The body mass index (BMI) has served public health and clinical medicine well in the recognition of obesity. However, its use has generated some instructive paradoxes and misunderstandings which argue for the apprecia- tion of body compositional disorders (BCD) as such and, in particular, for the parallel evaluation of muscle mass with a definition of ‘orthosarcal’ conditions to enable the early detection of sarcopenia. Across the life-span, and with gender and ethnic differentials, BCD is basic to the full spectrum of nutritionally-related disorders and dis- eases. In the case of metabolic diseases like diabetes, muscle, fatness and its distribution, and even bone seem to play pathogenetic roles. Optimal body fat and distribution are relevant to child development, maternal health and healthy ageing, with much more to learn about the mechanisms. The economic and societal costs of obesity tend to increase progressively with the BMI, but the health outcomes, at least for mortality, are J-or U-shaped. With some established chronic diseases, like diabetes, renal failure or cardiac failure, overfatness may be protective; sometimes this may be because contaminant fat-soluble endocrine disrupters are segregated in fat tissue. This means that some of the relatively favourable survival in the elderly who have more body fat is at the expense of the health care system. Younger children with chronic energy deficiency, on the other hand, may succumb before expenditure saves them. In these respects, our species is more vulnerable than we have thought. Fortunately, a better understanding of BMI and health is emerging.
Choline and betaine are involved in several similar health-relevant metabolic pathways, but the foods sources are different. We have assessed their intakes (individual, sums and ratios) from a dominantly Chinese food cultural point of view. A representative free-living Taiwanese population aged 13-64 years was drawn from the Nutrition and Health Survey in Taiwan (NAHSIT) 1993-1996. Food intake was derived from interviews as 24-hour recalls. The USDA database, with adaptations for Taiwan, provided choline and betaine food compositions. Major food contributors of these nutrients were identified and compared with data from the US Framingham offspring study. Mean and variance reduced median nutrient intakes were calculated. Top ten major food contributors of choline in Taiwan were eggs, pork, chicken, fish, soybean and its products, dark leafy vegetables, dairy, fruit, wheat products and light leafy vegetables in sequence. For betaine, the top ten were dark leafy vegetables, wheat prod- ucts, fish, pork, bread, chicken, cake/cookies, grain-based alcoholic beverages, rice and its products and sauces. The main contributors of choline in Taiwan and the USA were, respectively, eggs and red meat; and for betaine, greens were similarly best contributor. The rankings of the main food contributors of choline and betaine differed substantially between Taiwan and the USA. The total daily intakes (mean±SE, mg) in Taiwan for choline were 372±19 (median=348) in men and 265±9 (median 261) for women; for betaine, values were 101±3 (median 93) in men and 78±8 (median 76) for women. These allow for health outcome considerations.
Dietary habits of children, including snack foods consumption, in developing countries have seldom been investi- gated in relation to their nutrition and health. To assess the effects of snack foods consumption of 154 children aged 1-12 years in a rural village of West Java, Indonesia, a 3-hour-interval food recall survey for all meals and snack foods consumed in seven consecutive days for each subject, anthropometry, and interviews for socio- demographic indicators were conducted. Their overall prevalence of stunting and underweight was 69.5% and 35.7%. There were 221 foods consumed by the subjects, among which 68 foods were categorized as snack foods. Though the children of both <7 year and ≥7 year age groups consumed snack foods similarly throughout the day, the latter group only consumed larger amounts of energy from snack foods at school recess-times. The mean per- cent contribution of snack foods was 59.6% for fat, 40.0% for energy, 20.6% for calcium, and <10% for vitamins A and C. Half number of the subjects who snacked more than the median amount consumed less carbohydrate and vitamin C than the remaining half. Furthermore, the more snack-consuming group the lower z score for height-for-age (HAZ) among schoolchildren. To improve this nutritionally vulnerable situation, consumption of snack foods should be replaced by the non-snack foods which contain much higher nutrient density, i.e., 15 times for calcium and 32 times for vitamin A. Moreover, considering high snack foods consumption of ≥7 y age group at school, appropriate school nutrition programs should be promoted.
Undernutrition among children under five year is a significant public health problem in India. The present study was carried out to assess trends in nutritional status, nutrient and food intake among children under five year over two time periods. It was a community-based cross-sectional study, carried out in tribal areas of India. A total of 14,587 children, 0-5 years old were covered for nutritional assessment in terms of underweight, stunting and wasting. A 24 hour diet survey was carried out in a sub-sample of households surveyed. Wealth index was con- structed using principle component analysis. The prevalence of underweight and stunting had declined signifi- cantly over the periods (49% vs 57%, 51% vs 58%, respectively), while the prevalence of wasting remained simi- lar (22% vs 23%). There was marginal decrease in the intake of foods and nutrients over the periods, and was be- low recommended levels. Stepwise regression showed that the risk of underweight and stunting was significantly (p<0.01) higher among children of illiterate mothers and children from lowest and middle households wealth in- dex. Morbidities during preceding fortnight had 1.3 times higher risk of underweight and wasting. In conclusion, undernutrition is a significant health problem among tribal children and is associated with literacy status of moth- ers, household wealth index and morbidities. Therefore implementation of appropriate nutritional intervention strategies and improvement in households food security through public distribution systems, food intakes, socio- economic condition, literacy of parents and personal hygiene may help in improving the nutritional status of tribal children.
The U-shaped relationship between body mass index (BMI) and all-cause mortality has generated uncertainty about optimal BMI. For clarification, we have related BMI to both mortality and medical expenditure. The MJ Health examination cohort of 111,949 examinees established during 1994-1996 was followed with endpoint in- formation derived from death certificates and National Health Insurance records from 1996 to 2007. Age- and gender-specific relative risks between BMI groups were estimated by Cox and logistic regressions. The BMI and all-cause mortality relationship is U-shaped with the concave regions sitting in the region of BMI 22-26, butshifted rightward for the elderly. After excluding smokers and cancer patients at baseline, the low mortality region moved leftward to BMI 20-22. Cause-specific mortalities from respiratory disease, injury, and senility in- creased in the underweight group (BMI <18.5). Above 18.5, BMI was negatively associated with mortality from respiratory diseases and senility, but not with others. In contrast, irrespective of age and gender, the overall me- dian and mean medical expenditures progressively increased with BMI, particularly beyond 22. Expenditures for injury, respiratory, circulatory diseases and senility all increased with BMI. The U-shaped BMI-mortality rela- tion was a result of elevated death rate at both ends of the BMI scale. Increased mortality at the low end did not contribute to higher medical expenditure, maybe because the lean and frail deceased tend to die abruptly before large amount of medical expenditure was consumed. Our findings suggest that current recommendations to maintain BMI at the lower end of the desirable range remain tenable for the apparently healthy general public.
OBJECTIVE: While the protective nature of moderate alcohol consumption against diabetes mellitus is well known, inconsistent findings continue to be reported. The possibility of different mixes of effect modifiers has been raised as a reason for those inconsistent findings. Our study aim was to examine potential effect modifiers that can change the effect of alcohol consumption on type 2 diabetes. METHODS: From data in the third Korea National Health and Nutrition Examination Survey, 3,982 individuals over the age of 30 years who had not been diagnosed with diabetes were selected for inclusion in the study population. Breslow and Day's test and the Wald test between hypercholesterolemia and alcohol consumption in a multiple logistic regression model were used to assess effect modification. RESULTS: Odds ratios for diabetes stratified by alcohol consumption strata and as- sessed using Breslow and Day's tests for homogeneity indicated that hypercholesterolemia was not a significant confounding factor (p=0.01). However, the Wald test for interaction terms, which is a conservative method of ef- fect modification, was significant (p=0.03). CONCLUSIONS: The results indicate that moderate alcohol con- sumption is not necessarily protective for type 2 diabetes mellitus, if a person has hypercholesterolemia. People who have hypercholesterolemia should be aware of the risk associated with alcohol consumption, a risk that con- trasts with the reported protective effect of moderate alcohol consumption on diabetes.
Functional gastrointestinal disorders (FGID) are a group of disorders of the digestive system in which the chronic or recurrent symptoms cannot be explained by the presence of structural or tissue abnormality. This survey used a modified Rome III questionnaire on the health and nutrition status of a general population in Taiwan during 2005-2008. A total of 4,275 responders completed the questionnaire. The sample was evenly distributed for men (n=2,137) and women (n=2,138). The prevalence of FGID was 26.2%. Unspecified functional bowel disorder was the most prevalent (8.9%). The second was functional dyspepsia (5.3%), and the third were irritable bowel syndrome (4.4%) and functional constipation (4.4%). Women had a greater prevalence than males (33.2% com- pared to 22.4%, p<0.05) with regards to total FGID. Most categories of FGID were significantly prominent in women, except functional diarrhea. The FGID groups took fewer servings of vegetables and fruits than the non- FGID group each day (vegetables 2.51 vs 2.70, p<0.001; fruits 0.82 vs 0.91, p<0.001). Smoking, alcohol con- sumption, and betel nut chewing had no significant impaction on prevalence of FGID. The mean BSRS (brief- symptom rating scale) for screening depression and suicide ideation was higher in the FGID group (2.86 vs 1.63, p<0.001). In conclusion, FGID diagnosed with Rome III criteria are not uncommon in Taiwan’s general popula- tion. Subjects who met the Rome III criteria for FGID in Taiwan were younger, had less vegetables and fruits in- take, higher BSRS scores and were of greater female predominance.
This study assessed the effects of dietary habits and other lifestyle factors on the incidence of diabetes in a rural Japanese population. This 10.3-year study investigated a cohort of 1,995 men and 3,670 women aged 40-69 years without diabetes at baseline who underwent health check-ups between April 1990 and March 1992. Participants were followed up until diabetes was confirmed or until the end of 2006. The incidence of diabetes was deter- mined from fasting and random levels of plasma glucose, HbA1c levels or being under medical treatment for dia- betes. Principal component analysis identified a major dietary pattern characterized by more frequent consump- tion of vegetables, potatoes, seaweeds, fruits and soybean products that we labeled “healthy”. Diabetes developed in 446 of the participants during 58,151 person-years of follow-up. Consuming a healthy diet was associated with a lower risk of diabetes (multivariable-adjusted hazard ratio for highest vs lowest quartiles, 0.78 [95% CI, 0.61- 0.95]. In addition, scores for a healthy diet were associated with a lower risk for diabetes among persons who consumed regular meals (0.76 [0.58-0.96]), persons with an exercise habit (0.65 [0.44-0.96]) and non- and ex- smokers (0.72 [0.53-0.96]). Our findings suggest that consuming a healthy diet is associated with a lower risk for diabetes among the Japanese, particularly among those who eat regularly, those who habitually exercise and non- and ex-smokers.
This study investigated community attitudes to fast food companies’ sponsorship of community events. The aim was to inform future efforts to introduce greater restrictions on these marketing activities to reduce child obesity. While previous research has focused on the sponsorship of sporting events, the present study included all com- munity events and gauged public support for fast food company sponsorships in general as well as specific spon- sorship activities such as securing event naming rights, advertising on event premises, and distributing free items to children in the form of food and redeemable vouchers. A large and diverse sample of Western Australian adults (n=2,005) responded to a community attitudes telephone survey that included questions relating to event sponsor- ship. Almost half of the respondents reported that the promotion of fast foods is inappropriate at community events, and only a third considered it appropriate at events where children are likely to be present. Around two- thirds agreed that promoting fast foods at such events sends contradictory messages to children and just a quarter of respondents considered it acceptable for free fast food to be distributed at events or for children to be rewarded for participation with fast food vouchers. The results suggest that efforts to reduce child obesity that involve re- strictions on the sponsorship of community events by organisations promoting unhealthy foods may be supported by a substantial proportion of the population.
Korea has undergone a major opening of its food markets and economy in the past decade. Little is understood about the impact of these shifts on the diet of Koreans. This analysis studies the shifts in consumption of foods between 1998 and 2009 to provide a thorough understanding of the transition and insights into directions in the next decades in Korea. Data are from the Korea National Health and Nutrition Examination Survey (KNHANES). The sample used was a nationally representative sample of individuals age ≥2 in 1998 and 2009 (n=10,267 and 9,264, respectively). The data was corrected for seasonality, and the original raw food data was regrouped into 53 food groups. SAS was used to adjust for design effects and weight. Despite a decade of efforts to increase whole grains intake, and fruit and vegetable intake, the mean intake of whole grains increased only a small amount (16 kcal/person/day); however, the proportion consuming any whole grains doubled from 24% to 46.3%. Rice de- clined significantly, and several important less healthful food trends emerged: total alcohol intake increased from 39 kcal/person/day to 82 kcal/person/day. Also, energy from sugar-sweetened beverages increased among teens and energy from tea and coffee increased among adults. Remarkably, compared to other Asian countries and a general worldwide trend, vegetable intake remained relative high in South Korea during this last decade while fat energy increased modestly from relative low levels. Dynamic causes of these trends and the government’s re- sponse are discussed.
Dietitians can obtain nutrition-related information from a variety of sources. The current study was to investigate how registered dietitians look for nutritional information and perceive evidence-based nutrition (EBN). A postal questionnaire survey was conducted, with 67 valid returns collected. The most common informational sources were Web portals, followed by continuing education, colleague consultation, textbooks, online databases, elec- tronic journals, printed journals, and electronic textbooks. Among the 11 commonly used online databases, dieti- tians preferred to access MEDLINE and three databases in Chinese. Sixty-two dietitians (92.5%) were aware of EBN. Although they had a favorable impression of EBN, their knowledge of and skills in EBN were relatively lacking. The most common barrier to the implementation of EBN was a lack of library resources in Chinese (58.1%), followed by deficient skill in critical appraisal (54.8%), insufficient convenient kits (53.2%), and time constraints (50.0%). In conclusion, most registered dietitians search for information through non-EBN resources. Language is an important element relevant to the implementation of EBN. These findings may help the refining of strategies to promote the accessing of evidence-based information.
It is estimated that more than 200 million young children worldwide fail to reach their potential in cognitive de- velopment owing to undernutrition. Numerous studies have assessed the effects of micronutrient supplementation on growth and cognitive development in infants, toddlers and preschoolers. However, micronutrient interventions on the cognitive performance of older children are limited. This article seeks to provide an update on micronutri- ent interventions and cognitive outcomes among children aged 5-15 years in developing countries. A total of 13 randomized controlled trials published since 2000 were identified. Majority of these studies assessed the effects of micronutrient-fortified foods on various domains of cognitive function. Among key micronutrients assessed were iron, zinc, iodine and vitamin A. This review found a lack of consistency in the impact of micronutrient supplementation on intelligence, long term mental functions and school examination grades of the children. A beneficial effect of micronutrient supplementation on short term memory was more consistently reported. Overall, the evidence from this review for the impact of micronutrients on cognitive performance in older children re- mains equivocal. In light of the growing interest on the influence of nutrition on cognition, it is important that culturally-appropriate and sufficiently sensitive assessment tools be used for measuring the desired cognitive out- comes that are most likely to be affected by the nutrients under study.
Enteral nutritional support, a frequently applied technique for providing nutrition and energy, played a pivotal role in the treatment of high risk patients. However, severe complications induced by malposition of nasogastric tube caused great danger and even death to the patients. In this case report, we present a patient with severe acute respiratory distress syndrome (ARDS) induced by bronchopleural fistula (BPF) due to malposition of nasogastric tube. Repeated lung lavage combined with extracorporeal membrane oxygenation (ECMO) was performed after transferring to the ICU of our hospital. Finally, the patient recovered and discharged 7 days after admission.
We report a case of fat-soluble vitamin deficiency in a 14-year old boy who had chronic duodenal obstruction. He presented with periodic unexplained bleeding tendency. The laboratory results showed positive fat globules in stool and prolonged prothrombin time. His further investigation revealed low plasma vitamin A and undetectable plasma vitamin E. After parenteral vitamin K and oral vitamin A and E supplement, these abnormalities resolved although he still had absent knee jerk. We propose that fat malabsorption and fat-soluble vitamin deficiency can occur after prolonged duodenal obstruction that induce bacterial overgrowth following by bile acid deconjugation. Despite very few case reports, screening for fat malabsorption and fat-soluble vitamin deficiency might be war- ranted in patients with chronic small bowel obstruction.
Some countries have established fish advisories to manage fish consumption to minimize methylmercury expo- sure. Our objective was to compare the fish advisories and the resultant consumer behavior in the United States of America (USA) and Japan. Both countries have national consumption guidelines, but American states enjoy greater independence in issuing guidelines for local water bodies and vary in the information that is provided for the public. The proportion of the American public that has heard of state fish advisories is thought to be close to 30%. There is a concern that this low level of awareness extends to pregnant women. In Japan, the current prob- lem is the lack of comprehensive studies on the public awareness of fish advisories. Nonetheless, there is evi- dence that fish consumption has decreased in both countries. In USA, there is a possibility that the strong empha- sis on mercury toxicity drives the general population towards a trend of lower fish consumption. In Japan, the fish advisory encourages seafood consumption for nutritional benefits. Consequently, the decrease may be due to the shift towards a “Western diet”. Also, the Japanese fish advisory seems to be less active in advocating the issue of fish consumption and mercury exposure, which may be partly responsible for the possible lesser attention of the consumers. Cultural factors may explain for the baseline difference in consumption and account partly for the change in Japanese consumer behavior. However, the dissimilarities in fish advisories may also be responsible for the variations in consumer behavior.
The purpose of this study was to investigate the associations between chest circumference in infancy and rapid growth or obesity at 3 years of age. We conducted a retrospective observational study of 1353 children in Ku- mamoto, Japan. Data collected included chest circumference, head circumference, weight, and body mass index. The area under the receiver operating characteristic curves for chest circumference were analyzed to determine the ability of this index to identify obesity at 3 years of age. Chest circumference at 3-4 months of age and in- creases in chest circumference during the first 3-4 months of life had higher mean standard deviation scores for rapid growth than for slow or no change in growth (p<0.05). Chest circumference and the increase in chest cir- cumference were also positively correlated with rapid weight gain, and were associated with obesity at 3 years of age. The area under the curve for chest circumference was significantly different from the area under the curve for weight z-score at 6-9 months but not for weight z-score at 3-4 months. In conclusion, we found that chest cir- cumference is associated with obesity in young children, and is positively correlated with rapid growth. There- fore, chest circumference may be a useful marker for rapid growth, and may help clinicians to identify obese children at 3 years of age.
A randomised trial was carried out to determine the effect of supplementation of fish oil among 51 children with leukaemia aged 4 to 12 years on appetite level, caloric intake, body weight and lean body mass. They were ran- domly allocated into the trial group (TG) and the control group (CG). At baseline, 30.8% of TG subjects and 44.0% of CG subjects were malnourished and 7.7% of subject from TG and 28.0% from CG were classified as stunted. The majority of subjects from TG and CG were in the mild malnutrition category for mid upper arm muscle circumference (MUAMC)-for-age. The TG group showed significant increment in MUAMC (0.13 cm vs -0.09 cm) compared with CG at 8 weeks (p<0.001). There was a significant higher increase for appetite level (0.120.33) (p<0.05) and an increasing trend on energy and protein intake in the TG group (213554 kcal; 3.64 26.8 g) than in the CG group. In conclusion, supplementation of fish oil has a positive effect on appetite level, ca- loric intake and MUAMC among children with leukaemia.
Objective: Polycystic ovary syndrome (PCOS) is a common female endocrine disorder associated with several risk factors of type 2 diabetes and cardiovascular diseases. The objectives of this study were to investigate the ef- fects of omega−3 fatty acids on serum adiponectin levels and some metabolic risk factors in PCOS patients. Methods: This double-blind randomized controlled clinical trial was conducted on 64 overweight or obese PCOS patients; aged 20-35 years. Subjects in omega−3 fatty acids (n=32) and placebo (n=32) groups were given 4 ome- ga−3 fatty acids capsules (each one contained 180 mg eicosapentaenoic acid and 120 mg docosahexanoic acid) or placebo daily for 8 weeks. Fasting blood samples, anthropometric measurements and 3-day, 24-hour dietary re- callswerecollectedatthebaselineandattheendofthetrial. Results:Thestudywascompletedby61subjects. Omega−3 fatty acids significantly increased serum levels of adiponectin (p=0.003) and decreased glucose (p<0.001), insulin (p=0.002), homeostatic model assessment for insulin resistance (p<0.001), total cholesterol (p=0.002) and low-density lipoprotein cholesterol (p=0.003) compared with placebo. Serum levels of triglyceride significantly decreased (p=0.024) and high-density lipoprotein cholesterol increased (p=0.018) in the omega−3 fatty acids group, in comparison with baseline values. No significant changes were shown in serum high sensitive C-reactive protein (hs-CRP) levels in both groups. Conclusion: Omega−3 fatty acids had some beneficial effects on serum adiponectin levels, insulin resistance and lipid profile in PCOS patients and may contribute to the im- provement of metabolic complications in these patients.
Obesity and homocysteine (tHcy) are important risk factors for cardiovascular diseases (CVD). Plasma omega-3 fatty acids (ω-3 FAs) and omega-6 fatty acids (ω-6 FAs) are essential fatty acids with diverse biological effects in human health and disease. We have investigated the relation of plasma ω-3 FAs and ω-6 FAs levels with other cardiovascular risk factors including tHcy in severe obese subjects. This study was performed on 96 severe obese and 65 normal weight subjects. Plasma fatty acid composition was measured by GC/MS and serum tHcy level was measured by HPLC methods. There were no differences between groups in terms of concentrations of serum tHcy, plasma ω-3 FAs, ω-6 FAs and ω-3/ω-6 ratio, whereas serum vitamin B-12 (p<0.01) and folic acid (p<0.05) levels were lower than those of the normal weight subjects. Homocysteine positively correlated with ω-6 FAs and negatively correlated with ω-3 FAs in severe obese and normal weight subjects. Serum vitamin B-12 positively correlated with ω-3 FAs (p<0.01) and ω-3/ω-6 ratio (p<0.01) and negatively correlated with ω-6 FAs (p<0.05) in severe obese subjects. Serum folic acid positively correlated with ω-3 FAs (p<0.01) in severe obese subjects. Our results suggest an association between the plasma ω-3 FAs and ω-6 FAs and serum tHcy concentrations in severe obese and normal weight subjects. Low levels vitamin B-12 and folic acid may have been responsible for the elevated tHcy levels in severe obese subjects, increasing the risk for future development of cardiovascular diseases.
Purpose: Vitamin D deficiency is a global health problem that is associated with increased risks of major diseases. This study investigated the status of 25-hydroxyvitamin D [25(OH)D] and its demographic and lifestyle determi- nants among Korean adults. Methods: A total of 5,847 adults who had participated in the Korean National Health and Nutrition Examination Survey of 2008 (KNHANES) were included in the present study. Stepwise linear re- gression analysis was performed to determine the demographic and lifestyle determinants of 25(OH)D concentra- tion. Results: The weighted prevalence (standard error) of 25(OH)D deficiency (<20 ng/mL) was 49.9 (2.1)% among the males and 67.4 (1.7)% among the females. Severe 25(OH)D deficiencies (<10 ng/mL) were found in 5.7 (0.8)% of the males and 11.1 (1.0)% of the females. These peaked in spring and winter. Only 12.2 (1.1)% of the males and 6.4 (0.6)% of the females exhibited 25(OH)D sufficiency (≥30 ng/mL). The correlates with higher 25(OH)D concentration for both genders included summer, fall (vs spring), the 60s age group (vs 20s), rural resi- dence (vs urban), moderate and vigorous physical activity (vs sedentary), alcohol consumption, and multivitamin supplementation. Higher education and unmarried status were inversely associated with 25(OH)D concentration for both genders. The strongest predictors of 25(OH)D concentration were season and residential area. Conclu- sions: 25(OH)D deficiency is a prevalent condition in Korea. Understanding the determinants of 25(OH)D can facilitate identification of persons at risk of 25(OH)D deficiency.
Introduction: We present data from the Korean National Health and Nutritional Examination Survey (KNHANES) 2008-2009 on the association between 25-hydroxyvitamin D[25(OH)D] status and type 2 diabetes in a representa- tive sample of the adult Korean population. Methods: This study was based on data obtained from the KNHANES 2008–2009, which was conducted for 3 years (2007-2009) using a rolling sampling design that in- volved a complex, stratified, multistage, probability-cluster survey of a representative sample of the non- institutionalized civilian population of South Korea. Results: We showed that serum 25(OH)D concentration is inversely associated with type 2 diabetes in the Korean general population. In particular, low serum 25(OH)D concentration was associated with an increased prevalence of type 2 diabetes in young women and old men. The present study showed that 25(OH)D has a significant negative association with fasting insulin and insulin re- sistance. Conclusion: The age- and gender-specific association between low 25(OH)D level and type 2 diabetes may be related to interactions between vitamin D, sex hormone concentrations, and type 2 diabetes. In conclusion, we showed that low 25(OH)D concentration is associated with type 2 diabetes in the Korean general population in an age- and gender-specific pattern.