ABSTRACT
BACKGROUND: Cardiovascular prevention requires a diagnostic approach for population-based screening programmes aimed at early identification of modifiable risk factors. Dyslipidaemia, which is a major risk factor for cardiovascular disease, remains largely undiagnosed and undertreated. Point-of-care testing (POCT) provides immediate results for clinical decision-making, however, quality assessment is essential to ensure system performance requirements. CardioChek PA (CCPA), a portable whole blood analyser for rapid lipid measurement, has been on the market since 2002 but with limited evidence of performance levels. The aim of the study was to assess analytical performance issues of the device and possibly contribute to their solution. METHODS: Over a 3-year period, we repeatedly evaluated CCPA accuracy, precision, and discrepancies between instruments and between test strip lots by comparison with laboratory method. At our initial evaluation, the CCPA analyser underestimated total cholesterol (bias 6.5%) and gave within-assay CVs above 6% for all lipid fractions. Our results solicited sequential improvements to the CCPA system by the manufacturer up to the performance level certified by the Cholesterol Reference Method Laboratory Network in 2013: total error 1.3% for total cholesterol and 3.1% for high density lipoprotein (HDL) cholesterol. CONCLUSIONS: POCT diagnostic tests need continuous quality management, including both quality control and quality assurance, to monitor the analytical process. A 3-year external quality surveillance provided information useful in improving POCT performance. As a result, the device is now adequate for use in screening programmes aimed at early detection of lipid disorders.
Subject(s)
Blood Chemical Analysis/instrumentation , Lipids/blood , Point-of-Care Systems , Blood Chemical Analysis/standards , Blood Chemical Analysis/statistics & numerical data , Cardiovascular Diseases/blood , Cardiovascular Diseases/prevention & control , Cholesterol/blood , Cholesterol, HDL/blood , Diabetes Mellitus/blood , Dyslipidemias/blood , Dyslipidemias/diagnosis , Humans , Point-of-Care Systems/standards , Point-of-Care Systems/statistics & numerical data , Reproducibility of Results , Risk Factors , Triglycerides/bloodABSTRACT
BACKGROUND: Abnormal circadian blood pressure patterns have been associated with cardiovascular disease in diabetes mellitus. We have described that the acrophase of diastolic blood pressure (DBP) registered in type 1 diabetes (T1D) patients was significantly earlier than normal and DBP ecphasia was more pronounced in patients with lower heart rate variability during deep breathing. The aim of this study was to compare the circadian rhythm characteristics of BP among different groups: normotensive (NT) control subjects, patients affected by T1D and type 2 diabetes (T2D), and patients with essential hypertension (HT). FINDINGS: We retrospectively evaluated ambulatory blood pressure monitoring records in 30 NT, 20 T1D, 20 T2D, 20 HT whose fasting plasma glucose and HbA1c were contemporaneously measured. The four groups were well-matched regarding age, gender, and BMI.Systolic blood pressure (SBP) and DBP midline-estimating statistic of rhythm were higher in T1D, T2D, and HT groups. DBP ecphasia was present only in the diabetic individuals: the acrophase of DBP occurred four hours earlier than normal in T1D group, whereas two hours earlier in T2D group. In a multiple regression analysis, only HbA1c and SBP acrophase were statistically significant correlates of DBP acrophase. CONCLUSIONS: People with diabetes mellitus, both type 1 and type 2, have their circadian acrophase of DBP occurring 2-4 hours earlier than normotensive and hypertensive subjects. Altered circadian timing of DBP, potential trigger of cardiovascular events, seems to be a distinguishing feature of diabetes mellitus and correlates with the previous 2-3 months of glycaemic control.
