Unstimulated Parotid Saliva Is a Better Method for Blood Glucose Prediction

Objective: Saliva glucose has been widely used in diagnosing and monitoring diabetes, but the saliva collection method will affect saliva glucose concentration. So, this study aims to identify the ideal saliva collection method. Method: A total amount of six saliva collection methods were employed in 80 healthy participants in the morning. Besides, three unstimulated saliva methods were employed in another 30 healthy participants in the morning; in the meantime the blood glucose of these 30 participants was detected with a Roche blood glucose meter. The glucose oxidase method with 2, 4, 6-tribromo-3-hydroxybenzoic acid (TBHBA) as the chromogen has been improved to be suitable for healthy people, through the selection of the optimal pH value and ionic strength of the reaction system. This method was used for the detection of saliva glucose. Results: The improved method obtained absorbance at the wavelength of 520 nm, and the optimized parameter combination was pH 6.5 and 5 mg/dL NaCl. The lower limit of glucose detection was 0.1 mg/dL. Unstimulated saliva glucose concentration was higher than stimulated saliva glucose concentration. Unstimulated parotid saliva glucose concentration was the highest. Besides, unstimulated saliva glucose has a better normal distribution effect. Meantime, it was found that unstimulated parotid saliva was the most highly correlated with blood glucose (R2 = 0.707). Conclusions: the saliva collection method was an important factor that affected saliva glucose concentration. Unstimulated parotid saliva was the most highly correlated with blood glucose, which provided a reference for prediction of diabetes mellitus.

Comparing Glucose Concentration Among Six Saliva Collection Methods In The Newly Developed Saliva Glucose Detection System

Objective: This study aims to identify the ideal saliva collection technique and propose a newly sensitive approach to achieve daily non-invasive blood glucose monitoring for healthy people. Method: A total amount of six methods were employed for collecting saliva glucose in 20 healthy participants in the morning (9:00), before lunch (11:00), after lunch (14:00) and in the evening (17:00). Ultra-micro ultraviolet spectrophotometer was used to launch a new saliva glucose detection system in measuring the saliva glucose concentration.Results: The newly developed glucose detection system showed a statistically significant linear relationship in the range of 0.1-6 mg/dl with R2 = 0.999. Besides, the parotid saliva glucose concentration was higher than both the sublingual/submandibular saliva and the whole saliva. The parotid glucose concentration fluctuating after meal, and the sublingual/submandibular glucose concentration steady. Conclusions: The detection limit was 1/110 of the average blood glucose concentration of healthy people when fasting, which fully met the sensitivity requirements for detecting the saliva glucose concentration of healthy people. Besides, the collection method was an important factor that affected the saliva glucose concentration. The unstimulated parotid saliva glucose may be easier to reflect blood glucose concentration, which provided a reference for the evaluation of the health status of subjects and the early prediction of diabetes mellitus.

Unstimulated Parotid Saliva Sampling in Juvenile Idiopathic Arthritis and Healthy Controls: A Proof-of-Concept Study on Biomarkers

The aims of this proof-of-concept study were to develop a collecting method for unstimulated parotid saliva in juvenile idiopathic arthritis (JIA) patients and healthy children and to investigate if inflammatory biomarkers could be detected in these samples. Forty-five children with JIA (median age of 12 years and 25th–75th percentile of 10–15 years; 33 girls and 12 boys) and 16 healthy children as controls (median age of 13 years and 25–75th percentile of 10–13 years; 11 girls and 5 boys) were enrolled in this study. Unstimulated parotid saliva was collected with a modified Carlson–Crittenden collector. The salivary flow rate and salivary concentrations of total protein and inflammatory mediators were assessed. The Meso Scale Discovery electrochemiluminescence immunoassay was used for analyzing protein concentrations and the inflammatory biomarkers. Sufficient parotid saliva volumes to be analyzed could be collected with the collection device. JIA patients had a lower sampling saliva volume (p = 0.008) and saliva flow rate (p = 0.039) than controls. The total protein concentrations and inflammatory biomarkers were measured in the last six healthy subjects. The median protein concentration was 1312 µg/mL (25th percentile: 844 µg/mL and 75th percentile: 2062 µg/mL; n = 6) and quantifiable concentrations of 39 inflammatory proteins could be assessed in these samples. In conclusion, this study indicates that the saliva sampling method, as used in the present study, is able to collect sufficient sample volumes in children, and that it is possible to analyze various inflammatory biomarkers in the collected saliva.