Oleic acid to stearic acid ratio might be a potential marker for insulin resistance in non-obese Japanese.

Results from a recent study indicate that a higher level of oleic acid/stearic acid ratio was associated with metabolically unhealthy obesity. This was further validated in cross-sectional and interventional studies; however, this was not extensively studied in a non-obese population. We recruited 260 Japanese subjects with serum free fatty acid profiles undergoing anti-aging health examinations. The determinants for oleic acid/stearic acid ratio were investigated using multiple regression analyses. To compare different markers, the subjects were classified based on oleic acid/stearic acid ratio and the combination of oleic acid/stearic acid ratio and triglyceride levels. The oleic acid/stearic acid ratio exhibited a positive correlation with the logmatic transformed triglyceride/high-density lipoprotein cholesterol ratio and the fasting triglycerides-glucose index, both of which were used as markers for insulin resistance. Multiple regression analyses revealed that the triglyceride/high-density lipoprotein cholesterol ratio and fasting triglyceride-glucose index were positively associated with the oleic acid/stearic acid ratio. Most markers were the worst in the highest triglyceride group in both oleic acid/stearic acid groups. In addition, most markers were worse in high oleic acid/stearic acid ratio group than low group. In conclusion, oleic acid/stearic acid ratio might be a useful marker for insulin resistance in non-obese Japanese subjects.

Usefulness of Triglyceride to High-Density Lipoprotein Ratio and Alanine Aminotransferase for Predicting Insulin Resistance and Metabolic Syndrome in the Japanese Population.

Background: Considering the fact that both alanine aminotransferase (ALT) and the triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C) ratio are useful markers for cardiovascular disease, insulin resistance (IR), and metabolic syndrome (MetS), the possible association of ALT and TG/HDL-C ratio is conceivable, but the association is not well studied. Moreover, assessment of IR and MetS by a combination lipid and liver biomarkers has rarely been carried out. Methods: A total of 11,808 Japanese subjects who underwent an annual health examination and who were not taking medications were recruited. The association between TG/HDL-C ratio and ALT level was investigated using correlation and multiple linear regression analyses. Homeostasis model assessment of insulin resistance (HOMA-IR) and the number of MetS components were evaluated after subjects were stratified by TG/HDL-C ratio and ALT levels. Results: Correlation analysis revealed that ALT levels were positively associated with TG/HDL-C ratio. Moreover, multiple linear regression analysis revealed that TG/HDL-C ratio was positively associated with ALT levels, and the association was attenuated but persisted in both men and women after additional adjustment for visceral adiposity (body mass index, waist circumference, or fatty liver) and IR (HOMA-IR). HOMA-IR and MetS component number increased with either ALT or TG/HDL-C ratio in both men and women. HOMA-IR and MetS component number were particularly high (HOMA-IR: men 2.82, women 3.22, MetS component number: men 2.6, women 2.1) in subjects with highest ALT level and TG/HDL-C ratio. Conclusions: TG/HDL-C ratio showed a positive association with ALT levels in both sexes. Assessments of IR and MetS can become more precise by evaluating TG/HDL-C ratio and ALT, simultaneously.

Relationship between Serum Antioxidative Vitamin Concentrations and Type 2 Diabetes in Japanese Subjects.

A high intake of green leafy vegetables rich in antioxidative nutrients such as vitamin C and ß-carotene may protect against the risk of type 2 diabetes. Measurement of the circulating nutrient concentrations can indicate the nutrient status more directly, and vitamin C and carotenoids are recognized as good biomarkers for the intake of fruits and vegetables. The aim of this study was to investigate the relationships between serum antioxidative vitamin concentrations and type 2 diabetes in Japanese subjects. The study subjects comprised 506 men and 493 women who first underwent anti-aging health checks at Tokai University Tokyo Hospital. Serum concentration of vitamin (V) A, VC, α-tocoferol, ß-carotene, VB12, folate, ferritin and homocysteine, and fasting plasma glucose and HbA1c were used for analysis. Low levels of ß-carotene and VC were significantly associated with dysglycemia. Diabetic subjects showed significantly decreased ß-carotene and VC levels, and multivariate analyses suggested that low levels of ß-carotene and VC were factors related to diabetes. Low levels of ß-carotene and VC are significantly related to dysglycemia/type 2 diabetes, and encouraging people at a higher risk of diabetes to take more green vegetables may be useful as a dietary intervention to improve the antioxidative vitamin status and dysglycemia.

Uric acid, ferritin and γ-glutamyltransferase can be informative in prediction of the oxidative stress.

The anti-oxidant system is affected not only by aging but also many lifestyle factors. We aimed to clarify the determinants of medical check-up items affecting the anti-oxidant system. We studied 959 Japanese individuals who underwent anti-aging health check-ups (mean age: 61.1 years) at Tokai University from 2006 to 2016. As parameters of oxidative stress, we measured serum total anti-oxidant status, 8-hydroxy-2'-deoxyguanosine, and isoprostane. Anti-aging health check-up data and lifestyle information were collected from participants in this study. Step-wise multiple regression analyses were conducted to identify determinants that influence serum total anti-oxidant status, 8-hydroxy-2'-deoxyguanosine, and isoprostane, respectively. Serum total anti-oxidant status was significantly correlated with uric acid, vitamin A, folate, and valine. 8-hydroxy-2'-deoxyguanosine was significantly correlated with age, ferritin, drinking habit, and vitamin Eα. Isoprostane was significantly correlated with vitamin Eα, γ-glutamyltransferase, ferritin, and smoking habit. The strong antioxidant powers of uric acid and vitamins were confirmed. It was suggested that branched-chain amino acids themselves such as valine or peptides containing them may possess antioxidant ability because of its strong correlation. Uric acid, ferritin, and γ-glutamyltransferase, which are common items measured in medical checkups, can be informative in predicting the oxidative stress situation in a general medical examination.