Characteristics of bone metabolism in postmenopausal female patients with different types of idiopathic benign paroxysmal positional vertigo: A single-centre retrospective study.

OBJECTIVE: The association between benign paroxysmal positional vertigo (BPPV) and impaired calcium metabolism has attracted widespread interest. Several studies have suggested that decreased bone mineral density (BMD) and serum 25-hydroxyvitamin D (25(OH)D) level are related to the occurrence and/or recurrence of BPPV; however, the characteristics of bone metabolism in patients with BPPV subtypes have not been fully investigated, and conclusions have been controversial. This study aimed to evaluate BMD and serum levels of 25(OH)D and bone turnover markers to clarify the characteristics of bone metabolism in patients with different types of BPPV. METHOD: We retrospectively analysed the data of new-onset idiopathic postmenopausal female patients with BPPV at our institution from January 2016 to January 2020. The patients' demographic data including age, medication history, concomitant diseases, onset time, clinical form, laboratory indicators, such as serum levels of 25(OH)D, bone formation markers, namely, amino-terminal propeptide of type I procollagen (PINP) and osteocalcin (OC), bone resorption marker, namely, ß-isomerized carboxy-terminal telopeptide of type I collagen (ß-CTX), and BMD were collected and analysed. RESULTS: This study included 201 consecutive postmenopausal female patients with BPPV. Among them, 138 were diagnosed with posterior semicircular canal BPPV, 42 were diagnosed with lateral semicircular canal canalolithiasis, and 21 were diagnosed with lateral semicircular canal cupulolithiasis. There were no significant differences in age distribution, body mass index, clinical history, levels of albumin, globulin, uric acid, creatinine, or blood urea nitrogen, lipid profiles (except high-density lipoprotein cholesterol) and routine blood parameters among these groups (P > 0.05). There were no significant differences in the mean T-score and BMD values of different sites or in the serum levels of 25(OH)D and bone turnover markers (PINP, OC and ß-CTX) among the subgroups (P > 0.05). The proportion of reduction in BMD (T-score < -1 SD) and decreased serum vitamin D level (< 20 ng/ml) were not significantly different between the subgroups (P > 0.05). CONCLUSION: There were no significant differences in bone metabolism in postmenopausal female patients with different types of idiopathic BPPV.

[The study of pollutant's effects on macrophages and its significance in biological monitoring].

This study aimed to investigate the effects of environmental pollutant sulfite and inorganic mercury on the peritoneal macrophages (PM phi) of mice and further explore the significance of macrophage as a biomarker in biological monitoring. PM phi were taken from the peritoneal cavity of mice and cultivated with Na2SO3 and HgCl2 respectively in vitro, and then morphologic changes were detected under light microscope and electron microscope. Also the function of PM phi was detected in yielding nitric oxide (NO), reducing MTT and phagocytizing. After affected by the pollutants, marked morphologic changes of PM phi were observed, and NO reducing, cell vigor and phagocytizing of PM phi were obviously inhibited (p < 0.05 or p < 0.01). And some PM phi were necrotic caused by HgCl2 at high concentration(10(-4) mol/L). The results suggested that PM phi of mice was damaged distinctly by using Na2SO3 and HgCl2 which showed sulfite and inorganic mercury directly impacted on non-special defensive function of macrophages. Meanwhile the experiment indicated that macrophage could be used as an effective biomarker in biological monitoring of environmental contamination.