The Combined Effects of Genetic Variation in the CNDP1 and CNDP2 Genes and Dietary Carbohydrate and Carotene Intake on Obesity Risk

BACKGROUND/AIMS

It is possible that carnosinase (CNDP1) and cellular nonspecific dipeptidase (CNDP2) have important roles in protecting cells and tissues against the damage of oxidative stress. Oxidative stress and subsequent inflammation are key factors in the development of common chronic metabolic diseases, such as obesity. We aimed to investigate the combined effects of genetic variations in CNDP1 and CNDP2 and dietary carbohydrate and carotene intake on obesity risk.

METHODS

A total of 1,059 Japanese men were randomly selected from participants who visited a medical center for routine medical checkups. We analyzed the relationships between the genotypes of 4 single-nucleotide polymorphisms (SNPs) (rs12605520, rs7244647, rs4891558, and rs17089368) in the CNDP1/CNDP2 locus and body mass index or prevalence of obesity/overweight taking into account dietary carbohydrate and carotene intake.

RESULTS

We found that 2 SNPs (rs7244647 in CNDP1 and rs4891558 in CNDP2) were associated with obesity risk. In addition, these associations were observed only in the group with high carbohydrate and low carotene intake but not in the group with low carbohydrate and high carotene intake.

CONCLUSIONS

Our findings indicate that the combination of genetic variations in CNDP1 and CNDP2 and dietary carbohydrate/carotene intake modulate obesity risk.

Impact of Interactions Between Self-Reported Psychological Stress and Habitual Exercise on the Dietary Intake of Japanese Men and Women: a Large-Scale Cross-Sectional Study

BACKGROUND

Modifying lifestyle factors such as diet and exercise can reduce the risk of cancer. Psychological stress (PS) might be indirectly associated with cancer because it alters lifestyle factors. However, the relationship among these variables has not been fully investigated. Thus, we examined interactions between self-reported PS (SRPS) and habitual exercise on diet.

MATERIALS AND METHODS

In all, 5,587 men and 2,718 women were divided into "exerciser" and "non-exerciser" groups, based on whether they exercised regularly, and classified into three SRPS levels: low, moderate and high. Diet was estimated using a validated food frequency questionnaire. Using a general linear model, food and nutrient consumption was estimated for each SRPS level in the 2 exercise groups, and the interactions between SRPS levels and exercise were calculated.

RESULTS

In women, the intake of pork and beef, low fat milk and yogurt, natto (fermented soybean), carrots and squash, other root vegetables, mushrooms, seaweeds, and wine, along with the nutrients vegetable protein, soluble, insoluble and total dietary fiber, daidzein, genistein, carotene, retinol equivalents, vitamin B2, pantothenic acid, potassium, calcium, magnesium, phosphorus and iron demonstrated significant interaction with SRPS and habitual exercise (p for interaction <0.05). In men, raw and green leafy vegetables and fruit and vegetable juice significantly interacted with SRPS and habitual exercise (p for interaction <0.05).

CONCLUSIONS

We suggest that certain foods and nutrients, which are thought to have a protective effect against cancer, interact with SRPS and habitual exercise, especially in women. This information is valuable for understanding and improving interventions for cancer prevention.

Serum Fatty Acid Binding Protein 4 Concentrations Are Positively and Independently Associated with Blood Pressure and Abdominal Fat among Parameters in Health Check-Ups in Ordinary Middle-Aged Japanese Males

We wished to examine potential associations among blood concentrations of fatty acid-binding protein (FABP) 4 and parameters in health check-ups such as abdominal fat area (AFA) and blood pressure (BP) in middle-aged Japanese males. We conducted a cross-sectional study of males who participated in health check-ups in Japan. We excluded participants diagnosed with metabolic diseases by the time of their check-up. A total of 305 subjects (30-64 [mean±standard deviation, 47.3±8.5] y) were recruited. Areas of total-abdominal, visceral and subcutaneous fat were measured using computed tomography. We compared the association of serum concentrations of FABP4 with various clinical parameters by Pearson product-moment correlation coefficient (PPMCC) analyses, and by step-wise multivariate linear regression analyses (MLRA). PPMCC analyses showed that blood concentrations of FABP4 were positively associated with: body mass index; areas of fat (total abdominal, visceral, subcutaneous); systolic BP; diastolic BP; total cholesterol; low-density lipoprotein-cholesterol; triacylglycerol; activities of γ-glutamyl transpeptidase, aspartate aminotransferase and alanine aminotransferase; white blood cell count; and levels of creatinine. Step-wise MLRA showed that AFAs (visceral and subcutaneous) and diastolic BP were positively and independently associated with serum concentrations of FABP4 among the parameters tested. These data suggest that serum concentrations of FABP4 are independently and positively associated with BP and AFA among parameters measured in health check-ups in middle-aged Japanese males.

Plasma TNF-α Is Associated with Inflammation and Nutrition Status in Community-Dwelling Japanese Elderly

Inflammation has been suggested to play an important role in age-related chronic diseases and disability, and it is associated with nutritional status including obesity and malnutrition. While numerous studies have examined the validity of inflammatory markers in the population studies in Caucasian elderly people, very little information is available for the factors affecting inflammatory markers in Asian elderly people. Among inflammatory markers frequently used for the studies of aging, tumor necrosis factor α (TNF-α) is produced mainly by macrophages, and contributes to production of interleukin-6 (IL-6) and C-reactive protein (CRP), thus directing a chronic inflammatory process in the body. In the present study, we examined the associations between plasma TNF-α level and several factors related to nutrition status, including BMI, albumin, and energy intake in community-dwelling Japanese elderly. We conducted a cross-sectional study of 390 men and women aged 70-86 y (average 73.5 y), who participated in health check-ups. Associations between plasma TNF-α levels, other clinical parameters, and lifestyle factors were analyzed using Spearman's rank correlation coefficient analysis and multiple linear regression analysis. In elderly men, plasma TNF-α level was positively associated with age, white blood cell count, monocyte count, plasma CRP level, serum creatinine, ureic acid, and triacylglycerol levels, and negatively associated with albumin/globulin ratio, eGFR, and serum HDL-cholesterol level. In elderly women, plasma TNF-α level was positively associated with age, plasma CRP level, and serum triacylglycerol level, and negatively associated with serum albumin and HDL-cholesterol levels. The results of this study suggest that plasma TNF-α is associated with inflammation and insulin resistance in both Japanese elderly men and women, and a prominent association of TNF-α with malnutrition status was observed in elderly women.

Positive linear dose-response relationships, but no J-shaped relationship, between drinking habits and estimated glomerular filtration rate in middle-aged Japanese men

The relationship between drinking frequency and amount of alcohol consumption (i.e., drinking habits) and the risk of chronic kidney disease (CKD) remains unclear. We aimed to clarify either a linear or J-shaped dose-response relationship between drinking habits and estimated glomerular filtration rate (eGFR) as a biomarker for identifying individuals at high risk of CKD. In a large-scale cross-sectional study, 403 men and 121 women with an eGFR of 30-60 mL/min per 1.73 m(2) were defined as cases, and 1209 men and 363 women with ≥60 mL/min/1.73 m(2) were randomly extracted as controls (one case subject was matched with three control subjects, matched according to age and season of data collection). We calculated multivariate-adjusted CKD risk and the corresponding mean eGFR according to drinking habits. In men, negative and positive linear relationships with drinking habits were found for CKD risk and mean eGFR (p < 0.001 for all linear terms), respectively, but there were no corresponding J-shaped relationships (not significant for all quadratic terms). In regard to the mean eGFR, however, positive linear relationships were only shown in men in the highest eGFR quartile (p < 0.05 and p < 0.01 for drinking frequency and amount of alcohol consumption, respectively). In women, no association was found. Regarding each drinking habit, we found a positive linear dose-response relationship to eGFR in middle-aged men with an eGFR ≥30 mL/min/1.73 m(2).

Association between Smoking Status and Food and Nutrient Consumption in Japanese: a Large-Scale Cross-Sectional Study

BACKGROUND

In Japan, in comparison with the rest of the world the death rate of lung cancer is low although the smoking rate is relatively high. This is the so-called "Japanese smoking paradox". A healthy diet is proposed to attenuate the risk without quitting smoking. We here examined the relationships between smoking status (SS) and the consumption of food and nutrient in Japan.

MATERIALS AND METHODS

Totals of 5,587 men and 2,718 women were divided into three (non-smokers, smokers and heavy smokers) and two (non-smokers and smokers) groups, respectively, according to pack-year, which represents the amount of smoking over a long period. Food and nutrient consumption was estimated with a validated food frequency questionnaire. Using general linear models, food and nutrient consumption was estimated for each group in men and women, separately.

RESULTS

In men, SS was positively related to consumption of rice, 3 alcoholic beverages, carbohydrate, alcohol and other 8 foods/nutrients (p<0.05 for all) and negatively to those of protein animal, fat, fatty acids, dietary fiber, isoflavones and 36 other foods/nutrients (p<0.05 for all). In women, SS was positively associated with intake of 13 foods/nutrients, while being negatively associated with those of rice, energy, dietary fiber, and 14 other foods/nutrients (p<0.05 for all).

CONCLUSIONS

Our results support lower intake of vegetables and fruits rich in antioxidants, which are thought as preventive factors for many diseases, in smokers.

Polymorphism in microRNA-binding site in HNF1B influences the susceptibility of type 2 diabetes mellitus: a population based case-control study

Background

Recent genome-wide association studies (GWAS) have identified many SNPs associated with type 2 diabetes mellitus (T2DM). However, the functional roles for most of the SNPs have not been elucidated. MicroRNAs (miRNAs) are key regulators of gene expression involved in the development and progression of various diseases including T2DM. In this study, we investigated whether commonly occurring SNPs modulate miRNA-directed regulation of gene expression, and whether such SNPs in miRNA-binding sites are associated with the susceptibility for T2DM.

Methods

Genotypes of eleven 3′ untranslated region (UTR) SNPs of seven susceptibility genes for T2DM were determined in 353 T2DM patients and 448 control subjects. In addition, the interactions of miRNAs with the 3′UTR in the hepatocyte nuclear factor 1β (HNF1B) gene were investigated using luciferase reporter assays.

Results

One 3′UTR SNP (rs2229295) in the HNF1B gene was significantly associated with T2DM, and the frequency of an A allele (rs2229295) in T2DM patients was decreased compared with that in controls. Luciferase reporter assays showed that the SNP (rs2229295) altered the binding of two miRNAs (hsa-miR-214-5p and hsa-miR-550a-5p).

Conclusions

We have detected the interactions of hsa-miR-214-5p/hsa-miR-550a-5p and the 3′UTR SNP of the HNF1B gene by in vitro luciferase reporter assays, and propose that the binding of such miRNAs regulates the expression of the HNF1B gene and the susceptibility of T2DM.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-015-0219-5) contains supplementary material, which is available to authorized users.

Interactions between psychological stress and drinking status in relation to diet among middle-aged men and women: a large-scale cross-sectional study in Japan

The aim of this study was to investigate the interaction between psychological stress (PS) and drinking status in relation to diet among middle-aged Japanese men and women in a large-scale cross-sectional study. The study population included 5,587 middle-aged Japanese men and 2,718 middle-aged Japanese women who underwent annual health checkups. The subjects were divided into 2 groups (non-drinkers and drinkers) and classified as having low, moderate, or high self-reported PS levels. Energy-adjusted food and nutrient consumption was assessed with a validated food frequency questionnaire. Using a general linear model, food and nutrient consumption was estimated for each self-reported PS level in the 2 groups (non-drinkers and drinkers) and the interactions between self-reported PS levels and drinking status were calculated. In men, pork and beef; squid, octopus, shrimp, and clams; eggs; mushrooms; Japanese-style sweets; ice cream; bread; Chinese noodles; coffee; and soda as foods and protein, animal protein, fat, animal fat, carbohydrate, monounsaturated fatty acid, polyunsaturated fatty acid (PUFA), n-3 PUFA, n-6 PUFA, cholesterol, vitamin D, vitamin B2, vitamin B6, vitamin B12, niacin, pantothenic acid, magnesium, phosphorus, and zinc as nutrients significantly interacted with self-reported PS levels and drinking status (p for interaction <0.05 for all). No specific interactions were found in women. These findings suggest interactions between PS levels and drinking status with consumption of some foods and nutrients, especially macronutrient intake, in men but not in women.

Serum γ-GTP activity is closely associated with serum CRP levels in non-overweight and overweight middle-aged Japanese men

The relationship between γ-glutamyltransferase (γ-GTP) and C-reactive protein (CRP) has not been established, particularly in the lean or non-overweight population. In the present study, we examined the associations between γ-GTP and CRP in non-overweight and overweight middle-aged Japanese men. We conducted a cross-sectional study of 4,271 apparently healthy men aged 40 to 64 y (mean±SD, 50.5±6.6 y) who participated in health checkups. Associations between serum CRP levels, other clinical parameters, and lifestyle factors were analyzed using Spearman's rank correlation coefficient analysis and multiple linear regression analysis in the non-overweight (body mass index [BMI]<25 kg/m(2)) and overweight (BMI≥25 kg/m(2)) men. Associations between serum γ-GTP activity and serum CRP levels were analyzed using analysis of covariance by comparisons of serum CRP levels of four subgroups according to γ-GTP status. In non-overweight men, BMI, high-density lipoprotein cholesterol, triacylglycerols, fasting blood glucose, aspartate aminotransferase, γ-GTP, and smoking habit were positively associated with serum CRP levels. In overweight men, BMI, diastolic blood pressure, triacylglycerols, and γ-GTP were positively associated with serum CRP levels. After adjustment for age, BMI, smoking status, and alcohol intake, dose-response relationships were observed between γ-GTP and CRP levels in both overweight and non-overweight men. The results of this study indicate that an increase in serum γ-GTP activity is closely associated with elevated CRP levels in both non-overweight and overweight middle-aged Japanese men.

Plasma sE-selectin level is positively correlated with neutrophil count and diastolic blood pressure in Japanese men

Increased levels of circulating soluble type of E-selectin (sE-selectin), neutrophil counts and blood pressure are associated with the development of cardiovascular diseases (CVD). In this study, we conducted a cross-sectional study of men who participated in health check-ups, and selected those who were not diagnosed with or being treated for metabolic diseases such as diabetes, hypertension and lipid abnormality according to the health check-ups. We measured their basic clinical parameters including blood pressure and neutrophil count, plasma sE-selectin concentration and lifestyle factors, and assessed their interrelations by multivariate linear regression (MLR) analysis. A total of 351 subjects aged 47.5±8.41 (range, 30-64) y were recruited. Significantly correlated with sE-selectin concentration were neutrophil count, diastolic blood pressure (DBP), and systolic blood pressure (SBP) (Pearson's correlation coefficient, 0.194, 0.220 and 0.175, respectively). MLR analysis showed that sE-selectin concentration was independently positively related with DBP and neutrophil count, whereas neutrophil count was positively associated with sE-selectin concentration but not DBP. DBP, but not SBP, was independently positively correlated with sE-selectin concentration but not neutrophil count. These results indicate that circulating sE-selectin concentration may be a biomarker for indicating subsequent development of metabolic diseases, in particular CVD, from a healthy state.

The combined effects of genetic variation in the SIRT1 gene and dietary intake of n-3 and n-6 polyunsaturated fatty acids on serum LDL-C and HDL-C levels: a population based study

Background

Dyslipidemia due to high total cholesterol, LDL-cholesterol, triglycerides, or low HDL-cholesterol is an important risk factor for coronary heart disease (CHD). Both SIRT1 and PUFAs can influence the expression of genes for nuclear receptors and transcription factors related to lipid metabolism such as LXRα, LXRβ, PPARα, SREBP-1c.

Methods

A total of 707 Japanese males and 723 females were randomly selected from the participants who visited a medical center for routine medical check-ups. We analyzed the combined effects of the genotype/haplotype of the SIRT1 gene and dietary n-6/n-3 PUFA intake ratio on the determination of serum lipid levels.

Results

We found that the SIRT1 gene marked with haplotype 2 was associated with decreased serum LDL-cholesterol and increased HDL-cholesterol levels. In addition, the associations between the SIRT1 haplotype 2 and decreased LDL-C and increased HDL-C levels were only observed in the low n-6/n-3 PUFA intake ratio group, but not in the high n-6/n-3 PUFA intake ratio group.

Conclusions

Our findings indicate that the combination of genetic variation in the SIRT1 gene and dietary n-6 and/or n-3 PUFA intake influence the determination of inter-individual variations of serum levels of LDL-C and HDL-C.

Age-related changes in serum amino acids concentrations in healthy individuals

Serum amino acids, part of a pool of free amino acids, are influenced by metabolism and disease. Few reports exist describing their function and concentrations in serum. Our study aimed to determine age- and gender-related differences in serum amino acid concentrations in healthy Japanese patients, focusing on their inclusion in body proteins.

Healthy patients with normal liver and kidney function were selected based on biochemical variables. Serum amino acid concentrations in 23–88-year-old patients (312 males, 252 females; 52.1±15.0 years) were evaluated to determine the normal values and to clarify the differences in concentration. The patients were divided into 11 groups according to their gender and age (in 5-year increments), and serum amino acid concentrations were determined as the normal values for each group.

Some amino acids increased or decreased with age. Values of leucine, threonine, methionine, histidine, glycine, serine and taurine decreased with age in males, whereas, those of threonine and serine decreased with age in females (p<0.05). In contrast, values of phenylalanine, aspartate, asparagine, glutamate, alanine, citrulline, ornithine, arginine and tyrosine increased with age in males, whereas, values of phenylalanine, lysine, asparagine, glutamate, glutamine, alanine, citrulline, ornithine, arginine, tyrosine and proline increased with age in females (p<0.05).

We clarified basic trends of age- and gender-related amino acid concentrations in serum. In normal healthy Japanese people who ate normally and lived an independent life, there are significant age- and gender-related differences.

The combined effect of the T2DM susceptibility genes is an important risk factor for T2DM in non-obese Japanese: a population based case-control study

Background

Type 2 diabetes mellitus (T2DM) is a complex endocrine and metabolic disorder. Recently, several genome-wide association studies (GWAS) have identified many novel susceptibility loci for T2DM, and indicated that there are common genetic causes contributing to the susceptibility to T2DM in multiple populations worldwide. In addition, clinical and epidemiological studies have indicated that obesity is a major risk factor for T2DM. However, the prevalence of obesity varies among the various ethnic groups. We aimed to determine the combined effects of these susceptibility loci and obesity/overweight for development of T2DM in the Japanese.

Methods

Single nucleotide polymorphisms (SNPs) in or near 17 susceptibility loci for T2DM, identified through GWAS in Caucasian and Asian populations, were genotyped in 333 cases with T2DM and 417 control subjects.

Results

We confirmed that the cumulative number of risk alleles based on 17 susceptibility loci for T2DM was an important risk factor in the development of T2DM in Japanese population (P < 0.0001), although the effect of each risk allele was relatively small. In addition, the significant association between an increased number of risk alleles and an increased risk of T2DM was observed in the non-obese group (P < 0.0001 for trend), but not in the obese/overweight group (P = 0.88 for trend).

Conclusions

Our findings indicate that there is an etiological heterogeneity of T2DM between obese/overweight and non-obese subjects.

The combination of genetic variations in the PRDX3 gene and dietary fat intake contribute to obesity risk

Oxidative stress is caused by an imbalance between the production of reactive oxygen species (ROS) and the antioxidant capacity of the cell. This imbalance and an excess of ROS induce tissue/cellular damage, which are implicated in chronic inflammation disorders such as obesity, insulin resistance, and metabolic syndromes. Peroxiredoxins (Prxs) are the most abundant and ancient cellular antioxidant proteins that help to control intracellular peroxide levels and ROS-dependent signaling. Of the six mammalian isoforms, Prx III is specifically localized in mitochondria. In this study, we detected novel associations between genetic variations of the PRDX3 gene and BMI and obesity risk in the general Japanese population. In addition, these associations were observed only in the subjects with high dietary fat intake, but not in the subjects with low dietary fat intake. These findings indicate that the interaction between genetic variations in the PRDX3 gene and dietary fat intake is important for modulation of BMI and obesity risk.

Criteria for screening diabetes mellitus using serum fructosamine level and fasting plasma glucose level. The Japanese Society of Multiphasic Health Testing and Services (JMHT), Fructosamine Working Committee

A screening method using serum fructosamine level and the fasting plasma glucose level was used for screening patients with diabetes mellitus. The criteria for positive tests recommended by the Japanese Society of Multiphasic Health Testing and Services were evaluated. It was found that levels for the serum fructosamine of 290 mumol/l or higher (or, for the fasting plasma glucose of 110 mg/dl or higher) agreed with the standard oral glucose tolerance test in identifying patients with diabetes mellitus in 96.7% of cases, and the serum fructosamine test was simpler and less expensive.

Criteria for Screening Diabetes Mellitus Using Serum Fructosamine Level and Fasting Plasma Glucose Level

A screening method using serum fructosamine level and the fasting plasma glucose level was used for screening patients with diabetes mellitus. The criteria for positive tests recommended by the Japanese Society of Multiphasic Health Testing and Services were evaluated. It was found that levels for the serum fructosamine of 290 µmol/l or higher (or, for the fasting plasma glucose of 110 mg/dl or higher) agreed with the standard oral glucose tolerance test in identifying patients with diabetes mellitus in 96.7% of cases, and the serum fructosamine test was simpler and less expensive.

The significance of the ratio of body weight/height as a practical obesity index and the changes in the values in Japanese adults

1. It was observed that the W/H ratio highly correlated with body weight, while it had low correlation with age and height. From this fact, the W/H ratio was considered to have a practical value as an index from which adult obesity can be more easily judged than from BMI. 2. The W/H ratios of Japanese adults continue to increase in men of all age groups and women in the 50 or older age groups. That is, people tend towards obesity with age. Thus this fact may be associated with the increase in incidence of adult diseases in Japan.