Nam-Kyong Choi

Proton pump inhibitors and risk of Clostridium difficile infection: a multi-country study using sequence symmetry analysis

ABSTRACT Objective: To determine the association between incident proton pump inhibitor (PPI) use and Clostridium difficile infections across multiple countries Method: National data covering the total population in Australia and Korea, the Canadian population over 65 years and a 3 million person random sample data set from Taiwan were assessed, as were data from a worker insurance population and a hospital inpatient/outpatient population in Japan. Sequence symmetry analysis was used to assess the association with oral vancomycin dispensing as the outcome of interest. Results: 54,957 patients were included. Positive associations were observed in Australia; adjusted sequence ratio (ASR) 2.48 (95% CI 1.90, 3.12), Korea ASR 2.15 (95%CI 2.11, 2.19), Canada ASR 1.45 (95% CI 1.16, 1.79), Japan hospital dataset ASR 3.21 (95%CI 2.12, 4.55) and Japan worker insurance dataset ASR 5.40 (95% CI 2.73, 8.75). The pooled result was ASR 2.40 (95%CI 1.88, 3.05) and 3.16 (95%CI 1.95, 5.10) when limited to Japan, Korean and Taiwan. Results did not vary by individual PPI. The temporal analysis showed effects within the first two weeks of PPI initiation. Conclusion: Our study confirms the association between PPI initiation and C. difficile infections across countries in the Asia-Pacific region.

Comparative Safety and Effectiveness of Denosumab Versus Zoledronic Acid in Patients With Osteoporosis: A Cohort Study

Limited head‐to‐head comparative safety and effectiveness data exist between denosumab and zoledronic acid in real‐world healthcare. We aimed to examine the safety and effectiveness of denosumab compared to zoledronic acid with regard to risk of serious infection and cardiovascular disease (CVD) and osteoporotic fracture. We conducted a cohort study using claims data (2009–2013) from a US commercial insurance plan database. We included patients aged ≥50 years who were newly initiated on denosumab or zoledronic acid. The primary outcomes were (1) hospitalization for serious infection; (2) composite CVD endpoint including myocardial infarction, stroke, coronary revascularization, and heart failure; and (3) nonvertebral osteoporotic fracture including hip, wrist, forearm, and pelvic fracture. To control for potential confounders, we used 1:1 propensity score (PS) matching. Cox proportional hazards models compared the risk of serious infection, CVD, and osteoporotic fracture within 365 days after initiation of denosumab versus zoledronic acid. After PS matching, a total of 2467 pairs of denosumab and zoledronic acid initiators were selected with a mean age of 63 years and 96% were female. When compared with zoledronic acid, denosumab was not associated with an increased risk of serious infection (HR 0.81; 95% confidence interval [CI], 0.55 to 1.21) or CVD (HR 1.11; 95% CI, 0.60 to 2.03). Similar results were obtained for each component of CVD. The risk of osteoporotic fracture was also similar between groups (HR 1.21; 95% CI, 0.84 to 1.73). This large population‐based cohort study shows that denosumab and zoledronic acid have comparable clinical safety and effectiveness with regard to the risk of serious infection, CVD, and osteoporosis fracture within 365 days after initiation of medications.

Breastfeeding and Maternal Hypertension

BACKGROUNDnLittle is known about the relationship between breastfeeding and hypertension. We performed this study to identify whether breastfeeding itself influenced maternal hypertension and whether degree of obesity or insulin sensitivity would contribute to the relationship between breastfeeding and hypertension in postmenopausal women.nnnMETHODSnOur study population comprised 3,119 nonsmoking postmenopausal women aged 50 years or above in the 2010-2011 Korea National Health and Nutrition Examination Survey. We performed logistic regression analyses to examine the relationship between breastfeeding and hypertension and mediation analyses to examine the contributions of obesity and insulin sensitivity to the breastfeeding-hypertension relationship.nnnRESULTSnThe odds ratios, with 95% confidence intervals, for hypertension among the highest quintile of number of breastfed children (5-11) and the highest quintile of duration of breastfeeding (96-324 months) were 0.49 (0.31-0.75) and 0.55 (0.37-0.82), respectively, compared to each of lowest quintile groups. The population attributable fractions of hypertension caused by breastfeeding 3 or fewer children and breastfeeding for 56 months or less were 10.2% (P < 0.001) and 6.5% (P = 0.017), respectively. In the mediation analysis, unexpectedly, increased insulin resistance significantly attenuated the protective effect on hypertension of having breastfed more children; additionally, greater obesity and insulin resistance significantly attenuated the protective effects on hypertension of having breastfed for longer.nnnCONCLUSIONSnMore children breastfed and longer duration of breastfeeding were associated with lower risk of hypertension in postmenopausal women, and degree of obesity and insulin resistance moderated the breastfeeding-hypertension association.

Regional differences in the incidence of tuberculosis among patients with newly diagnosed diabetes mellitus

There are regional differences in the burden of tuberculosis (TB). Although these differences might be explained by regional differences in the risk factors of TB, whether such risk factors are actually associated with the regional differences in the TB burden remains unclear. This study aimed to investigate the relationship between the risk factors of and regional differences in TB incidence.

Factors associated with initial or subsequent choice of biologic disease-modifying antirheumatic drugs for treatment of rheumatoid arthritis

BackgroundBiologic disease-modifying antirheumatic drugs (DMARDs) are increasingly used for rheumatoid arthritis (RA) treatment. However, little is known based on contemporary data about the factors associated with DMARDs and patterns of use of biologic DMARDs for initial and subsequent RA treatment.MethodsWe conducted an observational cohort study using claims data from a commercial health plan (2004–2013) and Medicaid (2000–2010) in three study groups: patients with early untreated RA who were naïve to any type of DMARD and patients with prevalent RA with or without prior exposure to one biologic DMARD. Multivariable logistic regression models were used to examine the effect of patient demographics, clinical characteristics and healthcare utilization factors on the initial and subsequent choice of biologic DMARDs for RA.ResultsWe identified a total of 195,433 RA patients including 78,667 (40%) with early untreated RA and 93,534 (48%) and 23,232 (12%) with prevalent RA, without or with prior biologic DMARD treatment, respectively. Patients in the commercial insurance were 87% more likely to initiate a biologic DMARD versus patients in Medicaid (ORu2009=u20091.87, 95% CIu2009=u20091.70–2.05). In Medicaid, African-Americans had lower odds of initiating (ORu2009=u20090.59, 95% CIu2009=u20090.51–0.68 in early untreated RA; ORu2009=u20090.71, 95% CIu2009=u20090.61–0.74 in prevalent RA) and switching (ORu2009=u20090.71, 95% CIu2009=u20090.55–0.90) biologic DMARDs than non-Hispanic whites. Prior use of steroid and non-biologic DMARDs predicted both biologic DMARD initiation and subsequent switching. Etanercept, adalimumab, and infliximab were the most commonly used first-line and second-line biologic DMARDS; patients on anakinra and golimumab were most likely to be switched to other biologic DMARDS.ConclusionsInsurance type, race, and previous use of steroids and non-biologic DMARDs were strongly associated with initial or subsequent treatment with biologic DMARDs.

Mechanistic Pathways From Early Gestation Through Infancy and Neurodevelopment

OBJECTIVE: To identify pathways through which pre- and postnatal factors directly or indirectly affect infant neurodevelopment at 12 months of age among Filipino infants. METHODS: The Bayley Scales of Infant Development, third edition was used to assess the development of 314 infants of mothers enrolled in a trial examining the safety and efficacy of praziquantel during pregnancy. Maternal covariates included socioeconomic status, iron and nutritional status, cognitive performance, and alcohol intake. Infant covariates included birth weight and feeding practices, longitudinal growth and nutritional status, hemoglobin and iron status captured at birth, and 6 and 12 months of age. Multivariable regression and structural equation modeling were used to identify significant factors associated with infant development. RESULTS: In regression models, maternal education, cognition, and iron status as well as infant weight-for-age z-score (WAZ), weight-for-length z-score, and WAZ gains were significantly associated with infant development at 12 months of age. Structural equation modeling demonstrated a direct effect of maternal cognition on most subscales of infant development and indirect effects on expressive language through effects on infant WAZ. Maternal iron status was a stronger predictor of infant cognition subscale scores than was infant iron status. Exclusive breastfeeding had a direct influence on expressive language rather than acting through improved infant iron or nutritional status. CONCLUSIONS: We identified key modifiable risk factors for impaired neurodevelopment, including prenatal risk factors such as maternal iron status. Integrated nutritional interventions that impact both maternal and infant nutritional status are likely to positively affect infant neurodevelopment through identified pathways.

The relationship between metabolic syndrome and asthma in the elderly

The burden of asthma in the elderly is increasing, but the etiology of asthma in the elderly is not clearly understood. Recent studies have reported the epidemiological link between metabolic syndrome (MS) and asthma, but it has rarely been studied in the elderly. This study investigated the association between MS and asthma and the contribution of insulin resistance (IR) and systemic inflammation to this MS-asthma association in the elderly. Our study analyzed 4,060 elderly participants (≥65 years old) from a cross-sectional survey, the Korean National Health and Nutritional Examination Survey 2007–2012. Mediation analyses were performed to examine whether IR and systemic inflammation mediates the MS-asthma association. Participants with MS had significantly higher prevalence of asthma (adjusted odds ratiou2009=u20091.34; 95% confidence intervalu2009=u20091.09–1.64), and those who had greater waist circumference and lower HDL-C were especially likely to have asthma. Participants with IR and systemic inflammation were associated with higher prevalence of asthma. Prevalence of IR and systemic inflammation were higher in participants with MS or with each MS component. The MS-asthma association was substantially mediated by IR and systemic inflammation. Our study showed a significant association between MS and asthma in the elderly. MS might affect asthma through both IR and systemic inflammation.

The relationships between timing of first childbirth, parity, and health-related quality of life

PurposeA few studies have investigated the relationship between age at first childbirth and health-related quality of life (HRQoL). This study examined the relationship between age at first childbirth and HRQoL and whether parity mediates this timing of the first childbirth–HRQoL relationship in women aged 50xa0years or above.MethodsThe study population included 5146 parous womenu2009≥u200950xa0years in the cross-sectional survey, thexa0Korea National Health and Nutrition Examination Survey 2010–2012. HRQoL was evaluated by the EuroQol five-dimensional descriptive system. Participants were grouped according to quartiles of age at first childbirth (ranges: 13–21, 22–23, 24–25, and 26–44xa0years). This study used linear regression analysis to examine the relationship between age at first childbirth and HRQoL and on each dimension. Mediation analysis was used to examine the contribution of age at first childbirth to HRQoL and to each dimension.ResultsThis study found the increasing pattern of HRQoL across quartiles of age at first childbirth (P for trendu2009=u20090.030). Odds of problems in self-care and anxiety/depression dimensions significantly increased across the quartiles. Women with later age at first childbirth tended to have better HRQoL (Bu2009=u20090.352, Pu2009=u20090.003); parity significantly contributed to this relationship. Decreasing parity accounted for 33.5% of the relationship between late first childbirth and increased HRQoL. Early age at first childbirth significantly increased odds of the mobility problem through increasing parity.ConclusionsWomen of an early age at first childbirth tended to have lower HRQoL through giving more deliveries. Our findings suggest that more attention needs to be given to women with early pregnancy and more delivery to prevent impaired HRQoL.

Prescription of Zolpidem and the Risk of Fatal Motor Vehicle Collisions: A Population-Based, Case-Crossover Study from South Korea

BackgroundZolpidem is one of the most frequently used hypnotics worldwide, but associations with serious adverse effects such as motor vehicle collisions have been reported.ObjectiveThe objective of this study was to evaluate the association of fatal motor vehicle collisions with a prescription for zolpidem, considering the context of the motor vehicle collisions.MethodsWe conducted a case-crossover study, where each case served as its own control, by linking data about fatal motor vehicle collisions from the Korean Road Traffic Authority between 2010 and 2014 with national health insurance data. The case period was defined as 1xa0day before the fatal motor vehicle collisions, and was matched to four control periods at 90-day intervals. Conditional logistic regression was performed to calculate the odds ratio for fatal motor vehicle collisions associated with zolpidem exposure, and odds ratios were adjusted for time-varying exposure to confounding medications. A stratified analysis was performed by age group (younger than 65xa0years or not), the Charlson Comorbidity Index, and whether patients were new zolpidem users.ResultsAmong the 714 subjects, the adjusted odds ratio for a fatal motor vehicle collision associated with a prescription for zolpidem the previous day was 1.48 (95% confidence interval 1.06–2.07). After stratification, a significantly increased risk was observed in subjects with a high Charlson Comorbidity Index (odds ratio 1.81; 95% confidence interval 1.16–2.84), the younger age group (odds ratio: 1.62; 95% confidence interval 1.03–2.56), and new zolpidem users (odds ratio 2.37; 95% confidence interval 1.40–4.00).ConclusionA prescription for zolpidem on the previous day was significantly related to an increased risk of fatal motor vehicle collisions in this population-based case-crossover study.

Breastfeeding and Maternal Age-related Cataract

PURPOSEnNo studies addressed the influence of breastfeeding on cataract formation. The objective of this study was to address the relationship between breastfeeding and maternal age-related cataract.nnnDESIGNnA nationwide cross-sectional study.nnnMETHODSnThis study analyzed data for 3821 parous women aged 50 years or above in the Korea National Health and Nutrition Examination Survey 2010-2012. Participants were aggregated into quartiles according to the number of breastfed children and duration of breastfeeding. Logistic regression analysis was used to examine the relationships between less or short duration of breastfeeding and increased risks of cataract.nnnRESULTSnA total of 2197 women (57.5%) were classified as having age-related cataract. Women who breastfed 4-12 children (odds ratio [OR]xa0= 0.56; 95% confidence interval [CI]xa0= 0.35-0.89) had significantly lower risks for cortical cataract, compared to those who breastfed no or 1 child (P for trend across quartilesxa0= .010). Women who breastfed for 36-60xa0months (ORxa0= 0.61, 95% CIxa0=xa00.42-0.90) or 61-324xa0months (ORxa0= 0.53, 95% CIxa0= 0.33-0.83) had lower risks for cortical cataract compared to those who breastfed 16xa0months or less (P for trend across tertilesxa0= .003). The population-attributable fractions of cortical cataract induced by number of children breastfed less than 3 and duration of breastfeeding less than 36xa0months were 9.4% (95% CIxa0= 1.3%-17.6%) and 10.7% (95% CIxa0= 3.0%-18.4%), respectively.nnnCONCLUSIONSnBreastfeeding more children and long-term breastfeeding were associated with lower risk of cortical cataract formation in parous women.