Jooyoung Chang

A Nationwide Population-Based Cohort Study of Dementia Risk Among Acid Suppressant Users

OBJECTIVEnData regarding the potential link between acid suppressant use and dementia are inconsistent. This study assessed the association between cumulative exposure to proton pump inhibitors (PPIs) and histamine-2 receptor antagonists (H2RAs) and dementia risk among Korean adults.nnnDESIGN AND METHODSnA population-based longitudinal study was conducted using the Korean National Health Insurance Corporation claims database merged with national health examination data for 2002-2013. The study cohort included 70,529 subjects who were dementia-free in 2007. Incident dementia was assessed throughout follow-up until 2013. Exposure to acid suppressants prior to 2007 was assessed using a standardized defined daily dose system. Potential associations between acid suppressant use and dementia risk were analyzed using time-dependent Cox regression estimated hazard ratios (HRs) and 95% confidence intervals (CIs).nnnRESULTSnThere were 1,297 cases of dementia during the study period. Multivariate analyses identified several factors associated with dementia risk: old age, female, current smoker, Type 2 diabetes, comorbidities, and use of nonaspirin nonsteroidal anti-inflammatory drugs. H2RA users had a significantly increased risk of dementia compared with non-H2RA users (HR 1.31, 95% CI 1.13-1.51), whereas PPI use was not associated with increased risk.nnnCONCLUSIONnOur results indicate that exposure to H2RAs (but not PPIs) is associated with increased dementia risk. Further randomized controlled trials and basic research examining the underlying mechanism are needed to confirm this association.

Effect of post-cessation hyperglycemia on cardiovascular disease and mortality among middle-aged men: an eight-year longitudinal study

Smoking cessation reduces the risk of cardiovascular disease (CVD), but also elevates fasting serum glucose (FSG) levels. The effect of post-cessation hyperglycemia on cardiovascular disease is unknown. The study population consisted of 127,066 men without type 2 diabetes from the Korean National Health Insurance System – Health Screening Cohort database. Change in smoking habits and FSG was determined by the difference in smoking status and FSG levels from the first (2002 and 2003) and second (2004 and 2005) health examinations. Continual smokers, quitters, ex-smokers, and never smokers were stratified according to FSG elevation. The study participants were followed-up for CVD and CVD-related death from 2006 to 2013. Compared to continual smokers, quitters had decreased risk of CVD among those without FSG elevation (hazard ratio, HR, 0.76, 95% confidence interval, CI, 0.66–0.86) and with FSG elevation (HR 0.83, 95% CI 0.72–0.96). Similarly, quitters had a tendency towards reduced risk of CVD-related death among those without FSG elevation (HR 0.74, 95% CI 0.51–1.09) and with FSG elevation (HR 0.68, 95% CI 0.46–1.03). Post-cessation hyperglycemia did not attenuate the beneficiary risk-reducing effects of quitting on CVD and CVD-related death.

Emerging hazard effects of proton pump inhibitor on the risk of colorectal cancer in low-risk populations: A Korean nationwide prospective cohort study

Purpose Despite plausible mechanisms, the clinical significance of long-term proton pump inhibitor (PPI) use to colorectal cancer (CRC) remains unknown. The purpose of this study was to investigate the association between PPI use and CRC development. Methods We conducted a population-based prospective cohort study using the Korean nationwide claims database merged with national health examination data. The study cohort included a total of 451,284 participants who were tracked to identify cases of CRC since 2007. We assessed and standardized PPI use before the index date using the Defined Daily Dose system. We calculated the hazard ratios and their 95% confidence intervals to assess the association between PPI use and CRC occurrence using Cox proportional hazard regression models with adjustment for potential confounders. We performed subgroup analyses of the effect of PPI exposure on CRC development stratified by the CRC risk. Results There were 5,304 cases of CRC during the study period of 2,908,152 person-years. PPI use was not associated with CRC risk overall. The incidence of CRC was higher among individuals who were elderly, male, more obese, and drank alcohol more frequently and among those who had more comorbidities. Further subgroup analyses revealed that the hazard effect of PPI use increased linearly in a dose-dependent manner with the number of CRC risk factors for which the risk level was considered low. Conclusion Within the low-risk population, PPI use was associated with an increased risk of CRC, although the association did not weigh the effects of conventional risk factors.

Cumulative Dose Threshold for the Chemopreventive Effect of Aspirin Against Gastric Cancer

Many studies have found evidence that aspirin has protective effects against certain cancers, but quantitative dose–response data have been available only on a limited basis. This study aimed to confirm the dose–response relationship of aspirin usage and gastric cancer and to estimate the cumulative dose threshold of aspirin to achieve protective effects against gastric cancer in the general population. A total of 461,489 individuals in a population-based longitudinal cohort provided by the National Health Insurance Services (NHIS) in the Republic of Korea were observed from 2007 to 2012 to identify gastric cancer incident cases. The pharmacy claims data of these individuals from 2002 to 2006 were reviewed to assess cumulative medication exposure using the defined daily dose (DDD) system. Hazard ratios (HRs) of aspirin use for gastric cancer were estimated using multivariate Cox Proportional Hazard regression. Sensitivity analyses, including propensity-score matching and a nested case–control design, were performed to evaluate the variability caused by study design. A total of 5674 incident gastric cancers were identified from 2,965,500 person-years of follow-up observation, giving an overall incidence rate of 191.00 gastric cancers per 100,000 person-years. Compared to non-users, those with aspirin use of ≥3 DDD-years showed a statistically significant protective effect of aspirin use against gastric cancer; the adjusted HR (95% confidence intervals) were 0.79 (0.63–0.98) and 0.63 (0.48–0.83) for those with aspirin use of 3–4 DDD-years and 4–5 DDD-years, respectively (P for trendu2009<u20090.001). Sensitivity analyses using propensity-score matching and a nested case–control design consistently showed a chemopreventive effect of aspirin. Long-term aspirin use was associated with reduced gastric cancer incidence in the general population of South Korea when the cumulative dose was >3 DDD-years.

Effects of smoking habit change on all-cause mortality and cardiovascular diseases among patients with newly diagnosed diabetes in Korea

This study aimed to investigate the effects of smoking habit change on the risks of all-cause mortality and cardiovascular diseases (CVDs) among patients with newly diagnosed diabetes using the Korean National Sample Cohort data. Survival regression analyses for the risks of all-cause mortality and CVDs were performed. Quitters without body mass index (BMI) change (adjusted hazard ratio [aHR], 0.68; 95% confidence interval [CI], 0.46–1.00) and quitters with BMI loss (aHR, 1.76; 95% CI, 1.13–2.73) showed significantly reduced and substantially the increased risk of all-cause mortality, respectively, compared with sustained smokers. Smoking reduction after diabetes diagnosis may have potential positive effects. However, definite benefits on the health outcomes were not identified in this study. Participants who started smoking after diabetes diagnosis had higher risks of all-cause mortality and CVDs than those who were never smokers or ex-smokers, although not statistically significant. In conclusion, smoking cessation after diabetes diagnosis could reduce the risks of all-cause mortality and cardiovascular events among patients with newly diagnosed diabetes when accompanied by proper weight management. Therefore, physicians should advice patients with newly diagnosed type 2 diabetes on the importance of smoking cessation in combination with long-term weight management to maximize the benefits of smoking cessation.

Association between proton pump inhibitor use and the risk of pancreatic cancer: A Korean nationwide cohort study

Purpose Proton pump inhibitor (PPI) therapy causes hypergastrinemia, which could promote the development and progression of pancreatic cancer. Accordingly, this study aimed to investigate the association between PPI exposure and the risk of pancreatic cancer. Methods We conducted a twelve-year longitudinal population-based study (2002–2013) using the Korean National Health Insurance Corporation claims database merged with national health examination data. The study cohort included 453,655 cancer-free individuals in January 2007 (index date). Incident pancreatic cancer was assessed throughout follow up until December 2013. The exposure to PPIs before the index date was assessed using a standardized Defined Daily Dose (DDD) system. We calculated the hazard ratios (HRs) and their 95% confidence intervals (CIs) for pancreatic cancer risk associated with cumulative PPI use using Cox proportional hazard regression models. Results There were 3,086 cases of pancreatic cancer during the period of 2,920,000 person-years. PPI users exceeding 60 DDDs were at a higher risk of pancreatic cancer compared with non-users (HR, 1.34; 95% CI, 1.04–1.72). Subgroup analyses revealed that a significant association existed between PPI use and pancreatic cancer in low risk groups including individuals who were female, engaged in healthy lifestyle habits, and had no history of diabetes or chronic pancreatitis. Conclusion Exposure to PPI appears to increase the risk of pancreatic cancer, independent of conventional risk factors.

Factors associated with continued smoking after the diagnosis of type 2 diabetes: a retrospective study in the Korean cohort

Objective To investigate the factors associated with continued smoking in patients newly diagnosed with type 2 diabetes. Design Retrospective study using the Korean National Health Insurance Service-National Health Screening Cohort (2002–2013) database. Participants Male patients newly diagnosed with type 2 diabetes between 1 January 2004 and 31 December 2011. Measurement Change in smoking behaviour after the diabetes diagnosis was assessed using a self-reported questionnaire, which was administered before and after the diagnosis. To identify the factors associated with continued smoking after diabetes diagnosis, a multivariate-adjusted logistic regression was conducted using only the variables with statistical significance from the univariate analyses. Results Younger age, lower economic status, heavier smoking habit, lower Charlson Comorbidity Index and comorbid hypertension were identified as factors associated with continued smoking after the diagnosis of type 2 diabetes. Older patients (adjusted OR (aOR) 0.71, 95%u2009CI 0.63 to 0.79) and patients with longer diabetic duration (1–2 years OR 0.88, 95%u2009CI 0.80 to 0.98, ≥3 years OR 0.63, 95%u2009CI 0.55 to 0.73) were more likely to quit smoking. Contrastingly, smokers in the lower economic status (aOR 1.29, 95%u2009CI 1.18 to 1.42) and heavier smoking habit (moderate: aOR 1.53, 95%u2009CI 1.35 to 1.72; heavy: aOR 1.90, 95%u2009CI 1.67 to 2.17) categories were more likely to continue smoking after the diagnosis. Conclusions It is important to identify the factors associated with smoking behaviour in patients with type 2 diabetes. Recognising the factors that contribute to the vulnerability of patients to continued smoking will be helpful in developing policies and intervention strategies in future. Vulnerable patients may require intensive education and encouragement to quit smoking. We recommend physicians to take a more proactive approach, such as encouraging frequent clinical sessions for behavioural counselling and even early pharmacological interventions, when they encounter patients with the factors outlined in this study.

Effect of Smoking Cessation and Reduction on the Risk of Cancer in Korean Men: A Population Based Study

Purpose The purpose of this study was to investigate the effect of smoking habit change on the risk of cancer. Materials and Methods From the Korean National Health Insurance Service database, we determined the change in smoking habit between the first (2002 and 2003) and second (2004 and 2005) health examination periods. A total of 143,071 men were categorized into baseline heavy (≥ 20 cigarettes per day), moderate (10-19 cigarettes per day), light (< 10 cigarettes per day) smokers, quitters, and never smokers, after which the change in smoking status was determined during the second health examination. The participants were then followed up from 2006 to 2013 for all cancer, smoking related cancer, and lung cancer. Results Compared to heavy continual smokers, heavy smokers who quit had reduced risk of smoking related cancer (hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.56 to 0.97) and tended to have reduced risk of all cancer (HR, 0.87; 95% CI, 0.75 to 1.00). Moderate smokers who reduced the amount of smoking to light levels had decreased risk of all cancer (HR, 0.82; 95% CI, 0.72 to 0.94), smoking related cancer (HR, 0.74; 95% CI, 0.59 to 0.93), and lung cancer (HR, 0.55; 95% CI, 0.38 to 0.79) compared to heavy continual smokers. Conclusion Smoking reduction decreases the risk of all cancer, smoking related cancer, and lung cancer. While smoking cessation should be the treatment of choice for smokers, smoking reduction may serve as an alternative strategy for those who cannot quit.