Primary hyperparathyroidism is associated with a higher level of serum uric acid: A systematic review and meta-analysis

Objectives Studies have suggested that primary hyperparathyroidism could be a risk factor for hyperuricemia although the results were not consistent across the studies. This systematic review and meta-analysis was performed in order to identify all available studies and summarize their results together. Methods A systematic review was performed using EMBASE and MEDLINE from inception to August 2018 to identify all cohort studies that consisted of 2 cohorts, a cohort of patients with primary hyperparathyroidism and a cohort of individuals without hyperparathyroidism. Eligible studies had to provide data on mean serum uric acid level and standard deviation of both cohorts, which would be extracted to calculate mean difference (MD). Pooled MD was then calculated by combining MDs of each study using a random-effects model. Funnel plot was used for evaluation for publication bias. Results A total of 9 cohort studies met the inclusion criteria and were included into the meta-analysis. The pooled analysis found that patients with primary hyperparathyroidism had a significantly higher level of serum uric acid than individuals without hyperparathyroidism with the pooled MD of 65.00 mu mol/L (95% CI 37.74-92.25). The statistical heterogeneity was high with I-2 of 90%. The funnel plot was relatively symmetric and did not provide evidence for publication bias. Conclusion Patients with primary hyperparathyroidism had a significantly higher level of serum uric acid compared to individuals without hyperparathyroidism.