Modelling of increased homocysteine in ischaemic stroke: post-hoc cross-sectional matched case-control analysis in young patients

Hyperhomocysteinemia and Ischemic Stroke: A Potential Dose-Response Association-A Systematic Review and Meta-analysis

Background and Purpose  Previous studies suggest an association between increased homocysteine (Hcy) and risk of ischemic stroke. Yet, it remains unknown whether a dose-response association exists between Hcy levels and risk of ischemic stroke. Methods  Systematic literature searches were performed in PubMed, Embase, Scopus, and Web of Science. Inclusion criteria were studies investigating ischemic stroke risk in an adult population with measured Hcy levels. We computed odds ratios (ORs) for a 5 µmol/L increase in Hcy levels using a random effects meta-analysis. Results  In total, 108 studies met the inclusion criteria of which 22 were rated as high-quality studies, and 20 studies included a dose-response analysis. Hcy levels were analyzed either as a continuous or categorical variable. The majority of the studies found an increased risk of ischemic stroke when comparing the highest-to-lowest Hcy strata. A graded association was observed over the Hcy strata, indicating a dose-response association, with the most apparent effect when Hcy levels exceeded approximately 15 µmol/L. No studies explored a potential nonlinear association between Hcy levels and ischemic stroke. Six studies were included in a meta-analysis, showing an OR of 1.43 (95% confidence interval [CI]: 1.28-1.61) per 5 µmol/L increase in Hcy levels. Conclusion  This review and meta-analysis indicate a dose-response association between Hcy levels and ischemic stroke. An evident increase in effect measures was observed when Hcy levels exceeded 15 µmol/L, indicating a nonlinear association between ischemic stroke and Hcy levels. This nonlinear association warrants further study. This study is registered with clinical trial ( https://www.crd.york.ac.uk/prospero/ ; unique identifier: CRD42019130371).

Metabolic syndrome severity score: range and associations with cardiovascular risk factors

INTRODUCTION

Metabolic Syndrome Severity Score (MSSS) is a new clinical prediction rule (CPR) for diagnostic and therapeutic decisions and employs available components (sex, age, race, systolic blood pressure, waistline circumference, high-density lipoprotein, triglycerides and fasting blood glucose). The aim of our work was to perform cross-sectional pilot trial on middle-aged healthy volunteers and patients with metabolic syndrome (MetS) with and without type 2 diabetes mellitus (T2DM) for studying feasibility and implementation of MSSS and its associations with cardiovascular risk factors.

MATERIAL AND METHODS

We approached 64 eligible participants from Bulgaria. The MSSS values, together with demographic, anthropometric, medical history, laboratory findings, CVD risk factors, QRISK2 score for 10-year cardiovascular risk and predicted heart age, were analysed. Descriptive statistics with tests for comparison (e.g., t-test, χ2) between groups as well as ANOVA and logistic regression were applied.

RESULTS

We analysed data from 56 participants (aged 50.11 ±3.43 years). The MSSS was higher in MetS patients (including 6 T2DM patients) than in controls (n = 29; 51.8%) presented as percentiles (69.97% and 34.41%, respectively) and z-scores (0.60 and -0.45, respectively) (p < 0.05). The logistic regression model of MSSS indicated a positive association with MetS/T2DM cases (correctness > 85%, p < 0.01). For further validation purposes, positive correlations of MSSS with CVD risk factor as diastolic blood pressure (Rho = 0.399; p < 0.003) and QRISK2 score (Rho = 0.524; p < 0.001) or predicted heart age (Rho = 0.368; p < 0.007) were also found.

CONCLUSIONS

The pilot study of MSSS in Bulgaria indicated feasibility and consistency of its implementation among patients with metabolic syndrome and/or T2DM and healthy volunteers.

Impaired nocturnal melatonin in acute phase of ischaemic stroke: cross-sectional matched case-control analysis

Quantitative data on melatonin in stroke patients are scarce. A gender- and age-matched cross-sectional case-control study in 33 patients with ischaemic stroke was performed and associations between nocturnal melatonin and other factors (e.g. cortisol) were evaluated. Clinical and laboratory (e.g. melatonin and cortisol) measurements (03.00 h and 08.00 h) with statistical techniques [e.g. multifactorial regressions, receiver operating characteristic (ROC) curve and curvilinear estimations] were used. We identified mean value and 95% confidence interval (CI) (69.70 pg/ml; 95% CI = 53.86-85.54) for control levels of nocturnal melatonin in healthy subjects. The patients with stroke had lower melatonin (48.1 +/- 35.9 pg/ml) and higher cortisol (297.3 +/- 157.8 nmol/l) at 03.00 h (P < 0.05) but not at 08.00 h (P > 0.05). Stroke was the strongest factor of disturbed nocturnal cortisol (P < 0.001), whereas decreased melatonin depended on stroke (P = 0.010) and gender (P = 0.018). At the same time, vice versa, only nocturnal measures were associated with an increased probability of the presence of stroke (accuracy > 75%, Pmodel < 0.001). Thus, a hypothesis that a decrease of melatonin with 1.0 pg/ml might be associated with > 2% increase in the probability of the presence of stroke [adjusted odds ratio (OR) = 1.020; 95% CI = 1.002-1.037] was also suggested. The ROC curve (0.67, P = 0.0119) and optimisation techniques indicated that a novel best cut-off < 51.5 pg/ml for decreased nocturnal melatonin in the view of the presence of stroke (OR = 3.12, P = 0.0463) might exist. The classification performance of such a cut-off might be confirmed by existing nocturnal melatonin and cortisol differences between the sub-groups; potential differences in diurnal melatonin were also suggested. In conclusion, a novel melatonin cut-off of 51.5 pg/ml may be associated with the presence of ischaemic stroke. As a single marker (84% sensitivity, 74% specificity), it is hypothesised that modelling performance was independent of age, gender and cortisol. These new results, including the suggested hypothesis, might be further tested in follow-up (cohort), longitudinal studies and be applied to explore melatonin disturbances as targets in high-risk pre-stroke and post-stroke patients.

Diastolic blood pressure cut-off predicts major cerebrovascular events after minor ischaemic stroke: a post-hoc modelling study

Only few follow-up studies have studied in detail the role of most important risk factors, but no reports were found on critical values (cut-offs) for such factors in prospectively predicting cerebrovascular events (CVE) in patients with minor ischaemic stroke (MIS). Estimates of predictive importance of such cut-offs may better inform and contribute to optimize treatment. This was a post-hoc modelling study with unique data from Bulgaria on 54 consecutive patients with MIS, aged ł 40, followed for 12 months for nonfatal or fatal CV events. A set of routine clinical demographic and known risk factors (SBP, DBP, HDL cholesterol, etc.) were explored using univariate statistics and multivariate regression models to identify the most important independent predictors of secondary CVE. An artificial neural network (ANN) model, irrespective of usual statistical constraints, also confirmed the specific role and importance of identified predictors. A receiver operating characteristics (ROC) curve and stratified survival analyses were used to define the best cut-off of most important predictors and validate the final model. During follow-up period of 11.1±2.4 months, 8 secondary CV events (14.8%) were observed only in males with MIS at the 5.8±2.7 months mark. No difference in age of patients with CV event (61.1±12.6 years) vs. those without (62.1±9.6 years) was found (p>0.05). The one-year risk for CVE was.15% (95%CI 7.1, 27.7%). The two most important risk factors in patients with versus without CV events were acute MIS onset (62.5 vs. 13.0%) and mean DBP at day 30 post-MIS (101.3±9.9 vs. 92.3±10.8 mmHg), with a relative importance by ANN of 20.92 versus 15.9 points, respectively. At multivariate logistic analysis only MIS onset and DBP were independently associated with the risk for secondary CVE (79.6% model accuracy, p model=0.0015). An increase of DBP with 1 mmHg was associated with 8% higher risk of CVE [adjusted OR=1.08 (95%Cl 1.004, 1.158)]. With this method, a novel cut-off predictive DBP value of 95 mmHg (ROCAUC=0.79, 95%Cl 0.60, 0.99, p=0.009) for CV events in patients with MIS has been found. In conclusions the new DBP cut-off (sensitivity >87%, specificity >69%) clearly discriminated between absence and presence of secondary CVE as also confirmed by stratified survival analysis (7 vs. 1 events, plog-rank =0.0103). This cut-off may be applied to better precisely evaluate and define, as earlier as possible, MIS patients at increased risk of secondary CV events.