ABSTRACT
<p><b>OBJECTIVES</b>The ingestion of pesticides in the daily diet is assumed to be the main modality of pesticide exposure for most people. A widely used class of pesticides in agricultural or residential settings is pyrethroid. We have examined the relationship between the intake frequency of selected items of vegetables and fruits and urinary metabolites of pyrethroid pesticides in a healthy general population.</p><p><b>METHODS</b>A total of 535 residents (184 men and 351 women) who attended a healthcare checkup program conducted in a rural area of Hokkaido, Japan, in August 2005 provided informed consent for their spot urine samples to be used for the determination of 3-phenoxybenzoic acid (3-PBA) levels. They also completed a self-administered questionnaire regarding the intake frequency of 12 food items. The concentrations of creatinine-corrected 3-PBA were predicted by the intake frequency of each item, using analysis-of-covariance models to adjust for age, sex, body mass index, and drinking and smoking status.</p><p><b>RESULTS</b>Both a significant association between the 3-PBA concentration and the frequency of tomato consumption and a significant positive linear trend was found in female subjects. In contrast, no such association was found in the male subjects.</p><p><b>CONCLUSIONS</b>The frequency of tomato consumption was confirmed to strongly predict the urinary pyrethroid metabolite levels in the general population-presumably because tomatoes are most often consumed raw and unpeeled (more so than all other vegetables and fruits analyzed in the current study). However, it should be noted that the 3-PBA levels, even among those subjects with the highest consumption of tomatoes, were far below the levels of toxicological significance, although the health consequences from long-term low-level exposure to pyrethroid requires further exploration.</p>
ABSTRACT
<p><b>OBJECTIVES</b>The aim of this study was to determine whether the serum nitrite plus nitrate (NO( x )) level correlates with biomarkers that are known components of the metabolic syndrome (MetS).</p><p><b>METHODS</b>Serum NO( x ) levels were measured using a commercial kit in 608 Japanese men and women between the ages of 39 and 85 years. Multivariate adjustments for age, smoking status, alcohol consumption and exercise were made in the analysis of covariance (ANCOVA). The components of the metabolic syndrome were defined based on the following criteria: body mass index (BMI) >/=25.0 kg/m(2), glycated hemoglobin (HbA1c) >/=5.6%, systolic blood pressure >/=130 mmHg or diastolic blood pressure >/=85 mmHg, high-density lipoprotein-cholesterol (HDL-C) </=1.03 mmol/l for men and </=1.29 mmol/l for women and triglyceride >/=1.69 mmol/l.</p><p><b>RESULTS</b>The logarithmically transformed age-adjusted serum NO( x ) (lnNO( x )) value was significantly higher in the low HDL-C group (1.76 +/- 0.05 mumol/l; p < 0.05) than MetS component groups (1.65 +/- 0.01 mumol/l) in men, but no difference was found in women. The means of serum lnNO( x ) after multivariate adjustment were 1.64, 1.65, 1.64, 1.66, and 1.81 mumol/l for 0, 1, 2, 3, and 4-5 MetS components for all subjects, respectively. The results of ANCOVA confirmed that the serum lnNO( x ) level was significantly correlated with the clustering of MetS components in both men and women (p < 0.0001 for trend).</p><p><b>CONCLUSION</b>Our results suggest that an increase in the clustering of MetS components was associated with the increase in serum NO levels in our general population.</p>
ABSTRACT
<p><b>OBJECTIVES</b>Polyamines have long been known to have an insulin-like action, but their antiglycating effect has only recently attracted the attention of researchers. The aim of our investigation was to determine the whole blood polyamine concentration in a healthy population in order to examine its relationship with glycemic profiles.</p><p><b>METHODS</b>The study cohort comprised 622 men aged 40-59 who participated in a health checkup program conducted in 1997, when they underwent measurements of fasting plasma glucose (FPG), insulin (FPI), and fructosamine as glycemic indices. Colorimetric assay methods using oat and barley seedling polyamine oxidase were used to determine total polyamine (spermidine + spermine) and spermine concentrations in the whole blood, respectively. Polyamine concentrations adjusted for hemoglobin were quartiled for the analysis of covariance to assess the association with glycemic indices.</p><p><b>RESULTS</b>A significant association was demonstrated between the FPG and total polyamine concentrations. In the trend test, FPG and fructosamine levels increased in accordance with the shift of quartiles of total polyamine concentrations from low to high. In contrast, the association between the spermine and glycemic indices was not statistically significant based on the test for difference of multivariate-adjusted means or trend for linearity.</p><p><b>CONCLUSIONS</b>This is the first epidemiological study to reveal that the concentrations of blood polyamines are related with either FPG or fructosamine level in a healthy population. There may be some feedback mechanism for the elevation of circulating polyamines to quench the glycation reaction under hyperglycemic conditions. In addition, total polyamines, rather than spermine alone, seem to be a sensitive biomarker representing the antiglycation effect of polyamines.</p>