Search

Despite ethnic differences in cortisol sensitivity, only one study in Caucasians has assessed trabecular bone score (TBS) in patients with subclinical hypercortisolism (SH). We showed that both subtle cortisol excess and reduced adrenal androgen may contribute to impaired bone quality in Asian women with SH., Introduction: One study in Caucasians has assessed trabecular bone score (TBS), an index of bone microstructure, in adrenal incidentaloma (AI) patients with subclinical hypercortisolism (SH). There are ethnic differences in cortisol sensitivities between Caucasian and Asian populations. We investigated the associations of cortisol and the adrenal androgen dehydroepiandrosterone-sulfate (DHEA-S) with TBS in AI patients with SH, adrenal Cushing's syndrome (CS), and nonfunctional AI (NFAI)., Methods: We measured TBS, cortisol levels after the overnight 1 mg dexamethasone suppression test (1 mg DST), and cortisol/DHEA-S in 61 patients with SH (30 men; 31 women), 19 with adrenal CS (4 men; 15 women), and 355 with NFAI (213 men; 142 women)., Results: After adjusting for confounders, the serum cortisol level after 1 mg DST was inversely correlated with TBS in men (β = -0.133, P = 0.045) and women (β = - 0.140, P = 0.048). Higher cortisol/DHEA-S ratio was associated with lower TBS in women (β = - 0.252, P < 0.001), but not men. This inverse association of cortisol/DHEA-S ratio in women remained statistically significant after adjusting for the serum cortisol level after 1 mg DST (β = - 0.221, P = 0.008). Compared with women with NFAI, women with SH had 2.2% lower TBS (P = 0.040). Deteriorated bone microstructure (TBS < 1.230) was associated with the serum cortisol level after 1 mg DST (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.04-4.53) and cortisol/DHEA-S ratio (OR, 2.05; 95% CI, 1.03-4.08)., Conclusions: Subtle cortisol excess in both genders and reduced DHEA-S, especially in women, may contribute to impaired bone quality in Asian patients with SH.

Background: Sarcopenia is significantly associated with the degree of liver fibrosis. This study investigated the influence of sarcopenia on liver fibrosis in individuals with chronic hepatitis B., Methods: Data from the Korean National Health and Nutrition Examination Surveys 2008-2011 were analysed. The sarcopenia index (total appendicular skeletal muscle mass [kg]/body mass index [kg/m 2 ]) was calculated using dual-energy X-ray absorptiometry. Sarcopenia was defined as the lowest quintile sarcopenia index value (cut-offs: 0.89 for men and 0.58 for women). The fibrotic burden was assessed using the nonalcoholic fatty liver disease fibrosis score and fibrosis-4 index. Significant fibrosis was defined as the highest nonalcoholic fatty liver disease fibrosis score quartile and a fibrosis-4 index ≥2.67., Results: Among the 506 respondents with chronic hepatitis B (258 men and 248 women), the nonalcoholic fatty liver disease fibrosis score and fibrosis-4 index identified sarcopenia and significant fibrosis in 126 (24.9%) and 217 (42.9%), respectively. Sarcopenia was significantly associated with significant fibrosis, regardless of the fibrosis prediction model used (all P < 0.05). When the study population was stratified according to metabolic factors, sarcopenia was specifically associated with an increased risk of significant fibrosis among subgroups with obesity, insulin resistance, metabolic syndrome and liver steatosis (odds ratio 2.37-3.57; all P < 0.05). An independent association between sarcopenia and significant fibrosis was identified after adjusting for other confounders (odds ratio 2.67-3.62 by the nonalcoholic fatty liver disease fibrosis score and 2.04-2.62 by the fibrosis-4 index; all P < 0.05)., Conclusions: Sarcopenia is associated with significant fibrosis in subjects with chronic hepatitis B, specifically those with obesity, insulin resistance, metabolic syndrome and liver steatosis., (© 2018 John Wiley & Sons Ltd.)

Analyses using a nationally representative cohort have revealed that high fatty liver index (FLI) is associated with low bone mineral density (BMD) regardless of insulin resistance in men, thereby supporting the deteriorated bone metabolism in nonalcoholic fatty liver disease (NAFLD)., Introduction: NAFLD is linked to deteriorated bone health. We investigated the association of FLI, a scoring model for NAFLD, with BMD., Methods: This was a population-based, cross-sectional study from the Korea National Health and Nutrition Examination Surveys including 4264 Koreans (1908 men and 2356 women). FLI was calculated using body mass index, waist circumference, serum triglyceride, and gamma-glutamyltranspeptidase level. Insulin resistance was evaluated using the homeostasis model assessment-estimated insulin resistance (HOMA-IR) index. BMD was measured using dual-energy X-ray absorptiometry at the lumbar spine, total hip, femoral neck, and whole body., Results: Men had a higher FLI than women, while the HOMA-IR index was similar between men and women. The significant association between FLI and BMD was observed only in men, but not in women. FLI was negatively correlated with total hip, femoral neck, and whole body BMD in men after adjusting for all potential confounders, including HOMA-IR (P < 0.001 to 0.010). Lumbar spine, total hip, femoral neck, and whole body BMD in men showed a decreasing trend as the FLI tertile increased after adjusting for all potential confounders, including HOMA-IR (P for trends < 0.001 to 0.034). In men aged 50 years or older, odds ratios for combined osteopenia and osteoporosis increased across increasing FLI tertiles after adjusting for confounders (P for trends < 0.011 to 0.029)., Conclusion: NAFLD is associated with low bone density regardless of insulin resistance in men. These findings suggest an undiscovered direct link between liver and bone that increases the risk of osteoporosis in men with NAFLD.

Formation of magnetite in anaerobic sediments is thought to be enhanced by the activities of iron-reducing bacteria. Geobacter has been implicated as playing a major role, as in culture its cells are often associated with extracellular magnetite grains. We studied the bacterial community associated with magnetite grains in sediment of a freshwater pond in South Korea. Magnetite was isolated from the sediment using a magnet. The magnetite-depleted fraction of sediment was also taken for comparison. DNA was extracted from each set of samples, followed by PCR for 16S bacterial ribosomal RNA (rRNA) gene and HiSeq sequencing. The bacterial communities of the magnetite-enriched and magnetite-depleted fractions were significantly different. The enrichment of three abundant operational taxonomic units (OTUs) suggests that they may either be dependent upon the magnetite grain environment or may be playing a role in magnetite formation. The most abundant OTU in magnetite-enriched fractions was Geobacter, bolstering the case that this genus is important in magnetite formation in natural systems. Other major OTUs strongly associated with the magnetite-enriched fraction, rather than the magnetite-depleted fraction, include a Sulfuricella and a novel member of the Betaproteobacteria. The existence of distinct bacterial communities associated with particular mineral grain types may also be an example of niche separation and coexistence in sediments and soils, which cannot usually be detected due to difficulties in separating and concentrating minerals.

This study compared the molecular characteristics of vancomycin-resistant Enterococcus faecium (VREF) isolates recovered from 20 non-tertiary-care hospitals (36 isolates) and three tertiary-care hospitals (26 isolates) in diverse geographical areas of Korea from October 2010 to April 2011. All isolates carried the vanA gene only, but 42% and 73% of non-tertiary and tertiary-care isolates expressed the VanB phenotype (teicoplanin minimum inhibitory concentration ⩽16 μg/ml). All isolates harboured insertion sequences, IS1542 and IS1216V, within Tn1546. The isolates from tertiary-care hospitals tended to have reduced Tn1546 lengths by deletion of sequences adjacent to IS elements. Multilocus sequence typing revealed eight sequence types within clonal complex 17 (CC17), but DNA fingerprinting by rep-PCR did not show clonal relatedness between the intra- and inter-hospital isolates. These results suggest that vanA, which has prevailed in tertiary-care hospitals of Korea since the 1990s, had been transferred horizontally to non-tertiary-care hospitals while the genetic rearrangement driven by evolutionary adaptation to adverse environments may have occurred in tertiary-care hospitals.

Unlabelled: In this large longitudinal study of 16,078 Korean men aged 50 years or older, we observed that baseline elevation of serum uric acid level significantly associated with a lower risk of incident fractures at osteoporosis-related sites during an average follow-up period of 3 years., Introduction: Male osteoporosis and related fractures are becoming recognized as important public health concerns. Oxidative stress has detrimental effects on bone metabolism, and serum uric acid (UA) is known to be a strong endogenous antioxidant. In the present study, we performed a large longitudinal study with an average follow-up period of 3 years to clarify the role of UA on the risk of incident osteoporotic fractures (OFs)., Methods: A total of 16,078 Korean men aged 50 years or older who had undergone comprehensive routine health examinations were enrolled. Incident fractures at osteoporosis-related sites (e.g., hip, spine, distal radius, and proximal humerus) that occurred after the baseline examinations were identified from the nationwide claims database of the Health Insurance Review and Assessment Service of Korea by using selected International Classification of Diseases, 10th revision codes., Results: In total, 158 (1.0 %) men developed incident OFs. The event rate was 33.1 per 10,000 person-years. Subjects without incident OFs had 6.0 % higher serum UA levels than subjects with OFs (P = 0.001). Multivariable-adjusted Cox proportional hazard analyses adjusted for age, body mass index, glomerular filtration rate, lifestyle factors, medical and drug histories, and the presence of baseline radiological vertebral fractures revealed that the hazard ratio per standard deviation increase of baseline UA levels for the development of incident OFs was 0.829 (95 % CI = 0.695-0.989, P = 0.038)., Conclusions: These data provide the epidemiological evidence that serum UA may act as a protective factor against the development of incident OFs in Korean men.

Unlabelled: Higher serum uric acid (UA) was associated with higher bone mass, lower bone turnover, and lower prevalence of vertebral fracture in postmenopausal women. Furthermore, UA suppressed osteoclastogenesis and decreased production of reactive oxygen species in osteoclast precursors, indicating UA may have beneficial effects on bone metabolism as an antioxidant., Introduction: UA is known to play a physiological role as an antioxidant, and oxidative stress has detrimental effects on bone metabolism. In the present study, we investigated the association of serum UA level with the osteoporosis-related phenotypes and its direct effect on bone-resorbing osteoclasts using in vitro systems., Methods: This is a large cross-sectional study, including 7,502 healthy postmenopausal women. Bone mineral density (BMD) and serum UA concentrations were obtained from all subjects. Data on bone turnover markers and lateral thoracolumbar radiographs were available for 1,023 and 6,918 subjects, respectively. An in vitro study investigated osteoclastogenesis and reactive oxygen species (ROS) levels according to UA treatment., Results: After adjusting for multiple confounders, serum UA levels were positively associated with BMD at all sites (all p < 0.001). Compared with the participants in the highest UA quartile, the odds for osteoporosis were 40 % higher in those in the lowest quartile. The serum UA levels were inversely related to both serum C-terminal telopeptide of type I collagen and osteocalcin levels (p < 0.001 and p = 0.004, respectively). Consistently, subjects with vertebral fracture had lower serum UA levels, compared with those without it (p = 0.009). An in vitro study showed that UA decreased osteoclastogenesis in a dose-dependent manner and reduced the production of ROS in osteoclast precursors., Conclusion: These results provide epidemiological and experimental evidence that serum UA may have a beneficial effect on bone metabolism as an antioxidant in postmenopausal women.