Comprehensive laboratory reference intervals for routine biochemical markers and pro-oxidant-antioxidant balance (PAB) in male adults.

BACKGROUND: Reference values of biochemical markers are influenced by various parameters including age, sex, region, and lifestyle. Hence, we aimed to determine age- and BMI-specific reference intervals (RIs) for important clinical biomarkers in a healthy adult male population from northeastern Iran. This is also the first study to investigate reference values for pro-oxidant-antioxidant balance (PAB). METHODS: Seven hundred and twenty (720) healthy men, aged 20-60 years, were recruited from Sarakhs in the northeast region of Iran. Reference values for lipid profiles (total cholesterol, triglyceride, HDL-C and LDL-C), fasting blood glucose, inflammatory factors (hs-CRP and PAB), minerals (zinc and copper), uric acid, and blood pressure were measured and statistically analyzed to establish accurate age- and BMI-specific RIs in alignment with CLSI Ep28-A3 guidelines. RESULTS: RIs for lipid profiles, inflammatory factors, minerals, and uric acid required no age partitioning with the exception of fasting blood glucose and blood pressure, which demonstrated significantly higher values in subjects aged 50 years and older. Among these biomarkers, only uric acid, blood pressure, and triglycerides demonstrated statistically significant increases in reference value concentrations with increasing BMI. CONCLUSION: In this study, age- and BMI-specific RIs for several biochemical markers were determined in healthy adult Iranian men. Partitioning by age and BMI was only required for a few analytes with most demonstrating no statistically significant changes with these covariates. These data can be useful to monitor various diseases in male adults with varying BMI in this region and others.

Optimization the formulation parameters in preparation of α-tocopherol nanodispersions using low-energy solvent displacement technique.

α-Tocopherol is the main compound of vitamin E with great antioxidant activity. However, like other functional lipid bioactive compounds, it suffers from low bioavailability due to its low water solubility and liable chemical structure. A bottom-up procedure based on a solvent-displacement method was constructed for fabrication of α-tocopherol nanodispersions using response surface methodology (RSM). The effects of main formulation parameters, namely, weight ratio of emulsifier to α-tocopherol and volumetric percent of acetone to water on the average particle size (nm), polydispersity index, concentration of α-tocopherol loss (% w/w) and turbidity of the nanodispersions were evaluated and optimized to gain the most desirable nanodispersions (least particle size, polydispersity index, turbidity and highest α-tocopherol concentrations). Second order regression equations, holding quite high coefficients of determination (R2 and adjusted R2 > 0.882), were significantly (p-value < 0.05) fitted for predicting the α-tocopherol nanodispersion characteristics variations as functions of studied formulation parameters. A multiple optimization analysis offered 6.5 and 10% for weight ratio of Tween 20 to α-tocopherol and volume percent of acetone, respectively, as overall optimum values for studied parameters. Statistically insignificant differences between experimental and predicted values of studied responses, verified the satisfactoriness of presented models for explaining the response characteristics as a function of formulation parameters. Thus, the employed solvent-displacement technique may provide the most desired water dispersible α-tocopherol nanoparticles for several water-based foods, cosmetic nutraceutical formulations.