Eating Fast and Until Full Is Associated with Elevated Alanine Aminotransferase Activity in Japanese Schoolchildren: A Cross-Sectional Study.

Alanine aminotransferase (ALT) activity has been recognized as a marker for monitoring the risk of metabolic syndrome, diabetes and non-alcoholic fatty liver disease in children. Higher ALT activity was reported to be associated with eating fast in Japanese adults, but the association in children is unclear. Moreover, eating fast and eating until full are reported to be associated with being overweight. This study examined the association between elevated ALT and eating behaviors (eating fast and eating until full) among population-based schoolchildren (aged 9-10 years) in Ina Town, Saitama, Japan. Data for eating behaviors were obtained from a self-written questionnaire. Blood samples were drawn to measure ALT. Elevated ALT was defined as > 30 U/L in boys and > 19 U/L in girls. Logistic regression models and structural equation models were used to calculate the effect of eating behaviors on elevated ALT. Final data analysis was carried out for 1,870 boys and 1,739 girls. "Eating fast and eating until full" was significantly associated with elevated ALT in each sex. "Eating fast and not eating until full" was significantly associated with elevated ALT in boys, but after adjusting for exercise and body mass index, this association was not significant. In conclusion, "eating fast and eating until full" was associated with elevated ALT in schoolchildren. A sex difference in the association of "eating fast and not eating until full" with elevated ALT was observed. Modifying the behaviors of eating fast and eating until full is important for schoolchildren to prevent ALT elevation.

Changes in overweight/obesity and central obesity status from preadolescence to adolescence: a longitudinal study among schoolchildren in Japan.

BACKGROUND: Little is known about changes in overweight/obesity and central obesity status among schoolchildren from preadolescence to adolescence in Japan, where waist circumference (WC) is generally not measured in annual health examinations at elementary and junior high schools. This study examined changes of overweight/obesity and central obesity status among schoolboys and schoolgirls from preadolescence to adolescence in Japan. METHODS: Study subjects were fourth-grade school children (9 or 10 years of age) from all four of Ina town's elementary schools in Japan. Measurement of each participant's height, weight, and WC were made at baseline and 3 years later. Childhood overweight/obesity was determined according to the age- and sex-specific body mass index cut-off points proposed by the International Obesity Task Force. Central obesity was defined as waist-to-height ratio ≥ 0.5. Kappa (κ) statistic was calculated to examine the tracking of overweight/obesity and central obesity. RESULTS: Data from 1436 participants (boys: n = 720, girls: n = 716) were analyzed. Overweight/obesity status tracked substantially from fourth grade to seventh grade in both boys (κ = 0.614, P value < 0.001) and girls (κ = 0.619, P value < 0.001). Among participants who were overweight/obese in fourth grade, 55.2% of boys and 63.2% of girls were still overweight/obese in seventh grade. Tracking of central obesity from fourth graders to seventh graders was substantial in boys (κ = 0.651, P value < 0.001) and moderate in girls (κ = 0.544, P value < 0.001). Among participants who had central obesity in fourth grade, 54.1% of boys and 52.6% of girls still had central obesity in seventh grade. CONCLUSIONS: The present study showed that the tracking of overweight/obesity from preadolescence to adolescence was substantial in boys and girls. Moreover, more than half of those who had central obesity in preadolescence had central obesity in adolescence. This study suggests that it is important to implement a primary prevention program for overweight/obesity and central obesity in elementary schools before fourth grade.

Association of the combination of weight gain after 20 years of age and current obesity with chronic kidney disease in Japan: a cross-sectional study.

OBJECTIVES: Weight gain after 20 years of age is associated with chronic kidney disease (CKD). However, the impact of weight gain on CKD might differ by current obesity status. We investigated the association of the combination of weight gain after 20 years of age and current obesity with CKD among adults in Japan. DESIGN: A cross-sectional study. SETTING AND PARTICIPANTS: We analysed data from 94 822 adults aged 40-64 years who had an annual health check-up in Japan from April 2013 to March 2014. PRIMARY OUTCOME MEASURE: CKD was defined as an estimated glomerular filtration rate <60 mL/min/1.73 m2 and/or proteinuria. RESULTS: Both weight gain ≥10 kg after 20 years of age plus obesity (OR 2.21, 95% CI 2.07 to 2.36) and weight gain of ≥10 kg plus non-obesity (OR 1.31, 95% CI 1.21 to 1.42) significantly increased the OR for CKD when compared with weight gain <10 kg plus non-obesity in men. In women, weight gain ≥10 kg plus obesity (OR 2.04, 95% CI 1.84 to 2.25) and weight gain ≥10 kg plus non-obesity (OR 1.53, 95% CI 1.36 to 1.72) significantly increased the OR for CKD compared with weight gain <10 kg plus non-obesity. These results persisted even after adjustment for age, lifestyle factors, hypertension, dyslipidaemia and diabetes. CONCLUSIONS: Weight gain ≥10 kg after 20 years of age was significantly associated with CKD in both obese and non-obese subjects. Moreover, the influence of weight gain ≥10 kg plus obesity on CKD was greater than that of weight gain ≥10 kg plus non-obesity on CKD. The present study results suggest that it is important to consider weight gain after maturity in both obese and non-obese subjects to prevent CKD among Japanese middle-aged adults.

Association between serum lipids and low back pain among a middle-aged Japanese population: a large-scale cross-sectional study.

BACKGROUND: Abnormal lipid levels have been suggested as a mechanism leading to atherosclerosis of the lumbar vessels, resulting in low back pain (LBP). This study examined whether abnormal lipid levels were associated with LBP among middle-aged adults in Japan. METHODS: The present study included adults between 40 and 64 years old who underwent an annual health checkup. A total of 258,367 eligible participants were analyzed to investigate associations of LBP with low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and LDL-C/HDL-C ratio. Participants were categorized into two groups according to each of LDL-C, HDL-C, and LDL-C/HDL-C ratio (LDL-C: ≥ 140 vs. < 140 mg/dL; HDL-C: ≥ 40 vs. < 40 mg/dL; LDL-C/HDL-C ratio: ≥ 2.5 vs. < 2.5). Information on LBP was obtained using a self-administered questionnaire. Logistic regression modeling was used to calculate the odds ratio (OR) and 95% confidence interval (CI) for LBP. RESULTS: The prevalence of LBP was 2.2% in men and 2.1% in women. Multivariable analysis adjusting for age, body mass index, and lifestyle factors found significant associations for HDL-C <  40 mg/dL (OR, 1.34; 95%CI, 1.20-1.48 in men; OR, 1.32; 95%CI, 1.02-1.72 in women) and LDL-C/HDL-C ratio ≥ 2.5 (OR, 1.17; 95%CI, 1.09-1.26 in men; OR, 1.15; 95%CI, 1.03-1.29 in women) with LBP. CONCLUSIONS: Low HDL-C and high LDL-C/HDL-C ratio were significantly associated with LBP in a middle-aged Japanese population. These findings might support the atherosclerosis-LBP hypothesis.

NADH Dehydrogenase Subunit-2 237 Leu/Met Polymorphism Influences the Association of Coffee Consumption with Serum Chloride Levels in Male Japanese Health Checkup Examinees: An Exploratory Cross-Sectional Analysis.

BACKGROUND: Nicotinamide adenine dinucleotide (NADH) dehydrogenase subunit-2 237 leucine/methionine (ND2-237 Leu/Met) polymorphism has been shown to modify the association of coffee consumption with the risk of hypertension, dyslipidemia, and abnormal glucose tolerance, and low serum chloride levels have been shown to be associated with all-cause and cardiovascular disease mortality. Therefore, the purpose of the present study was to investigate whether ND2-237 Leu/Met polymorphism influences the association of coffee consumption with serum chloride levels in male Japanese health checkup examinees. METHODS: From among individuals visiting the hospital for a regular medical checkup, 402 men (mean age ± standard deviation, 53.9 ± 7.8 years) were selected for inclusion in the study. After ND2-237 Leu/Met genotyping, we conducted an exploratory cross-sectional study to examine the combined association of ND2-237 Leu/Met polymorphism and coffee consumption with serum electrolyte levels. RESULTS: After adjusting for age, body mass index, habitual smoking, alcohol consumption, green tea consumption, and antihypertensive medication, coffee consumption significantly increased serum chloride levels (p for trend = 0.001) in men with the ND2-237Leu genotype. After these adjustments, the odds ratios (ORs) for low levels of serum chloride, defined as <100 mEq/L, were found to be dependent on coffee consumption (p for trend = 0.001). In addition, the OR for low levels of serum chloride was significantly lower in men with the ND2-237Leu genotype who consumed ≥4 compared with <1 cup of coffee per day (OR = 0.096, 95% confidence interval = 0.010⁻0.934; p = 0.044). However, neither serum chloride levels nor risk of low levels of serum chloride appeared to be dependent on coffee consumption. CONCLUSIONS: The results suggest that ND2-237 Leu/Met polymorphism modifies the association of coffee consumption with serum chloride levels in middle-aged Japanese men.

Relationship between Eating Quickly and Overweight : A Cohort Study of Schoolchildren in Japan.

Several cross-sectional studies have shown that eating quickly is associated with overweight in children and adolescents. However, few cohort studies have examined this relationship. Here we investigated the relationship between eating quickly and overweight in a cohort study of fourth-grade schoolchildren (aged 9 or 10 years) who attended elementary schools in Ina-town, Japan. The children were followed for 3 years from 2001-2004 (at baseline) to 2004-2007. A questionnaire survey including information about eating speed (fast, medium, or slow) was administered, and height and weight measurements were obtained at baseline and follow-up. Overweight was defined according to the body mass index cutoff points proposed by the International Obesity Task Force. We used a Poisson regression model to examine the association between eating quickly at baseline and being overweight 3 years later. Data from 934 non-overweight children (465 boys, 469 girls) were analyzed. Eating quickly was not significantly associated with being overweight in the boys, whereas it was significantly associated with being overweight in the girls. Our analysis indicates that among girls, eating quickly leads to overweight, and that the modification of eating quickly could help prevent overweight in adolescents.

Effects of eating dinner alone on overweight in Japanese adolescents: a cross-sectional survey.

BACKGROUND: The decrease in the frequency of family meals among Asian youth is often lamented. In Japan, adolescents who eat breakfast alone might have an unhealthy diet, which increases the risk of overweight or obese. However, there are few studies on the relationship between eating dinner alone and overweight in Japanese adolescents. Here, we investigated if eating dinner alone is associated with being overweight in Japanese adolescents of each sex. METHODS: The participants consisted of 890 seventh graders (12-13 years of age) from the junior high schools of Ina, Japan who were recruited from 2011 to 2012. Information about eating dinner alone was obtained using a self-reported questionnaire, which was given to each participant. The participants were classified into the following three groups: does not eat alone, eats alone 1-2 times/week, or eats alone ≥3 times/week. A logistic regression model was used to examine the relationship between eating dinner alone and being overweight. The height and weight of each participant were measured. Childhood overweight status was defined using the body mass index cutoff points proposed by the International Obesity Task Force. RESULTS: When compared with girls who did not eat dinner alone, a significantly increased odds ratio (OR) was observed among girls who ate dinner alone ≥1 time/week (adjusted OR = 2.78; 95% confidence interval = 1.21-6.38). In contrast, there was no statistically significant difference between eating dinner alone and being overweight among boys. CONCLUSION: The present study found that eating dinner alone is associated with being overweight among adolescent girls in this community in Japan. Therefore, reducing the frequency of eating dinner alone might contribute to decreasing the risk for becoming overweight or obese among adolescent girls.

Lifestyle factors associated with underweight among Japanese adolescents: a cross-sectional study.

BACKGROUND: Because underweight in adolescents poses several health problems, it is important to prevent it in adolescence. For the prevention of underweight, it is necessary to investigate risk factors, especially lifestyles, because these can be modified. However, a limited number of studies exist regarding lifestyle factors associated with underweight among adolescents. The present study aimed to investigate the relationship between lifestyle factors and underweight among Japanese adolescents. METHODS: Study subjects comprised 2641 seventh-grade school children (age 12 or 13 years) from the town of Ina, Saitama Prefecture, Japan. Measurements of height and weight were made for each subject, while information regarding lifestyles of each subject was obtained using a self-administered questionnaire. Underweight was determined by the age- and sex-specific body mass index cut-off points. A logistic regression model was used to estimate the odds ratio (OR) and 95% confidence interval (95% CI) for underweight. RESULTS: Adolescents who ate slowly were more likely to be underweight than those who did not eat slowly; the OR (95% CI) was 2.78 (1.77-4.39) in boys and 2.69 (1.81-3.98) in girls. Girls who did not exercise were more likely than those who exercised to be underweight (OR: 1.64, 95% CI: 1.07-2.51). CONCLUSIONS: The present study showed that eating slowly and exercise were associated with underweight among Japanese adolescents. These results suggest that eating speed and exercise need to be considered in school health programs for healthy body weight.

Association between distorted body image and changes in weight status among normal weight preadolescents in Japan: a population-based cohort study.

BACKGROUND: Distorted body image may be important risk factors for being underweight and overweight. The objective of this study was to investigate the association between having a distorted body image and being overweight or underweight among normal weight preadolescents in a population-based cohort study in Japan for each sex. METHODS: The study participants were 1431 normal weight fourth-grade students (age range: 9-10 years) in Ina town, Japan from 2002 to 2007. The height and weight of each student were measured while they were in the fourth grade (at baseline) and seventh grade (3 years later). Childhood underweight and overweight were defined using the body mass index cut-off points proposed by the International Obesity Task Force. Information regarding the self-perceived weight status of each student at baseline was collected using a self-administered questionnaire. Children who were normal weight but perceived themselves as heavy or thin were regarded as having a distorted body images. A logistic regression model was used to calculate the odds ratios (ORs) and 95 % confidence interval (95 % CI) for being overweight or underweight 3 years later among those having a distorted body image at baseline. RESULTS: Both boys and girls who perceived themselves to be heavy at baseline were at a statistically significantly greater risk of being overweight 3 years later as compared to boys and girls, respectively, who identified as being at a normal weight at baseline (boys: adjusted OR: 4.66, 95 % CI: 1.01-21.48; girls: 3.88, 1.56-9.65). Both boys and girls who perceived oneself to be thin at baseline were at a statistically significantly greater risk of bring underweight 3 years later as compared to boys and girls, respectively, who identified as being at a normal weight at baseline (boys: 5.51, 2.20-13.80; girls: 2.93, 1.40-6.11). CONCLUSION: The results of the present study suggest that having a distorted body image in preadolescence is associated with being overweight or underweight in adolescence, among boys and girls, separately. Therefore, education regarding self-perceived weight could be important to help prevent underweight and overweight/obesity among preadolescent boys and girls in Japan.

Eating quickly is associated with waist-to-height ratio among Japanese adolescents: a cross-sectional survey.

BACKGROUND: Central obesity, based on waist circumference (WC), has more adverse effects on health than general obesity, determined by body mass index. To date, eating quickly has been reported to be risk factors for overweight/obesity among children, adolescents, and adults. In contrast, there are few studies on the relationship between fast eating and central obesity among adolescents, particularly in Japan, where WC is not commonly measured in junior high schools. The aim of the present study was to investigate the relationship between eating quickly and waist-to-height ratio (WHtR), an index of central obesity, among adolescents in Japan. METHODS: Study subjects were 2136 seventh-grade school children (12 or 13 years of age) from Ina town junior high schools in Japan, between 2004 and 2009. Measurements of height, weight, and WC were performed, and information about eating habits was collected using a self-administered questionnaire. A logistic regression model was used to calculate the odds ratio (OR) and 95 % confidence interval (95 % CI) for WHtR ≥ 0.5. RESULTS: Eating quickly significantly increased the OR for WHtR ≥ 0.5 in boys (OR: 2.05, 95 % CI: 1.31-3.23) and girls (2.09, 1.15-3.81). When compared with the "not eating quickly and not eating until full" group, the OR for WHtR ≥ 0.5 in the "eating quickly and eating until full" group was 2.67 (95 % CI: 1.50-4.73) in boys and 2.59 (1.17-5.73) in girls, whereas that in the "eating quickly and not eating until full" group or the "not eating quickly and eating until full" group was not statistically significant regardless of sex. CONCLUSIONS: The present study showed that eating quickly was associated with WHtR ≥ 0.5, and "eating quickly and eating until full" had a substantial impact on WHtR ≥ 0.5 among adolescents. This study suggests that modifying fast eating to a slower pace may help prevent central obesity among adolescents.

The relationship between distorted body image and lifestyle among Japanese adolescents: a population-based study.

BACKGROUND: Distorted body image plays a significant role in the development of obesity, eating problems, and eating disorders. The aim of this study was to investigate the relationship between distorted body image and lifestyle among Japanese adolescent boys and girls. METHODS: Subjects were 1731 seventh graders (age 12-13 years) from the Ina-town's junior high schools, Japan, from 2005-2009. The height and weight of each subject were measured. Childhood underweight, overweight, and obesity were defined using the body mass index cutoff points proposed by the International Obesity Task Force. Information regarding the self-perceived weight status and lifestyles (exercise, snacking after dinner, breakfast, wakeup time, bedtime) of each subject was collected using a self-administered questionnaire. Self-perceived weight status was categorized into three groups (thin, normal, or heavy), and compared with the subjects' actual weight status. Body image perception was categorized into the following three groups: an underestimated own weight status group (underestimated group), a correct own weight status group (correct group) and an overestimated own weight status group (overestimated group). RESULTS: The proportion of boys in the underestimated group was higher than that of girls, while the opposite was true for the overestimated group (P < 0.001). There were no statistically significant differences in lifestyle between the underestimated group and the correct group regardless of sex. In contrast, there were statistically significant differences between the overestimated group and the correct group in the lifestyle factors of exercise among boys and snacking after dinner among girls. The adjusted odds ratio (OR) in boys who exercised daily significantly decreased (OR: 0.35, 95 % CI: 0.16-0.77), while a significantly increased OR was observed in girls who snacked after dinner (OR: 1.53, 95 % CI: 1.07-2.19). CONCLUSION: Adolescent boys tended to underestimate their body weight, whereas adolescent girls were likely to overestimate their body weight. Furthermore, lifestyle factors associated with distorted body image differed by sex, with exercise affecting body image perception among boys and snacking after dinner affecting body image perception among girls. Thus, lifestyle may lead to distorted body image among adolescents.

Trends of Underweight and Overweight/Obesity Among Japanese Schoolchildren From 2003 to 2012, Defined by Body Mass Index and Percentage Overweight Cutoffs.

BACKGROUND: We investigated the prevalence and trends of underweight and overweight/obesity in a population-based sample of Japanese schoolchildren from 2003 to 2012, defined by body mass index (BMI) and percentage overweight (POW). METHODS: Subjects comprised fourth and seventh graders from the town of Ina, Japan, from 2003 to 2012. The height and weight of each subject were measured. Children were classified as underweight, normal weight, or overweight/obese using two criteria: BMI cutoff points proposed by the International Obesity Task Force and cutoffs based on POW in Japan. RESULTS: Data from 4367 fourth graders and 3724 seventh graders were analyzed. The prevalence of underweight and overweight as defined by POW criteria were lower than those based on BMI criteria. There was a decrease in the prevalence of overweight among fourth-grade boys and girls and seventh-grade girls according to BMI; this decrease was also observed when POW criteria were used for the definition of overweight. CONCLUSIONS: The prevalence and trends of both underweight and overweight as defined by POW were underestimated among Japanese schoolchildren compared to those determined using BMI. The results of this study also suggest that trends in underweight and overweight/obesity using POW criteria are similar to those based on BMI criteria among schoolchildren in Japan.

Waist-to-height ratio is more closely associated with alanine aminotransferase levels than body mass index and waist circumference among population-based children: a cross-sectional study in Japan.

BACKGROUND: An association between anthropometric measurements, including waist circumference (WC), and alanine aminotransferase (ALT) levels has been reported among adults. However, studies conducted among population-based elementary schoolchildren to date have been limited, especially in Japan, where the measurement of WC and blood collection are not usually performed in the annual health examination at elementary schools. The present study investigated the association between anthropometric measurements and ALT levels among population-based elementary schoolchildren in Japan. METHODS: Subjects were fourth-grade schoolchildren (aged 9 or 10) from the town of Ina in Saitama Prefecture, Japan during 2004-2009. The height, weight, and WC of each subject were measured, and blood samples were drawn to measure ALT levels. Childhood overweight or obesity was defined according to the age- and sex-specific cut-off points proposed by the International Obesity Task Force. Spearman's correlation coefficients between anthropometric measurements (body mass index (BMI), WC, and waist-to-height ratio (WHtR)) and ALT levels were calculated. RESULTS: Data from 2499 subjects (1293 boys and 1206 girls) were analyzed. BMI, WC, and WHtR were significantly positively correlated with ALT levels; the correlation coefficient of ALT levels with WHtR was higher than that with BMI and WC in boys and girls. In the analysis stratified by physique (non-overweight/obesity, overweight, or obesity), all anthropometric measurements were significantly positively correlated with ALT levels among boys, while only WHtR was significantly positively correlated with ALT levels among girls. Moreover, the correlation coefficient of ALT levels with WHtR was more pronounced than that with BMI and WC in the non-overweight/obesity group, in the overweight group, and in the obesity group for each sex. CONCLUSIONS: The present study showed that WHtR was more closely associated with ALT levels than BMI and WC. Furthermore, only WHtR was significantly positively associated with ALT levels regardless of sex and physique. This study suggests that it is more useful to monitor WHtR than BMI and WC as a surrogate for ALT levels among population-based elementary schoolchildren.

Longevity-associated mitochondrial DNA 5178 C/A polymorphism modulates the effects of coffee consumption on erythrocytic parameters in Japanese men: an exploratory cross-sectional analysis.

BACKGROUND: Mitochondrial DNA 5178 cytosine/adenine (Mt5178 C/A) polymorphism reportedly modulates the effects of coffee consumption on the risk of hypertension, dyslipidemia and abnormal glucose tolerance. The objective of this analysis was to investigate whether Mt5178 C/A polymorphism modifies the effects of coffee consumption on erythrocytic parameters in male Japanese health check-up examinees. METHODS: A total of 436 men (mean age ± standard deviation, 54.1 ± 7.8 years) were selected from among individuals visiting the hospital for regular medical check-ups. After Mt5178 C/A genotyping, an exploratory cross-sectional analysis assessing the joint effects of Mt5178 C/A polymorphism and coffee consumption on red blood cell counts, hematocrit and hemoglobin was conducted. RESULTS: For Mt5178C genotypic men, after adjustment for age, body mass index, alcohol consumption, habitual smoking and green tea consumption, coffee consumption significantly decreased red blood cell counts (P for trend = 0.022) and hemoglobin (P for trend = 0.035). The risk of anemia, defined as hemoglobin of <14 g/dL, after the aforementioned adjustment, appeared to depend on coffee consumption (P for trend = 0.078), and the adjusted odds ratio for anemia was significantly higher in men who consumed ≥4 cups of coffee per day than in those who consumed <1 cup per day (odds ratio = 3.771, 95% confidence interval: 1.088 to 13.06, P = 0.036). For Mt5178A genotypic men, coffee consumption possibly reduced the risk of anemia (P for trend = 0.049). However, after the aforementioned adjustment, the statistical significance disappeared (P for trend = 0.137). CONCLUSIONS: This exploratory cross-sectional analysis suggests that Mt5178 C/A polymorphism modulates the effects of coffee consumption on erythrocytic parameters and the risk of anemia in male Japanese health check-up examinees.

NADH dehydrogenase subunit-2 237 Leu/Met polymorphism modifies effects of cigarette smoking on risk of elevated levels of serum liver enzyme in male Japanese health check-up examinees: a cross-sectional study.

BACKGROUND: NADH dehydrogenase subunit-2 237 leucine/methionine (ND2-237 Leu/Met) polymorphism reportedly influences the effects of cigarette smoking on respiratory function, risk of dyslipidemia, serum non-high-density lipoprotein cholesterol levels, hematological parameters and intraocular pressure. The objective of this study was to investigate whether ND2-237 Leu/Met polymorphism modifies the effects of cigarette smoking on serum liver enzyme levels in male Japanese health check-up examinees. METHODS: A total of 421 male subjects (mean age ± SD, 54.1 ± 7.7 years) were selected from among individuals visiting the hospital for regular medical check-ups. After ND2-237 Leu/Met genotyping, a cross-sectional study assessing the combined effects of ND2-237 Leu/Met polymorphism and cigarette smoking on serum aspartate aminotransferase levels, serum alanine aminotransferase (ALT) levels and serum gamma-glutamyltransferase (GGT) levels was then conducted. RESULTS: No statistically significant differences in serum liver enzyme levels among the three smoking status groups (never- or ex-smokers, 1-20 cigarettes smoked per day and >20 cigarettes smoked per day) by ND2-237 Leu/Met genotype were observed. However, for men with ND2-237Met, cigarette smoking significantly increased the risk of elevated levels of serum ALT (>30 U/L) or serum GGT (≥60 U/L or >51 U/L) (P for trend = 0.031, P for trend = 0.007 and P for trend = 0.004, respectively). After adjustment for age, body mass index, alcohol consumption, coffee consumption, antihypertensive treatment and antidiabetic treatment, a significant association between cigarette smoking and risk of elevated levels of serum ALT (>30 U/L) or serum GGT (≥60 U/L or >51 U/L) was also observed (P for trend = 0.032, P for trend = 0.019 and P for trend = 0.009, respectively). Surprisingly, for men with ND2-237Leu, cigarette smoking significantly decreased the risk of elevated levels of serum ALT (>30 U/L or ≥25 U/L) (P for trend = 0.026 and P for trend = 0.003, respectively). CONCLUSIONS: Cigarette smoking appears to increase the risk of elevated levels of serum ALT or serum GGT in ND2-237Met genotypic men, but to decrease the risk of elevated levels of serum ALT in ND2-237Leu genotypic men.

Searching for genomic region of high-fat diet-induced type 2 diabetes in mouse chromosome 2 by analysis of congenic strains.

SMXA-5 mice are a high-fat diet-induced type 2 diabetes animal model established from non-diabetic SM/J and A/J mice. By using F2 intercross mice between SMXA-5 and SM/J mice under feeding with a high-fat diet, we previously mapped a major diabetogenic QTL (T2dm2sa) on chromosome 2. We then produced the congenic strain (SM.A-T2dm2sa (R0), 20.8-163.0 Mb) and demonstrated that the A/J allele of T2dm2sa impaired glucose tolerance and increased body weight and body mass index in the congenic strain compared to SM/J mice. We also showed that the combination of T2dm2sa and other diabetogenic loci was needed to develop the high-fat diet-induced type 2 diabetes. In this study, to narrow the potential genomic region containing the gene(s) responsible for T2dm2sa, we constructed R1 and R2 congenic strains. Both R1 (69.6-163.0 Mb) and R2 (20.8-128.2 Mb) congenic mice exhibited increases in body weight and abdominal fat weight and impaired glucose tolerance compared to SM/J mice. The R1 and R2 congenic analyses strongly suggested that the responsible genes existed in the overlapping genomic interval (69.6-128.2 Mb) between R1 and R2. In addition, studies using the newly established R1A congenic strain showed that the narrowed genomic region (69.6-75.4 Mb) affected not only obesity but also glucose tolerance. To search for candidate genes within the R1A genomic region, we performed exome sequencing analysis between SM/J and A/J mice and extracted 4 genes (Itga6, Zak, Gpr155, and Mtx2) with non-synonymous coding SNPs. These four genes might be candidate genes for type 2 diabetes caused by gene-gene interactions. This study indicated that one of the genes responsible for high-fat diet-induced diabetes exists in the 5.8 Mb genomic interval on mouse chromosome 2.

Abdominal obesity and serum adiponectin complexes among population-based elementary school children in Japan: a cross-sectional study.

BACKGROUND: There are a limited number of studies regarding the association between abdominal obesity and serum adiponectin complexes (high, medium, and low molecular weight adiponectins) among population-based elementary school children, especially in Japan, where blood collection is not usually performed during annual health examinations of school children. The aim of the present study was to investigate the relationship between abdominal obesity and serum adiponectin complexes among population-based elementary school children in Japan. METHODS: Subjects were all the fourth-grade school children (9 or 10 years of age) in the town of Ina during 2005-2008 (N = 1675). The height, weight, percent body fat, and waist circumference (WC) of each subject were measured. Blood samples were drawn from subjects to measure adiponectin isoform values. Childhood abdominal obesity was defined as "a waist-to-height ratio greater than or equal to 0.5" or "a WC greater than or equal to 75 cm". The Wilcoxon rank-sum test and the logistic regression model were used to analyze the association between abdominal obesity and each adiponectin isoform value. RESULTS: Data from 1654 subjects (846 boys and 808 girls) were analyzed. Adiponectin complexes were lower in the abdominal obesity group than in the non-abdominal obesity group regardless of sex. Abdominal obesity significantly increased the odds ratio (OR) for each adiponectin isoform level less than or equal to the median value in boys; the OR (95% confidence interval [CI]) was 2.50 (1.59-3.92) for high molecular weight adiponectin (HMW-adn), 2.47 (1.57-3.88) for medium molecular weight adiponectin (MMW-adn), and 1.75 (1.13-2.70) for low molecular weight adiponectin (LMW-adn). In girls, the OR (95% CI) was 1.95 (1.18-3.21) for HMW-adn, 1.40 (0.86-2.28) for MMW-adn, and 1.06 (0.65-1.70) for LMW-adn. CONCLUSIONS: Abdominal obesity was associated with lower adiponectin complexes and the influence of abdominal obesity varied by adiponectin isoform. Furthermore, the impact of abdominal obesity was larger in boys than in girls. The present study results suggest that prevention of abdominal obesity could contribute to the prevention of lower adiponectin levels, especially in boys.

Difference in effects of cigarette smoking or alcohol consumption on serum non-high-density lipoprotein cholesterol levels is related to mitochondrial DNA 5178 C/A polymorphism in middle-aged Japanese men: a cross-sectional study.

BACKGROUND: Mitochondrial DNA 5178 cytosine/adenosine (Mt5178 C/A) polymorphism is associated with longevity in the Japanese. The purpose of this study is to investigate whether Mt5178 C/A polymorphism modifies the effects of habitual smoking or habitual drinking on serum non-high-density lipoprotein (non-HDL) cholesterol levels in middle-aged Japanese men. METHODS: A total of 394 male subjects (age 53.9 ± 7.9 years; mean ± SD) were selected from among individuals visiting the hospital for regular medical check-ups. After Mt5178 C/A genotyping, a cross-sectional study assessing the joint effects of Mt5178 C/A polymorphism and cigarette smoking or alcohol drinking on serum non-HDL cholesterol levels was conducted. High levels of serum non-HDL cholesterol were defined as serum non-HDL cholesterol levels ≥160 mg/dl or ≥190 mg/dl. RESULTS: For men with Mt5178A, cigarette smoking may increase serum non-HDL cholesterol levels (P for trend < 0.001), as well as the risk of high levels of non-HDL cholesterol (serum non-HDL cholesterol levels ≥160 mg/dl, P for trend < 0.001; serum non-HDL cholesterol levels ≥190 mg/dl, P for trend = 0.004). On the other hand, for men with Mt5178C, after adjusting for age and body mass index, alcohol consumption may decrease serum non-HDL cholesterol levels (P for trend = 0.043) and the risk of high levels of non-HDL cholesterol (serum non-HDL cholesterol level ≥160 mg/dl, P for trend = 0.005). CONCLUSIONS: These gene-environment interactions on serum non-HDL cholesterol levels may contribute to the establishment of individualized prevention of the risk of high levels of serum non-HDL cholesterol.

Joint effects of mitochondrial DNA 5178 C/A polymorphism and coffee consumption or alcohol consumption on clustering of cardiovascular risk factors in middle-aged Japanese men: a cross-sectional study.

BACKGROUND: Longevity-associated mitochondrial DNA 5178 (Mt5178) C/A reportedly modulates the effects of coffee consumption on the risk of hypertension, dyslipidemia and abnormal glucose tolerance, and those of alcohol consumption on the risk of hypertension, dyslipidemia and hyperuricemia in middle-aged Japanese men. However, there has been no research examining whether Mt5178 C/A polymorphism influences the effects of coffee consumption or alcohol consumption on the clustering of cardiovascular risk factors (CRFs). METHODS: A total of 332 male subjects (mean age ± SD, 52.8 ± 7.8 years) were selected from among individuals visiting the hospital for regular medical check-ups. After Mt5178 C/A genotyping, a cross-sectional study assessing the joint effects of Mt5178 C/A polymorphism and coffee consumption or alcohol consumption on the clustering of CRFs, namely hypertension, abnormal glucose tolerance, hyper-low-density lipoprotein cholesterolemia, hypo-high density lipoprotein cholesterolemia, hypertriglyceridemia and hyperuricemia, was then conducted. RESULTS: After adjustment for confounding factors, significant and negative associations were observed between coffee consumption and clustering of ≥2 CRFs in subjects with Mt5178C. The adjusted odds ratio (OR) for the clustering of ≥2 or ≥3 CRFs was significantly lower in subjects who consumed 1-3 cups of coffee per day than in those who consumed <1 cup of coffee per day (OR = 0.496, 95% confidence interval (CI): 0.249-0.989, and OR = 0.369, 95% CI: 0.165-0.826, respectively). On the other hand, after adjustment, positive associations between coffee consumption and clustering of ≥2 CRFs were observed in subjects with Mt5178A. However, these associations did not reach a significant level. For Mt5178C genotypic men, the adjusted OR for the clustering of ≥2 or ≥3 CRFs was significantly higher in daily drinkers than in occasional drinkers (OR = 2.737, 95% CI: 1.361-5.502, and OR = 3.024, 95% CI: 1.269-7.210, respectively). On the other hand, the association between Mt5178A genotype and the clustering of ≥2 or ≥3 CRFs did not appear to depend on alcohol consumption. CONCLUSIONS: The present results suggest that Mt5178 C/A polymorphism modifies the effects of coffee consumption or alcohol consumption on the clustering of CRFs in middle-aged Japanese men.

The impact of eating quickly on anthropometric variables among schoolgirls: a prospective cohort study in Japan.

BACKGROUND: Because most studies about the relationship between eating quickly and overweight/obesity have been cross-sectional, it is necessary to investigate prospectively the influence of eating quickly on anthropometric variables in order to examine the causal relationship. The aim of the present study was to investigate the impact of eating quickly on anthropometric variables among schoolgirls in a prospective cohort study. METHODS: We investigated 427 non-overweight/obese schoolgirls from fourth grade (aged 9 or 10 years) in Ina-town, Japan from 2004 to 2006. Physical examinations and a questionnaire survey were conducted in fourth grade and 3 years later (in seventh grade). Height, weight, percent body fat (%BF) and waist circumference (WC) were measured in physical examinations, and information on eating speed was collected in a questionnaire survey. RESULTS: The differences in anthropometric variables (body mass index, %BF, WC and waist-to-height ratio) between fourth and seventh grade were significantly greater in girls who continued to eat quickly from fourth to seventh grade than in those who did not continue to eat quickly during this 3-year period. In contrast, these differences were not statistically significant in girls who ate quickly in fourth grade but not in seventh grade compared with those who did not continue to eat quickly during the 3-year period. CONCLUSION: Eating quickly was associated with excess gains in anthropometric variables. The present study also suggested that stopping a habit of eating quickly prevents these excess gains in non-overweight/obese girls, which could contribute to the prevention of childhood overweight and obesity.