Trends in underweight and severe underweight disparities in Korean adults and older adults: a nationwide, repeated cross-sectional study

OBJECTIVES

Little is known about the disparities in underweight prevalence among the general population in high-income countries. We investigated the trends in underweight prevalence and disparities across sociodemographic groups among Korean adults and older adults.

SETTING AND PARTICIPANTS

A series of cross-sectional data on Korean national health checkups for adults aged ≥20 years were analyzed from 2005 to 2016.

MEASUREMENTS

Based on body mass index (kg/m2), underweight was graded as mild (17.0-18.49), moderate (16.0-16.9), and severe (<16.0). Underweight prevalence was compared across sociodemographic subgroups in 2015-2016. Trends in underweight disparities were examined from 2005-2006 to 2015-2016. Multivariable-adjusted odds ratios (ORs; 95% confidence intervals, CIs) were calculated using logistic regression.

RESULTS

Approximately 11-22 million adults were included in each wave. In 2015-2016, the overall prevalence of underweight was 3.6% (men 2.0%, women 5.2%); severe underweight was 0.2% (men 0.1%, women 0.3%). The prevalence of underweight varied by sex and age groups. In men, those aged ≥80 years had the highest prevalence (overall 7.33%, severe underweight 0.84%). In women, those aged 20-29 years had the highest prevalence of overall underweight (14.57%), whereas those aged ≥80 years had the highest prevalence of severe underweight (1.38%). Compared with individuals in the lowest income quartile, men in the highest income had lower ORs of overall (0.59, 95% CI 0.59-0.60) and severe underweight (0.46, 95% CI 0.44-0.48); women in the highest income quartile had a higher OR of overall (1.12, 95% CI 1.12-1.13) but a lower OR of severe underweight (0.89, 95% CI 0.86-0.92). From 2005-2006 to 2015-2016, severe underweight consistently declined in older men but remained constant in women aged ≥80 years, widening sex disparities among older adults. Severe underweight decreased or leveled off in the highest income quartile but steadily increased in the lowest quartile, worsening income disparities.

CONCLUSION

In this nationwide study, underweight was more prevalent among women, older adults aged ≥80 years, and low-income individuals. Disparities in severe underweight widened across sociodemographic subgroups over time.

Association between Obstructive Sleep Apnea and Glaucoma

Background

Obstructive sleep apnea (OSA) and glaucoma are major global health challenges. However, the probable association between them is yet to be fully elucidated. This study aimed to investigate the association between OSA and glaucoma.

Methods

Data for this cross-sectional study were obtained from the eighth Korea National Health and Nutrition Examination Survey (2019-2021). From among 9,495 individuals who completed the STOP-Bang questionnaire on OSA (for those aged ≥40 years) and provided their glaucoma prevalence/intraocular pressure (IOP) data, 8,741 were selected for glaucoma prevalence analysis. A total of 754 individuals aged 80 years or older or those with missing confounding variable data were excluded. A separate subgroup of 8,627 individuals was selected for IOP analysis after excluding 114 individuals who use glaucoma eye drops. The study employed linear and logistic regression analyses with Stata/MP ver. 17.0 (Stata Corp., USA) to understand the relationship between the risk of OSA assessed using the STOP-Bang score and key glaucoma indicators, adjusted for confounders. Statistical significance was set at a P-value <0.05.

Results

The average±standard deviation [SD] age of the glaucoma prevalence study group was 56.59±10.48, and 42.98% were male. Notably, every unit increase in the STOP-Bang score was associated with a greater risk of glaucoma (odds ratio, 1.097; P=0.044). In the IOP subgroup, the average±SD age was 56.49±10.45 years, with 42.88% being males. The linear regression showed a statistically significant relationship between the STOP-Bang score and IOP after adjusting for confounding variables (β=0.171, P<0.001).

Conclusion

Our findings revealed a significant positive association between OSA risk, as measured using the STOP-Bang score, and both the likelihood of glaucoma and high IOP.

Higher Physical Activity is Associated with Reduced Lower Urinary Tract Symptoms in Korean Men

PURPOSE

Identifying and managing risk factors for lower urinary tract symptoms (LUTS) is crucial because it impacts the quality of life of elderly individuals. Lifestyle factors, including physical activity (PA), and their relationship with LUTS have not been well studied. This objective of this study was to investigate the association between PA and LUTS.

MATERIALS AND METHODS

A total of 7,296 men were included in this cross-sectional study. PA was quantified in metabolic equivalent (MET)-hours per week, and LUTS severity was assessed using the international prostate symptom score. Logistic regression was used to analyze the association between PA and LUTS, including voiding and storage symptoms.

RESULTS

The average age of the participants was 57.8 years, and the prevalence of LUTS was 41.3%. After adjusting for potential confounders, PA was inversely associated with the prevalence and severity of moderate-to-severe LUTS, showing a dose-response pattern (all p for trend <0.01). Compared to the minimal activity group, which engaged in <5 MET-hours per week of PA, the odds ratios for moderate to severe LUTS were 0.83 (95% confidence interval [CI]: 0.72-0.97) for men engaging in 15-30 MET-hours per week, 0.82 (95% CI: 0.71-0.95) for 30-60 MET-hours per week, and 0.72 (95% CI: 0.62-0.84) for ≥60 MET-hours per week. The possible protective effect of PA was still observed in the additional analysis for voiding and storage symptoms showing the same dose-response pattern (all p for trend <0.01).

CONCLUSIONS

A higher PA level was associated with a lower prevalence and severity of total, voiding, and storage LUTS in a dose-dependent manner in Korean men.

Association between Chronic Atrophic Gastritis and Bone Mineral Density among Women Older than 40 Years of Age in Korea

Background

Chronic atrophic gastritis causes hypochlorhydria, hypergastrinemia, and malabsorption of nutrients, leading to lower bone mineral density. The few studies that investigated the association between chronic atrophic gastritis and bone mineral density have reported inconsistent findings. As such, the present study assessed the association between chronic atrophic gastritis and bone mineral density among a large sample of women >40 years of age in Korea.

Methods

Data from 8,748 women >40 years of age who underwent esophagogastroduodenoscopy and bone densitometry were analyzed. Chronic atrophic gastritis was diagnosed using esophagogastroduodenoscopy. Bone mineral density of the lumbar vertebrae (L), femur neck, and femur total, measured using dual-energy X-ray absorptiometry, were the primary outcome variables. Low bone mineral density, which could be diagnosed as osteoporosis or osteopenia, was defined and analyzed as a secondary outcome. Linear regression was used to calculate adjusted mean values of bone mineral density. The association between low bone mineral density and chronic atrophic gastritis was analyzed using multiple logistic regression.

Results

The adjusted mean bone mineral density for L1-L4 was 1.063±0.003, femur neck (0.826±0.002), and femur total (0.890±0.002) were significantly lower in patients with chronic atrophic gastritis than others (1.073±0.002, 0.836±0.001, 0.898±0.002, respectively; all P<0.01). Women with chronic atrophic gastritis exhibited an increased likelihood for osteopenia or osteoporosis, even after adjusting for age and other confounding factors (odds ratio, 1.25; 95% confidence interval, 1.13-1.40; P<0.01). However, subgroup analysis revealed statistical significance only in postmenopausal women (odds ratio, 1.27; P<0.001).

Conclusion

Chronic atrophic gastritis was associated with lower bone mineral density and a higher risk for osteopenia or osteoporosis among postmenopausal women.

Effects of the abdominal fat distribution on the relationship between exposure to air pollutants and thyroid hormones among Korean adult males

BACKGROUND

Several significant associations between air pollution and thyroid function have been reported, but few studies have identified whether these associations differ by obesity, particularly its regional distribution. We assessed the relationship between ambient air pollution and thyroid hormone, and whether this relationship is modified by abdominal adiposity, as indicated by the waist circumference, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and visceral-to-subcutaneous fat ratio (VSR) in Korean men.

METHODS

We included 2440 male adults in the final analysis and used each person's annual average exposure to four air pollutants: particulate matter with an aerodynamic diameter ≤ 10 μm (PM10), nitrogen dioxide, sulfur dioxide (SO2), and carbon monoxide (CO). Abdominal fat deposition was quantified by computed tomography. Serum thyrotropin (TSH) and free thyroxine (FT4) concentrations were measured for thyroid hormone. To evaluate the relationship between air pollution and thyroid hormone according to adiposity, we performed multiple linear regression analysis on the two subgroups stratified by abdominal fat level.

RESULTS

Abdominal adiposity was significantly related to FT4 concentration. The exposures to air pollutants were associated with increased TSH and decreased FT4 concentrations. In stratified analysis using abdominal fat traits, ambient air pollution except for SO2 was significantly related to increased TSH and decreased FT4 concentrations in the high adiposity group (all p < 0.05), but not in the normal adiposity group. Among the air pollutants, PM10 showed an association with an increase of TSH concentration in all group with high adiposity, including high VAT, high SAT, and high VSR groups (all p < 0.05). In case of FT4, CO showed a similar pattern. Among the abdominal fat-related traits, the VSR in the high adiposity group had the largest effect on the relationship between exposure to air pollutants and thyroid hormone.

CONCLUSIONS

This study suggests the first clue that the relationship between air pollution exposure and thyroid hormone differs according to abdominal fat distribution among Korean adult males.

A genome-wide by PM10 exposure interaction study for blood pressure in Korean adults

Blood pressure (BP) is a typical complex trait, and the genetic susceptibility of individuals to changes in BP induced by air pollution exposure is different. Although interactions of exposure to air pollutants with several candidate genes have been identified, genome-wide interaction studies (GWISs) are needed to understand the association between them with BP. Therefore, we aimed to discover the unique genetic loci for BP that interact with exposure to air pollutants in Korean adults. We ultimately included 1868 participants in the discovery step and classified them into groups of those with low-to-moderate exposure and high exposure to average annual concentration of particulate matter with an aerodynamic diameter ≤ 10 μm (PM10). Because none of the single nucleotide polymorphisms (SNPs) achieved a genome-wide level of significance of pint < 5 × 10-8 for either systolic BP (SBP) or diastolic BP (DBP), we considered the top 10 ranking SNPs for each BP trait. To validate these suggestive SNPs, we finally selected six genetic variants for SBP and five variants for DBP, respectively. In a replication result for SBP, only one SNP (rs12914147) located in an intergenic region of the NR2F2 showed a significant interaction. We also identified several genetic susceptibility loci (e.g., CHST11, TEK, and ITGA1) implicated in candidate mechanisms such as inflammation and oxidative stress in the discovery step, although their interaction effects were not replicated. Our study reports the first GWIS finding to our knowledge, and the association between exposure to PM10 and BP levels may be determined in part by several newly discovered genetic suggestive loci, including NR2F2.

A whole-genome reference panel of 14,393 individuals for East Asian populations accelerates discovery of rare functional variants

Underrepresentation of non-European (EUR) populations hinders growth of global precision medicine. Resources such as imputation reference panels that match the study population are necessary to find low-frequency variants with substantial effects. We created a reference panel consisting of 14,393 whole-genome sequences including more than 11,000 Asian individuals. Genome-wide association studies were conducted using the reference panel and a population-specific genotype array of 72,298 subjects for eight phenotypes. This panel yields improved imputation accuracy of rare and low-frequency variants within East Asian populations compared with the largest reference panel. Thirty-nine previously unidentified associations were found, and more than half of the variants were East Asian specific. We discovered genes with rare protein-altering variants, including LTBP1 for height and GPR75 for body mass index, as well as putative regulatory mechanisms for rare noncoding variants with cell type-specific effects. We suggest that this dataset will add to the potential value of Asian precision medicine.

Allergic Diseases and Risk of Incident Dementia and Alzheimer's Disease

OBJECTIVE

To examine the associations between the allergic triad (asthma, allergic rhinitis, atopic dermatitis) and risk of dementia.

METHODS

Participants comprised 6,785,948 adults aged ≥40 years who participated in a national health examination in 2009 without any history of dementia before baseline. From 2009 to 2017, we prospectively investigated the associations between physician-diagnosed allergic diseases and risk of incident dementia (all-cause, Alzheimer's disease [AD], vascular dementia [VaD]) ascertained using national health insurance claims data.

RESULTS

During 8.1 years of follow-up, 260,705 dementia cases (195,739 AD, 32,789 VaD) were identified. Allergic diseases were positively associated with dementia risk. Compared with individuals without allergic diseases, multivariable hazard ratios (HRs) of all-cause dementia were 1.20 (95% confidence interval [CI] 1.19-1.22) in those with asthma, 1.10 (95% CI 1.09-1.12) with allergic rhinitis, 1.16 (95% CI 1.11-1.21) with atopic dermatitis, and 1.13 (95% CI 1.12-1.14) with any of these allergies. Similarly, individuals with any of the allergic triad had a higher risk of AD (HR 1.16, 95% CI 1.14-1.17) and VaD (HR 1.04; 95% CI 1.01-1.06) than those without any allergic disease. As the number of comorbid allergic diseases increased, the risk of dementia increased linearly (P_trend  ≤ 0.002). Compared with individuals without allergies, those with all three allergic diseases had substantially increased risk of all-cause dementia (HR 1.54, 95% CI 1.35-1.75), AD (HR 1.46; 95% CI 1.25-1.70), and VaD (HR 1.99, 95% CI 1.44-2.75).

INTERPRETATION

Asthma, allergic rhinitis, and atopic dermatitis were significantly associated with increased risk of all-cause dementia and subtypes, with dose-effect relationships with the severity of allergic diseases. ANN NEUROL 2023;93:384-397.

Association between long-term air pollution exposure and insulin resistance independent of abdominal adiposity in Korean adults

Significant associations between air pollution (AP) and insulin resistance (IR) have been reported in limited populations or certain patient groups, but few studies have addressed this association in the general population, especially in Asians. Although abdominal fat is a major contributor to IR, previous studies have not fully controlled for its effect in the association between AP and IR. We investigated the association between exposure to AP and IR in Korean adults in the general population and whether this association is maintained even after controlling for the effects of abdominal fat, particularly visceral fat. This was a cross-sectional study. Data were obtained for Korean adults who participated in screening health checkups at Seoul National University Health Examination Center from 2006 to 2014. A total of 4251 men and women aged 22-84 years were included. IR was represented by the homeostasis model assessment of insulin resistance (HOMA-IR). Adiposity traits such as visceral adipose tissue (VAT) and subcutaneous adipose tissue areas were measured by computed tomography. We assessed the annual mean concentrations of air pollutants, including particulate matter with an aerodynamic diameter of 10 µm or less (PM₁₀), nitrogen dioxide, sulfur dioxide, and carbon monoxide. HOMA-IR was significantly associated with increased annual mean exposure to PM₁₀ in both men (β = 0.15; 95% CI 0.09, 0.22) and women (β = 0.16; 95% CI 0.09, 0.23), and these associations were maintained even after controlling for VAT area (both p < 0.05). The adjusted mean HOMA-IR increased gradually with the level of long-term PM₁₀ exposure (low, intermediate, and high exposure) (all p for trend < 0.001) in the subgroup analysis. After adjusting for possible confounding factors, including VAT area, the annual mean exposure to PM₁₀ was significantly associated with the presence of IR in both men (OR 1.18; 95% CI 1.03, 1.35) and women (OR 1.44; 95% CI 1.18, 1.76). Other air pollutants, such as NO₂, SO₂ and CO, did not show any significant associations with HOMA-IR or the presence of IR. Persistent exposure to PM₁₀ is the main independent risk factor for IR and exhibits a dose-dependent association regardless of visceral fatness in both men and women.

Comparing Non-Communicable Disease Risk Factors in Asian Migrants and Native Koreans among the Asian Population

Assessing the health of international migrants is crucial in the Republic of Korea, Asia, and even worldwide. We compared the risk factors for non-communicable diseases among Asian migrants in Korea and the Korean population. This cross-sectional (2015) and longitudinal (2009-2015) observational study comprised a population-wide analysis spanning 2009 to 2015. Asian migrants (n=987,214) in Korea and Korean nationals (n=1,693,281) aged ≥20 were included. The Asian migrants were classified as Chinese, Japanese, Filipino, Vietnamese, and other. The prevalence of risk factors for non-communicable diseases (current smoking, obesity, diabetes mellitus, and hypertension) were analyzed. Regarding the age-adjusted prevalence, direct age standardization was conducted separately by sex using 10-year age bands; the World Standard Population was used as the standard population. Among the participants aged ≥20, the age-adjusted prevalence of current smoking was higher among Chinese and other Asian migrant men than among Korean men and women (p<0.001 and p<0.001, respectively). The age-adjusted prevalence of obesity was higher among Chinese, Filipino, and other Asian migrant women than in Korean women (p<0.001, p=0.002, and p<0.001, respectively). Among the participants aged 20-49, the age-adjusted prevalence of diabetes mellitus and hypertension was higher in Filipino migrant women than in Korean women (p=0.009 and p<0.001, respectively). Current rates of smoking and obesity were worse among Asian migrants of specific nationalities than among native Koreans. The health inequalities among Filipino migrant women in Korea, especially those aged 20-49, should be addressed.

Association between timed up and go test and future incidence of disability: A nationwide representative longitudinal study in Korea

Although previous studies examined the association between mobility and disability, they have used either subjective measure disability such as activity of daily living or instrumental activity of daily living or indirect measure such as long-term care service use with small size of participants. This study aimed to examine the association between timed up and go (TUG) test and disability incidence with national disability registration data in Korea longitudinally, by using a national representative sample. We used the National Health Insurance Service–National Health Screening Cohort (NHIS–HEALS) database of National Health Information Database. The NHIS–HEALS dataset includes disability information of National Screening Programme participants, including registration date and type of disability, which is merged from Korean National Disability Registry (KNDR). We used Cox proportional hazard models to evaluate the association between TUG and disability incidence. We constructed three models with different levels of adjustment; Model 3 was a fully adjusted model. We conducted subgroup analysis according to the risk factors for disability. The study population comprised 81,473 participants; 86 of them were newly registered to KNDR, which were observed during a mean follow-up of 4.1 ± 2.6 (maximum, 8.9) years. For 334,200.9 person-year (PY) follow-up, the disability incidence rate was 0.208 per 1,000 PY. Disability incidence was significantly higher in participants with abnormal TUG results than in those with normal TUG results. (adjusted hazard ratio [aHR] 1.600, 95% confidence interval [CI] 1.036–2.472). In subgroup analysis, the disability incidence increased in participants of normal cognition, without obesity or without cardiovascular (CV) disease. Increased incidence in disability was noted in participants with abnormal TUG results. The increase was more evident for participants with normal cognition, without obesity or CV disease.

Analysis of Continuity of Care and Its Related Factors in Diabetic Patients: A Cross-Sectional Study

BACKGROUND

Continuity of care in primary care settings is crucial for managing diabetes. We aimed to statistically define and analyze continuity factors associated with demographics, clinical workforce, and geographical relationships.

METHODS

We used 2014-2015 National Health Insurance Service claims data from the Korean registry, with 39,096 eligible outpatient attendance. We applied multivariable logistic regression to analyze factors that may affect the continuity of care indices for each patient: the most frequent provider continuity index (MFPCI), modified-modified continuity index (MMCI), and continuity of care index (COCI).

RESULTS

The mean continuity of care indices were 0.90, 0.96, and 0.85 for MFPCI, MMCI and COCI, respectively. Among patient factors, old age >80 years (MFPCI: odds ratio [OR], 0.81; 95% confidence interval [CI], 0.74-0.89; MMCI: OR, 0.84; 95% CI, 0.76-0.92; and COCI: OR, 0.81; 95% CI, 0.74-0.89) and mild disability were strongly associated with lower continuity of care. Another significant factor was the residential area: the farther the patients lived from their primary care clinic, the lower the continuity of diabetes care (MFPCI: OR, 0.74; 95% CI, 0.70-0.78; MMCI: OR, 0.70; 95% CI, 0.66-0.73; and COCI: OR, 0.74; 95% CI, 0.70-0.78).

CONCLUSION

The geographical proximity of patients' residential areas and clinic locations showed the strongest correlation as a continuity factor. Further efforts are needed to improve continuity of care to address the geographical imbalance in diabetic care.

Comparison of Two Strategies to Increase Serum Vitamin D Levels in a Real-World Setting: Sunlight Exposure and Oral Supplementation

Sunlight exposure and oral supplementation are the key strategies to increase serum 25-hydroxyvitamin D [25(OH)D] concentration. We aimed to determine elevation in serum 25(OH)D levels by comparing sunlight exposure and oral vitamin D supplementation in vitamin D-deficient participants who chose the treatment strategy by shared decision-making. We enrolled 197 participants aged ≥19 y who had vitamin D deficiency (serum 25(OH)D<20 ng/mL). Participants selected their treatment method through shared decision-making by preference: sunlight exposure or 1,000 IU oral vitamin D3 supplementation daily. Changes in serum 25(OH)D concentration and duration of sunlight exposure were evaluated after 3 mo. Among 197 participants, 26 (13%) selected sunlight exposure and 171 (87%) selected oral vitamin D supplementation. Seasonal distribution of participants and follow-up rate after 3 mo were not significantly different. There was no significant increase in mean serum 25(OH)D levels in the sunlight exposure group. Conversely, the mean serum 25(OH)D level increased by 11 ng/mL after 3 mo in the oral vitamin D supplementation group. The duration of mean sunlight exposure per day during the study period was not significantly different between the groups. Oral supplementation with 1,000 IU vitamin D3 daily significantly increased serum 25(OH)D levels in vitamin D-deficient participants after 3 mo, while sunlight exposure did not. This study suggests that oral supplementation is more effective than sun exposure in increasing vitamin D levels in the Korean population. Therefore, new recommendations on maintaining adequate vitamin D levels are needed in the Korean population.

A Genome-Wide Association Study on Abdominal Adiposity-Related Traits in Adult Korean Men

INTRODUCTION

Although previous genome-wide association studies (GWASs) have identified genetic susceptibility loci for abdominal adiposity, GWASs on Asian samples remain scarce. Therefore, we performed a GWAS for abdominal adipose tissue depots in a Korean population.

METHODS

A total of 1,937 Korean men were included in the study. Areas of abdominal fat were quantified by computed tomography. We performed a GWAS analysis under an additive model, and a replication study was conducted on 480 additional Korean adult men.

RESULTS

In the discovery step, we identified a total of 10 single-nucleotide polymorphisms (SNPs) associated with adiposity indicators (p < 1 × 10-5). The top SNP, rs1028014, for visceral adipose tissue (VAT) was located in the ZMAT4 gene and remained significant after adjustment for body mass index (BMI). Three additional SNPs were also associated with VAT-adj-BMI and located within the SLC26A10, FAM155A, and COL4A1-COL4A2 genes, respectively. In addition, we identified a SNP (rs4668224) of the MYO3B gene for visceral-to-subcutaneous fat ratio. For subcutaneous adipose tissue and total adipose tissue, two (rs6585735 and rs363527) and three SNPs (rs1487892, rs9357565, and rs1985358) were found, respectively. Overall, eight SNPs were used in the replication study; however, none of the SNPs reached our level of significance for replication (p < 0.0063). Nevertheless, rs4773144 of COL4A1-COL4A2 for VAT-adj-BMI was the most interesting SNP identified in previous GWASs for coronary artery disease (based on the same risk allele "G"), along with functional effects.

CONCLUSION

This study suggests for the first time that an SNP (rs4773144) of COL4A1-COL4A2 may contribute to the increase in VAT level, especially in adult Korean men.

Coronavirus Disease 2019 Patients with Mild Symptoms or without Symptom Using Residential Treatment Center Model

Background

The rapid rise in coronavirus disease worldwide has drastically limited the availability of hospital facilities for patients. Residential treatment centers were opened in South Korea for the admission of asymptomatic or patients with mild symptoms. This study discusses the appropriateness of the admission criteria set by the centers in a pandemic situation, the prioritization of patients for admission, and ways to minimize the risk of self-isolation.

Methods

A total of 217 low-risk patients (n=217) were admitted to the Nowon Residential Treatment Center between August 22 and October 14, 2020. The following criteria were met at the time of admission: patients (1) were asymptomatic or had mild symptoms, (2) had either a controlled or no underlying chronic disease, and (3) did not need oxygen treatment. Among them, 202 patients who were eligible for inclusion in the study were retrospectively investigated through periodic interviews.

Results

Of the 202 patients, 153 satisfied the criteria for symptomatic isolation standards, and 25 for asymptomatic isolation standards. The clinical conditions of 24 patients were aggravated, and these patients were transferred to other hospitals, among which 12 had persistent fever and 13 were suffering dyspnea with oxygen saturation (SpO₂) <95%.

Conclusion

In the event of another large-scale epidemic, it would be appropriate to prioritize accommodating patients who are elderly or have underlying diseases and self-isolate young patients with no underlying diseases and provide them with SpO₂ meters and thermometers to self-measure SpO₂ and body temperature.

Efficacy and Tolerability of Cyproheptadine in Poor Appetite: A Multicenter, Randomized, Double-blind, Placebo-controlled Study

PURPOSE

Cyproheptadine, an antihistamine and antiserotonergic agent, is an appetite stimulant that is efficacious in promoting weight gain in children and adults with poor appetite. Despite numerous studies showing that cyproheptadine achieved positive outcomes, studies documenting its effectiveness on appetite are limited. This study evaluated the efficacy and tolerability of cyproheptadine in adults with poor appetite in South Korea.

METHODS

Patients aged 19 to 64 years with poor appetite were randomly assigned to receive either cyproheptadine or placebo for 8 weeks. The primary end point was the difference between the groups in change in appetite, as measured by the Korean version of the Edmonton Symptom Assessment System from the beginning to the end of the study period. The secondary end points included effects on weight, anthropometrics, body composition, Simplified Nutritional Appetite Questionnaire-measured appetite, and toxicities. A total of 375 patients were randomly assigned to the two groups (189 cyproheptadine, 186 placebo).

FINDINGS

The cyproheptadine group experienced a mean (SD) change in appetite score of -2.42 (0.12) compared with -2.03 (0.13) in the placebo arm, representing a statistically significant appetite gain in the cyproheptadine group (difference, +0.38 [0.18]; 95% CI, -0.73 to -0.04; P = 0.0307). Patients in the cyproheptadine group experienced significant increases in weight and body mass index. The most common adverse event was somnolence, as predicted. Cyproheptadine was well tolerated, with one serious adverse event (colitis) which was classified as a moderate adverse effect unlikely to be related to the study drug.

IMPLICATIONS

We present the largest randomized, double-blind, placebo-controlled clinical trial of cyproheptadine versus placebo in healthy adults with poor appetite using the lowest effective dosage of cyproheptadine. Cyproheptadine is a safe treatment option in patients with poor appetite. Our findings provide important information for the use of cyproheptadine to ameliorate poor appetite in adults. Further randomized studies focused on the effect of cyproheptadine in older populations are needed.

Behavioral therapy and pharmacotherapy for relapse prevention in abstinent smokers: a rapid review and meta-analysis for the Korea Preventive Service Task Force

Objectives

This study aimed to assess the effectiveness of relapse prevention interventions involving behavioral and pharmacological treatment among abstinent smokers.

Methods

This rapid review was conducted using MEDLINE, Cochrane CENTRAL, CINAHL, Embase, KMbase, and KoreaMed to identify studies published until June 20, 2020. The participants were abstinent smokers who quit smoking on their own, due to pregnancy, hospitalization, or by participating in a smoking cessation program. We found a systematic review that fit the objective of this study and included 81 randomized controlled trials (RCTs). Studies that did not present information on smoking cessation status, had no control group, or used reward-based interventions were excluded. Random effect and fixed effect meta-analyses were used to estimate the relative risk (RR) and 95% confidence interval (CI). In subgroup analyses, differences between subgroups were verified based on the participant setting, characteristics, intervention type, and intensity.

Results

Following screening, 44 RCTs were included in the meta-analysis. The review reported no differences in the success rate of relapse prevention between the behavioral interventions. Pharmacotherapy interventions showed higher success rates (RR, 1.15; 95% CI, 1.05−1.26; I²=40.71%), depending on prior abstinence duration and the drug type.

Conclusion

The results indicated that pharmacotherapy has a significant effect on preventing relapse among abstinent smokers.

Behavioral interventions for smoking cessation among adolescents: a rapid review and meta-analysis for the Korea Preventive Services Task Force

Objectives

The aim of this study was to evaluate the effectiveness of behavioral smoking cessation interventions among adolescents.

Methods

MEDLINE, CENTRAL, Embase, CINAHL, KoreaMed, and KMbase were searched from inception to June 2020. Systematic reviews (SRs) or meta-analyses of randomized controlled trials (RCTs) were initially searched to perform a rapid SR. After selecting the final SR, RCTs after the publication year of the selected SR were searched. The primary outcome was smoking status after at least 6 months of follow-up, and the secondary outcome was smoking status at 4 weeks. Two reviewers independently assessed the selected studies’ quality using the Cochrane risk of bias tool. The meta-analysis utilized a Mantel-Haenszel fixed-effect model reporting the relative risk (RR) and 95% confidence interval (CI). The subgroup analysis utilized Cochrane’s Q.

Results

Thirty-two RCTs (11,637 participants) from a single SR were meta-analyzed. After 6 months of follow-up, the intervention group had significantly higher abstinence rates (RR, 1.30; 95% CI, 1.20−1.41; I²=26.46%). At 4 weeks of follow-up, the intervention group also had significantly higher abstinence rates (RR, 1.92; 95% CI, 1.49–2.47; I²=0.00%). The subgroup analysis indicated a significant difference in the abstinence rate according to the study setting and the period between intervention completion and follow-up.

Conclusion

This review showed that adolescent behavioral smoking cessation intervention programs significantly increased abstinence rates compared to the usual care.

Incidence of cardiovascular disease and mortality in underweight individuals

BACKGROUND

Few studies have evaluated the association between being underweight and having cardiovascular disease in the general population. We investigated the incidence of stroke, myocardial infarction (MI), and all-cause mortality according to detailed underweight categories in a large population cohort.

METHODS

We included 4 164 364 individuals who underwent a health examination that was conducted as part of the Korean National Health Insurance Service between January 2009 and December 2012 and followed them up to determine the incidence of stroke, MI, and all-cause mortality until 31 December 2016. Based on the body mass index, the study population was categorized into normal (18.50-22.99), mild (17.00-18.49), moderate (16.00-16.99), and severe underweight (<16.00) groups. Cox proportional hazards analyses were performed to calculate the hazard ratio for stroke, MI, and mortality according to the severity of underweight in reference to the normal weight. We adjusted for age, sex, lifestyle, economic status, co-morbidity, blood pressure, glucose, lipid level, and waist circumference.

RESULTS

The mean age of the 4 164 364 eligible subjects in this study cohort was 44.4 ± 14.3 years, and 46.1% of the participants were male; 46 728 strokes, 30 074 MIs, and 121 080 deaths occurred during 27 449 902 person-years. The incidence of stroke, MI, and all-cause mortality increased proportionally with the severity of underweight in the multivariate model. This proportional association became more evident when the waist circumference was additionally adjusted. The respective hazard ratios (95% confidence intervals) for mild, moderate, and severe underweight were 1.10 (1.06-1.15), 1.11 (1.02-1.20), and 1.38 (1.24-1.53) for stroke; 1.19 (1.14-1.25), 1.40 (1.27-1.53), and 1.86 (1.64-2.11) for MI; and 1.63 (1.60-1.67), 2.10 (2.02-2.17), and 2.98 (2.85-3.11) for all-cause mortality. In stratified analyses based on waist circumference, the severity of underweight was consistently associated with a higher risk of stroke, MI, and death.

CONCLUSIONS

The severity of underweight was associated with a higher risk of stroke, MI, and all-cause mortality.

All-cause mortality, cardiovascular mortality, and incidence of cardiovascular disease according to a screening program of cardiovascular risk in South Korea among young adults: a nationwide cohort study

OBJECTIVES

We aimed to determine whether there are any differences in all-cause and cause-specific mortality with cardiovascular disease (CVD) risk between health screening attenders and non-attenders among young adults.

STUDY DESIGN

We performed a retrospective cohort study using claim data from the Korean National Health Insurance Service database.

METHODS

Individuals aged 20-39 years who had received health screening at least once between 2002 and 2005 were classified as attenders, and the others were classified as non-attenders. After propensity score matching according to attendance of health screening, 2,060,409 attenders and 2,060,409 non-attenders were included. We estimated adjusted hazard ratios (HRs) and 95% confidence interval (CI) for all-cause mortality, cause-specific mortality, and hospitalization of CVD from 2006 to 2015.

RESULTS

Survival from all-cause mortality was greater among attenders than among non-attenders (log rank P < 0.001). Similarly, death from CVD (log rank P = 0.007) and CVD events (log rank P < 0.001) were less likely among attenders. The risk for all-cause mortality in attenders was significantly lower than that in non-attenders (HR = 0.83, 95% CI = 0.81 to 0.84). The risk for CVD mortality (HR = 0.80, 95% CI = 0.73 to 0.87) and hospitalization of CVD (HR = 0.92, 95% CI = 0.91 to 0.94) were lower in attenders. In stratified analyses, the risk for all-cause and cause-specific mortalities was lower among attenders regardless of insurance type.

CONCLUSIONS

Among young adults, the risk for all-cause mortality, CVD mortality, and hospitalization of CVD were lower for those who underwent health screenings. Future studies that evaluate the cost-effectiveness of health screening with additional consideration of psychosocial aspects are needed.

Association of anemia with mobility capacity in older adults: a Korean nationwide population-based cross-sectional study

BACKGROUND

Over 10% of adults aged ≥65 years have anemia, as defined by the World Health Organization (WHO). As the timed up and go (TUG) test is one of the most widely used tests of mobility, this study investigated whether anemia was associated with mobility capacity assessed using the TUG test in older adults.

METHODS

Subjects belonging to the Korean National Health Insurance Service-National Health Screening Cohort of the National Health Information Database were reviewed. Subjects were included if they had completed the TUG test as part of the National Screening Program for Transitional Ages in Korea. An abnormal TUG test result was defined as a time of ≥10 s and anemia was defined according to the WHO criteria as a hemoglobin (Hb) concentration of < 13.0 g/dL in men and < 12.0 g/dL in women. The association between anemia and TUG test results was evaluated using four multiple logistic regression models with different levels of adjustment. Stratified analysis according to risk factors was performed.

RESULTS

The 81,473 subjects included 41,063 (50.4%) women and 40,410 (49.6%) men. Mean TUG time was 8.44 ± 3.08 s, and abnormal TUG test results were observed in 22,138 (27.2%) subjects. Mean Hb concentration was 13.72 ± 1.41 g/dL, and 10,237 (12.6%) subjects had anemia. U-shaped associations between Hb concentration and TUG test results were observed in both sexes. Subjects with anemia were 19% more likely to have abnormal TUG test results, according to the fully adjusted model (adjusted odds ratio: 1.192, 95% confidence interval: 1.137-1.247). Similar results were observed for both sexes. Stratified analysis showed that subjects with anemia were more likely to have abnormal TUG test results regardless of risk factors.

CONCLUSIONS

Individuals with anemia are more likely to have abnormal TUG test results, regardless of risk factors, than individuals without anemia. U-shaped relationships between Hb concentrations and TUG test results were observed in both sexes, although the optimal Hb concentration differed between men and women.

Association Between Exposure to Ambient Air Pollution and Thyroid Function in Korean Adults

CONTEXT

Although a significant relationship has been reported between air pollution and thyroid function in limited samples or regions, few studies have addressed this association in the general population.

OBJECTIVE

Using a nationwide sample of Korean adults, we investigated the association between exposure to air pollution and thyroid function, and whether this association differed between subgroups stratified according to age or body mass index (BMI).

METHODS

We included 4704 adults in the final analysis and used each person's annual average exposure to 4 air pollutants, namely, particulate matter with an aerodynamic diameter less than or equal to 10 μm (PM10), nitrogen dioxide (NO2), sulfur dioxide, and carbon monoxide (CO). We measured serum thyrotropin (TSH) and free thyroxine (FT4) concentrations as indicators of thyroid function according to age and BMI.

RESULTS

The annual average exposure to NO2 and CO was significantly associated with an elevated TSH and reduced FT4 concentration after adjusting for possible confounding factors (all P < .05). In men, in addition to these 2 pollutants, PM10 exposure was positively associated with TSH level (P = .03). Age-stratified analysis showed stronger effects of NO2 and CO exposure in older than in younger adults. Exposure to these air pollutants was related to serum TSH and FT4 concentrations in people with overweight or obesity but not in those of normal weight.

CONCLUSIONS

This study provides the first evidence that air pollution exposure is linked to thyroid function in the general population and that this association may be stronger in older or overweight or obese adults.

Explaining the Rationale of Deep Learning Glaucoma Decisions with Adversarial Examples

PURPOSE

To illustrate what is inside the so-called black box of deep learning models (DLMs) so that clinicians can have greater confidence in the conclusions of artificial intelligence by evaluating adversarial explanation on its ability to explain the rationale of DLM decisions for glaucoma and glaucoma-related findings. Adversarial explanation generates adversarial examples (AEs), or images that have been changed to gain or lose pathologic characteristic-specific traits, to explain the DLM's rationale.

DESIGN

Evaluation of explanation methods for DLMs.

PARTICIPANTS

Health screening participants (n = 1653) at the Seoul National University Hospital Health Promotion Center, Seoul, Republic of Korea.

METHODS

We trained DLMs for referable glaucoma (RG), increased cup-to-disc ratio (ICDR), disc rim narrowing (DRN), and retinal nerve fiber layer defect (RNFLD) using 6430 retinal fundus images. Surveys consisting of explanations using AE and gradient-weighted class activation mapping (GradCAM), a conventional heatmap-based explanation method, were generated for 400 pathologic and healthy patient eyes. For each method, board-trained glaucoma specialists rated location explainability, the ability to pinpoint decision-relevant areas in the image, and rationale explainability, the ability to inform the user on the model's reasoning for the decision based on pathologic features. Scores were compared by paired Wilcoxon signed-rank test.

MAIN OUTCOME MEASURES

Area under the receiver operating characteristic curve (AUC), sensitivities, and specificities of DLMs; visualization of clinical pathologic changes of AEs; and survey scores for locational and rationale explainability.

RESULTS

The AUCs were 0.90, 0.99, 0.95, and 0.79 and sensitivities were 0.79, 1.00, 0.82, and 0.55 at 0.90 specificity for RG, ICDR, DRN, and RNFLD DLMs, respectively. Generated AEs showed valid clinical feature changes, and survey results for location explainability were 3.94 ± 1.33 and 2.55 ± 1.24 using AEs and GradCAMs, respectively, of a possible maximum score of 5 points. The scores for rationale explainability were 3.97 ± 1.31 and 2.10 ± 1.25 for AEs and GradCAM, respectively. Adversarial example provided significantly better explainability than GradCAM.

CONCLUSIONS

Adversarial explanation increased the explainability over GradCAM, a conventional heatmap-based explanation method. Adversarial explanation may help medical professionals understand more clearly the rationale of DLMs when using them for clinical decisions.

Sex- and age-specific effects of energy intake and physical activity on sarcopenia

Sarcopenia is a common health issue that is not limited to only elderly patients. However, many studies have reported factors to prevent sarcopenia only in susceptible groups. This study evaluates the relationship of the total energy intake to basal metabolic rate ratio (EI/BMR) and physical activity (PA) with sarcopenia. A second aim was to analyze the interaction between EI/BMR and PA by sex and age. We analyzed 16,313 subjects aged ≥ 19 years who had dual‒energy X-ray absorptiometry data. Sarcopenia was defined as appendicular lean mass/weight (%) that was 1 standard deviation below the sex-specific mean value for a young reference group. Multivariate logistic regression analysis was used to examine the interaction between EI/BMR and PA. In this study, as EI/BMR increased, the risk of sarcopenia decreased, particularly in the older groups. Both high PA and high EI/BMR were independently related to the reduced risk of sarcopenia and showed additive effects on reducing the risk in young male and older groups. However, high PA was associated with an increased risk of sarcopenia in the young female group with low energy intake. Our findings suggest that an adequate balance between energy intake and PA is related to a low risk of sarcopenia, especially in young females.

Analysis of the Comprehensiveness of Primary Care Clinics in Korea

BACKGROUND

In the Republic of Korea, which medical specialties should take the responsibility for primary care and what the role of primary care should be are still unclear. In this study, we focused on the comprehensiveness of primary care to identify related factors.

METHODS

The National Health Insurance Service (NHIS)-National Sample Cohort is a population-based cohort, sampled in the 2002 NHIS database and followed up until 2015. We used data collected from January 2014 to December 2015, including 20,423,832 outpatient visits in 19,557 office-based clinics. The Korean government has designated 52 simple or minor disease groups (SMDGs) to enhance the experience of patients who attend primary care for managing those diseases. We assessed comprehensiveness for each clinic as the number of SMDGs treated in each clinic for 2 years. We also identified the factors related to higher comprehensiveness, using logistic regression for analysis.

RESULTS

The clinics included in the study had provided treatment for an average of 14 SMDGs during a 2-year period. Compared to general practitioners, internal medicine physicians presented higher comprehensiveness with an odds ratio (OR) of 2.29 (95% confidence interval [CI], 2.03-2.59), and family medicine physicians illustrated higher comprehensiveness (OR, 4.96; 95% CI, 3.59-6.83). Other specialties showed lower comprehensiveness than general practitioners. Clinics located in the capital city and metropolitan area tended to have lower comprehensiveness. Clinics hiring more doctors and having hospitalization facility showed higher comprehensiveness.

CONCLUSION

General physician, internal medicine, and family medicine are the fields providing comprehensive medical care in Korea. Clinics located in metropolitan area and capital city show lower comprehensiveness. The number of physicians is related to higher comprehensiveness of clinics.

A genome-wide by PM10 interaction study identifies novel loci for lung function near BICD1 and IL1RN-IL1F10 genes in Korean adults

Although several genome-wide interaction studies (GWIS) have been performed in specific European populations to understand the missing link between genetic and environmental factors for lung function, GWIS of Asian samples remain rare. Therefore, we performed a GWIS of exposure to air pollution to identify loci for lung function in Korean adult men. A total of 1826 adult men recruited from two health check-up centers were included in the analysis and the annual mean concentrations of ambient particulate matter with an aerodynamic diameter ≤10 μm (PM₁₀) were used. In case of forced vital capacity (FVC), one SNP (rs12312730) that passed our genome-wide threshold of pint < 1 × 10-5 was detected in the intronic region of the BICD1 gene on chromosome 12. In addition, we found two variants (rs6743376 and rs17042888) located near the IL1RN-IL1F10 gene that were involved in the inflammatory response and associated with decreased FVC via interaction with PM₁₀ exposure. A stratified association analysis according to these SNP genotypes showed that PM₁₀ concentrations in subjects with one or two of the risk alleles, compared with those with the non-risk allele, were significantly correlated with a reduction in FVC. This pattern was replicated in another 892 Korean adult samples. The current study reports the first GWIS discovery in an Asian population: the BICD1 and IL1RN-IL1F10 genes may contribute to the decrease in FVC levels by interacting with PM₁₀ exposure.

Association of timed up and go test outcomes with future incidence of cardiovascular disease and mortality in adults aged 66 years: Korean national representative longitudinal study over 5.7 years

Background

The timed up and go test (TUG) is one of the most widely used tests of mobility. We aimed to examine whether the TUG is associated with cardiovascular (CV) events, CV mortality, and all-cause mortality.

Methods

Subjects in the senior cohort database of the Korean National Health Insurance Service (2002–2013) who completed the TUG as part of the National Screening Program for Transitional Ages (NSPTA) during 2007–2008 were identified. An abnormal TUG result was defined as a time ≥ 10 s. Cox proportional hazard models were used to assess the associations between TUG results and CV events, CV mortality, and all-cause mortality.

Results

The mean follow-up period was 5.7 years. Incidence rates of CV events in the normal and abnormal TUG groups were 7.93 and 8.98 per 1000 person-years, while CV mortality rates were 0.96 and 1.51 per 1000 person-years, respectively. In a fully adjusted model, we found that abnormal TUG results were not associated with the incidences of CV events and CV mortality. However, abnormal TUG results (≥10 s) resulted in a 2.9-fold increase in CV mortality in women (adjusted hazard ratio 2.90, 95% confidence interval 1.15–7.30). Further, participants lacking certain CV risk factors, such as current cigarette smoking, obesity, or diabetes, had a higher CV mortality rate when TUG results were abnormal.

Conclusions

Abnormal TUG results in subjects aged 66 years were associated with future CV mortality in women and in subjects without obesity, diabetes, or cigarette smoking. In patient with mobility impairment, physicians should consider CV disease risk, especially in women.

Longitudinal Study of Diabetic Differences between International Migrants and Natives among the Asian Population

Migration presents a substantial social and public health issue. However, it is unclear whether diabetes is worse among Asian migrants than natives of South Korea over time. This longitudinal study investigated the nationwide population, including 2,680,495 adults aged 20 years and older (987,214 Asian migrants and 1,693,281 natives), who received health check-ups, using the Korean National Health Insurance Service data (2009-2015). Joinpoint regression was used to estimate the annual percentage change of diabetes, and multivariable logistic regression was used to examine differences in incident type 2 diabetes between Asian migrants and natives adjusting for age, sex, economic status, body mass index, smoking status, any alcohol use, and physical activity. The age-adjusted prevalence of diabetes increased among native men (from 8.8% in 2009 to 9.7% in 2015, APC=1.64, p<0.05) compared to Asian migrant men, and the age-adjusted prevalence of diabetes increased among native women (from 6.0% in 2009 to 6.7% in 2015, APC=1.88, p<0.05) compared to Asian migrant women. In the multivariate analyses, Asian migrants were less likely to get type 2 diabetes than natives (odds ratio, 0.82; 95% CI, 0.78 to 0.86) between the first and last health check-ups. However, the odds ratio for developing type 2 diabetes was 1.15 (95% CI, 1.10 to 1.20) among low-income levels compared to high-income levels, regardless of whether they were Asian migrants or natives. The results could help to establish a new strategy for prevention, treatment, and management of diabetes among the Asian population.

Long-term Mortality Risks Among Living Kidney Donors in Korea

RATIONALE & OBJECTIVE

Living kidney donors may have a higher risk for death and kidney failure. This study aimed to investigate the long-term mortality experience of living kidney donors compared with members of the general public in Korea who underwent voluntary health examinations.

STUDY DESIGN

Cohort study.

SETTING & PARTICIPANTS

We first calculated standardized mortality ratios for 1,292 Korean living kidney donors who underwent donor nephrectomy between 1982 and 2016 and 72,286 individuals who underwent voluntary health examinations between 1995 and 2016. Next we compared survival between the 1,292 living kidney donors and a subgroup of the health examination population (n=33,805) who had no evident contraindications to living kidney donation at the time of their examinations. Last, a matched comparator group was created from the health examination population without apparent contraindication to donation by matching 4,387 of them to donors (n=1,237) on age, sex, body mass index, estimated glomerular filtration rate, urine dipstick albumin excretion, previously diagnosed hypertension and diabetes, and era.

EXPOSURES

Donor nephrectomy.

OUTCOMES

All-cause mortality and other clinical outcomes after kidney donation.

ANALYTICAL APPROACH

First, standardized mortality ratios were calculated separately for living kidney donors and the health examination population standardized to the general population. Second, we used Cox regression analysis to compare mortality between living kidney donors versus the subgroup of the health examination population without evident donation contraindications. Third, we used Cox regression analysis to compare mortality between living kidney donors and matched comparators from the health examination population without apparent contraindication to donation.

RESULTS

The living kidney donors and health examination population had excellent survival rates compared with the general population. 52 (4.0%) of 1,292 kidney donors died during a mean follow-up of 12.3±8.1 years and 1,072 (3.2%) of 33,805 in the health examiner subgroup without donation contraindications died during a mean follow-up of 11.4±6.1 years. Donor nephrectomy did not elevate the hazard for mortality after multivariable adjustment in kidney donors and the 33,805 comparators (adjusted HR, 1.01; 95% CI, 0.71-1.44; P=0.9). Moreover, living donors showed a similar mortality rate compared with the group of matched healthy comparators.

LIMITATIONS

Donors from a single transplantation center. Residual confounding owing to the observational study design.

CONCLUSIONS

Kidney donors experienced long-term rates of death comparable to nondonor comparators with similar health status.

Interactions of CDH13 gene polymorphisms and ambient PM10 air pollution exposure with blood pressure and hypertension in Korean men

Associations between air pollution and blood pressure (BP) traits can be modified by several candidate genes, which might explain differences in individual genetic susceptibility. Based on recent evidence hypothesized to link air pollution and BP traits, we examined whether the polymorphisms of CDH13-a candidate gene-would modify the relationship between them in adult Korean men. A total of 1816 subjects were included. We divided them into two groups of high or low to moderate exposure using the annual average concentration of particulate matter with an aerodynamic diameter ≤10 μm (PM₁₀). We conducted an interaction analysis of PM₁₀ exposure using 200 single-nucleotide polymorphisms (SNPs), located within CDH13, in subjects with regard to BP traits and hypertension. The rs7500599 intronic SNP of CDH13 had the strongest signals for all BP traits including systolic blood pressure (SBP), diastolic blood pressure, and hypertension, by interacting with PM₁₀ exposure. An additional stratified analysis showed that the effects of PM₁₀ exposure on elevated BP and hypertension increased gradually in proportion to the number of minor alleles in this SNP. In addition, PM₁₀ exposure in the TT or GT genotype groups did not show significant associations with BP traits, whereas in a homozygous risk allele (GG) group, PM₁₀ exposure was significantly associated with BP traits and hypertension. For SBP, these patterns were reproducible at two independent sampling sites. This CDH13 polymorphism amplifies the negative associations of PM₁₀ exposure and elevated BP or hypertension in Korean men.

Increased cardiovascular risk in thyroid cancer patients taking levothyroxine: a nationwide cohort study in Korea

Objective Many thyroid cancer patients are exposed to long-term thyroid-stimulating hormone (TSH) suppression, often as lifetime treatment, and are consequently at risk for cardiovascular disease. We investigated the incidence of coronary heart disease (CHD) and ischemic stroke among thyroid cancer patients compared with matched control subjects. Design Retrospective cohort study. Methods A total of 182 419 subjects who received thyroidectomy for thyroid cancer during 2004-2012 were selected from the Korean National Health Insurance data, which cover approximately 97% of the entire Korean population. Propensity score matching was used to select non-cancer controls. Cox proportional hazards regression analysis was used to determine relative risk of coronary heart disease and ischemic stroke. Mean follow-up was 4.32 years. Results Thyroid cancer patients had elevated risk for CHD and ischemic stroke with hazard ratio (HR) of 1.15 (95% confidence interval (CI): 1.10-1.22) and 1.15 (1.09-1.22), respectively. This risk was increased in those who took a higher dosage of levothyroxine (HR: 1.47, 95% CI: 1.34-1.60 for CHD and HR: 1.56, 95% CI: 1.42-1.72 for ischemic stroke among those who took ≥170 μg/day levothyroxine). Although risk of atrial fibrillation was dose-dependently associated with levothyroxine dosage, it represents only a small proportion of ischemic stroke incidence (4.4%, 128/2914). Conclusions The risk for CHD and ischemic stroke was higher in thyroid cancer patients who received thyroidectomy, and the dosage of levothyroxine administered appears to play a major role. Greater caution is suggested for the screening and treatment of thyroid cancer and subsequent TSH suppression therapy, as well as proper management for cardiovascular disease prevention.

Association between cognitive impairment and poor antihypertensive medication adherence in elderly hypertensive patients without dementia

Adherence to antihypertensive medication is a critical factor to control blood pressure and prevent complications. However, cognitive impairment can negatively affect medication adherence. In this study, we investigated the association between cognitive function and antihypertensive medication adherence among elderly hypertensive patients using the Korean National Health Insurance Service National Sample Cohort Data of the Elderly Cohort. The study included 20,071 elderly hypertensive patients and the prevalence of poor medication adherence to antihypertensive medications was 16.4%. A multivariate logistic regression analysis showed that lower cognitive function was associated with poor medication adherence (adjusted odds ratio 0.980, 95% confidence interval 0.961–0.999). Additionally, high income levels, living in metropolitan areas, and comorbidities (such as stroke, coronary heart disease, diabetes, and dyslipidemia) were positively associated with medication adherence, while patients diagnosed with cancers showed poor medication adherence. Our study demonstrated that cognitive impairment is a possible risk factor for poor antihypertensive medication adherence, even in patients without dementia. Thus, clinicians involved with geriatric care should monitor patients’ cognitive function and medication adherence. And if a patient shows cognitive impairment, clinicians need to educate patients and caregivers about the importance of proper adherence, and consider proper interventions to optimize the cognitive function of elderly patients.

Risk of Coronary Heart Disease and Ischemic Stroke Incidence in Gastric Cancer Survivors: A Nationwide Study in Korea

BACKGROUND

Small studies suggest improvement of cardiovascular risk profiles and reduced cardiovascular mortality after gastrectomy for gastric cancer. In our study using national health insurance data, we investigated coronary heart disease (CHD) and ischemic stroke incidence among gastric cancer patients who received gastrectomy compared with general population controls.

METHODS

A total of 98,936 gastric cancer patients were included in the study and matched to non-cancer controls via 1:1 propensity score matching. Competing risk regression analysis was used to determine the relative risk of CHD and ischemic stroke, with cancer mortality as the competing risk. Changes in cardiovascular risk profile before and after gastrectomy were tested, and factors associated with CHD or ischemic stroke incidence among gastric cancer patients were analyzed.

RESULTS

Compared with the matched controls, gastric cancer patients who received gastrectomy were shown to have a decreased risk for both CHD (subdistribution hazard ratio [SHR] 0.60, 95% confidence interval [CI] 0.57-0.63) and ischemic stroke (SHR 0.72, 95% CI 0.69-0.75). Decreases in body mass index (BMI), blood pressure, blood sugar, and lipid and hemoglobin levels were marked after gastrectomy. Among gastric cancer patients, those who lost > 5% of their body weight were at lower risk of developing CHD (SHR 0.82, 95% CI 0.71-0.96) and ischemic stroke (SHR 0.85, 95% CI 0.75-0.98).

CONCLUSIONS

CHD and ischemic stroke risk decreased after gastrectomy. The amount of weight loss and accompanying metabolic changes seemed to mediate the reduction of such risk. Reassessment of cardiovascular risk factors after gastrectomy and consideration of cardiovascular risk in the selection of treatment modality are suggested.

CYP1A1 gene polymorphisms modify the association between PM10 exposure and lung function

Genetic epidemiological studies have provided evidence that several genes modify the link between air pollution and lung function. We assessed whether the adverse impacts of particulate matter with an aerodynamic diameter ≤10 μm (PM₁₀) on lung function are modified by CYP1A1 gene polymorphisms in Korean adults. We used health check-up data from 1817 men, and the annual mean concentrations of ambient PM₁₀ estimated from the ambient data. Three single nucleotide polymorphisms (SNPs) of CYP1A1 were selected for our study. We identified significant CYP1A1 SNPs-by-PM₁₀ interactions for forced expiratory volume 1 s (FEV₁) and forced vital capacity (FVC) (all p_int < 0.05). Minor allele carriers of the SNPs were more susceptible to PM₁₀-induced FEV₁ and FVC reduction. The subgroup analysis of SNP genotypes showed that no significant association between PM₁₀ and FEV₁ or FVC was observed in homozygous reference genotype groups of all SNPs (all p_assoc > 0.05), whereas in heterozygous or homozygous alternate genotype groups, PM₁₀ was significantly associated with decreased FEV₁ (all p_assoc for FEV₁ < 0.05). The association between persistent exposure to PM₁₀ and lung function decline in Korean men may be determined in part by several functional variants of the CYP1A1 gene.

J-Shaped Association Between Postoperative Levothyroxine Dosage and Fracture Risk in Thyroid Cancer Patients: A Retrospective Cohort Study

Long-term administration of supraphysiologic dosages of levothyroxine can have detrimental effect on the bone. We aimed to investigate fracture incidence among post-thyroidectomy thyroid cancer patients compared with a matched comparison group, and explore the association between levothyroxine dosage and fracture risk. From the Korean National Health Insurance database, virtually all thyroid cancer patients who received thyroidectomy in Korea from January 1, 2004 to December 31, 2012 were included. Matched subjects were selected by 1:1 propensity score matching. Cox proportional hazards regression analysis was used to determine relative risk of osteoporotic fracture. Of 185,956 thyroid cancer patients identified, fracture events were observed in 1096 subjects (0.56%) over a mean 4.35 years of follow-up. Compared to the matched comparison group, thyroid cancer patients had no elevated risk of osteoporotic fracture (hazard ratio [HR] 1.03; 95% confidence interval [CI], 0.94 to 1.12); however, the highest dosage group (≥170 μg/day) showed significantly higher risk (HR 1.25; 95% CI, 1.07 to 1.45), while the second quartile dosage group (115-144 μg/day) showed lower risk (HR 0.71; 95% CI, 0.59 to 0.84) compared to a matched comparison group. When the second quartile dosage group was considered as reference, increased fracture risk was observed in those who took either lower (first quartile: adjusted HR 1.31; 95% CI, 1.08 to 1.59) or higher dosage of levothyroxine (third quartile: adjusted HR 1.50; 95% CI, 1.26 to 1.79; fourth quartile: adjusted HR 1.79; 95% CI, 1.51 to 2.13). Thyroid cancer patients were more likely to be treated with osteoporosis medication (HR 1.22; 95% CI, 1.18 to 1.26) than the matched comparison group. Both high and low dosage of levothyroxine treatment was associated with a higher risk for fractures in a J-shaped dose-dependent manner in post-thyroidectomy patients. Future studies are needed to determine how to optimize thyroid-stimulating hormone (TSH) suppression and how to screen and manage fracture risk. © 2018 American Society for Bone and Mineral Research.

Lactobacillus gasseri BNR17 Supplementation Reduces the Visceral Fat Accumulation and Waist Circumference in Obese Adults: A Randomized, Double-Blind, Placebo-Controlled Trial

Lactobacillus gasseri BNR17 is a probiotic strain isolated from human breast milk. Animal studies reported that BNR17 inhibited increases in body weight and adipose tissue weights. The purpose of this study was to evaluate the antiobesity effects of BNR17 in humans. In a randomized, double-blind, placebo-controlled trial, 90 volunteers aged 20-75 years with body mass index (BMI) from 25 to 35 kg/m² were randomized to receive a placebo, low-dose BNR (BNR-L, 10⁹ CFU/day), or high-dose BNR (BNR-H, 10¹⁰ CFU/day) for 12 weeks. Body weight, BMI, waist and hip circumferences, waist-to-hip ratio, abdominal adipose tissue areas, body fat mass, lean body mass, and biochemical parameters were assessed at the beginning and end of the trial. Visceral adipose tissue (VAT) was significantly decreased in the BNR-H group compared with the placebo group (P = .038). Difference of VAT areas of the BNR-H group compared with the placebo group after 12-week consumption of BNR17 was significant (-21.6 cm², P = .012). Waist circumferences were significantly decreased in both the BNR-L and BNL-H groups (P = .045 and .012, respectively) compared with the baseline values, but not in the placebo group. Biochemical parameters were not significantly different among the groups. These findings suggest that daily consumption of BNR17 may contribute to reduced visceral fat mass in obese adults.

Testosterone Replacement, Muscle Strength, and Physical Function

Muscle strength and physical function decrease in older men, as do testosterone levels. Nonetheless, the effects of testosterone replacement therapy on muscle strength and physical function remain inconclusive and equivocal. We conducted a rapid systematic review, the results of which showed that testosterone replacement does not affect muscle strength (measured by hand grip strength and leg muscle strength), although it may increase physical function (measured by the 6-minute walk test, Physical Activity Scale for the Elderly score, and other physical performance tests). However, most of the studies were conducted in the United States or Europe and did not include participants from Asian or other ethnic backgrounds; therefore, further studies are needed to evaluate the effects of testosterone replacement in a broader population.

Trends and Cut-Point Changes in Obesity Parameters by Age Groups Considering Metabolic Syndrome

BACKGROUND

Non-communicable diseases (NCDs) are an important issue worldwide. Obesity has a close relationship with NCDs. Various age-related changes should be considered when evaluating obesity.

METHODS

National representative cohort data from the National Health Insurance Service National Sample Cohort from 2012 to 2013 were used. Sex-specific and age group-specific (10-year intervals) means for body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WtHR) were calculated. Optimal cut-points for obesity parameters were defined as the value predicting two or more components of metabolic syndrome (except WC).

RESULTS

The mean value and optimal cut-point for BMI decreased with age for men. The mean BMI value for women increased with age, but optimal cut-points showed no remarkable difference. The mean WC of men increased with age, but the optimal cut-points were similar for age groups. For women, the mean value and optimal cut-point for WC increased with age. Regarding WtHR, the mean value and optimal cut-point increased with age for men and women. Differences across age groups were larger for women.

CONCLUSION

The mean values of the obesity indices and the optimal cut-points were changed according to age groups. This study supports the necessity of applying age group-specific cut-points for the various obesity parameters.

Persistent smoking after a cardiovascular event: A nationwide retrospective study in Korea

Smoking is a major risk factor of cardiovascular disease (CVD) such as stroke and ischemic heart disease. Prior studies have observed people continued smoking even after being diagnosed with CVD. However, population-level data regarding smoking behavior changes among people who are diagnosed with CVD are still lacking. From the National Health Insurance sample cohort database, we identified 1,700 patients diagnosed as having CVD between 2003 and 2012, and underwent the national health screening examination in the year before and after the CVD event. We found that 486 (28.6%) were smokers before the CVD event. Among them, 240 (49.4%) continued to smoke despite the diagnosis. We observed that a higher smoking amount and longer smoking duration before the diagnosis were associated with persistent smoking. Our finding that approximately 50% of smokers continue smoking even after CVD events supports the need for an assessment of patients' smoking statuses during follow-up after a CVD event and for health-care providers to offer the appropriate smoking cessation interventions to those who continue smoking.

Effect of one-time brief additional counseling on periodic health examination for 40- and 66-year-olds: 2-Year follow up of 101 260 participants

AIM

The aim of the present study was to evaluate whether the effect of one-time brief additional counseling in periodic health examinations (PHE) through the National Screening Program for the Translational Ages in Korea is sustained after 2 years.

METHODS

We collected data from National Screening Program for the Translational Ages participants in 2007 and 2008. To evaluate behavior change after 2 years, we collected the participants' health behavior data 2 years later (2009 and 2010). We defined the basic group as participants who only received PHE, and the additional group as received PHE and counseling. We carried out propensity score matching to ensure that additional counseling was the only different variable affecting health behavior between the two groups.

RESULTS

After propensity score matching, 50 630 remaining matched participants were matched for each group. Of these participants, 26.5% (26 855/101 260) were aged 66 years, and 60.9% (61 653/101 260) were men. The additional group showed a significant increase in odds of smoking cessation among the 66-year-olds (adjusted OR 1.173, 95% CI 1.003-1.372). This effect was significant, especially when the participants did not have hypertension or hypercholesterolemia (adjusted OR 1.193, 95% CI 1.000-1.423 for hypertension and adjusted OR 1.188, 95% CI 1.009-1.398 for hypercholesterolemia). However, there was no significant association for alcohol drinking and regular exercise.

CONCLUSIONS

The effect of one-time brief counseling added to a PHE in cigarette smoking was observed only among the 66-year-olds. However, the effect was so small that it is doubtful to be clinically relevant. Repeated counseling is required to sustain the effect of the initial motivation of counseling. Geriatr Gerontol Int 2018; 18: 329-337.

Kidney dysfunction and silent brain infarction in generally healthy adults

BACKGROUND

The association between silent brain infarction (SBI) and estimated glomerular filtration rate (eGFR)-based kidney dysfunction has not yet been definitively confirmed. This study aimed to investigate the association in generally healthy adults without a previous history of stroke or overt kidney disease.

METHODS

The data from the screening health check-up program in the Seoul National University Hospital Health Promotion Center from January 1, 2009 to December 31, 2013 were used. A total of 2594 subjects who underwent brain MRI as part of health screening were included. SBIs were identified using T2-weighted and FLAIR images. Kidney dysfunction was defined as eGFR<60ml/min/1.73m². To assess the effect of kidney dysfunction on the small perforating branches of cerebral vessels, subgroup analysis was performed using the presence of SLI as a dependent variable.

RESULTS

The mean age was 56.8±9.3years, and 1422 subjects (54.8%) were male. The mean eGFR level was 81.9±15.4ml/min/1.73m². The prevalence rates of kidney dysfunction and SBI were 5.1% and 7.1%, respectively. A higher proportion of subjects with SBI had kidney dysfunction than subjects without SBI (14.6% vs. 4.4%). The number of SBI lesions tended to increase with the progression of kidney dysfunction (p for trend<0.001). In multivariate logistic regression analyses, kidney dysfunction was significantly associated with the presence of SBI (adjusted odd ratio=1.99 to 2.21 in all four models). The same significant association was consistently identified in subgroup analyses using silent lacunar infarction (adjusted odd ratio=1.71 to 1.87 in all four models).

CONCLUSION

Kidney dysfunction was found to be an independent risk factor for the presence and number of SBI in generally healthy adults. Physicians treating patients with a decreased creatinine-based eGFR level should try to identify and modify the coexisting risk factors of stroke followed by SBI.

Disparity in Health Screening and Health Utilization according to Economic Status

BACKGROUND

Cardiovascular disease (CVD) has become the most common cause of mortality and morbidity worldwide. Health screening is associated with higher outpatient visits for detection and treatment of CVD-related diseases (diabetes mellitus, hypertension, and dyslipidemia). We examined the association between health screening, health utilization, and economic status.

METHODS

A sampled cohort database from the National Health Insurance Corporation was used. We included 306,206 participants, aged over 40 years, without CVD (myocardial infarction, stroke, and cerebral hemorrhage), CVD-related disease, cancer, and chronic renal disease. The follow-up period was from January 1, 2003 through December 31, 2005.

RESULTS

Totally, 104,584 participants received at least one health screening in 2003-2004. The odds ratio of the health screening attendance rate for the five economic status categories was 1.27 (95% confidence interval [CI], 1.24 to 1.31), 1.05 (95% CI, 1.02 to 1.08), 1, 1.16 (95% CI, 1.13 to 1.19) and 1.50 (95% CI, 1.46 to 1.53), respectively. For economic status 1, 3, and 5, respectively, the diagnostic rate after health screening was as follows: diabetes mellitus: 5.94%, 5.36%, and 3.77%; hypertension: 32.75%, 30.16%, and 25.23%; and dyslipidemia: 13.43%, 12.69%, and 12.20%. The outpatient visit rate for attendees diagnosed with CVD-related disease was as follows for economic status 1, 3, and 5, respectively: diabetes mellitus: 37.69%, 37.30%, and 43.70%; hypertension: 34.44%, 30.09%, and 32.31%; and dyslipidemia: 18.83%, 20.35%, and 23.48%.

CONCLUSION

Thus, higher or lower economic status groups had a higher health screening attendance rate than the middle economic status group. The lower economic status group showed lower outpatient visits after screening, although it had a higher rate of CVD diagnosis.

Association between Weight Changes after Smoking Cessation and Cardiovascular Disease among the Korean Population

Background

Cigarette smoking is a risk factor for cardiovascular disease (CVD) and has both beneficial and harmful effects in CVD. We hypothesized that weight gain following smoking cessation does not attenuate the CVD mortality of smoking cessation in the general Korean population.

Methods

Study subjects comprised 2.2% randomly selected patients from the Korean National Health Insurance Corporation, between 2002 and 2013. We identified 61,055 subjects who were classified as current smokers in 2003–2004. After excluding 21,956 subjects for missing data, we studied 30,004 subjects. We divided the 9,095 ex-smokers into two groups: those who gained over 2 kg (2,714), and those who did not gain over 2 kg (6,381, including weight loss), after smoking cessation. Cox proportional hazards regression models were used to estimate the association between weight gain following smoking cessation and CVD mortality.

Results

In the primary analysis, the hazard ratios of all-cause deaths and CVD deaths were assessed in the three groups. The CVD risk factors and Charlson comorbidity index adjusted hazard ratios (aHRs) for CVD deaths were 0.80 (95% confidence interval [CI], 0.37 to 1.75) for ex-smokers with weight gain and 0.80 (95% CI, 0.50 to 1.27) for ex-smokers with no weight gain, compared to one for sustained smokers. The associations were stronger for events other than mortality. The aHRs for CVD events were 0.69 (95% CI, 0.54 to 0.88) and 0.81 (95% CI, 0.70 to 0.94) for the ex-smokers with and without weight gain, respectively.

Conclusion

Although smoking cessation leads to weight gain, it does not increase the risk of CVD death.

Kidney dysfunction and cerebral microbleeds in neurologically healthy adults

INTRODUCTION

Cerebral microbleed (CMB) is a potent risk factor for overt cerebrovascular disease. Although some studies indicated the possible role of renal dysfunction as a risk factor of CMB, the findings could not be generalized. This study aimed to investigate the association between renal dysfunction and cerebral microbleed (CMB) in neurologically healthy adults.

MATERIALS AND METHODS

A total of 2,518 subjects who underwent brain MRI as part of health screening were involved in the study. CMBs were defined as well-demarcated focal areas of low signal intensity with associated blooming on the T2-weighted MRI measuring less than 5mm in diameter. The glomerular filtration rate (GFR) was estimated using the Modification of Diet in Renal Disease formula. Kidney function was classified as normal (≥90), mild (60 to 89.9), moderate (30 to 59.9), and severe (<30 mL/min/1.73 m2) renal dysfunction according to the GFR.

RESULTS

The mean age of the participants was 57.5 ± 8.3 years (ranged 40 to 79), and 1,367 subjects (54.3%) were male. The mean GFR level was 81.5 ± 15.5, and the prevalence of CMB was 4.1% (n = 103). Subjects with CMB demonstrated a higher proportion of moderate-to-severe renal dysfunction than those without CMB (15.5% vs. 5.0%, p < 0.001). In the multivariate logistic regression analysis, moderate-to-severe renal dysfunction showed a significant association with CMB (adjusted odd ratio = 2.63; p = 0.008). Furthermore, a decrease in the GFR level was associated with an increasing trend of the presence of CMB (p for trend = 0.031) and number of CMB lesions (p for trend = 0.003).

CONCLUSIONS

Renal dysfunction was significantly associated with the presence of CMB in neurologically healthy adults. More studies are needed to evaluate if treatment of kidney disease and risk factor modification may prevent further progress of CMB.

Abstract TP173: Kidney Dysfunction and Silent Brain Infarction in Generally Healthy Adults

Purpose: The association between silent brain infarction (SBI) and estimated glomerular filtration rate (eGFR)-based kidney dysfunction has not yet been definitively confirmed. This study aimed to investigate the association in generally healthy adults without a previous history of stroke or overt kidney disease.

Methods: A total of 2,594 subjects who underwent brain MRI as part of health screening were included. SBIs were identified using gradient-recalled echo MRI. Kidney dysfunction was defined as eGFR < 60 ml/min/1.73 m 2 .

Results: The mean age was 56.8 ± 9.3 years, and 1,422 subjects (54.8%) were male. The mean eGFR level was 81.9 ± 15.4 ml/min/1.73 m 2 . The prevalence rates of kidney dysfunction and SBI were 5.1% and 7.1%, respectively. A higher proportion of subjects with SBI had kidney dysfunction than subjects without SBI (14.6% vs. 4.4%). The number of SBI lesions tended to increase with the progression of kidney dysfunction (p for trend < 0.001). In multivariate logistic regression analyses, kidney dysfunction was significantly associated with the presence of SBI (adjusted odd ratio = 1.99 to 2.21 in all four models). The same significant association was consistently identified in subgroup analyses using silent lacunar infarction (adjusted odd ratio = 1.71 to 1.87 in all four models).

Conclusion: Kidney dysfunction was found to be an independent risk factor for the presence and number of SBI in generally healthy adults. Physicians treating patients with a decreased creatinine-based eGFR level should try to identify and modify the coexisting risk factors ofstroke followed by SBI.

Enhancing physical activity and reducing obesity through smartcare and financial incentives: A pilot randomized trial

OBJECTIVE

A pilot randomized trial assessed the feasibility and effectiveness of an intervention combining Smartcare (activity tracker with a smartphone application) and financial incentives.

METHODS

A three-arm, open-label randomized controlled trial design involving traditional education, Smartcare, and Smartcare with financial incentives was involved in this study. The latter group received financial incentives depending on the achievement of daily physical activity goals (process incentive) and weight loss targets (outcome incentive). Male university students (N = 105) with body mass index of ≥27 were enrolled.

RESULTS

The average weight loss in the traditional education, Smartcare, and Smartcare with financial incentives groups was -0.4, -1.1, and -3.1 kg, respectively, with significantly greater weight loss in the third group (both Ps < 0.01). The final weight loss goal was achieved by 0, 2, and 10 participants in the traditional education, Smartcare, and Smartcare with financial incentives groups (odds ratio for the Smartcare with financial incentive vs. Smartcare = 7.27, 95% confidence interval: 1.45-36.47). Levels of physical activity were significantly higher in this group.

CONCLUSIONS

The addition of financial incentives to Smartcare was effective in increasing physical activity and reducing obesity.

CDH13 gene-by-PM10 interaction effect on lung function decline in Korean men

Lung function can be influenced by genetic factors, which may explain individual differences in susceptibility to the effects of air pollution. This study investigated whether the effect of particulate matter with an aerodynamic diameter ≤10 μm (PM₁₀) on lung function is modified by Cadherin 13 (CDH13) genetic variants in Korean men. This study included a total of 1827 men who were recruited from two health check-up centers, and the annual average PM₁₀ concentrations were used. A total of 200 single-nucleotide polymorphisms (SNPs) of the CDH13 gene were selected for this study. We found that a SNP in CHD13 intron, rs1862830, had the strongest associations with both forced expiratory volume in 1 s (FEV₁) (p_int = 1.90 × 10^-4) and forced vital capacity (FVC) (p_int = 1.88 × 10^-3) by interacting with PM₁₀ in a recessive model. A stratified association analysis according to this SNP showed that PM₁₀ in the AG or GG genotype group was not significantly associated with either FEV₁ or FVC, whereas in homozygous risk-allele carriers (AA), FEV₁ and FVC decreased significantly (by 3.8% and 3.1%, respectively) per 10 μg/m³ of increase in PM₁₀ concentration. This pattern was also reproducible in the independent subgroups that were classified according to recruitment site. The present study replicated the CDH13 gene-by-PM₁₀ interaction effect on lung function at the gene level, revealing that a genetic variant of CDH13 modified the relationship between PM₁₀ and lung function decline in Korean men.