Impact of body mass index on size and composition of urinary stones: a systematic review and meta-analysis

Abstract

Background Several studies have explored the impact of BMI on size and composition of urinary stones. Because there were controversies, a meta-analysis was necessary to be carried out to provide some evidence of the relationship of BMI and urolithiasis. Materials and Methods PubMed, Medline, Embase, Web of Science databases, and the Cochrane Library were searched up to August 12th 2022 for eligible studies. The urolithiasis patients were summarized into two groups: BMI < 25 and ≥ 25 kg/m2. Summary weighted mean difference (WMD), relative risk (RR) and 95% confidence intervals (CI) were calculated through random effects models in RevMan 5.4 software. Results A total of fifteen studies involving 13,233 patients were enrolled in this meta-analysis. There was no significant correlation of BMI and size of urinary stone (WMD -0.13mm, 95% CI [-0.98, 0.73], p = 0.77). Overweight and obesity increased the risk of uric acid stones in both genders and in different regions (RR=0.87, [95% CI] = 0.83, 0.91, p<0.00001). There was a higher risk of calcium oxalate stones formation in overweight and obesity group in total patients (RR=0.95, [95% CI] = 0.91, 0.98, p = 0.006). The relationship of BMI and calcium phosphate was not observed in this meta-analysis (RR=1.12, [95% CI] = 0.98, 1.26, p = 0.09). Sensitivity analysis was performed and indicated similar results. Conclusions The current evidence suggests a positive association between BMI and uric acid and calcium oxalate stones. It would be of great guiding significance to consider losing weight when treating and preventing urinary stones.

The Multidisciplinary Approach in the Management of Patients with Kidney Stone Disease—A State-of-the-Art Review

“…Moreover, an increased risk of calcium oxalate stone formation was observed in the excess weight group across all patients. Conversely, in this meta-analysis, no significant association between BMI and calcium phosphate was indicated [ 105 ].…”

“…While the exact cause of kidney stone disease is still uncertain, individuals with MetS or DM have been found to have higher levels of urinary acidification and production of uric acid stones compared to those without these conditions. Interestingly, as BMI increases in both diabetic and non-diabetic patients, the occurrence of uric acid stones tends to increase while the occurrence of calcium oxalate stones decreases [ 105 , 115 ].…”

MRI-TRUS fusion targeted biopsy is highligheted in International Brazilian Journal of Urology

“…Dr. Wang and collegues from China, presented in page 281 ( 1 ) a nice systematic review about the impact of body mass index (BMI) on size and composition of urinary stones and concluded that the current evidence suggests a positive association between BMI and uric acid and calcium oxalate stones. It would be of great guiding significance to con- sider losing weight when treating and preventing urinary stones.…”