Use of human teardrop fluid for the determination of trace elements in healthy individuals and diabetic patients

Atomic spectrometry update: review of advances in the analysis of clinical and biological materials, foods and beverages

“…Levels of As, Cd, Cr, Cu, Fe, Mn, Sr, V and Zn were measured by ICP-MS in 173 teardrop fluid samples. 198 Teardrop As, Cu and V concentrations were higher in healthy subjects ( n = 129) compared with type 2 diabetics ( n = 44), however these observations contradict previously reported trends in other sample types. Teardrop fluid collection presents an attractive alternative to invasive sample techniques, however more detailed information regarding elemental composition of this fluid is required before it can have any true clinical application.…”

Recent advances in the application of ionomics in metabolic diseases

“…To date, the ionomes in blood (including whole blood, plasma, and serum), urine, hair, and even teardrops have been examined in different cohorts of patients with T2DM, implying that changes in elemental profiles represent a potential source of biomarkers of this complex disease ( 60 – 70 ). The majority of significantly changed elements in different biofluids (especially in the blood samples) are positively associated with T2DM, including several heavy metals (such as Cu and Cd) and Se whose accumulation in the body may be a high risk for T2DM.…”

“…Moreover, significant correlations (|correlation coefficient| > 0.3 and p < 0.05) between elements and increased Cu/Zn ratio were also reported, suggesting possible benefits of the use of such information in detection and prognosis evaluation of T2DM (61,63). By using machine learning algorithms [such as discriminate analysis, support vector machine (SVM), and random forest], several new approaches and models for the early detection of T2DM based on multi-elemental contents have been developed, which exhibit good prediction performance and may serve as a valuable tool of its diagnosis (66,(70)(71)(72). Very recently, the blood levels of several essential trace elements (such as V, Cr, Mn, and Se) were found to be negatively correlated with hemoglobin A1c (HbA1c) in diabetic subjects, especially in those with HbA1c ≥ 7.0%, suggesting mutual effects between them and metabolic abnormalities of blood glucose during the onset and progression of T2DM (69).…”