OBJECTIVESPolyamines 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.

METHODSThe 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.

RESULTSA 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.

CONCLUSIONSThis 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.

  Using healthy volunteers, we examined the influence of emulsified oil and a low concentration of CO2 gas on cutaneous blood flow in the forearm. The forearm of each subject was immersed in 25 liters of warm water containing either 10 ppm emulsified oil or 60 ppm CO2 gas or both. Forearm cutaneous blood flow was measured for 20 minutes. Emulsified oil had no effect on cutaneous blood flow, whereas CO2 gas caused a gradual and significant increase. When CO2 gas was used with emulsified oil, cutaneous blood flow was significantly increased in comparison to CO2 alone, suggesting that emulsified oil enhances the vasodilation caused by CO2. We then prepared bath salts releasing CO2 and emulsified oil, and tested for their influence on sweating function in sixteen healthy adults. Each subject bathed daily 10 minutes either in tap water (control group) or in tap water dissolving bath salts releasing CO2 and emulsified oil (bath-salts group) at 40°C for successive 14 days. A sweating test was performed before and after the session of bathing. In the bath-salts group, the baseline tympanic temperature after successive bathing tended to be lower than that before successive bathing. Although the rise of body temperature during the heat exposure was not different between the groups, sweating rate was significantly greater after successive bathing. The analysis of the rate of sweat expulsion suggested that the greater sweat rate after the successive bathing is mediated by the central mechanism for sweating. Such changes were not observed in the control group. Thus, successive bathing using bath salts that release CO2 and emulsified oil may have a beneficial effect on sweating function.