Dhillon, J., C.R. Ferreira, T.J.P. Sobreira, R.D. Mattes, 2017. Multiple reaction monitoring proﬁling to assess compliance with an almond consumption intervention. Curr Dev Nutr. 1(9):e001545. doi: 10.3945/cdn.117.001545.
Background: Almonds are extremely rich sources of lipids and ﬂavonoids, and their consumption is associated with several health beneﬁts. However, there are no analytical methods available to document compliance with prescribed or self-reported chronic almond consumption. Objective: The aim was to use an analytical approach that identiﬁes metabolic proﬁles associated with long-term almond consumption to ascertain compliance with prescribed consumption. Methods: A multiple reaction monitoring (MRM)–proﬁling strategy was designed to isolate metabolic changes in erythrocytes after 12 wk of almond consumption. MRM-proﬁling data acquisition and analysis involve performing separate discovery and screening steps to detect molecular features related to metabolic changes between experimental groups. Samples used for this research were erythrocytes recovered at baseline, after 12 wk of almond consumption (W12almond group), and after 12 wk of a nut-free diet (W12-control group). For the MRM-proﬁling discovery step, representative samples (pools) of erythrocytes from individuals of all groups were interrogated by precursor ion and neutral loss scan experiments on the basis of previous knowledge of chemical functional groups present in the samples. The outputs of the discovery phase were methods used for the MRM-proﬁling screening phase to interrogate individual samples on the basis of fast-MRM measurements. In addition, we screened the literature for ﬂavonoids identiﬁed in almond skins and included them for individual sample screening. Results: Of the 254 m/z values monitored, 5 ratios and combinations of speciﬁc ions with receiver operating characteristic curve AUCs >0.89 provided a sensitivity of 74.2% and a speciﬁcity of 90% for blind samples presented in the model. Eight of the 31participants (25.8%) in the W12-almond group and 3 of the 30 (10%) participants in the W12-control group were misclassiﬁed by all 5 ratios. Ratios and combinations of speciﬁc transitions were mainly related to membrane lipids. Conclusion: The misclassiﬁcations observed as a result of ratio performance evaluation may indicate noncompliance as supported by the dietary intake data.
previous abstractIntramyocellular triacylglycerol accumulation across weight loss strategies; Sub-study of the CENTRAL trial.