Association between Sedentary Time and Cardiovascular Risk Factors in Korean Adults / 가정의학회지

BACKGROUND: Sedentary behavior has been shown to have deleterious effects on cardiovascular outcomes. This study aimed to examine the association between sedentary time and cardiovascular risk factors in Korean adults. METHODS: A cross-sectional study was performed using data from adults aged 19 years and above in the 2013 Korean National Health and Nutrition Examination Survey. Sedentary time was self-reported and categorized into quintiles. Cardiovascular risk factors, including blood pressure (BP), total cholesterol, high-density lipoprotein (HDL) cholesterol, triglycerides, low-density lipoprotein cholesterol, and fasting glucose levels, were categorized into dichotomous variables according to the Adult Treatment Panel III criteria. Multivariate logistic regression was performed with adjustment for various demographic and lifestyle variables, body mass index (BMI), waist circumference (WC), and moderate-to-vigorous physical activity. Complex sampling design was used, and survey weights and sample design variables were applied in analyses. RESULTS: A total of 3,301 individuals were included in the analyses, and mean sedentary time was 6.1 h/d. Prolonged sedentary time was significantly associated with high diastolic BP (top vs. bottom quintile: adjusted odds ratio [OR], 1.71; 95% confidence interval [CI], 1.09–2.68; Ptrend=0.03) and low HDL cholesterol level (top vs. bottom quintile: adjusted OR, 1.42; 95% CI, 1.02–1.98; Ptrend=0.02) after adjustment for BMI, WC, moderate-to-vigorous physical activity, and other variables. No significant associations were found between sedentary time and other cardiovascular risk factors. CONCLUSION: Prolonged sedentary time was significantly associated with high diastolic BP and low HDL cholesterol level in Korean adults. The associations were independent of general and abdominal obesity and moderate-to-vigorous physical activities.

Increased bone mineral density according to increase of skeletal muscle mass in 534 Korean women: A retrospective cohort study conducted over 2.7 years

OBJECTIVE: To determine the impact of the changes in the amount of abdominal fat, directly measured by computed tomography, body composition, and the metabolic syndrome (MetS) risk factors on the bone mineral density (BMD) of Korean women. METHODS: A retrospective cohort study involving 534 Korean women aged 29 to 78 years, who had undergone both dual-energy X-ray absorptiometry and abdominal adipose tissue analysis by computed tomography scan more than twice between January 2004 and December 2010. The changes in the BMD values were examined in association with the changes in fat amount, body composition parameters, and risk factors of MetS. RESULTS: On cross sectional analysis, there was a significant positive correlation between femoral BMD and total abdominal fat amount at the initial visit. However, the correlation disappeared when the impact of change of the fat amount on the change in BMD was analyzed over the study period. When the MetS and body composition parameters were analyzed, a significantly positive correlation was found between skeletal muscle mass and BMD. There was no significant relationship between the MetS risk factors or other body composition parameters and BMD throughout the study period after adjusting for age (time interval). CONCLUSION: Among body composition parameters, only increased skeletal muscle mass had a positive correlation with increased BMD over the study period of 2.7 years.

Dietary Fat Intake and the Risk of Metabolic Syndrome in Korean Adults / 가정의학회지

BACKGROUND: The effect of dietary fat intake on the risk of cardiovascular disease remains unclear. We investigated the association between dietary fat and specific types of fat intake and the risk of metabolic syndrome. METHODS: The study population included 1,662 healthy adults who were 50.2 years of age and had no known hypertension, diabetes, hyperlipidemia, or metabolic syndrome at the initial visit. Dietary intake was obtained from a 1-day food record. During 20.7 months of follow-up, we documented 147 cases of metabolic syndrome confirmed by self-report, anthropometric data, and blood test results. The intakes of total fat, vegetable fat, animal fat, saturated fatty acid (SFA), polyunsaturated fatty acid (PUFA), monounsaturated fatty acid (MUFA), and cholesterol level divided by quintile. Multivariate analyses included age, sex, body mass index, smoking status, alcohol intake, physical activity, total calorie, and protein intake. RESULTS: Vegetable fat intake was inversely associated with metabolic syndrome risk (odds ratio for the highest vs. the lowest quintile, 0.33; 95% confidence interval, 0.14 to 0.76). Total fat, animal fat, SFA, PUFA, MUFA, and cholesterol intakes showed no association with metabolic syndrome. Vegetable fat intake was inversely associated with the risk of hypertriglyceridemia among the components of metabolic syndrome. CONCLUSION: These data support an inverse association between vegetable fat and the risk of metabolic syndrome.

Lack of Association between Self-reported Saltiness of Eating and Actual Salt Intake / 가정의학회지

BACKGROUND: Reducing salt intake is known to be an important factor for lowering blood pressure and preventing cardiovascular disease. Estimating amount of salt intake is a necessary step towards salt intake reduction. Self-reported saltiness of diet is a method most easily used to measure a patient's salt intake. The purpose of this study was to examine the value of self-reported saltiness of diet in measuring salt intake. METHODS: We used data from 681 participants who visited a health center at a university hospital between August 2003 and November 2005. A self-administered questionnaire was used to collect information on self-reported saltiness of diet, other dietary habits and lifestyle factors. Salt intake was estimated on the basis of 24-hour dietary recall with a computer-aided nutritional analysis program (CAN-Pro 2.0, Korean Nutrition Society). RESULTS: There was no statistically significant difference between the mean salt intake of the self-reported salty diet group (13.7 +/- 4.8 g/d) and the self-reported unsalty diet group (13.3 +/- 4.4 g/d). If we assume calculated salt intake as the gold standard, the sensitivity and specificity of self-reported saltiness were 39.5% and 63.6%, respectively. Salt intake was increased with higher calorie intake, frequency of eating breakfast (> or =5 times/wk) and being satiated with usual diet in men, but it was increased only with higher calorie intake in women. Regardless of actual salt intake, the group satiated with a usual diet tended to be in the group of self-reported salty diet. CONCLUSION: Self-reported saltiness of diet was not associated with actual salt intake. Further studies will be needed on the simpler and more objective tools to estimate salt intake.

Impact of Visceral Adiposity Measured by Abdominal Computed Tomography on Pulmonary Function

Although an inverse relationship between abdominal adiposity and pulmonary function has been suggested, direct measurement of abdominal adipose tissue has rarely been attempted. Our object is to determine the impact of abdominal adiposity on pulmonary function by directly measuring abdominal adipose tissue with abdominal computed tomography (CT). In this cross-sectional study, we included never-smokers between the ages of 18 and 85 yr, who had undergone spirometry and abdominal adipose tissue analysis with CT scans during November 1, 2005 to October 31, 2009 as part of the comprehensive health examination. Among a total of 3,469 participants, 890 (25.7%) were male. The mean body mass index and waist circumference among males and females were 24.6 kg/m2 and 87.8 cm and 23.0 kg/m2 and 83.0 cm, respectively. Although total adipose tissue (TAT) of the abdomen in males (269.1 cm2) was similar to that in females (273.6 cm2), the ratio of visceral adipose tissue (VAT)/subcutaneous adipose tissue (SAT) was different; 0.99 in males and 0.50 in females. In males, TAT, SAT, and VAT were inversely associated with the absolute value of forced vital capacity (FVC), and TAT and VAT were inversely associated with forced expiratory volume in one second (FEV1). However, in females, TAT and VAT, but not SAT, were inversely associated with absolute FVC and FEV1 values. In conclusion, the amount of abdominal adipose tissue directly measured using CT is inversely associated with lung function.

Milk Intake and Its Association with Metabolic Syndrome in Korean: Analysis of the Third Korea National Health and Nutrition Examination Survey (KNHANES III)

Although previous studies have shown that milk intake has some protective effects on metabolic syndrome (MS), there are few data on the relation between MS and milk consumption in Korean. To evaluate the association between milk intake frequency and MS, 4,890 subjects (2,052 men and 2,838 women) were included in the analysis, based on the national data from representative random sample of the third Korea National Health and Nutrition Examination Survey (KNHANES III) in 2005. We conducted both univariate and multivariate logistic regression analysis with adjustment for confounding factors associated with MS. Mean (+/-SD) age of subjects was 47.1+/-15.5 yr. In univariate analysis, the risk of MS was inversely associated with the frequency of milk intake, but this relation was attenuated in multivariate regression. In the individuals with BMI > or =23 kg/m2, those with highest quartile of milk consumption (once daily or more) had significantly lower risk of MS (OR [95% CI] 0.72 [0.57-0.92] compared with lowest quartile [those rarely consumed]) after adjustment, but not among leaner individuals (BMI <23 kg/m2). Korean overweight adults who drink milk more frequently may be protected against MS. But it seems that this relation is somewhat different among MS components.

Dietary Intake of Calcium and Distal Colorectal Adenomatous Polyps in Korean Adults / 가정의학회지

BACKGROUND: Colorectal cancer is fourth in prevalence of carcinoma and fourth most cause of death from malignant neoplasm, which has been increasing in Korea. In this study, we tried to investigate the association of dietary intake of calcium and distal colorectal adenomatous polyps known as precursors of colorectal cancer. METHODS: A total of 2,456 subjects who visited a health promotion center in one university hospital in Seoul, Korea, from June 2003 to June 2006 underwent sigmoidoscopy and completed a 24-hour dietary recall. RESULTS: Among the selected 2,408 subjects, the prevalence of distal colorectal adenoma found in sigmoidoscopy was 12.54%. After adjusting for age and total serum cholesterol by multiple logistic regression, the odds ratio of the male subjects who had the highest quintile of dietary intake of calcium was 0.512 (95% CI: 0.305-0.859; P = 0.011) compared with the lowest. CONCLUSION: In male subjects with the highest quintile of dietary calcium density was associated with a low risk of distal colorectal adenomatous polyps.

Relationship between the Awareness and Health Behavior in Middle-aged Koreans

BACKGROUND: Despite growing awareness of health behavior, making actual behavioral change seems to be more complex. This study assessed factors influencing discrepancy between the awareness and health behavior in Korean middle-aged people. METHODS: A random-digit-dial telephone survey of 1,047 middle-aged Koreans was carried out in 2004. Through the survey, the agreement between the level of awareness and health behavior was analyzed. And factors related to health-risk behaviors in the group of appropriate awareness were analyzed. RESULTS: In the group of appropriate awareness, males tended to be smokers, problem-drinkers and were not maintaining normal weight. In men, younger age, longer work-hours and more frequent stress were significantly related to both smoking and problem-drinking despite appropriate awareness. Higher income and blue-color working class were also predictors for the problem- drinking. In women, older age, lower education, lower income and comorbid disease were significantly related to abnormal weight. Physical inactivity was significantly related to lower education, longer working hours and lower income. CONCLUSION: This study showed that sociodemographic factors and stress were related with health-risk behavior with appropriate awareness in middle-aged people. These findings are expected to have implications for development of health promotion program focusing on stress management, improvement of sociocultural perception and simultaneous intervention for both smoking and alcohol. For middle-aged Korean women, more efforts must be made to remove economical and sociocultural barriers.