systematic Review of Literature

“…The Mediterranean diet might play an important protective role against urinary stone formation. This was thoroughly demonstrated in a detailed study by Prieto et al, in which the calcium and uric acid urinary crystallization risks were calculated [84]. The authors found that a high consumption of vegetables was the strongest dietary factor for decreased calcium crystallization risk.…”

Kidney Stone Prevention

“…Some dietary styles, such as Mediterranean diet pattern (defined as high consumption of plant-derived foods with monounsaturated to saturated fatty acids and low consumption of meats), are associated with a lower risk of KSD [ [57] , [58] , [59] ]. Several metabolic abnormalities, such as hypercalciuria, hyperoxaluria, hypocitraturia, hypomagnesuria, and hyperuricosuria, are the known risk factors for kidney stone formation.…”

Diet and Stone Disease in 2022

“…After a mean follow-up of 9.6 years, there was a 36% reduced risk of incident stones among those with the greatest adherence to a Mediterranean diet (HR 0.64, 95% CI 0.48–87, p = 0.01) [ 123 ]. The benefit of this diet has been postulated to be related to a lower risk of CaOx crystallization risk on this diet [ 124 ]. In contrast, Soldati and co-workers found no association between adherence to a Mediterranean diet and stone events in 478 obese Caucasian subjects [ 125 ].…”