Association between statin treatment and new-onset diabetes mellitus: a population based case-control study.

BACKGROUND: Several studies suggest that statin may increase the risk of new-onset diabetes mellitus (NODM). This study aimed to evaluate the association between the duration and recent use of statin, and the risk of NODM, based on population-based data sets. METHODS: We used the South Korean National Health Insurance Service National Sample Cohort database for this nationwide case-control study. Of the 1 million participants, 6417 participants with NODM in 2012-2013 and 32,085 controls without diabetes (1:5 propensity score matched with age, sex, index year, and year of diabetes diagnosis) were included. In these patients, we examined the statin prescription record for 3 years preceding the outcome. We used conditional logistic regression to calculate the odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: After adjustment of covariates, there were no significant differences in the risk of NODM when analyzed according to cumulative use days. The risk of NODM was increased only in the short-term and recent user group (OR 1.48, 95% CI 1.21 to 1.82) whose cumulative prescription days are less than 6 months and whose last prescription is within 6 months of diagnosis. CONCLUSIONS: The risk of NODM was not associated with an increase in the cumulative duration of statin use or with non-recent use. Only recent short-term use of statin was associated with an increased risk of NODM. Diabetes screening are warranted during initial statin therapy.

Association between body mass index and mortality in the Korean elderly: A nationwide cohort study.

The objective of this study was to investigate the relationship between body mass index (BMI) and mortality in the elderly. This study was a nation-wide population-based retrospective cohort study of the National Health Insurance System-Senior Database (NHIS-SD). In this study, a total of 75,856 subjects were identified and selected from among 251,593 individuals aged ≥ 65 years who underwent health screening at least once between 2009 and 2012 and who had no history of diabetes, cardiovascular disease, stroke, cancer, or chronic obstructive pulmonary disease (COPD). The subjects of this study were followed-up until 2013 to identify the total mortality and the cause-specific mortality of 6 groups divided according to BMI. The hazard ratio (HR) by reference group (23 ≤ BMI < 25 kg/m2) of each group was calculated. A significant increase in the HR with a decreased BMI was observed in the group with a BMI < 23 kg/m2, whereas the HR in the group with a BMI ≥ 25 kg/m2 was not significantly different than that of the reference group (23 ≤ BMI < 25 kg/m2). This pattern was also seen in the subgroup analyses in relation to age, smoking history, alcohol use, exercise level, and socioeconomic status. In this study, we found that a low BMI was a risk factor for death in the elderly and that no significant difference in mortality was seen in the elderly with a BMI of 25 or over. In terms of an optimal BMI in the elderly, it is important to maintain an appropriately healthy range of BMI with the aim of preventing weight loss.

Association between serum ferritin and hemoglobin levels and bone health in Korean adolescents: A nationwide population-based study.

It is important to identify risk factors for low bone mass at a young age. An influence of iron store on bone health in the general population has been reported but has not been studied in adolescents. This study aimed to investigate the relationship between hemoglobin and serum ferritin levels and bone mineral content (BMC) in South Korean adolescents.This study was based on data collected during the 2009to 2010 Korea National Health and Nutrition Examination Survey. We included 1321 participants aged 10 to 18 years. BMC was measured at the femur and lumbar spine using dual-energy x-ray absorptiometry, and hemoglobin and serum ferritin levels were examined.In boys, hemoglobin and serum ferritin levels were positively associated with BMC of the total femur and lumbar spine after adjusting for confounders, and hemoglobin levels significantly increased as BMC increased at all sites (P for trend = .001 for total femur, .01 for femur neck, and <.001 for lumbar spine). Likewise, serum ferritin levels showed increasing trends according to increasing BMC of the total femur and lumbar spine in boys (P for trend = .04 for total femur; and <.001 for lumbar spine). However, these associations were not observed in girls.This study suggests a positive relationship between serum ferritin and hemoglobin levels and BMC in South Korean adolescent boys.

Arsenic removal from water using iron-impregnated granular activated carbon in the presence of bacteria.

This study investigated the adsorption of arsenite [As(III)] and arsenate [As(V)] to iron-impregnated granular activated carbon (Fe-GAC), focusing on the effects of bacteria on arsenic removal. Characteristics of Fe-GAC were analyzed using field emission scanning electron microscopy along with energy dispersive X-ray spectrometry. Batch experiments were performed under various experimental conditions to determine the adsorption of As(III) and As(V) to Fe-GAC in the absence and presence of bacteria (Enterococcus faecalis, Escherichia coli, or Bacillus subtilis). In addition, biosorption of As(III) and As(V) to bacteria was observed with batch experiments. Experimental results showed that Fe-GAC was characterized by mosaic-like deposition layers separated by interspacing on the surface. Iron impregnation increased the removal of As(III) and As(V) in GAC. Biosorption experiments indicated that a small amount of As(V) adsorbed to bacteria while no adsorption of As(III) was observed. This phenomenon can be attributed to interactions of anionic As(V) with positively-charged amine groups present on bacterial surfaces. Results also showed that the influence of bacteria on arsenic removal in Fe-GAC was not eminent in our experimental conditions even though bacteria could occupy surface adsorption sites on iron (hydr)oxides. This study demonstrated that hindrance effects of bacteria on arsenic adsorption to the surfaces of Fe-GAC were minimal.

Bacterial attachment to iron-impregnated granular activated carbon.

Bacterial attachment to iron-impregnated granular activated carbon (Fe-GAC) was investigated in this study using Enterococcus faecalis ATCC 10100 and charcoal-based GAC. Two sets of column experiments were performed under different ionic strengths and pH conditions. Breakthrough curves of bacteria were obtained by monitoring effluent. Mass recoveries and attachment rate coefficients were quantified from these curves. In addition, characteristics of Fe-GAC were analyzed using field emission scanning electron microscopy (FESEM) and X-ray spectrometry (EDS). Results show that Fe-GAC was characterized by mosaic-like deposition layers of iron oxides with about 2 microm in thickness. Color mapping with FESEM visualized the spatial distribution of carbon (yellow-green) and iron (red) on Fe-GAC. EDS indicates that iron was distinctly found from Fe-GAC at three peak positions. Results also reveal that bacterial attachment to Fe-GAC was affected by ionic strength and pH. Bacterial mass recoveries decreased from 62.9 to 41.7% with increasing ionic strength from 1 to 50 mM. This indicates that bacterial attachment to the surfaces of Fe-GAC was enhanced with increasing ionic strength. With increasing pH from 6.46 to 9.19, mass recoveries increased from 50.5 to 84.2%, indicating that bacterial attachment to Fe-GAC was reduced with increasing pH. This study demonstrates that iron oxides offer favorable attachment sites for bacteria on the surfaces of Fe-GAC and further improves the knowledge of bacterial removal in Fe-GAC.

Determination of bacterial mass recovery in iron-coated sand: influence of ionic strength.

Column experiments were performed in this study to investigate the influence of ionic strength on the mass recovery of Escherichia coli in iron-coated sand. The first set of the experiments was performed in the coated sand under various NaCl concentrations. The second experiments were carried out in the coated sand under various NaCl concentrations with a fixed phosphate concentration. Bacterial mass recoveries were quantified from breakthrough curves. The mass recoveries were compared with those obtained from the experiments in quartz sand under the same ionic strength/composition. Experimental results show that the mass recovery in quartz sand decreased from 76.7 to 9.2% with increasing effective ionic strength (I(e)) from 0 to 149.4 mM using NaCl. In the coated sand, however, the mass recovery remained constant in the range between 2.7 and 3.7% even though I(e) increased in the same range. This indicates that bacterial adhesion to the coated sand may not be affected by ionic strength in the presence of NaCl. Results also illustrate that the mass recovery in quartz sand decreased from 64.7 to 13.3% with increasing I(e) from 0.97 to 149.6 mM using NaCl under a fixed phosphate concentration (0.97 mM as I(e)). In the coated sand, the mass recovery increased sharply to 58.5% in 0.97 mM phosphate concentration compared to the case in deionized water (3.0%). This indicates that in the coated sand bacterial mass recovery can increase due to the presence of phosphate. In addition, the mass recovery in the coated sand decreased from 58.5 to 6.7% with increasing I(e) from 0.97 to 149.6 mM using NaCl under a fixed phosphate concentration (0.97 mM as I(e)). This demonstrates that bacterial adhesion to the coated sand may be influenced by ionic strength in the presence of phosphate.