Prognostic value of resting heart rate in predicting undiagnosed diabetes in adults: Korean National Health and Nutrition Examination Survey 2008-2018.

BACKGROUND AND AIM: Although resting heart rate (RHR) is associated with prevalence and incidence of diabetes, whether it is associated with undiagnosed diabetes is still unclear. We aimed to investigate whether the RHR is associated with the prevalence of undiagnosed diabetes in a large Korean national dataset. METHODS AND RESULTS: The Korean National Health and Nutrition Examination Survey data from 2008 to 2018 were used. After screening, 51,637 participants were included in this study. The odds ratios and 95% confidence intervals (CIs) for undiagnosed diabetes were calculated using multivariable-adjusted logistic regression analyses. Analyses showed that participants with a RHR of ≥90 bpm showed a 4.00- (95% CI: 2.77-5.77) and 3.21-times (95% CI: 2.01-5.14) higher prevalence of undiagnosed diabetes for men and women, respectively, than those with a RHR of <60 bpm. The linear dose-response analyses showed that each 10-bpm increment in RHR was associated with a 1.39- (95% CI: 1.32-1.48) and 1.28-times (95% CI: 1.19-1.37) higher prevalence of undiagnosed diabetes for men and women, respectively. In the stratified analyses, the positive association between RHR and the prevalence of undiagnosed diabetes was tended to be stronger among those who were younger (age: <40 years) and lean (BMI: <23 kg/m2). CONCLUSIONS: Elevated RHR was significantly associated with a higher prevalence of undiagnosed diabetes in Korean men and women, independent of demographic, lifestyle, and medical factors. Accordingly, the value of RHR as a clinical indicator and health marker, especially in reducing the prevalence of undiagnosed diabetes, is suggestible.

Associations Between Korean Coronary Heart Disease Risk Score and Cognitive Function in Dementia-Free Korean Older Adults.

BACKGROUND: Cardiovascular risk is a modifiable factor that can help prevent dementia. Given the dearth of optimal treatment options, managing dementia risk factors is crucial. We examined the association between cardiovascular risk, as measured by the Korean coronary heart disease risk score (KRS), and cognitive function in dementia-free elderly individuals. METHODS: We enrolled 8,600 individuals (average age: 69.74 years; 5,206 women) who underwent a medical evaluation from the National Health Insurance Service. KRS was calculated using age, sex, blood pressure, lipid profile, diabetes, and smoking status. Cognitive function was evaluated using Korean Dementia Screening Questionnaire-Cognition (KDSQ-C). Scores of ≥ 6 indicated a cognitive decline. Logistic regression analysis was used to estimate the odds ratio (OR) and 95% confidence interval (CI). Weight, height, stroke history, coronary heart disease history, alcohol consumption, and physical activity engagement were adjusted. RESULTS: The lowest, middle, and highest groups, according to the KRS, were 5,923 (68.9%), 2,343 (27.2%), and 334 (3.9%), respectively. The highest KRS group in all participants exhibited a greater risk of cognitive decline than the lowest KRS group (OR, 1.339; 95% CI, 1.034-1.734; P = 0.027). The highest KRS female group aged 71-75 years old exhibited greater cognitive decline than the corresponding lowest KRS group (OR, 1.595; 95% CI, 1.045-2.434; P = 0.031). CONCLUSION: Individuals with high cardiovascular risk were associated with poorer cognitive function than those with low risk, especially older women. Cardiovascular risk factors should be carefully managed to promote healthy mental aging in dementia-free elderly individuals.

Causal Associations Between Serum Bilirubin Levels and Decreased Stroke Risk: A Two-Sample Mendelian Randomization Study.

OBJECTIVE: A number of epidemiological studies have reported that decreased serum bilirubin, an endogenous antioxidant, is associated with cardiovascular disease. However, previous Mendelian randomization analyses conducted using a single sample have shown no evidence of association. Approach and Results: A 2-sample summary Mendelian randomization study was performed by obtaining exposure and outcome data from separate nonoverlapping samples. We utilized data from the KoGES (Korean Genome and Epidemiology Study; n=25 406) and KCPS-II (Korean Cancer Prevention Study-II; n=14 541) biobank for serum bilirubin and stroke, respectively. Using KoGES, a total of 1784 single nucleotide polymorphisms associated with serum bilirubin levels were discovered using a genome-wide significance threshold (P<5×10-8), of which 10 single nucleotide polymorphisms were identified as independent (R2<0.005) and adopted as genetic instruments. From KCPS-II, total and ischemic stroke cases were identified (n=1489 and n=686), with 12 366 acting as controls. Various 2-sample summary Mendelian randomization methods were employed, with Mendelian randomization estimates showing an inverse causal association between serum bilirubin levels and total stroke risk (odds ratio, 0.481 [95% CI, 0.234-0.988]; P=0.046). This association increased in magnitude when restricting the analysis to ischemic stroke cases (odds ratio, 0.302 [95% CI, 0.105-0.868]; P=0.026). CONCLUSIONS: Our findings provide evidence of significant causal relationship between high levels of bilirubin and decreased stroke risk in Korean population in agreement with observational approaches. This highlights the potential for bilirubin to serve as a therapeutic target for oxidative stress-related diseases such as stroke and suggests that previous findings were not a consequence of unmeasured confounding.

Genotypes of Blastocystis sp. among elderly health checkup people in South Korea with a questionnaire on risk factors.

Blastocystis sp. is a common zoonotic intestinal parasite of humans and animals, and has been classified into at least 17 distinct subtypes. Despite its potential impact on public health, the prevalence and subtype distribution of Blastocystis sp. have seldom been the study subject in South Korea. To determine the prevalence and subtype distribution of Blastocystis sp. and to obtain information on risk factors, we performed a cross-sectional study targeting elderly health checkup people, who visited Seoul Western Branch of the Korea Association of Health Promotion (KAHP) in October 2019. Stool samples were collected from 293 participants consisting of 128 males and 165 females with a mean age of 64.7 years (from 50 to 88 years) with a questionnaire on potential risk factors. All the samples were tested by PCR targeting the SSU rRNA gene of Blastocystis sp., and nucleotide sequences of positive samples were used to identify the subtypes. The overall prevalence of Blastocystis sp. was 9.2% (27/293). Among the positive samples, subtype 3 was predominant (59%; 16/27), followed by subtype 1 (41%; 11/27). No other subtypes were detected. In the univariable analysis, the age, sex, presence of digestive symptoms, source of drinking water, and history of drug intake were not significantly associated with Blastocystis sp. infection. Two parameters, including the Enterococcus hirae bacterial infection and the frequency of intake of cooked or boiled vegetables less than twice a week, showed statistical significance. However, the multivariable regression analysis revealed that only the latter parameter was statistically significant. The results suggested that subtypes 3 and 1 are the 2 major genotypes of Blastocystis sp. among elderly people in South Korea, and low frequency of consuming cooked or boiled vegetables is a potential risk factor.

A Meta-analysis of the Association of Estimated GFR, Albuminuria, Age, Race, and Sex With Acute Kidney Injury.

BACKGROUND: Acute kidney injury (AKI) is a serious global public health problem. We aimed to quantify the risk of AKI associated with estimated glomerular filtration rate (eGFR), albuminuria (albumin-creatinine ratio [ACR]), age, sex, and race (African American and white). STUDY DESIGN: Collaborative meta-analysis. SETTING & POPULATION: 8 general-population cohorts (1,285,049 participants) and 5 chronic kidney disease (CKD) cohorts (79,519 participants). SELECTION CRITERIA FOR STUDIES: Available eGFR, ACR, and 50 or more AKI events. PREDICTORS: Age, sex, race, eGFR, urine ACR, and interactions. OUTCOME: Hospitalized with or for AKI, using Cox proportional hazards models to estimate HRs of AKI and random-effects meta-analysis to pool results. RESULTS: 16,480 (1.3%) general-population cohort participants had AKI over a mean follow-up of 4 years; 2,087 (2.6%) CKD participants had AKI over a mean follow-up of 1 year. Lower eGFR and higher ACR were strongly associated with AKI. Compared with eGFR of 80mL/min/1.73m(2), the adjusted HR of AKI at eGFR of 45mL/min/1.73m(2) was 3.35 (95% CI, 2.75-4.07). Compared with ACR of 5mg/g, the risk of AKI at ACR of 300mg/g was 2.73 (95% CI, 2.18-3.43). Older age was associated with higher risk of AKI, but this effect was attenuated with lower eGFR or higher ACR. Male sex was associated with higher risk of AKI, with a slight attenuation in lower eGFR but not in higher ACR. African Americans had higher AKI risk at higher levels of eGFR and most levels of ACR. LIMITATIONS: Only 2 general-population cohorts could contribute to analyses by race; AKI identified by diagnostic code. CONCLUSIONS: Reduced eGFR and increased ACR are consistent strong risk factors for AKI, whereas associations of AKI with age, sex, and race may be weaker in more advanced stages of CKD.

Smoking-attributable mortality among Korean adults in 2019.

OBJECTIVES: Tobacco use ranks among the leading preventable causes of death worldwide. This study was conducted to calculate the mortality rate attributable to smoking in Korea for 2019 and to highlight the importance of tracking and monitoring smoking-related deaths for public health purposes. METHODS: Population attributable risk (PAR) was used to estimate the number of deaths related to smoking in 2019. PAR percentages were applied to the estimated mortality figures for various diseases, with PAR determined based on relative risk (RR). Levin's formula was used to calculate PAR, and RR was adjusted for age and alcohol consumption using Cox proportional hazards regression model to derive disease-specific regression coefficients. The analysis incorporated previously determined smoking rates from 1985, and use rates of novel tobacco products were not considered. RESULTS: The findings revealed a total of 67,982 smoking-attributable deaths in Korea in 2019, 56,993 of which occurred in men and 11,049 in women. The PAR of smoking for various causes of death in adult men was highest for lung cancer at 74.9%, followed by pneumonia (29.4%), ischemic heart disease (42.3%), and stroke (30.2%). For women, the PAR for smoking-related death was highest for lung cancer (19.9%), followed by stroke (7.6%), pneumonia (5.7%), and ischemic heart disease (9.1%). CONCLUSIONS: In countries experiencing rapid fluctuations in smoking rates, including Korea, regular studies on smoking-related mortality is imperative. Furthermore, it is necessary to investigate smoking-related deaths, including the prevalence of novel tobacco product use, to accurately gauge the risks associated with emerging tobacco products.

Factors Influencing Compliance With Social Distancing as a Nonpharmaceutical Intervention Before Vaccine Availability During the COVID-19 Pandemic: A Cross-Sectional Study in South Korea.

This study aimed to identify factors influencing compliance with social distancing, a key nonpharmaceutical intervention during the early stages of the coronavirus disease (COVID-19) pandemic. The study population comprised 182 758 Koreans who participated in the 2020 Community Health Survey. Personal characteristics were classified into sociodemographic, health behavioral, and psychosocial factors, and factors associated with social distancing compliance were identified. Health behaviors and psychosocial factors were highly related to compliance with social distancing. Approximately 13% of smokers were less likely to practice physical distancing and 50% of high-risk drinkers were less likely to limit going out or attending gatherings and events. Higher concern about COVID-19 and a more positive perception of the government's response policy were associated with a higher compliance with social distancing. Strategic public health policies considering the characteristics of the public are needed to enhance compliance with nonpharmaceutical interventions during disease outbreaks lacking effective treatments and vaccines.

Genome-wide association studies in a large Korean cohort identify novel quantitative trait loci for 36 traits and illuminates their genetic architectures.

Genome-wide association studies (GWAS) have been predominantly conducted in populations of European ancestry, limiting opportunities for biological discovery in diverse populations. We report GWAS findings from 153,950 individuals across 36 quantitative traits in the Korean Cancer Prevention Study-II (KCPS2) Biobank. We discovered 616 novel genetic loci in KCPS2, including an association between thyroid-stimulating hormone and CD36. Meta-analysis with the Korean Genome and Epidemiology Study, Biobank Japan, Taiwan Biobank, and UK Biobank identified 3,524 loci that were not significant in any contributing GWAS. We describe differences in genetic architectures across these East Asian and European samples. We also highlight East Asian specific associations, including a known pleiotropic missense variant in ALDH2, which fine-mapping identified as a likely causal variant for a diverse set of traits. Our findings provide insights into the genetic architecture of complex traits in East Asian populations and highlight how broadening the population diversity of GWAS samples can aid discovery.

Adiponectin concentrations: a genome-wide association study.

Adiponectin is associated with obesity and insulin resistance. To date, there has been no genome-wide association study (GWAS) of adiponectin levels in Asians. Here we present a GWAS of a cohort of Korean volunteers. A total of 4,001 subjects were genotyped by using a genome-wide marker panel in a two-stage design (979 subjects initially and 3,022 in a second stage). Another 2,304 subjects were used for follow-up replication studies with selected markers. In the discovery phase, the top SNP associated with mean log adiponectin was rs3865188 in CDH13 on chromosome 16 (p = 1.69 × 10(-15) in the initial sample, p = 6.58 × 10(-39) in the second genome-wide sample, and p = 2.12 × 10(-32) in the replication sample). The meta-analysis p value for rs3865188 in all 6,305 individuals was 2.82 × 10(-83). The association of rs3865188 with high-molecular-weight adiponectin (p = 7.36 × 10(-58)) was even stronger in the third sample. A reporter assay that evaluated the effects of a CDH13 promoter SNP in complete linkage disequilibrium with rs3865188 revealed that the major allele increased expression 2.2-fold. This study clearly shows that genetic variants in CDH13 influence adiponectin levels in Korean adults.

Thigh circumference and diabetes: obesity as a potential effect modifier.

BACKGROUND: Thigh circumference is associated with diabetes risk; however, the role of obesity as a potential effect modifier has not been well studied. METHODS: We examined the association between thigh circumference and diabetes in a cross-sectional study of 384 612 Koreans aged 30 to 79 years. The association between diabetes and thigh circumference in relation to body mass index (BMI) was analyzed among 315 628 participants, using multivariate logistic regression. Thigh circumference was categorized into 9 percentile categories-namely, the 2.5th, 5th, 10th, 25th, 50th, 75th, 90th, 95th, and 97.5th percentiles-and the 50th percentile was used as the reference value for thigh circumference. Separate analyses were performed for men and women. RESULTS: The association of thigh circumference with diabetes showed contradictory patterns before and after adjustment for BMI and waist circumference. Small thigh circumference was associated with greater risk of diabetes among men and women. This relationship was stronger among participants younger than 50 years, although age was not a significant effect modifier. BMI was a significant effect modifier among men with a BMI of less than 25 kg/m(2). Among women, diabetes risk increased with smaller thigh circumference. CONCLUSIONS: Small thigh circumference was associated with diabetes, and this association was stronger among participants with a BMI of less than 25 kg/m(2). Thigh circumference might be a useful diabetes marker in lean populations.

Correction: Heated tobacco product use and its relationship to quitting combustible cigarettes in Korean adults.

[This corrects the article DOI: 10.1371/journal.pone.0251243.].

Metabolic changes preceding bladder cancer occurrence among Korean men: a nested case-control study from the KCPS-II cohort.

BACKGROUND: Bladder cancer (BLCA) research in Koreans is still lacking, especially in focusing on the prediction of BLCA. The current study aimed to discover metabolic signatures related to BLCA onset and confirm its potential as a biomarker. METHODS: We designed two nested case-control studies using Korean Cancer Prevention Study (KCPS)-II. Only males aged 35-69 were randomly selected and divided into two sets by recruitment organizations [set 1, BLCA (n = 35) vs. control (n = 35); set 2, BLCA (n = 31) vs. control (n = 31)]. Baseline serum samples were analyzed by non-targeted metabolomics profiling, and OPLS-DA and network analysis were performed. Calculated genetic risk score (GRS) for BLCA from all KCPS participants was utilized for interpreting metabolomics data. RESULTS: Critical metabolic signatures shown in the BLCA group were dysregulation of lysine metabolism and tryptophan-indole metabolism. Furthermore, the prediction model consisting of metabolites (lysine, tryptophan, indole, indoleacrylic acid, and indoleacetaldehyde) reflecting these metabolic signatures showed mighty BLCA predictive power (AUC: 0.959 [0.929-0.989]). The results of metabolic differences between GRS-high and GRS-low groups in BLCA indicated that the pathogenesis of BLCA is associated with a genetic predisposition. Besides, the predictive ability for BLCA on the model using GRS and five significant metabolites was powerful (AUC: 0.990 [0.980-1.000]). CONCLUSION: Metabolic signatures shown in the present research may be closely associated with BLCA pathogenesis. Metabolites involved in these could be predictive biomarkers for BLCA. It could be utilized for early diagnosis, prognostic diagnosis, and therapeutic targets for BLCA.

Do Weight Changes Affect the Association between Smoking Cessation and the Risk of Stroke Subtypes in Korean Males?

(1) Background: We investigated whether weight changes affect the association between smoking cessation and stroke risk; (2) Methods: Overall, 719,040 males were categorized into eight groups according to smoking status (sustained smokers, non-smokers, long-term quitters (quit > 4 years), and recent quitters (quit < 4 years)) and post-cessation weight change (-5 kg, -5.0 to 0.1 kg, maintainers, 0.1-5.0 kg, and >5.0 kg). The hazard ratios (HR) and 95% confidence intervals (CI) for incident total, ischemic, and hemorrhagic strokes, including subarachnoid and intracerebral hemorrhage, were calculated using Cox proportional hazard models; (3) Results: We detected 38,730 strokes (median follow-up, 25.7 years), including 30,609 ischemic and 9055 hemorrhagic strokes. For recent quitters with a >5.0 kg or 0.1-5.0 kg weight increase, maintainers, or those who lost 0.1-5 kg, the multivariable HR for total stroke was 0.73 (95% CI, 0.67-0.79), 0.78 (95% CI, 0.74-0.82), 0.77 (95% CI, 0.69-0.85), 0.84 (95% CI, 0.77-0.90), and 1.06 (95% CI, 0.92-1.23), respectively, compared with that of sustained smokers; (4) Conclusions: Comparable patterns were obtained for stroke subtypes. Thus, we strongly recommend quitting smoking, as weight gain after quitting smoking does not alter the stroke-related benefits.

Physical activity level and risk of death: the severance cohort study.

BACKGROUND: Physical activity decreases deaths from cardiovascular disease and other causes; however, it is unclear whether physical activity is associated with cancer incidence and death in Asian populations. METHODS: Data from 59 636 Koreans aged 30 to 93 years were collected using a questionnaire and medical examination at the Severance Hospital Health Promotion Center between 1994 and 2004. Study participants were followed for a mean duration of 10.3 years. RESULTS: In the exercising group, the multivariate Cox proportional hazards model showed a lower risk of cancer death (hazard ratio [HR] = 0.72, 95% CI = 0.62-0.85) in men but not in women. Those who exercised, as compared with those who did not, had lower risks of all-cause death (men: HR = 0.68, 95% CI = 0.60-0.76; women: HR = 0.65, 95% CI = 0.53-0.79) and noncancer death (men: 0.63, 0.53-0.75; women: 0.52, 0.39-0.69). Physical activity was inversely associated with risk of noncancer death among men and women. CONCLUSIONS: Physical activity was associated with lower risks of cancer death and noncancer death.

Effects of a combined lifestyle score on 10-year mortality in Korean men and women: a prospective cohort study.

BACKGROUND: Most studies that have evaluated the association between combined lifestyle factors and mortality outcomes have been conducted in populations of Caucasian origin. The objective of this study was to examine the association between combined lifestyle scores and the risk of mortality in Korean men and women. METHODS: The study population included 59,941 Koreans, 30-84 years of age, who had visited the Severance Health Promotion Center between 1994 and 2003. Cox regression models were fitted to establish the association between combined lifestyle factors (current smoker, heavy daily alcohol use, overweight or obese weight, physical inactivity, and unhealthy diet) and mortality outcomes. RESULTS: During 10.3 years of follow-up, there were 2,398 cases of death from any cause. Individual and combined lifestyle factors were found to be associated with the risk of mortality. Compared to those having none or only one risk factor, in men with a combination of four lifestyle factors, the relative risk for cancer mortality was 2.04-fold, for non-cancer mortality 1.92-fold, and for all-cause mortality 2.00-fold. In women, the relative risk was 2.00-fold for cancer mortality, 2.17-fold for non-cancer mortality, and 2.09-fold for all-cause mortality. The population attributable risks for all-cause mortality for the four risk factors combined was 44.5% for men and 26.5% for women. CONCLUSION: This study suggests that having a high (unhealthy) lifestyle score, in contrast to a low (healthy) score, can substantially increase the risk of death by any cause, cancer, and non-cancer in Korean men and women.

Life satisfaction and mortality in elderly people: the Kangwha Cohort Study.

BACKGROUND: As well as biomedical risk factors, psychological factors have been reported to be related to mortality rate. The purpose of this study was to examine the relationship between life satisfaction and mortality in elderly people through an 11.8-year follow-up study of a prospective cohort. METHODS: Among 3,600 participants of the Kangwha Cohort Study who survived in 1994, 1,939 respondents of the Life Satisfaction Index (LSI)-A questionnaire were included (men, 821; women, 1118). The mortality risk for the period up to December 2005 was measured using the Cox Proportional Hazard Model. RESULTS: When the relationship between LSI and mortality was evaluated in men, the unsatisfied group with lower LSI scores showed a significantly higher risk of all-cause mortality (hazard ratio [HR], 1.42; 95% confidence interval [CI], 1.11-1.83) than the satisfied group with higher LSI scores. In women, the unsatisfied group showed a significantly higher risk of all-cause mortality (HR, 1.51; 95% CI, 1.18-1.92) and cardiovascular mortality (HR, 2.23; 95% CI, 1.30-3.85) than the satisfied group. CONCLUSION: We found that elderly people with a lower LSI score, regardless of gender, were at risk of increased mortality from all causes, and low LSI score was also associated with cardiovascular mortality.

Overall quit in triple users of conventional cigarette, e-cigarette and heated tobacco product among healthy adults: a Korea Medical Institute health check-up study.

OBJECTIVE: While multiuse patterns of e-cigarettes (EC) or heated tobacco products (HTP) with conventional cigarettes (CC) have been reported, smoking cessation of multiusers is not well known. We aimed to analyse overall quit in triple users of CC, EC and HTP among healthy adults. METHODS: A questionnaire was conducted on 89 360 adults who visited the Korea Medical Institute health check-ups in Seoul, Korea, from May 2018 to September 2019. Among 38 812 ever smokers, 9252 were ever triple users of CC, EC and HTP. Frequency and related factors of overall quit were analysed in the cross-sectional study. RESULTS: The average age was 38.8±9.0 years, and 8458 (91.4%) were men. There were 5329 (57.6%) current triple users, 3547 (38.3%) single or dual product quitters and 376 (4.1%) overall quitters. Among the former triple users, the most common tobacco product use pattern was 'dual quit of EC and HTP (eg, current CC use)' both in men (21.3%) and women (26.3%). Age 60s or older (OR 8.5, 95% CI 5.2 to 13.8), women (OR 1.7, 95% CI 1.1 to 2.5), no hyperlipidaemia and married status were significantly related to overall quit. CONCLUSION: The most common pathway for 'ever triple users' of the three tobacco products was 'current triple users', and the second was 'CC users'. Single or dual product quitters could continue to smoke by EC or HTP instead of quit. Further research on overall quit will be needed to develop effective regulations.

Prediction of cancer survivors' mortality risk in Korea: a 25-year nationwide prospective cohort study.

OBJECTIVES: This study aimed to investigate the factors affecting cancer survival and develop a mortality prediction model for Korean cancer survivors. Our study identified lifestyle and mortality risk factors and attempted to determine whether health-promoting lifestyles affect mortality. METHODS: Among the 1,637,287 participants in the Korean Cancer Prevention Study (KCPS) cohort, 200,834 cancer survivors who were alive after cancer diagnosis were analyzed. Discrimination and calibration for predicting the 10-year mortality risk were evaluated. A prediction model was derived using the Cox model coefficients, mean risk factor values, and mean mortality from the cancer survivors in the KCPS cohort. RESULTS: During the 21.6-year follow-up, the all-cause mortality rates of cancer survivors were 57.2% and 39.4% in men and women, respectively. Men, older age, current smoking, and a history of diabetes were high-risk factors for mortality, while exercise habits and a family history of cancer were associated with reduced risk. The prediction model discrimination in the validation dataset for both KCPS all-cause mortality and KCPS cancer mortality was shown by C-statistics of 0.69 and 0.68, respectively. Based on the constructed prediction models, when we modified exercise status and smoking status, as modifiable factors, the cancer survivors' risk of mortality decreased linearly. CONCLUSIONS: A mortality prediction model for cancer survivors was developed that may be helpful in supporting a healthy life. Lifestyle modifications in cancer survivors may affect their risk of mortality in the future.

Alanine aminotransferase is associated with metabolic syndrome independently of insulin resistance.

BACKGROUND: Few studies have examined the effect of insulin resistance on the association between alanine aminotransferase (ALT) and metabolic syndrome. The association between ALT levels and metabolic syndrome were determined, independently of insulin resistance in Korean populations. METHODS AND RESULTS: The association between ALT and metabolic syndrome were examined in 28,456 subjects who visited 7 Health Promotion Centers at University Hospitals in Korea from 2006 to 2008. HOMA-IR index was used to represent insulin resistance index. ALT levels were found to be positively associated with metabolic syndrome after adjusting for age, alcohol intake, and smoking status. Furthermore, when additional adjustment was made for insulin resistance, this association between ALT and metabolic syndrome, although slightly attenuated, remained strongly significant. Subjects in the highest ALT quartile were found to have a higher risk of having metabolic syndrome than those in the lowest quartile (odds ratio (OR)=4.45, 95% confidence interval (CI)=3.96-4.99 for men and OR=3.51, 95%CI=2.73-4.52 for women). In addition, the association between ALT level and the risk of metabolic syndrome was significantly higher in the relatively low risk group. CONCLUSIONS: ALT levels were found to be significantly associated with metabolic syndrome independently of insulin resistance and with an interaction by age. Further cohort studies are needed to determine the usefulness of ALT levels for predicting the risk of metabolic syndrome.

Association of the leptin to high-molecular-weight adiponectin ratio with metabolic syndrome.

Recent studies have reported that leptin and adiponectin are associated with metabolic syndrome. The leptin/adiponectin ratio has been suggested as an atherosclerotic index. The objective of this study was to compare the degree of association of metabolic syndrome with adiponectin levels, leptin levels, leptin/adiponectin ratio, and leptin/high-molecular-weight (HMW) adiponectin ratio. The study population included 3272 Koreans (men: 1915, women: 1357; age, 30-84 years), who had visited the Health Examination Center. Adipokines were divided into quartiles, and metabolic syndrome was defined by the National Cholesterol Education Program Adult Treatment Panel-III (NCEP ATP III). A logistic regression model was fitted to establish the association between adipokines and metabolic syndrome. Adipokines, such as adiponectin, HMW adiponectin, and leptin, were found to be statistically related to metabolic syndrome. Compared to the lowest quartile, the leptin/HMW adiponectin ratio in the highest quartile was associated with a 5-fold increase in the probability of prevalent metabolic syndrome, which was independent of age, smoking status, exercise, low-density lipoprotein (LDL) cholesterol, and body mass index. There was a linear increase in the leptin/HMW adiponectin ratio as the number of metabolic syndrome components increased. The leptin/HMW adiponectin ratio had the highest odds ratio in women. In addition, compared to adiponectin or leptin alone, the AUC of the leptin/adiponectin ratio and leptin/HMW adiponectin ratio was higher for metabolic syndrome. We may suggest that the leptin/HMW adiponectin ratio is not superior to other adipokine markers, but is as effective as the leptin/total adiponectin ratio.