There are a few studies that reported the association of sleep duration with calorie intake and energy expenditure. Using cross-sectional data from a population-based prospective study, we evaluated the association of sleep duration with indicators of obesity including body mass index and waist circumference, calorie intake and its proportion of macronutrients, and physical activity. The study subjects were 4,226 male and female adults, who were aged 40 to 69 years and were free of diagnosed cardiovascular disease, diabetes mellitus, and dyslipidemia at baseline. Robust regression analysis was used to analyze associations. The study found that sleep duration is inversely associated with waist circumference, calorie intake, and percent of calories from fat intake and is positively associated with percent of calories from carbohydrate intake and physical activity. The inverse association between sleep duration and waist circumference was stronger among men than among women. The inverse association between sleep duration and calorie intake was stronger among women than among men and such association was also stronger among obese persons than those with a normal body mass index. The positive association between sleep duration and physical activity was strongly demonstrated regardless of sex or obesity. Physical activity is positively associated with sleep duration independent of potential confounding factors including age, sex, income, occupation, marital status, education, smoking status, waist circumference, calorie and macronutrient intake, and alcohol intake.
Adult ; Aged ; Body Mass Index ; Cardiovascular Diseases ; Diabetes Mellitus ; Dyslipidemias ; Energy Metabolism ; Female ; Humans ; Male ; Marital Status ; Motor Activity ; Obesity ; Occupations ; Prospective Studies ; Smoke ; Smoking ; Waist Circumference

Folate, vitamin B12, and homocysteine (HCY) are involved in the metabolism of nucleic acid precursors and it has been hypothesized that they also influence telomere length, a biomarker of aging. However, previous studies have reported inconsistent findings, and data for older adults are limited. Our study aimed to evaluate associations between leukocyte telomere length (LTL) and serum folate, vitamin B12, and HCY levels among adults aged 55 years and over. In a cross-sectional study in 798 men and women aged 55-79 years, serum folate, vitamin B12, and HCY levels were measured using chemiluminescent immunometric assays, and relative LTL was assessed using quantitative real-time polymerase chain reaction. To evaluate associations between LTL and serum folate, vitamin B12, and HCY levels, multiple linear regression models were used. In multiple models adjusted for age, sex, serum high sensitive C-reactive protein (hs-CRP) levels, and other potential confounding factors, we found no association between LTL and serum folate, vitamin B12, and HCY levels. However, we did find a significant inverse association between HCY levels and LTL in participants with serum hs-CRP levels of > or = 2 mg/L (p < 0.05). Moreover, there was a trend toward an association between HCY and vitamin B12 levels in these individuals (p = 0.08). In those with serum hs-CRP levels of < 2 mg/L, HCY was inversely associated with vitamin B12 levels (p < 0.001) and had no association with LTL. Our findings suggest that increased serum HCY levels, when combined with the presence of systemic inflammation, may play a role in accelerating biological aging.
Adult* ; Aging ; C-Reactive Protein ; Cross-Sectional Studies ; Female ; Folic Acid ; Homocysteine* ; Humans ; Inflammation* ; Leukocytes* ; Linear Models ; Male ; Metabolism ; Nucleic Acid Precursors ; Real-Time Polymerase Chain Reaction ; Telomere* ; Vitamin B 12* ; Vitamin B Complex ; Vitamins*

There are few studies reporting optimal waist circumference that can be utilized to prevent the incidence of cardiovascular disease (CVD). We evaluated the association of waist circumference and waist and hip circumference ratio (WHR) with incident cases of CVD developed over 6 years in a population-based prospective study including Korean adults. Analyses for receiver-operating characteristic (ROC) curve were performed with data for 1,733 men and 1,579 women who were aged 40 to 69 years and were free of a physician-diagnosis of CVD at baseline. Information on the diagnosis of CVD was periodically reported using interviewer-administered questionnaires and anthropometric measures were obtained by biennial health examinations. We newly identified 77 cases of CVD during a follow-up period between 2003 and 2008. On the basis of measures of diagnostic accuracy including minimum distance to ROC curve and Youden index, waist circumference of 85 cm for men, in particular for male nonsmokers, and of 80 cm for women and WHR of 0.88 to 0.90 for men and of 0.83 for women were found to be optimal cutoff points to identify individuals at CVD risks. The study also found that the use of the suggested optimal values for waist circumference show higher sensitivity and lower specificity compared with 90 cm for men and 85 cm for women, which are waist cutoff points given by the Korean Society for the Study of Obesity to define abdominal obesity for Korean adults. Although lower cutoff points of waist circumference (83 cm) and WHR (0.87) were observed to be optimal for male smokers compared with male nonsmokers, whether suggesting waist cutoff points specific to smokers is needed warrants further studies. After taking into account other cardiovascular risk factors including smoking, men with waist circumference of 85 cm or greater and women with 80 cm or greater were at an increased risk of CVD. Thus, these cutoff points of waist circumference may be able to capture more individuals at CVD risks contributing to the prevention of future development of CVD.
Adult ; Aged ; Cardiovascular Diseases ; Female ; Follow-Up Studies ; Hip ; Humans ; Incidence ; Male ; Obesity ; Obesity, Abdominal ; Prospective Studies ; Surveys and Questionnaires ; Risk Factors ; ROC Curve ; Sensitivity and Specificity ; Smoke ; Smoking ; Waist Circumference

It has been suggested that iron overload, which indicates the accumulation of iron, generates cellular reactive oxygens and causes peroxide damages to the body. Such oxidative stresses, in a broader context, are also caused by lifestyles such as alcohol consumption and smoking. However, there are limited data on the association between these lifestyle factors and internal iron overload. In present study, we evaluated associations between lifestyle factors, such as smoking status, alcohol consumption, and physical activity, and serum markers of iron overload. In a population-based cross-sectional study including 2,347 Korean men and women aged 49–79 years, we assessed serum transferrin saturation (TSAT) levels and defined iron overload as TSAT levels > 50% for men and > 45% for women. After excluding persons with chronic diseases and iron deficiency, multivariate odds ratio (OR) and its 95% confidence interval (CI) were estimated to evaluate associations between lifestyle factors and iron overload in 1,973 participants. In all participants, we examined a significantly positive association between heavy alcohol consumption (> 30 g/day) and iron overload; heavy drinkers showed 1.6-fold higher OR (95% CI, 1.11–2.36) than non-drinkers. Stratified analysis by sex showed that this association was significant only among men. In addition, we observed a potential association between heavy smoking > 10 cigarettes/day and iron overload (p = 0.07). In stratified analysis by sex, we examined a significant association between smoking and iron overload only among women; former or current smokers had 1.9-fold higher OR (95% CI, 1.01–3.63) than never-smoker. Our findings suggest that heavy alcohol consumption and smoking may worsen iron accumulation in the body.
Adult* ; Alcohol Drinking ; Biomarkers ; Chronic Disease ; Cross-Sectional Studies ; Female ; Humans ; Iron Overload* ; Iron* ; Life Style* ; Male ; Motor Activity ; Odds Ratio ; Oxidative Stress ; Oxygen ; Smoke ; Smoking ; Transferrin

OBJECTIVES: This prospective cohort study investigated the association between blood pressure (BP) as measured in different body postures and all-cause and cardiovascular (CV) mortality risk. METHODS: This population-based investigation included 8,901 Korean adults in 2001 and 2002. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured sequentially in the sitting, supine, and standing positions and classified into 4 categories: (1) normal, SBP <120 mmHg and DBP <80 mmHg; (2) high normal/prehypertension, SBP 120-129 mmHg and DBP <80 mmHg/SBP 130-139 mmHg or DBP 80-89 mmHg; (3) grade 1 hypertension (HTN), with SBP 140-159 mmHg or DBP 90-99 mmHg; and (4) grade 2 HTN, SBP ≥160 mmHg or DBP ≥100 mmHg. The date and cause of individual deaths were confirmed in the death record data compiled until 2013. Data were analyzed using Cox proportional hazard regression. RESULTS: Significant associations were found between the BP categories and all-cause mortality, but only when BPs were measured in the supine position. The multivariate hazard ratios (95% confidence intervals, [CIs]) were 1.36 (95% CI, 1.06 to 1.75) and 1.59 (95% CI, 1.06 to 2.39) for grade 1 HTN and grade 2 HTN, respectively, compared with the normal category. The associations between the BP categories and CV mortality were significant regardless of body posture among participants ≥65 years, whereas they were significant for supine BP measurements only in those <65 years. CONCLUSIONS BP measured in the supine position predicted all-cause mortality and CV mortality better than BP measured in other postures.

Whether the FTO polymorphisms interact with environmental factors has not yet been evaluated in associations with metabolic syndrome (MS) risk. The present study investigated the association of the FTO rs9939609 genotypes, body mass index (BMI), and lifestyle-related factors including smoking, alcohol drinking, physical activity, and diet with MS incidence. A population-based prospective cohort study comprised 3,504 male and female Koreans aged 40 to 69 years. At the beginning of the study, all individuals were free of MS and known cardiovascular disease. Incident cases of MS were identified by biennial health examinations during a follow-up period from April 17, 2003 to April 15, 2009. Pooled logistic regression analysis was applied to obtain relative odds (RO) of MS with its 95% confidence interval (CI). After controlling for potential MS risk factors, we observed no association between the rs9939609 genotypes and MS incidence. In analysis stratified by BMI, however, carriers with the FTO risk allele whose BMI is 29 kg/m2 or greater showed an approximately 6-fold higher RO (95% CI: 3.82 to 9.30) compared with non-carriers with BMI less than 25 kg/m2. In particular, the association between the rs9939609 variants and MS risk was significantly modified by high BMI (P-value for interaction < 0.05). Such significant interaction appeared in associations with central obesity and high blood pressure among the MS components. Because carriers of the FTO risk alleles who had BMI of 29 kg/m2 or greater are considered a high risk population, we suggest that they may need intensive weight loss regimens to prevent MS development.
Aged ; Alcohol Drinking ; Alleles ; Body Mass Index ; Cardiovascular Diseases ; Cohort Studies ; Diet ; Female ; Follow-Up Studies ; Genotype ; Humans ; Hypertension ; Incidence ; Life Style ; Logistic Models ; Male ; Motor Activity ; Obesity, Abdominal ; Odds Ratio ; Prospective Studies ; Risk Factors ; Smoke ; Smoking ; Weight Loss

BACKGROUND/OBJECTIVES: It is well-known that alcohol consumption is associated with stroke risk as well as with aldehyde dehydrogenase 2 gene (ALDH2) polymorphisms. However, it is unclear whether ALDH2 polymorphisms are associated with stroke risk independent of alcohol consumption and whether such association is modified by sex. We evaluated sex-specific associations of a common ALDH2 polymorphism and alcohol consumption with stroke risk in a Korean population. SUBJECTS/METHODS: We conducted a prospective cohort study involving 8,465 men and women, aged 40-69 years and free of stroke between June, 2001 and January, 2003, and followed for the development of stroke. We identified new cases of stroke, which were self-reported or ascertained from vital registration data. Based on genome-wide association data, we selected a single-nucleotide polymorphism (rs2074356), which shows high linkage disequilibrium with the functional polymorphism of ALDH2. We conducted Cox proportional hazards regression analysis considering potential risk factors collected from a baseline questionnaire. RESULTS: Over the median follow-up of 8 years, 121 cases of stroke were identified. Carrying the wild-type allele of the ALDH2 polymorphism increased stroke risk among men. The multivariate hazard ratio [95% confidence interval] of stroke was 2.02 [1.03-3.99] for the wild-type allele compared with the mutant alleles, but the association was attenuated after controlling for alcohol consumption. Combinations of the wild-type allele and other risk factors of stroke, such as old age, diabetes mellitus, and habitual snoring, synergistically increased the risk among men. Among women, however, the ALDH2 polymorphism was not associated with stroke risk. CONCLUSIONS: The prospective cohort study showed a significant association between a common ALDH2 polymorphism and stroke risk in Korean men, but not in Korean women, and also demonstrated that men with genetic disadvantages gain more risk when having risk factors of stroke. Thus, these men may need to make more concerted efforts to control modifiable risk factors of stroke.
Alcohol Drinking* ; Aldehyde Dehydrogenase* ; Alleles ; Cohort Studies* ; Diabetes Mellitus ; Female ; Follow-Up Studies ; Humans ; Linkage Disequilibrium ; Male ; Prospective Studies* ; Surveys and Questionnaires ; Risk Factors ; Snoring ; Stroke*

There has been no genome-wide association study (GWAS) for macronutrient intake as a quantitative trait. To explore genetic loci associated with total calorie and macronutrient intake, genome-wide association data of autosomal single nucleotide polymorphisms (SNPs) from Korean adults were analyzed. We conducted a GWAS in 3,690 men and women aged 40 to 60 years from an urban population-based cohort. At the baseline examination (June 18, 2001 through January 29, 2003), DNA samples of the study subjects were collected and analyzed for genotyping. The information of average daily consumption of total calorie, carbohydrate, protein, and fat was obtained from a semi-quantitative food frequency questionnaire and transformed by natural logarithm for analyses after adjustment of calorie intake. Using multivariate linear regression analysis adjusted for age, sex, and height, we tested for 352,021 SNPs and found weak associations, which do not reach genome-wide association significance, with calorie and macronutrient intake. However, a number of SNPs were found to have potential associations with macronutrient intake; in particular, signals in SORBS1 and those in PRKCB1 were likely associated with carbohydrate and fat intake, respectively. We observed an inverse association between the minor allele of the SNPs in these genes and the amount of consumption of carbohydrate or fat. Our GWAS identified loci and minor alleles weakly associated with macronutrient intake. Because SORBS1 and PRKCB1 are reportedly associated with the metabolism of glucose and lipid as well as with obesity-related diseases, further investigations on biological and functional roles of polymorphism of these genes in the relation to macronutrient intake are warranted.
Adult ; Aged ; Alleles ; Cohort Studies ; DNA ; Female ; Genetic Loci ; Genome-Wide Association Study ; Glucose ; Humans ; Linear Models ; Lipid A ; Male ; Polymorphism, Single Nucleotide ; Surveys and Questionnaires

There are limited data on healthy dietary patterns protective against metabolic syndrome (MetSyn) development. We identified dietary patterns among middle-aged and older adults and investigated the associations with the incidence of MetSyn. A population-based prospective cohort study included 5,251 male and female Koreans aged 40-69 years. At baseline, all individuals were free of MetSyn, other major metabolic diseases, and known cardiovascular disease or cancer. Cases of MetSyn were ascertained over a 6-year of follow-up. Dietary patterns and their factor scores were generated by factor analysis using the data of a food frequency questionnaire. We performed pooled logistic regression analysis to estimate multivariable-adjusted relative risk (RR) and 95% confidence interval (CI) for associations between factor scores and MetSyn risk. Two dietary patterns were identified; (1) a healthy dietary pattern, which included a variety of foods such as fish, seafood, vegetables, seaweed, protein foods, fruits, dairy products, and grains; and (2) an unhealthy dietary pattern, which included a limited number of food items. After controlling for confounding factors, factor scores for the healthy dietary pattern were inversely associated with MetSyn risk (P-value for trend < 0.05) while those for the unhealthy dietary pattern had no association. Individuals in the top quintile of the healthy diet scores showed a multivariable-adjusted RR [95% CI] of 0.76 [0.60-0.97] for MetSyn risk compared with those in the bottom quintile. The beneficial effects were derived from inverse associations with abdominal obesity, low HDL-cholesterol levels, and high fasting glucose levels. Our findings suggest that a variety of healthy food choices is recommended to prevent MetSyn.
Adult ; Aged ; Cardiovascular Diseases ; Cohort Studies ; Dairy Products ; Diet ; Fasting ; Female ; Follow-Up Studies ; Fruit ; Glucose ; Humans ; Incidence ; Logistic Models ; Male ; Metabolic Diseases ; Obesity, Abdominal ; Prospective Studies ; Surveys and Questionnaires ; Seafood ; Seaweed ; Vegetables

Lipoprotein lipase (LPL) plays an essential role in the regulation of high-density lipoprotein cholesterol (HDLC) and triglyceride levels, which have been closely associated with cardiovascular diseases. Genetic studies in European have shown that LPL single-nucleotide polymorphisms (SNPs) are strongly associated with lipid levels. However, studies about the influence of interactions between LPL SNPs and lifestyle factors have not been sufficiently performed. Here, we examine if LPL polymorphisms, as well as their interaction with lifestyle factors, influence lipid concentrations in a Korean population. A two-stage association study was performed using genotype data for SNPs on the LPL gene, including the 3' flanking region from 7,536 (stage 1) and 3,703 (stage 2) individuals. The association study showed that 15 SNPs and 4 haplotypes were strongly associated with HDLC (lowest p = 2.86 x 10(-22)) and triglyceride levels (lowest p = 3.0 x 10(-15)). Interactions between LPL polymorphisms and lifestyle factors (lowest p = 9.6 x 10(-4)) were also observed on lipid concentrations. These findings suggest that there are interaction effects of LPL polymorphisms with lifestyle variables, including energy intake, fat intake, smoking, and alcohol consumption, as well as effects of LPL polymorphisms themselves, on lipid concentrations in a Korean population.
3' Flanking Region ; Alcohol Drinking ; Cardiovascular Diseases ; Cholesterol ; Cross-Sectional Studies ; Energy Intake ; Genotype ; Haplotypes ; Life Style ; Lipoprotein Lipase ; Lipoproteins ; Polymorphism, Single Nucleotide ; Smoke ; Smoking