To investigate the direct relationship of oxidative stress with obesity and insulin resistance in men, we measured the plasma levels of 8-epi-prostaglandin F2alpha (PGF2alpha) in 14 obese and 17 nonobese men and evaluated their relationship with body mass index; body fat weight; visceral, sc, and total fat areas, measured by computed tomography; and glucose infusion rate during a euglycemic hyperinsulinemic clamp study. Obese men had significantly higher plasma concentrations of 8-epi-PGF2alpha than nonobese men (P < 0.05). The plasma levels of 8-epi-PGF2alpha were significantly correlated with body mass index (r = 0.408; P < 0.05), body fat weight (r = 0.467; P < 0.05), visceral (r = 0.387; P < 0.05) and total fat area (r = 0.359; P < 0.05) in all (obese and nonobese) men. There was also a significant correlation between the plasma levels of 8-epi-PGF2alpha and glucose infusion rate in obese men (r = -0.552; P < 0.05) and all men (r = -0.668; P < 0.01). In all subjects, the plasma levels of 8-epi-PGF2alpha were significantly correlated with fasting serum levels of insulin (r = 0.487; P < 0.01). In brief, these findings showed that the circulating levels of 8-epi-PGF2alpha are related to adiposity and insulin resistance in men. Although correlation does not prove causation, the results of this study suggest that obesity is an important factor for enhanced oxidative stress and that this oxidative stress triggers the development of insulin resistance in men.

The oral microbiota change dramatically with each part of the oral cavity, even within the same mouth. Nevertheless, the microbiota associated with peri-implantitis and periodontitis have been considered the same. To improve our knowledge of the different communities of complex oral microbiota, we compared the microbial features between peri-implantitis and periodontitis in 20 patients with both diseases. Although the clinical symptoms of peri-implantitis were similar to those of periodontitis, the core microbiota of the diseases differed. Correlation analysis revealed the specific microbial co-occurrence patterns and found some of the species were associated with the clinical parameters in a disease-specific manner. The proportion of Prevotella nigrescens was significantly higher in peri-implantitis than in periodontitis, while the proportions of Peptostreptococcaceae sp. and Desulfomicrobium orale were significantly higher in periodontitis than in peri-implantitis. The severity of the peri-implantitis was also species-associated, including with an uncultured Treponema sp. that correlated to 4 clinical parameters. These results indicate that peri-implantitis and periodontitis are both polymicrobial infections with different causative pathogens. Our study provides a framework for the ecologically different bacterial communities between peri-implantitis and periodontitis, and it will be useful for further studies to understand the complex microbiota and pathogenic mechanisms of oral polymicrobial diseases.

OBJECTIVE -The purpose of this study was to investigate the association between visceral adiposity or triglyceride (TG) metabolism and insulin resistance in metabolically obese, normal weight (MONW) Japanese individuals with normal glucose tolerance.RESEARCH DESIGN AND METHODS -We evaluated body fat areas, lipid profiles, and the glucose infusion rate (GIR) during a euglycemic-hyperinsulinemic clamp study in 20 MONW subjects (BMI Ͻ25 kg/m 2 and visceral fat areas 100 cm 2 ) with normal glucose tolerance. Body fat areas were measured by computed tomography scans. Control data were obtained from 20 normal subjects (BMI Ͻ25 kg/m 2 and visceral fat areas Ͻ100 cm 2 ).RESULTS -MONW subjects showed a significant increase in fasting serum levels of TG (P Ͻ 0.01) and a decrease in GIR (P Ͻ 0.01) compared with normal subjects. There were significant correlations between visceral fat areas (r ϭ Ϫ0.563, P Ͻ 0.01) or serum levels of TG (r ϭ Ϫ0.474, P Ͻ 0.05) and GIR in MONW subjects. Multiple regression analyses showed that visceral fat areas (F ϭ 7.702, P Ͻ 0.02) and serum levels of TG (F ϭ 7.114, P Ͻ 0.05) were significantly associated with GIR in all (MONW and normal) subjects.CONCLUSIONS -Increased visceral fat and serum levels of TG are associated with insulin resistance in Japanese MONW subjects with normal glucose tolerance. Excess visceral fat and elevated TG levels may play important roles in the development of insulin resistance in Japanese MONW subjects with normal glucose tolerance. Diabetes Care 26:2341-2344, 2003R ecent reports described the existence of individuals with normal body weight but with a cluster of obesity-related characteristics (1,2). They are characterized by excess visceral fat, insulin resistance, and hyperinsulinemia and have been called metabolically obese, normal weight (MONW) subjects. Ethnic differences should be considered for identifying MONW subjects. In the Japanese population, nonobese (BMI Ͻ25 kg/ m 2 ) subjects with increased visceral fat areas (100 cm 2 ) fulfill the criteria for categorizing them in the MONW group (2-6). Regarding the association of the MONW state with diabetes, higher prevalence of hyperglycemia has been observed in MONW subjects than in normal individuals (3,4).Previous studies have demonstrated that visceral fat areas are associated with insulin resistance in Japanese subjects with normal glucose tolerance and impaired glucose tolerance and in nonobese Japanese patients with type 2 diabetes (7-9). Visceral fat accumulation is also associated with serum triglyceride (TG) levels, and the disturbance of TG metabolism precedes the development of insulin resistance in nonobese Japanese type 2 diabetic patients (9,10). However, the relationships of visceral adiposity and TG metabolism with insulin resistance in Japanese MONW subjects with normal glucose tolerance have not been evaluated. To clarify these points, in the present study, we investigated the relationship between visceral fat areas or serum levels of TG and insulin resistance in Japanese MONW subjects wit...

Aim: The microbial differences between peri-implantitis and periodontitis in the same subjects were examined using 16S rRNA gene clone library analysis and real-time polymerase chain reaction. Materials and methods: Subgingival plaque samples were taken from the deepest pockets of peri-implantitis and periodontitis sites in six subjects. The prevalence of bacteria was analysed using a 16S rRNA gene clone library and real-time polymerase chain reaction. Results: A total of 333 different taxa were identified from 799 sequenced clones; 231 (69%) were uncultivated phylotypes, of which 75 were novel. The numbers of bacterial taxa identified at the sites of peri-implantitis and periodontitis were 192 and 148 respectively. The microbial composition of peri-implantitis was more diverse when compared with that of periodontitis. Fusobacterium spp. and Streptococcus spp. were predominant in both peri-implantitis and periodontitis, while bacteria such as Parvimonas micra were only detected in peri-implantitis. The prevalence of periodontopathic bacteria was not high, while quantitative evaluation revealed that, in most cases, prevalence was higher at peri-implantitis sites than at periodontitis sites. Conclusions: The biofilm in peri-implantitis showed a more complex microbial composition when compared with periodontitis. Common periodontopathic bacteria showed low prevalence, and several bacteria were identified as candidate pathogens in peri-implantitis.