PO-158 Association Of Glucose Metabolism and Physical Activity By Chronotype in Elderly Japanese Adults: There is no full text article associated with this abstract

Objective Chronotype is a trait determining individual circadian preference in behavioral and biological rhythm relative to external light-dark cycle. Although evening chronotype has been reported to be associated with bad glucose control and low physical activity in middle-aged adults, it is not known whether it is true in elderly people. Therefore, the aim of this study was to investigate the relationship between glucose metabolism and physical activity by chronotype (circadian rhythm) in elderly Japanese adults. Methods A cross-sectional study was conducted in 178 adults (72 men and 106 women), aged 60-79 years, who were classified into three chronotype groups, ”definitely morning type (DMT)”, “moderately morning type (MMT)” and “neither type (NET)”, based on the Morningness/Eveningness Questionnaire scores (MEQ-Score). All participants were required to report their daily rhythms of behavior, such as meal time and sleep-wake cycle. Additionally, their physical activity were measured by an uniaxial accelerometer (Kenz Lifecorder EX, SUZUKEN, Nagoya, Japan). Energy intake was assessed by a brief self-administered diet-history questionnaire. Blood was drawn for biochemical analysis after an overnight fast. Results BMI and serum insulin in the DMT group was significantly higher than MMT and NET groups in male. The DMT group had a significantly shorter time interval between dinner and sleep than the other two groups, both in male and female. After adjustment for covariates (age, smoking and alcohol status, energy intakes, moderate-vigorous physical activity (MVPA) and sleep duration), the BMI, serum insulin, fasting blood glucose (FBG) and HOMA-IR in the DMT group was significantly higher than other groups. However, after adjustment for the time interval between dinner and sleep, the significant difference had disappeared. There was significant difference in terms of low-intensity physical activity between male and female. And MVPA in the DMT group, the subjects with low MVPA (<23Mets·hour/week) had higher FBG, serum insulin and HOMA-IR than the subjects with high MVPA (>23Mets·hour/week) in men, but not in women. Conclusions This study demonstrated that the DMT group with early sleep-wake lifestyle had higher BMI,  FBG, serum insulin and HOMA-IR, specially in elderly Japanese men with low MVPA, but not in women

Cyclic phosphatidic acid inhibits the secretion of vascular endothelial growth factor from diabetic human coronary artery endothelial cells through peroxisome proliferator-activated receptor gamma

Atherosclerosis is a disease characterized by building up plaques formation and leads to a potentially serious condition in which arteries are clogged by fatty substances such as cholesterol. Increasing evidence suggests that atherosclerosis is accelerated in type 2 diabetes. Recent study reported that high level of alkyl glycerophosphate (AGP) was accumulated in atherosclerotic lesions. The presence of this phospholipid in mildly oxidized low-density lipoprotein (LDL) is likely to be involved in atherogenesis. It has been reported that the activation of peroxisome proliferator-activated receptor gamma plays a key role in developing atherosclerosis. Our previous result indicates that cyclic phosphatidic acid (cPA), one of bioactive lipids, potently suppresses neointima formation by inhibiting the activation of peroxisome proliferator-activated receptor gamma (PPARγ). However, the detailed mechanism is still unclear. In this study, to elucidate the mechanism of the cPA-PPARγ axis in the coronary artery endothelium, especially in patients with type 2 diabetes, we investigated the proliferation, migration, and secretion of VEGF in human coronary artery endothelial cells from diabetes patients (D-HCAECs). AGP induced cell growth and migration; however, cPA suppressed the AGP-elicited growth and migration in D-HCAECs. Moreover, AGP increased VEGF secretion from D-HCAECs, and this event was attenuated by cPA. Taken together, these results suggest that cPA suppresses VEGF-stimulated growth and migration in D-HCAECs. These findings could be important for regulatory roles of PPARγ and VEGF in the vascular processes associated with diabetes and atherosclerosis

Hippocampal neuronal position selectivity remains fixed to room cues only in rats alternating between place navigation and beacon approach tasks

International audienceTo study the relationship between brain representations and behaviour, we recorded hippocampal neuronal activity in rats repeatedly alternating between two different tasks on a circular platform with four reward boxes along the edge. In the beacon approach task, rewards were provided only at the pair of diametrically opposite boxes that was illuminated. In the place navigation task, rewards were available only at the boxes positioned near the north-east and south-west corners of the room. Performance levels were high and rats rapidly reoriented to changes in lamp cues in the beacon approach task. Neuropsychological studies show that rats with hippocampal lesions readily employ beacon approach strategies, while place navigation is severely impaired. Previous studies suggested that the neurons might change their behavioural correlates as the rat performed the respective tasks. However, of 34 hippocampal ‘place cells’ recorded, all showed position selectivity fixed with respect to room cues, even in the beacon approach task where coding the position of the rat in the room was of no use for locating rewards. Whether or not hippocampal signals are actually employed for ongoing behaviour would then be decided by structures downstream from the hippocampus. If this is the case, then the ‘counterproductive’ room referred place-related discharges in the beacon approach task would be a background representation. This would provide support for proposals of multiple memory systems underlying different types of information processing and contrasts with the popular notion that local neuronal activity levels are selectively increased to the degree that the brain region is required for the ongoing function