{'fraction_non_alphanumeric': 0.03345070422535211, 'fraction_numerical': 0.051643192488262914, 'mean_word_length': 5.177536231884058, 'pattern_counts': {'":': 0, '<': 1, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Prevalence of Hyperoxaluria in Urinary Stone Formers: Chronological and Geographical Trends and a Literature Review.

PURPOSE
To report chronological trends and geographical distributions related to the prevalence of hyperoxaluria in stone-forming patients.


MATERIALS AND METHODS
We systematically reviewed the existing literature between 1982 and 2013 seeking studies that assessed for hyperoxaluria (>45 mg/day [499.5 μmol/24 hour]) in recurrent stone formers. Studies that performed 24-hour urine analysis for urine oxalate in patients with recurrent urinary stones were included. Studies were divided chronologically and by geographical region, and prevalence rates of hyperoxaluria were compared between groups.


RESULTS
Our literature search provided 22 peer-reviewed articles involving 3636 patients in total. Ten studies were performed between 1982 and 2000, and 12 studies were performed between 2001 and 2013. The prevalence of hyperoxaluria in stone-forming patient cohorts was 24.8% and 45.1% (p = 0.019) in studies performed between 1982 and 2000 and 2001 and 2013, respectively. Hyperoxaluria rates were significantly higher in non-American cohorts compared with American cohorts (40.7% vs 23.0%; p = 0.018). Reported hyperoxaluria rates were higher in Asian countries compared with Western countries (56.8% and 23.8%; p < 0.001).


CONCLUSIONS
The prevalence of hyperoxaluria in stone-forming patients has increased over the past two decades and may be a contributing factor to the rising global prevalence of urolithiasis. A geographical disparity in hyperoxaluria may exist between Asian and Western countries. Future studies are needed to explain these trends and their consequences.