Molecular diagnosis of polycystic ovary syndrome in obese and non-obese women by targeted plasma miRNA profiling.

OBJECTIVE: Polycystic ovary syndrome (PCOS) is diagnosed based on the clinical signs, but its presentation is heterogeneous and potentially confounded by concurrent conditions, such as obesity and insulin resistance. miRNA have recently emerged as putative pathophysiological and diagnostic factors in PCOS. However, no reliable miRNA-based method for molecular diagnosis of PCOS has been reported. The aim of this study was to develop a tool for accurate diagnosis of PCOS by targeted miRNA profiling of plasma samples, defined on the basis of unbiased biomarker-finding analyses and biostatistical tools. METHODS: A case-control PCOS cohort was cross-sectionally studied, including 170 women classified into four groups: non-PCOS/lean, non-PCOS/obese, PCOS/lean, and PCOS/obese women. High-throughput miRNA analyses were performed in plasma, using NanoString technology and a 800 human miRNA panel, followed by targeted quantitative real-timePCR validation. Statistics were applied to define optimal normalization methods, identify deregulated biomarker miRNAs, and build classification algorithms, considering PCOS and obesity as major categories. RESULTS: The geometric mean of circulating hsa-miR-103a-3p, hsa-miR-125a-5p, and hsa-miR-1976, selected among 125 unchanged miRNAs, was defined as optimal reference for internal normalization (named mR3-method). Ten miRNAs were identified and validated after mR3-normalization as differentially expressed across the groups. Multinomial least absolute shrinkage and selection operator regression and decision-tree models were built to reliably discriminate PCOS vs non-PCOS, either in obese or non-obese women, using subsets of these miRNAs as performers. CONCLUSIONS: We define herein a robust method for molecular classification of PCOS based on unbiased identification of miRNA biomarkers and decision-tree protocols. This method allows not only reliable diagnosis of non-obese women with PCOS but also discrimination between PCOS and obesity. CAPSULE: We define a novel protocol, based on plasma miRNA profiling, for molecular diagnosis of PCOS. This tool not only allows proper discrimination of the condition in non-obese women but also permits distinction between PCOS and obesity, which often display overlapping clinical presentations.

Prediabetes diagnosis criteria, type 2 diabetes risk and dietary modulation: The CORDIOPREV study.

AIM: Our objective was to investigate the role of two healthy diets in modulating the risk of type 2 diabetes (T2DM) development associated with each prediabetes diagnosis criteria in coronary heart disease patients. Additionally, we explored the pathophysiological characteristics and the risk of developing T2DM in patients with different prediabetes criteria. METHODS: We included 462 patients from the CORDIOPREV study without T2DM at baseline: 213 had prediabetes defined by impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) (PreDM-IFG/IGT); 180 had prediabetes by isolated hemoglobin glycated plasma levels (PreDM-isolated-HbA1c), and 69 were not prediabetics (non-PreDM), according to the American Diabetes Association criteria. Patients were randomized to consume either a Mediterranean or a low-fat diet. We performed a COX proportional hazards regression analysis to determine the T2DM risk according to diet and the prediabetes criteria after a median follow-up of 60 months. RESULTS: We found higher T2DM risk (HR: 2.98; 95% CI 1.27-6.98) in PreDM-IFG/IGT than in PreDM-isolated-HbA1c (HR: 2.31; 95% CI 0.97-5.49) compared with non-PreDM. Long-term consumption of a low-fat diet was associated with a lower risk of T2DM when compared to the Mediterranean diet in the PreDM-IFG/IGT group (HR: 3.20; 95% CI 0.75-13.69 versus HR: 4.70; 95% CI 1.12-19.67, respectively). Moreover, we found the highest risk of T2DM development associated with patients who had both IFG and IGT (HR: 2.15; 95% CI 1.11-4.16). Patients who had both IFG and IGT and consumed a low-fat diet had a lower T2DM risk than those who consumed a Mediterranean diet (HR: 1.53; 95% CI 0.53-4.39 versus HR: 3.33; 95% CI 1.34-8.30, respectively). CONCLUSION: Our results suggest that the type of diet consumed may modulate the risk of T2DM development according to the prediabetes diagnosis criteria. Specifically, our study showed that the consumption of a low-fat diet was more beneficial than a Mediterranean diet in patients with IFG and IGT. CLINICAL TRIAL REGISTRATION NUMBER: ClinicalTrials.govNCT00924937.

A plasma circulating miRNAs profile predicts type 2 diabetes mellitus and prediabetes: from the CORDIOPREV study.

We aimed to explore whether changes in circulating levels of miRNAs according to type 2 diabetes mellitus (T2DM) or prediabetes status could be used as biomarkers to evaluate the risk of developing the disease. The study included 462 patients without T2DM at baseline from the CORDIOPREV trial. After a median follow-up of 60 months, 107 of the subjects developed T2DM, 30 developed prediabetes, 223 maintained prediabetes and 78 remained disease-free. Plasma levels of four miRNAs related to insulin signaling and beta-cell function were measured by RT-PCR. We analyzed the relationship between miRNAs levels and insulin signaling and release indexes at baseline and after the follow-up period. The risk of developing disease based on tertiles (T1-T2-T3) of baseline miRNAs levels was evaluated by COX analysis. Thus, we observed higher miR-150 and miR-30a-5p and lower miR-15a and miR-375 baseline levels in subjects with T2DM than in disease-free subjects. Patients with high miR-150 and miR-30a-5p baseline levels had lower disposition index (p = 0.047 and p = 0.007, respectively). The higher risk of disease was associated with high levels (T3) of miR-150 and miR-30a-5p (HRT3-T1 = 4.218 and HRT3-T1 = 2.527, respectively) and low levels (T1) of miR-15a and miR-375 (HRT1-T3 = 3.269 and HRT1-T3 = 1.604, respectively). In conclusion, our study showed that deregulated plasma levels of miR-150, miR-30a-5p, miR-15a, and miR-375 were observed years before the onset of T2DM and pre-DM and could be used to evaluate the risk of developing the disease, which may improve prediction and prevention among individuals at high risk for T2DM.