Interlaboratory proficiency survey of high-density lipoprotein cholesterol measurement.

1983 ◽  
Vol 29 (3) ◽  
pp. 516-519 ◽  
Author(s):  
G R Warnick ◽  
J M Benderson ◽  
J J Albers

Abstract Proficiency surveys of Seattle-area laboratories suggest only slight improvement in overall performance in high-density lipoprotein (HDL) measurement between 1978 and 1982, although the reported workload for HDL has increased by 15%. The mean interlaboratory SD was 64 mg/L (ranging from 34 for a pool averaging 299 mg/L to 136 for a pool averaging 886 mg of HDL cholesterol per liter) in 1982, compared with 79 mg/L (range 48-155) in 1978-79. Of the individual laboratory results in the current survey, 39% deviated by more than 50 mg/L from target values as compared with 37% in 1978-79. The discrepant values were primarily ascribable to method inaccuracy: only 30% of laboratories in 1982 reported results that averaged within 30 mg/L of target values (vs 50% in 1978). For within-run precision, 80% of laboratories in 1982 had SDs of less than 30 mg/L, vs 70% in 1978. The 1982 survey included a lyophilized serum prepared by spray freezing and bulk lyophilization (Hyland Omega), identical to the pools used in the College of American Pathologists Comprehensive Chemistry Survey, and five pools of frozen plasma. Interlaboratory variation and biases for the Omega pool were similar to those for the frozen pools.

1994 ◽  
Vol 40 (4) ◽  
pp. 574-578 ◽  
Author(s):  
S M Marcovina ◽  
V P Gaur ◽  
J J Albers

Abstract Biological variability is a major contributor to the inaccuracy of cardiovascular risk assessments based on measurement of lipids, lipoproteins, or apolipoproteins. We obtained estimates of biological variation (CVb) for 20 healthy adults and calculated the percentiles of CVb as an expression of the variability of CVb among individuals for cholesterol, triglyceride, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein (apo) A-I, apo B, and lipoprotein(a) [Lp(a)] by four biweekly measurements of these analytes. The CVb for the group was approximately 6-7% for cholesterol, HDL cholesterol, apo A-I, and apo B; approximately 9% for LDL cholesterol; and 28% for triglyceride. However, for each analyte, there was a considerable variation of CVb among individuals. For all analytes except Lp(a), there was no relation between the individual's CVb and the analyte concentration. Lp(a) was inversely related to CVb, and there was a very wide variation in the CVb for Lp(a) among the participants, ranging from 1% to 51%. The number of independent analyses to perform to accurately assess an individual's risk for coronary artery disease should be determined on the basis of the individual CVb for a given analyte rather than the average CVb.


1988 ◽  
Vol 34 (8) ◽  
pp. 1629-1632 ◽  
Author(s):  
T A McMillan ◽  
G R Warnick

Abstract We conducted a proficiency survey of cholesterol and high-density lipoprotein (HDL) cholesterol analysis in local clinical laboratories to determine whether increased national emphasis on cholesterol measurement had resulted in changes in performance from previous surveys. Sets of frozen aliquots of plasma and HDL supernate pools were sent to nine laboratories for analysis; results were compared with Northwest Lipid Research Center values, and relationships were determined by linear regression. Of all the cholesterol measurements, 81% were considered acceptable (i.e., within 9% of the NWLRC value), and 61% of the HDL cholesterol measurements were considered acceptable (within 50 mg/L of NWLRC values). These data represented no improvement over previous surveys. Workload had increased significantly: 79% for cholesterol and 284% for HDL cholesterol. On a bias plot, six of the laboratories demonstrated inaccuracy greater than the +/- 3% recommendation within the critical range of 2000-2400 mg/L for total cholesterol. For HDL cholesterol, two laboratories demonstrated bias greater than 10% at the critical point of 350 mg/L, with three additional laboratories displaying strong bias outside the decision point. The survey results indicate that apparently further improvements must be made for laboratories to achieve acceptable performance in cholesterol analysis.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 574
Author(s):  
Maria Pia Adorni ◽  
Nicoletta Ronda ◽  
Franco Bernini ◽  
Francesca Zimetti

Over the years, the relationship between high-density lipoprotein (HDL) and atherosclerosis, initially highlighted by the Framingham study, has been revealed to be extremely complex, due to the multiple HDL functions involved in atheroprotection. Among them, HDL cholesterol efflux capacity (CEC), the ability of HDL to promote cell cholesterol efflux from cells, has emerged as a better predictor of cardiovascular (CV) risk compared to merely plasma HDL-cholesterol (HDL-C) levels. HDL CEC is impaired in many genetic and pathological conditions associated to high CV risk such as dyslipidemia, chronic kidney disease, diabetes, inflammatory and autoimmune diseases, endocrine disorders, etc. The present review describes the current knowledge on HDL CEC modifications in these conditions, focusing on the most recent human studies and on genetic and pathophysiologic aspects. In addition, the most relevant strategies possibly modulating HDL CEC, including lifestyle modifications, as well as nutraceutical and pharmacological interventions, will be discussed. The objective of this review is to help understanding whether, from the current evidence, HDL CEC may be considered as a valid biomarker of CV risk and a potential pharmacological target for novel therapeutic approaches.


Author(s):  
Dilay Karabulut ◽  
Mustafa Gürkan Yenice

Objective: Elevated uric acid (UA) and low levels of high-density lipoprotein (HDL) cholesterol are associated with cardiovascular events and mortality. Erectile dysfunction (ED) has been considered an early marker of cardiovascular disease (CVD). Therefore, this study aimed to investigate the uric acid/ HDL ratio (UHR) as a nowel marker in patients with ED. Materials and Methods: The study included 147 patients with a mean age of 50 years (range 32-76 years). Retrospective analyses were performed on the patients who were admitted to urology outpatient clinics. The laboratory parameter results were retrieved from the hospital medical records, and the UHR value was calculated. Patients were categorized into three groups according to the International Index of Erectile Function (IIEF) score. UHR was compared between groups, and its predictive value was evaluated using regression analysis and ROC curve analysis. Results: Age was found to be significantly different in all three groups (Groups 1-2, p=0.001; Groups 1-3, p=0.000; Groups 2-3, p=0.001). It was observed that the degree of ED increased with age. The values of UA and HDL were similar in all groups (p>0.05). In contrast, the UHR value was statistically significantly higher 0.15 (0.083-0.288, p =0.047) in the moderate-severe ED (Group 3). ROC curve analyses revealed that UHR predicted severe ED (IIEF 5-11) with 42.9% sensitivity and 87.3% specificity (AUC:0.66, CI 95% 0.538-0.781, p=0.019). Conclusion: UHR may serve as a severe ED indicator in patients admitted to the cardiology outpatient clinic since it has a significant association with a low IIEF score.


2021 ◽  

Background: Dyslipidemia, a genetic and multifactorial disorder of lipoprotein metabolism, is defined by elevations in levels of total cholesterol, low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non–HDL-C), triglyceride, or some combination thereof, as well as lower levels of high-density lipoprotein (HDL) cholesterol. Objectives: This study aimed to investigate the prevalence and predictors of dyslipidemia in children and adolescents in the Yazd Greater Area, Yazd, Iran. Methods: This cross-sectional study was conducted as a part of the national project implemented in Yazd Greater Area, Yazd, Iran. The sampling was performed using a multi-stage cluster sampling method on three age groups of girls and boys (6-9, 10-14, and 15-18 years old). Out of the total 1,035 children and adolescents who participated in this study, only 784 participants remained in the study until the end. Data collection was performed using lifestyle questionnaires including Kiddie-SADS-Present and Lifetime Version. Results: The prevalence of high triglyceride was estimated at 1.4% and 4.2% in 6-9 and 10-18 years old children and adolescents, respectively. The prevalence of high cholesterol, LDL, and HDL was 3.2%, 3.2%, and 25.6%, respectively. The prevalence of dyslipidemia in the total population of children and adolescents in terms of demographic variables was 64.6% and 57.3% in boys and girls, respectively (P=0.038). Gender and increase in body mass index were significantly associated with dyslipidemia with OR=1.35; 95% CI: 1.01-1.81 and OR=13.781; 95% CI: 3.78- 46.43, respectively. However, after adjustment for other factors, only an increase in BMI was significantly associated with dyslipidemia (OR=16.08; 95% CI: 4.49-57.59). Conclusions: Overweight and obese adolescents had a higher concentration of serum blood triglycerides, compared to other adolescents. Weight control, lifestyle modification, and diet are three ways to reduce lipid disorders in adolescents.


2018 ◽  
Vol 35 (5) ◽  
pp. 438-444 ◽  
Author(s):  
Farzin Brian Boudi ◽  
Nicholas Kalayeh ◽  
Mohammad Reza Movahed

Objective: Acute coronary syndrome is frequently complicated by rhythm disturbances, yet any association between high-density lipoprotein (HDL) cholesterol levels and arrhythmias in the setting of non-ST-segment elevation myocardial infarction (non-STEMI) is uncertain. The goal of this study was to evaluate any association between HDL-cholesterol levels and arrhythmias in the setting of non-STEMI. Methods: Retrospective data from Phoenix Veterans Affair Medical Center records were utilized for our study. A total of 6881 patients were found who presented during 2000 to 2003 with non-STEMI with available fasting lipid panels collected within the first 24 hours of admission. Patients were followed for the development of rhythm disturbances up to 6 years after initial presentation, with a mean follow up of 1269 days. Results: We found that high triglycerides/HDL and low-density lipid/HDL ratios were predictive of arrhythmias. However, low HDL levels had strongest association with highest odds ratio (OR) for development of arrhythmias (for HDL <31 mg/dL, OR = 3.72, 95% confidence interval [CI] = 2.55-5.44, P < .05) in patients with diabetes and (for HDL < 31 mg/dL, OR = 3.69, 95% CI = 2.85-4.71, P < .05) in patients without diabetes. Using multivariate analysis adjusting for comorbidities, low HDL level remained independently associated with arrhythmias. Conclusions: Patients with low HDL levels during hospitalization with non-STEMI have a greater risk of developing cardiac rhythm disturbances independent of other risk factors. These data suggest a possible protective role of HDL in preventing arrhythmias in the setting of acute coronary syndrome.


Circulation ◽  
2012 ◽  
Vol 125 (suppl_10) ◽  
Author(s):  
Catherine Rahilly-Tierney ◽  
Howard D Sesso ◽  
J. Michael Gaziano ◽  
Luc Djousse

BACKGROUND: Few studies have examined prospectively the relationship between baseline high-density lipoprotein (HDL) cholesterol and longevity. OBJECTIVES: We sought to examine whether higher HDL levels were associated with lower risk of all-cause, cardiovascular (CVD), and non-CVD mortality prior to age 90 in the Physicians’ Health Study (PHS). METHODS: We considered a baseline cohort of 1351 PHS participants who provided bloods between 1997 and 2001 and were old enough to reach age 90 by March 4, 2009. Included subjects had complete baseline data on HDL and total cholesterol; lifestyle factors including smoking, exercise, alcohol consumption, and BMI; and comorbidities including hypertension, diabetes mellitus, congestive heart failure, cancer, and stroke. We used Cox proportional hazards to determine the HRs and 95% CIs for all-cause, CVD, and non-CVD mortality prior to age 90, adjusting for baseline age, co-morbidities, and non-HDL cholesterol. RESULTS: At baseline, the cohort had a mean (SD) age of 81.9 (2.9) years and a mean (SD) HDL cholesterol of 44.8(16.5) mg/dL. After a mean follow-up of 6.8 years (maximum 12.3 years), 501 (37.1%) of men died prior to age 90. In multi-variable adjusted analyses, men in the highest HDL-C quartile (≥54.1 mg/dL) had a 28% lower risk (HR 0.72, 95% CI 0.55-0.95) of all-cause mortality prior to age 90 compared to men in the lowest HDL-C quartile (<32.8 mg/dL). From the lowest to highest HDL quartile, age-adjusted HR(95%CI) for CVD mortality prior to age 90 were 0.66 (0.44-0.99), 0.58 (0.38-0.90), and 0.53 (0.34-0.82) (p for trend 0.004). There was no significant association between baseline HDL cholesterol and non-CVD death. CONCLUSION: In a cohort of older male physicians with long-term follow-up, baseline HDL cholesterol was inversely associated with the risk of dying prior to age 90, largely explained by an inverse association between HDL and CVD mortality.


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