Non-Linear Relationship between Serum 25-Hydroxyvitamin D and Hemoglobin in Korean Females: The Korean National Health and Nutrition Examination Survey 2010–2011

Background

Anemia and vitamin D deficiency are both important health issues; however, the nature of the association between vitamin D and either hemoglobin or anemia remains unresolved in the general population.

Methods

Data on 11,206 adults were obtained from the fifth Korean National Health and Nutritional Examination Survey. A generalized additive model was used to examine the threshold level for relationship between serum 25-hydroxyvitamin D [25(OH)D] and hemoglobin levels. A multivariate logistic regression for anemia was conducted according to 25(OH)D quintiles. All analyses were stratified according to sex and menstrual status.

Results

The generalized additive model confirmed a threshold 25(OH)D level of 26.4 ng/mL (male, 27.4 ng/mL; premenopausal females, 11.8 ng/mL; postmenopausal females, 13.4 ng/mL). The threshold level affected the pattern of association between 25(OH)D and anemia risk: the odds ratio of the 1^st quintile but not the 2^nd, 3^rd, and 4^th quintiles were significantly different from the 5^th quintile in both premenopausal and postmenopausal females, however there was no obvious trend in males.

Conclusions

This population-based study demonstrated a non-linear relationship with a threshold effect between serum 25(OH)D and hemoglobin levels in females. Further interventional studies are warranted to determine whether the appropriate level of hemoglobin can be achieved by the correction of vitamin D deficiency.     

Examining Impacts of Allergic Diseases on Psychological Problems and Tobacco Use in Korean Adolescents: The 2008–2011 Korean National Health and Nutrition Examination Survey

Purpose

Asthma during adolescence can induce social, psychological, and behavioral problems. We examined the impact of asthma and other allergic diseases on psychological symptoms and health risk behaviors among South Korean adolescents.

Methods

In this population-based cross-sectional study, 3192 adolescents (10–18 years of age) participating in the 2008–2011 Korean National Health and Nutrition Examination Survey were enrolled. Psychological problems associated with clinically diagnosed asthma, allergic rhinitis, and atopic dermatitis were assessed using questionnaires and surveys. Data was analyzed using logistic regression to determine the association of depression with allergic disease while controlling for age, sex, body mass index, smoking experience, and alcohol use.

Results

Asthma and atopic dermatitis were associated with a higher prevalence of depression (17.2% and 13%, respectively). After adjusting for the covariates, asthma patients were approximately two times as likely to have depression as non-allergic participants (odds ratio, 1.81; 95% confidence interval, 1.22–2.68). Psychosocial stress significantly increased in the following order: no allergy, any allergy without asthma, asthma only, and asthma with any allergy (p for linear trend = 0.01). The asthma without other allergies group showed the highest prevalence of cigarette smoking (p = 0.007).

Conclusions

In this study, asthma with or without other allergies was significantly related to increases in depression, psychosocial stress, and smoking experience. Thus, care should be taken to adjust treatment to account for the psychological symptoms and health risk behaviors common among asthmatic adolescents.     

Association between Self-Reported Smoking and Hemoglobin A1c in a Korean Population without Diabetes: The 2011–2012 Korean National Health and Nutrition Examination Survey

BackgroundSeveral Western studies have revealed that among non-diabetics, glycosylated hemoglobin A1c (HbA1c) levels are higher in smokers than non-smokers. While studies conducted in Western populations consistently support this association, a recent meta-analysis reported that studies carried out in non-Western populations, including studies of Chinese, Egyptian, and Japanese-Americans, did not detect any significant differences in HbA1c levels between smokers and non-smokers.ObjectivesWe assessed the association between smoking habits and HbA1c levels in the general Korean adult population using data from the Korean National Health and Nutrition Examination Survey (KNHANES) performed in 2011–2012.MethodsA total of 10,241 participants (weighted n=33,946,561 including 16,769,320 men and 17,177,241 women) without diabetes were divided into four categories according to their smoking habits: never smokers (unweighted n/ weighted n= 6,349/19,105,564), ex-smokers (unweighted n/ weighted n= 1,912/6,207,144), current light smokers (<15 cigarettes per day, unweighted n/ weighted n=1,205/5,130,073), and current heavy smokers (≥15 cigarettes per day, unweighted n/ weighted n=775/3,503,781).ResultsIn age- and gender-adjusted comparisons, the HbA1c levels of each group were 5.52 ± 0.01% in non-smokers, 5.49 ± 0.01% in ex-smokers, 5.53 ± 0.01% in light smokers, and 5.61 ± 0.02% in heavy smokers. HbA1c levels were significantly higher in light smokers than in ex-smokers (p = 0.033), and in heavy smokers compared with light smokers (p < 0.001). The significant differences remained after adjusting for age, gender, fasting plasma glucose, heavy alcohol drinking, hematocrit, college graduation, and waist circumference. Linear regression analyses for HbA1c using the above-mentioned variables as covariates revealed that a significant association between current smoking and HbA1c (coefficient 0.021, 95% CI 0.003–0.039, p = 0.019).ConclusionsCurrent smoking was independently associated with higher HbA1c levels in a cigarette exposure-dependent manner in a representative population of Korean non-diabetic adults. In this study, we have observed an association between smoking status and HbA1c levels in non-diabetics drawn from a non-Western population, consistent with previous findings in Western populations.     

Historian‐judges of Korean nationalism

Studies of Korean nationalism have not only been less researched but they have also been predominantly nationalistic and moralistic. Authors have tended to assume an already present nationalism ever since the late‐nineteenth century. They have omitted analysis of the mechanism of the emergence of Korean nationalism and so have merely substantiated the concept. This tendency is attributed both to the lack of methodological sophistication ‐ most of them apply the concept of nationalism teleologically and without theoretical rigour ‐ and also to the ideology of the authors themselves. The aim of this article is to expose some of the current problems recognized in this area through the examination of works by selected authors.     

Prevalence and Risk Factors of Chronic Otitis Media: The Korean National Health and Nutrition Examination Survey 2010–2012

BackgroundThe performance of nationwide studies of chronic otitis media (COM) in adults has been insufficient in Korea. We evaluated the prevalence and risk factors of COM in Korea.MethodsThis study was conducted using data from the fifth Korean National Health and Nutrition Examination Survey (n = 23,621). After excluding the subjects under 20 year old and suffered from cancers, 16,063 patients were evaluated for COM. Participants underwent a medical interview, physical examination, endoscopic examination, and blood and urine test. COM was diagnosed by trained residents in the Department of Otorhinolaryngology using an ear, nose, and throat questionnaire and otoendoscopy findings. Data on the presence and absence of COM were collected. Multivariate logistic regression analyses were performed to identify its risk factors.ResultsOf the 16,063 participants aged above 20 year old, the weighted prevalence of COM was 3.8%. In the multivariate analyses, the following factors showed high odds ratios (ORs) for COM: pulmonary tuberculosis (adjusted OR, 1.78; 95% confidence interval [CI], 1.06-3.01), chronic rhinosinusitis (adjusted OR, 1.87; 95% CI, 1.17-2.98), mild hearing impairment (adjusted OR, 1.95; 95% CI, 1.34-2.85), moderate hearing impairment (adjusted OR, 4.00; 95% CI, 2.21-7.22), tinnitus (adjusted OR, 1.82; 95% CI, 1.34-2.49), increased hearing thresholds in pure tone audiometry in the right ear (adjusted OR, 1.02; 95% CI, 1.01-1.03), and left ear (adjusted OR, 1.03; 95% CI, 1.02-1.04). The following factors showed low odds ratios for COM: hepatitis B (adjusted OR, 0.28; 95% CI, 0.08-0.94) and rhinitis (adjusted OR, 0.60; 95% CI, 0.42-0.88). In addition, high levels of vitamin D, lead, and cadmium, EQ-5D index; and low red blood cell counts were associated with development of COM (Student’s t-test, P < 0.01).ConclusionsOur population-based study showed that COM is not rare in Korea, and its development may be associated with various host and environmental factors. Further research on its relationships and the pathogenesis are needed.     

The Relationship between Serum Ferritin Levels and Insulin Resistance in Pre- and Postmenopausal Korean Women: KNHANES 2007–2010

BackgroundSerum ferritin levels increase in postmenopausal women, and they are reported to be linked to major health problems. Here, we investigated the association between serum ferritin levels and insulin resistance (IR) in postmenopausal women.MethodsA total of 6632 healthy Korean women (4357 premenopausal and 2275 postmenopausal) who participated in the Korean National Health and Nutrition Examination Survey (KNHANES) in 2007–2010 were enrolled in the study. Serum ferritin values were divided into six groups for the premenopausal and postmenopausal groups. IR and obesity indices were evaluated according to the six serum ferritin groups. Statistical analysis was carried out using SAS software, version 9.2 (SAS Institute Inc., Cary, NC, USA).ResultsThe association between the IR indices and ferritin groups had a higher level of statistical significance in the postmenopausal group than in the premenopausal group. In addition, for the postmenopausal group, the estimates increased significantly in the sixth ferritin group compared to those in the first ferritin group. However, the association between the obesity indices and ferritin levels was not significantly different between the premenopausal and postmenopausal groups.ConclusionElevated serum ferritin levels were associated with an increased risk of insulin resistance in postmenopausal women.     

Potassium Intake and the Prevalence of Metabolic Syndrome: The Korean National Health and Nutrition Examination Survey 2008–2010

Lower potassium intake is considered to be correlated with diabetes incidence. However, few studies have investigated the effect of potassium intake on metabolic syndrome (MetS). Data was taken from the Korean National Health and Nutritional Examination Survey (2008–2010) using weighted adjustment. MetS was defined as per the revised National Cholesterol Education Program criteria. Homeostasis model assessment indices were calculated to diagnosis insulin resistance (IR). A total of 16,637 participants (44±0.25 years) were included. Women ingested lower amounts of potassium (2.71±0.02 g/day) than men (3.45±0.03 g/day). A curvilinear association between potassium intake and MetS prevalence was found among women. Women with less than the Adequate Intake (4.7 g/day) of potassium had an 11% risk reduction for MetS (adjusted odds ratio [OR], 0.89; 95% confidence interval [CI], 0.82–0.96; P = 0.004) and a 10% risk reduction for IR (OR, 0.90; 95% CI, 0.82–0.99; P = 0.026) for every 1 g/day potassium increase. Compared with the reference group (3.5–4.5 g/day), potassium intake was inversely associated with an increased risk of MetS (1.5–2.5 g/day; OR, 1.29; 95% CI, 1.02–1.63; P = 0.035; <1.5 g/day; OR, 1.40; 95% CI, 1.06–1.85; P = 0.017) and IR (<1.5 g/day; OR, 1.36; 95% CI, 1.05–1.76; P = 0.021). This relationship was more prominent in postmenopausal women, but not observed among men. Higher potassium intake is significantly associated with a lower MetS prevalence in women, and IR is believed to be connected.     

Comparing the genetic diversity and structure of indigenous Korean and Chinese populations of Laodelphax striatellus Fallén using mitochondrial haplotypes

The small brown planthopper, Laodelphax striatellus Fallén, is a major migratory pest from China to Korea and transmits viral diseases of rice plants. In this study, we compared the genetic structures of overwintered indigenous Korean and Chinese populations. The eight Korean populations consisted of 33 haplotypes, and 16 of these were newly identified. The genetic diversity of the Korean population revealed high haplotype diversity (Hd) and low nucleotide diversity (π) of 0.86 ± 0.017 and 0.0024 ± 0.0001 on average, respectively. These values for the Chinese population were Hd = 0.92 ± 0.016 and π = 0.0026 ± 0.0002. Overall, genetic distances by pairwise F_ST were generally low, ranging from ? 0.022 to 0.089. Moreover, the Korean population revealed its ongoing population expansion by showing negative values in the neutrality test (Tajima's D = ? 1.4, Fu's Fs = ? 15.8) and a unimodal pattern in the mismatch distribution analysis. The genetic structures and population relationships were determined using 8 indigenous Korean and 30 Chinese populations by Bayesian approaches and population tree construction, respectively. The genetic structure was inferred as five (K = 5), and all indigenous Korean populations as well as 10 Chinese populations from the Shanghai city, Anhui, Henan, Jiangsu, Liaoning, Shandong, and Zhejiang provinces were grouped into ‘G3’. These results provide partial support for unidirectional gene flow by migratory Chinese populations into Korea. Further analysis conducted using specimens from China and Korea collected in similar periods is necessary to clarify the migration population's origin and its effect on the genetic structure of the indigenous populations.     

QTL analysis of clinical-chemical traits in an F₂ intercross between Landrace and Korean native pigs

Clinical-chemical traits are essential when examining the health status of individuals. The aim of this study was to identify quantitative trait loci (QTL) and the associated positional candidate genes affecting clinical-chemical traits in a reciprocal F(2) intercross between Landrace and Korean native pigs. Following an overnight fast, 25 serum phenotypes related to clinical-chemical traits (e.g., hepatic function parameters, renal function parameters, electrolyte, lipids) were measured in >970 F(2) progeny. All experimental samples were subjected to genotyping analysis using 165 microsatellite markers located across the genome. We identified eleven genome-wide significant QTL in six chromosomal regions (SSC 2, 7, 8, 13, 14, and 15) and 59 suggestive QTL in 17 chromosomal regions (SSC 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16, 17, and 18). We also observed significant effects of reciprocal crosses on some of the traits, which would seem to result from maternal effect, QTL on sex chromosomes, imprinted genes, or genetic difference in mitochondrial DNA. The role of genomic imprinting in clinical-chemical traits also was investigated. Genome-wide analysis revealed a significant evidence for an imprinted QTL in SSC4 affecting serum amylase levels. Additionally, a series of bivariate linkage analysis provided strong evidence that QTL in SSC 2, 13, 15, and 18 have a pleiotropic effect on clinical-chemical traits. In conclusion, our study detected both novel and previously reported QTL influencing clinical-chemical traits in pigs. The identified QTL together with the positional candidate genes identified here could play an important role in elucidating the genetic structure of clinical-chemical phenotype variation in humans and swine.     

Association between Levels of Serum Ferritin and Bone Mineral Density in Korean Premenopausal and Postmenopausal Women: KNHANES 2008–2010

Background

As women go through menopause, serum estrogen decreases and ferritin increases. Decreased serum estrogen is well known to cause detrimental effects on bone health; however, data on the associations of serum ferritin with BMD before and after menopause are still lacking. Therefore, this study aimed to investigate the association between serum ferritin levels and BMD in premenopausal and postmenopausal Korean women.

Methods

This study was performed using data from the 2008–2010 Korean National Health and Nutrition Examination Survey, including 7300 women (4229 premenopausal and 3071 postmenopausal). BMD was measured using dual X-ray absorptiometry at the femur and the lumbar spine, and serum ferritin levels were measured by chemiluminescent immunoassay.

Results

Median serum ferritin levels in postmenopausal women were higher than those in premenopausal women despite the same age ranges. Serum ferritin levels were only significantly correlated with BMD on the lumbar spine (β = −0.189, p-value = 0.005) in premenopausal women after adjusting confounding factors. Additionally, BMD on the lumbar spine had tended to decrease as serum ferritin quartiles increase (P for trend = 0.035) in premenopausal women after adjusting confounding factors. On the other hand, there were no significant associations between serum ferritin levels and BMD on the total femur and, femur neck in premenopausal women, and BMD on the total femur, femur neck, and lumbar spine in postmenopausal women.

Conclusion

Increased serum ferritin levels were significantly associated with BMD in premenopausal women, particularly on the lumbar spine, but not in postmenopausal women.     

Normal Range Albuminuria and Metabolic Syndrome in South Korea: The 2011–2012 Korean National Health and Nutrition Examination Survey

BackgroundIt is well-known that there is a close relationship between metabolic syndrome (MetS) and microalbuminuria. However, some recent studies have found that even normal range albuminuria was associated with MetS and cardiometabolic risk factors. The purpose of this study is to analyze the relationship between MetS and normal range albuminuria and to calculate the cutoff value for albuminuria that correlates with MetS in the representative fraction of Korean population.MethodsData were obtained from the 2011–2012 Korea National Health and Nutrition Examination Survey and included 9,650 subjects aged ≥19 years. We measured metabolic parameters: fasting blood glucose, waist circumference, blood pressure, and lipids, and albumin-to-creatinine ratio (ACR). The optimal ACR cutoff points for MetS were examined by the receiver operating characteristic curve. Multivariate logistic regression was used to obtain the prevalence of MetS and its components according to the ACR levels.ResultsThe first cutoff value of ACR were 4.8 mg/g for subjects with ≥3 components of MetS. There was a graded association between ACR and prevalence of MetS and its components. If ACR was <4 mg/g, there was no significant increase in the prevalence of MetS or its components. From the ACR level of 4–5 mg/g, the prevalence of MetS significantly increased after adjusting for age, sex, body mass index, smoking, alcohol intake, exercise, and medications for diabetes mellitus and hypertension (odds ratio; 95% confidence intervals = 1.416; 1.041–1.926).ConclusionsAlbuminuria within the normal range (around 5 mg/g) was associated with prevalence of MetS in the Korean population.     

Association between Low-Grade Albuminuria and Cardiovascular Risk in Korean Adults: The 2011–2012 Korea National Health and Nutrition Examination Survey

Background

Recent studies have indicated that low UACR levels (<30 μg/mg) previously considered to be in the normal range (‘low-grade albuminuria’) are associated with cardiovascular morbidity and mortality in the general population.

Methods

We studied 9,736 participants with albuminuria in the normal range from the 2011–2012 Korea National Health and Nutrition Examination Survey (KNHANES).

Results

The weighted prevalences of metabolic syndrome (MS) and the 10-year risk for coronary heart disease measured using the Framingham risk score (FRS) ≥ 20% (high risk) were 22.5 ± 0.7% and 14.5 ± 0.7%, respectively, in males and 23.3 ± 0.8% and 8.5 ± 0.4%, respectively in females. Weighted comparisons among the tertiles of UACR revealed that the prevalences of MS and high-risk FRS increased with increasing UACR (MS: males, 15.9 ± 1.1, 20.2 ± 1.2, 32.4 ± 1.5%, respectively; P < 0.001; and females, 17.6 ± 1.0, 22.7 ± 1.0, 30.2 ± 1.4%, respectively; P < 0.001. High-risk FRS: males, 9.5 ± 0.7, 12.3 ± 0.9, 22.5 ± 1.2, respectively; P < 0.001; and females, 5.8 ± 0.6, 7.9 ± 0.7, 12.0 ± 0.9%, respectively; P < 0.001). The positive association persisted after adjusting for hypertension and diabetes. The weighted comparisons among the deciles of UACR revealed that the prevalences of MS and high-risk FRS began to increase at the ranges of 3.89–5.15 and 5.16–7.36 mg/g Cr, respectively.

Conclusion

Low-grade albuminuria was significantly associated with estimated cardiovascular risk and MS in a nationally representative sample of Koreans.     

The construction of ‘Asian American’: Reflections on intermarriage and ethnic identity among second‐generation Chinese and Korean Americans

This article explores the ethnic self‐identification of second‐generation children whose immigrant parents came to the United States from Latin America. The focus of the analysis is the adoption of the pan‐ethnic label, ‘Hispanic’, in contrast to national designators and non‐hyphenated American identities. Using data from a recent large survey of children of immigrants in south Florida and southern California, the analysis explores the determinants of ethnic self‐identities and the potential consequences of the adoption of one of these symbolic labels on children's self‐esteem, educational expectations and perceptions of discrimination. Contrary to the commonly‐held assumption that the label ‘Hispanic’ denotes greater assimilation into the mainstream of US society, our findings indicate that children who adopt the Hispanic label are the least well assimilated: they report poorer English skills, lower self‐esteem and higher rates of poverty than their counterparts who identify themselves as Americans or as hyphenated Americans. Theoretical and policy implications of findings as they bear on prospects for successful adaptation of second‐generation youth are discussed.     

Age- and Gender-Related Mean Hearing Threshold in a Highly-Screened Population: The Korean National Health and Nutrition Examination Survey 2010–2012

Background

In evaluating hearing disability in medicolegal work, the apportionment of age- and gender-related sensorineural hearing loss should be considered as a prior factor, especially for the elderly. However, in the literature written in the English language no studies have reported on the age- and gender-related mean hearing threshold for the South Korean population.

Objective

This study aimed to identify the mean hearing thresholds in the South Korean population to establish reference data and to identify the age- and gender-related characteristics.

Methods

This study is based on the Korea National Health and Nutrition Examination Survey (KNHANES) 2010–2012, which was conducted by the Korean government, the data of which was disclosed to the public. A total of 15,606 participants (unweighted) representing 33,011,778 Koreans (weighted) with normal tympanic membrane and no history of regular or occupational noise exposure were selected and analyzed in this study. The relationship between the hearing threshold level and frequency, age, and gender was investigated and analyzed in a highly-screened population by considering the sample weights of a complex survey design.

Results

A gender ratio difference was found between the unweighted and the weighted designs: male:female, 41.0%: 59.0% (unweighted, participants) vs. 47.2%:52.8% (weighted, representing population). As age increased, the hearing threshold increased for all frequencies. Hearing thresholds of 3 kHz, 4 kHz, and 6 kHz showed a statistical difference between both genders for people older than 30, with the 4 kHz frequency showing the largest difference. This paper presents details about the mean hearing threshold based on age and gender.

Conclusions

The data from KNHANES 2010–2012 showed gender differences at hearing thresholds of 3 kHz, 4 kHz, and 6 kHz in a highly-screened population. The most significant gender difference in relation to hearing threshold was observed at 4 kHz. The hearing thresholds at all of the tested frequencies worsened with increasing age. The mean hearing thresholds suggested in this study will be useful for the formulation of healthcare-related hearing policies and used as reference data for disability ratings for hearing loss due to various causes.     

Prevalence and Control of Hypertension and Albuminuria in South Korea: Focus on Obesity and Abdominal Obesity in the Korean National Health and Nutrition Examination Survey, 2011–2012

Background

Albuminuria is associated with cardiovascular disease, and the relationship between albuminuria and hypertension is well established in many studies. So the control of hypertension is critical for decreasing cardiovascular events and albuminuria. Obesity and abdominal obesity are also associated with hypertension and albuminuria. Therefore, we analyzed the relationship between albuminuria and the prevalence and control of hypertension in the general Korean population according to obesity status.

Methods

We analyzed data from the 2011–2012 Korea National Health and Nutrition Examination Survey, and 9,519 subjects were included. Subjects were divided into four groups: non-obese/normal waist circumference, non-obese/high waist circumference, obese/normal waist circumference, and obese/high waist circumference.

Results

Systolic blood pressure and diastolic blood pressure were positively associated with albumin–creatinine ratio in all groups (all p values <0.005). Non-obese/normal waist circumference group were more likely to have hypertension (odds ratios [95% confidential intervals (CIs)] were 3.20 [2.21–4.63] in microalbuminuria level and 3.09 [1.05–9.14] in macroalbuminuria level), and less likely to have controlled hypertension (odds ratios <1 for both albuminuria levels) after adjusting for all covariates. Obese/normal waist circumference group were also more likely to have hypertension (odds ratio [95% CI] were 3.10 [1.56–6.15] in microalbuminuria level and 21.75 [3.66–129.04] in macroalbuminuria level), and less likely to have controlled hypertension in macroalbuminuria level (odds ratio [95% CI], 0.04 [0.01–0.15]).

Conclusions

Non-obese and normal waist circumference subjects have an increased prevalence and decreased control of hypertension in microalbuminuria and macroalbuminuria levels. Screening for albuminuria may provide helpful information about hypertension and blood pressure control, particularly in the non-obese and normal waist circumference subjects.     

Effects of Temperature on Photosynthetic Rates in Korean Fir （Abies koreana） between Healthy and Dieback Population

The present study was carried out on natural Korean fir forests (Abies koreana) growing In Mount Halla in Jeju Island, Korea (33°13-36′ N and 126° 12-57′ E). Mount Halla is the highest mountain (1950 m a.s.l.) in South Korea. On the Korean fir forests near the top of Mount Halla in Korea, we established permanent plots between dieback and healthy population. Each permanent plot includes both dieback and relatively healthy Korean fir individuals. Three sites in this study showed similar altitude, topographic position, aspects, slope, diameter at breast height, average height and ages. Net photosynthetic rates (PN) on different temperature regimes were evaluated to explain the forest dieback phenomenon on Korean fir populations. Light response curves were determined on three different temperature regimes: 15℃, 20℃and 25℃. The Irradiance response curve showed higher values in lower air temperatures. Generally, Irradiance response curves of healthy Korean fir populations were higher than the dieback population at all sites.     

Prevalence of and Factors Associated with Lens Opacities in a Korean Adult Population with and without Diabetes: The 2008–2009 Korea National Health and Nutrition Examination Survey

Objective

We examined the prevalence of and factors associated with lens opacities in a Korean adult population with and without diabetes.

Research Design and Methods

Among the 11,163 adults (≥19 years old) from the fourth Korea National Health and Nutrition Examination Survey in 2008–2009, the data from laboratory tests, nutritional surveys, and slit-lamp examinations of 10,248 persons (4,397 men, 5,851 women) were examined. Cataract was defined as the presence of any nuclear, cortical, subcapsular, or mixed cataract in at least one eye, using the Lens Opacities Classification System III.

Results

The weighted prevalence of cataracts were 23.5% [95% confidence interval (CI), 21.7–25.4] in a Korean adult population (19–39 years old, 1.8% [1.3–2.5], 40–64 years old, 25.2% [22.5–28.1],≥65 years old, 87.8% [85.4–89.9])and 54.7% [50.1–59.2] in a diabetic population(19–39 years old, 11.6% [4.5–26.5], 40–64 years old, 41.1% [35.4–47.0], ≥65 years old, 88.3% [83.5–91.8]). In a logistic regression analysis, age, myopia, and the presence of diabetes were independent risk factors. For young (age 19–39 years) and middle aged (age 40–65 years) adults with diabetes, the OR of having a lens opacity is 5.04 [1.41–17.98] and 1.47 [1.11–1.94], respectively, as those without diabetes, whereas for adults aged 65 and older, there was no difference in the prevalence of cataract.

Conclusions

According to these national survey data, ∼ 24% of Korean adults and ∼ 55% of people with diabetes have cataracts. The presence of diabetes was independently associated with cataracts in young and middle aged adults.     

Relationship between Dietary Magnesium, Manganese, and Copper and Metabolic Syndrome Risk in Korean Adults: The Korea National Health and Nutrition Examination Survey (2007–2008)

Recent studies have reported correlations between mineral intake and metabolic syndrome (MS), but accurate relationships and consistency in the results are difficult to confirm. Accordingly, this study aims to assess the dietary intakes of magnesium (Mg), manganese (Mn), and copper (Cu) to determine their relationship with MS. Data from a total of 5,136 adults (2,084 men, 3,052 women) was collected from the 2007–2008 Korea National Health and Nutrition Examination Survey (KNHANES), and the intakes of Mg, Mn, and Cu of the MS patients were compared with those of healthy adults. The relationship between the intakes of these minerals and the MS risks was analyzed. Diagnosis of MS was evaluated by the National Cholesterol Education Program's Adult Treatment Panel III (NCEP-ATP III) standards. Among all study subjects, 25.9 % (540 subjects) of the men and 24.5 % (748 subjects) of the women met diagnostic criteria for inclusion in the MS group. In the men, daily intakes of Mg and Cu in the MS group were significantly lower than those in control group, and in the women, daily intakes of energy, Mg, Mn, and Cu in the MS group were significantly lower than those of the control group. The women subjects with high blood pressure showed significantly lower intakes of Mg, Mn, and Cu than control subjects. In addition, in the women, the highest quartile of Mg and Cu was inversely associated with MS, but with adjustment were not maintained. However, in the postmenopausal women, MS was significant and inversely associated with the highest quartiles of Cu intake and the association remained significant after adjustments. Considering that MS incidence increases and dietary intake and nutrient density decrease with increasing age, and mineral intake is reduced accordingly, these results suggest that meal management with adequate mineral intake is advisable to control MS.     

Age at First Delivery and Osteoporosis Risk in Korean Postmenopausal Women: The 2008–2011 Korea National Health and Nutrition Examination Survey (KNHANES)

It has been reported in several studies that there may be a significant correlation between reproductive history and the risk of osteoporosis due to the effect of estrogen. Under this hypothesis, however, it is unclear whether the age at first delivery has any major influences on the risk of osteoporosis. Therefore, this study aimed to investigate the relationship between the age at first delivery and the risk of osteoporosis in Korean menopausal women. This study was performed using data from the 2008–2011 Korea National Health and Nutrition Examination Survey and included 2,530 Korean postmenopausal women. The diagnosis of osteoporosis was made using the World Health Organization T-score criteria (T-score ≤ -2.5, at the femoral neck or lumbar spine). Participants were categorized into 3 groups according to age at first delivery: ≤23, 24–29, and ≥30 years. Older age, lower body mass index, lower calcium intake, later menarche, and earlier menopause increased the risk of osteoporosis, whereas hormone therapy and oral contraceptive use were associated with a decreased risk of osteoporosis. Postmenopausal women whose first delivery occurred at age 24–29 years were shown to have a significantly increased risk of osteoporosis (odds ratio, 2.124; 95% confidence interval, 1.096–4.113; P = 0.026) compared to those who first gave birth after the age of 30 years. These findings suggest that postmenopausal women whose first delivery occurred in their mid to late 20s, a period during which bone mass slowly accumulates to the peak, are at an increased risk of osteoporosis.     

Deletion commonly found in Waxy gene of Japanese and Korean cultivars of Job’s tears (Coix lacryma-jobi L.)

We isolated the entire sequence of the coding region of Waxy gene of a non-waxy accession of Job??s tears (Coix lacryma-jobi) by PCR-based methods. We also compared the entire sequences of the gene between two non-waxy accessions and three waxy cultivars and found a 275-bp deletion in the coding region (exons 10?C11) of this gene specific to waxy cultivars. We showed by PCR genotyping that this deletion is commonly found in Japanese and Korean cultivars and confirmed that this deletion resulted in lack of Wx protein. We also confirmed that this polymorphism of the gene co-segregates with phenotypes in endosperm and pollen. These results suggest that this PCR-based marker will be useful in breeding of Job??s tears and that genetic information obtained in other grass species will be also useful in genetics and breeding of Job??s tears.