Comparison of cardiometabolic risk biomarkers from a national clinical laboratory with the US adult population.

Background: Clinical laboratory patient databases are an untapped source of valuable diagnostic and prognostic information. However, the lack of associated clinical and/or demographic information and questionable generalizability to nonpatient populations often limit utility of these data.

Objectives: This study compared levels of cardiometabolic biomarkers between a national clinical laboratory patient cohort (Health Diagnostic Laboratory [HD Lab]) and the US population as inferred from the National Health and Nutrition Examination Survey (NHANES, 2011-2012).

Hypertriglyceridaemia unresponsive to multiple treatments.

A 52-year-old man with a longstanding history of hypertriglyceridaemia (approximately 7 mmol/L (600 mg/dL)), unresponsive to treatment, presented to a lipid-specialty clinic. Additional triglyceride-lowering therapies were added with no effect. It was then noted that despite the apparent hypertriglyceridaemia, his serum sample was clear.

Race is a key variable in assigning lipoprotein(a) cutoff values for coronary heart disease risk assessment: the Multi-Ethnic Study of Atherosclerosis.

Objective: We aimed to examine associations of lipoprotein(a) (Lp(a)) concentrations with coronary heart disease (CHD) and determine whether current Lp(a) clinical laboratory cut points identify risk of disease incidence in 4 races/ethnicities of the Multi-Ethnic Study of Atherosclerosis (MESA).

Approach And Results: A subcohort of 1323 black, 1677 white, 548 Chinese American, and 1044 Hispanic MESA participants were followed up during a mean 8.5-year period in which 235 incident CHD events were recorded.

Lipoprotein(a) mass: a massively misunderstood metric.

The importance of lipoprotein (a)-Lp(a)-as a cardiovascular (CV) risk marker has been underscored by recent findings that CV risk is directly related to baseline Lp(a) levels, even in well-treated patients. Although there is currently little that can be done pharmacologically to lower Lp(a) levels, knowledge of its serum concentration is important in overall risk assessment. This review focuses on 1 aspect of Lp(a) that is rarely discussed directly: how to express its levels in serum.

Validation of a lipoprotein(a) particle concentration assay by quantitative lipoprotein immunofixation electrophoresis.

Background: Low-density lipoprotein (LDL) particle (P, or molar) concentration has been shown to be a more sensitive marker of cardiovascular disease (CVD) risk than LDL cholesterol. Although elevated circulating lipoprotein(a) [Lp(a)] cholesterol and mass have been associated with CV risk, no practicable method exists to measure Lp(a)-P. We have developed a method of determining Lp(a)-P suitable for routine clinical use.

New automated assay of small dense low-density lipoprotein cholesterol identifies risk of coronary heart disease: the Multi-ethnic Study of Atherosclerosis.

Objective: Coronary heart disease (CHD) is the leading cause of death in the United States, yet assessing risk of its development remains challenging. The present study evaluates a new automated assay of small dense low-density lipoprotein cholesterol content (sdLDL-C) and whether sdLDL-C is a risk factor for CHD compared with LDL-C or small LDL particle concentrations derived from nuclear magnetic resonance spectroscopy.

Approach And Results: sdLDL-C was measured using a new automated enzymatic method, and small LDL concentrations were obtained by nuclear magnetic resonance in 4387 Multi-Ethnic Study of Atherosclerosis participants.

Myocardial tissue remodeling in adolescent obesity.

Background: Childhood obesity is a significant risk factor for cardiovascular disease in adulthood. Although ventricular remodeling has been reported in obese youth, early tissue-level markers within the myocardium that precede organ-level alterations have not been described.

Methods And Results: We studied 21 obese adolescents (mean age, 17.

Association of apolipoprotein B and nuclear magnetic resonance spectroscopy-derived LDL particle number with outcomes in 25 clinical studies: assessment by the AACC Lipoprotein and Vascular Diseases Division Working Group on Best Practices.

Background: The number of circulating LDL particles is a strong indicator of future cardiovascular disease (CVD) events, even superior to the concentration of LDL cholesterol. Atherogenic (primarily LDL) particle number is typically determined either directly by the serum concentration of apolipoprotein B (apo B) or indirectly by nuclear magnetic resonance (NMR) spectroscopy of serum to obtain NMR-derived LDL particle number (LDL-P).

Content: To assess the comparability of apo B and LDL-P, we reviewed 25 clinical studies containing 85 outcomes for which both biomarkers were determined.

Apolipoprotein B and cardiovascular disease risk: position statement from the AACC Lipoproteins and Vascular Diseases Division Working Group on Best Practices.

Background: Low-density lipoprotein cholesterol (LDL-C) has been the cornerstone measurement for assessing cardiovascular risk for nearly 20 years.

Content: Recent data demonstrate that apolipoprotein B (apo B) is a better measure of circulating LDL particle number (LDL-P) concentration and is a more reliable indicator of risk than LDL-C, and there is growing support for the idea that addition of apo B measurement to the routine lipid panel for assessing and monitoring patients at risk for cardiovascular disease (CVD) would enhance patient management. In this report, we review the studies of apo B and LDL-P reported to date, discuss potential advantages of their measurement over that of LDL-C, and present information related to standardization.

Lipoprotein-associated phospholipase A2.

Lipoprotein-associated phospholipase A2 (LP-PLA2) is an emerging inflammatory marker that is used to assess the risk for cardiovascular disease (CVD) and associated events. Several epidemiologic studies have demonstrated an independent association between plasma Lp-PLA2 concentration and risk for cardiovascular events. HMG-CoA reductase inhibitors (statins) and fenofibrates can reduce Lp-PLA2 concentrations in plasma, and orally active, specific Lp-PLA2 inhibitors have been developed and are in clinical trials to evaluate the potential of Lp-PLA2 as a therapeutic target.

Serum tumor markers: part II--practical considerations and limitations of testing.

The attributes of an ideal tumor marker are well beyond the capacity of the tests that are currently available. While some markers do an adequate job at the early detection of recurrence and as a means to monitor the efficacy of treatment, there are serious deficits regarding sensitivity and specificity. In addition, although they are easily measured and cost-effective, the limitations of immunoassays are also a detriment.

Serum tumor markers. Part I: Clinical utility.

Most tumor markers in current use are glycoproteins that are measured by routine immunoassay techniques. The primary utility of serum tumor markers is for evaluating the effectiveness of therapy in advanced stages of cancer; in addition, they are used for monitoring "cured" patients for cancer recurrence. Regrettably, this latter use has not led to a significant improvement in patient outcomes when a recurrence is detected early.