Purslane-induced oxalate nephropathy: case report and literature review.

BACKGROUND: The kidney is particularly vulnerable to toxins due to its abundant blood supply, active tubular reabsorption, and medullary interstitial concentration. Currently, calcium phosphate-induced and calcium oxalate-induced nephropathies are the most common crystalline nephropathies. Hyperoxaluria may lead to kidney stones and progressive kidney disease due to calcium oxalate deposition leading to oxalate nephropathy. Hyperoxaluria can be primary or secondary. Primary hyperoxaluria is an autosomal recessive disease that usually develops in childhood, whereas secondary hyperoxaluria is observed following excessive oxalate intake or reduced excretion, with no difference in age of onset. Oxalate nephropathy may be overlooked, and the diagnosis is often delayed or missed owning to the physician's inadequate awareness of its etiology and pathogenesis. Herein, we discuss the pathogenesis of hyperoxaluria with two case reports, and our report may be helpful to make appropriate treatment plans in clinical settings in the future. CASE PRESENTATION: We report two cases of acute kidney injury, which were considered to be due to oxalate nephropathy in the setting of purslane (portulaca oleracea) ingestion. The two patients were elderly and presented with oliguria, nausea, vomiting, and clinical manifestations of acute kidney injury requiring renal replacement therapy. One patient underwent an ultrasound-guided renal biopsy, which showed acute tubulointerstitial injury and partial tubular oxalate deposition. Both patients underwent hemodialysis and were discharged following improvement in creatinine levels. CONCLUSIONS: Our report illustrates two cases of acute oxalate nephropathy in the setting of high dietary consumption of purslane. If a renal biopsy shows calcium oxalate crystals and acute tubular injury, oxalate nephropathy should be considered and the secondary causes of hyperoxaluria should be eliminated.

The Racial Disparities in the Epidemic of Metabolic Syndrome With Increased Age: A Study From 28,049 Chinese and American Adults.

BACKGROUND: Previous studies have revealed ethnic disparities in the prevalence of metabolic syndrome (MetS); however, the literature regarding aging-related patterns of disparities in MetS and its components remains limited. METHODS: This cross-sectional study recruited 28,049 subjects, consisting of one Chinese race and three American races, 18-85 years of age, from the National Health and Nutrition Examination Survey (NHANES, 1999-2018) of the United States, and the Guangdong Gut Microbiome Project (GGMP, 2018) of China. MetS was defined in accordance with the National Cholesterol Education Program Adult Treatment Panel III. A modified sliding-window-based algorithm was used to depict the trajectories of the prevalence of MetS with increased age. Logistic regression analysis was performed to investigate associations between MetS and its components. RESULTS: The prevalence of MetS increased non-linearly with age, with growth speed reaching its maximum at approximately 40-50 years. Chinese subjects exhibited a lower prevalence of MetS than non-Hispanic whites, non-Hispanic blacks, and Mexican Americans in all age groups. The two most prevalent components in Chinese subjects were reduced high-density lipoprotein cholesterol levels (42.0%) and elevated blood pressure (49.5%), and elevated triglyceride levels (36.3-49.5%) and abdominal obesity (55.8-55.9%) in Americans. Before 40 years of age, the top two MetS-associated components were abdominal obesity and elevated triglyceride levels in all races, while after 40 years, the prominent associations between MetS and its components varied among the different races and age groups. CONCLUSIONS: Although racial disparities in the epidemic of MetS varied with increased age, abdominal obesity and elevated triglyceride levels were the top two MetS-associated components in all younger adults of different races.