Prevalence, clinical characteristics and treatment patterns of low high-density lipoprotein cholesterol in the US population

The role of antisense oligonucleotide therapy against apolipoprotein-CIII in hypertriglyceridemia

Increased triglyceride levels (higher than ∼1000 mg/dL) are associated with an increased risk for pancreatitis. Apolipoprotein-CIII (apo-CIII) plays a key role in the metabolism of triglycerides and triglyceride-rich lipoproteins. While loss of function mutations in the gene encoding apo-CIII (APOC3) are associated with low triglyceride levels and a decreased risk for cardiovascular disease (CVD), overexpression of APOC3 is associated with hypertriglyceridemia. Although many drugs such as fibrates, statins and omega-3 fatty acids modestly decrease triglyceride levels (and apo-CIII concentrations), there are many patients who still have severe hypertriglyceridemia and are at risk for pancreatitis and potentially CVD. The antisense oligonucleotide (ASO) against APOC3 mRNA volanesorsen (previously called ISIS 304801, ISIS-ApoCIIIRx and IONIS-ApoCIIIRx) robustly decreases both, apo-CIII production and triglyceride concentrations and is being currently evaluated in phase 3 trials. In this narrative review we present the currently available clinical evidence on the efficacy and safety of volanesorsen for the treatment of hypertriglyceridemia.

Cholesterol screening in US adults and awareness of high cholesterol among individuals with severe hypertriglyceridemia: National Health and Nutrition Examination Surveys 2001-2008

BACKGROUND

Cholesterol screening is an effective method for identifying individuals with elevated triglyceride levels. Individuals with severe hypertriglyceridemia (SHTG; ≥500 mg/dL) have a substantially higher risk for developing coronary heart disease and acute pancreatitis than individuals with lower triglyceride levels.

OBJECTIVE

The aims of this study were to estimate the proportion of US adults who reported having their cholesterol checked, to evaluate the characteristics associated with having cholesterol checked, and to assess factors that are associated with awareness of having high cholesterol among adults with SHTG.

METHODS

The sample included 7988 adults who participated in the National Health and Nutrition Examination Surveys 2001-2008. Polytomous logistic regression models were used to identify factors that were associated with time since the last cholesterol screening, categorized as never screened, screened less than 2 years ago, and screened 2 or more years ago.

RESULTS

Approximately 71% of the US adults reported ever having their cholesterol checked. Only 56% of the individuals with SHTG were aware of having high cholesterol. Factors associated with awareness of high cholesterol among those with SHTG included obesity, education, having insurance, having diabetes, and having a history of cardiovascular events.

CONCLUSIONS

Most adults in the United States have had their cholesterol checked; however, only half of those with SHTG were aware of having high cholesterol. Awareness is the first step in implementing strategies to attenuate the health risks associated with dyslipidemia.

Targeting APOC3 in the familial chylomicronemia syndrome

The familial chylomicronemia syndrome is a genetic disorder characterized by severe hypertriglyceridemia and recurrent pancreatitis due to a deficiency in lipoprotein lipase (LPL). Currently, there are no effective therapies except for extreme restriction in the consumption of dietary fat. Apolipoprotein C-III (APOC3) is known to inhibit LPL, although there is also evidence that APOC3 increases the level of plasma triglycerides through an LPL-independent mechanism. We administered an inhibitor of APOC3 messenger RNA (mRNA), called ISIS 304801, to treat three patients with the familial chylomicronemia syndrome and triglyceride levels ranging from 1406 to 2083 mg per deciliter (15.9 to 23.5 mmol per liter). After 13 weeks of study-drug administration, plasma APOC3 levels were reduced by 71 to 90% and triglyceride levels by 56 to 86%. During the study, all patients had a triglyceride level of less than 500 mg per deciliter (5.7 mmol per liter) with treatment. These data support the role of APOC3 as a key regulator of LPL-independent pathways of triglyceride metabolism.

Prevalence and trend of dyslipidaemia from 1996 to 2006 among normal and overweight adolescents in Taiwan

OBJECTIVES

To evaluate the trend of dyslipidaemia from 1996 to 2006 and examine its relationship with weight status among adolescents in Taiwan.

DESIGN

2 cross-sectional surveys were conducted in 1996 and 2006.

SETTING

The junior high schools in Taipei.

PARTICIPANTS

After multistage sampling, total of 1500 and 1283 junior high school students were chosen in 1996 and 2006. After excluding missing data, a total of 1353 (676 boys and 677 girls) and 1203 (585 boys and 618 girls) children were included in the final analyses in 1996 and 2006.

OUTCOME MEASURES

Anthropometric measures as body height and weight were measured, and body mass index (BMI) was calculated. Blood lipid profiles as total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol were measured.

RESULTS

From 1996 to 2006, the prevalence of dyslipidaemia and hypercholesterolaemia significantly increased from 13% (95% CI 11.3% to 15.0%) to 22.3% (95% CI 20.0% to 24.7%) and 6.2% (95% CI 5.0% to 7.6%) to 13.8% (95% CI 11.9% to 15.9%), respectively. The prevalence of hypertriglyceridaemia and low HDL-C dyslipidaemia increased from 3% (95% CI 1.8% to 4.5%) to 4.3% (95% CI 2.8% to 6.2%) and 6.5% (95% CI 4.8% to 8.6%) to 11.6% (95% CI 9.1% to 14.5%), with significance seen only in boys. When compared with normal weight participants, overweight boys and girls faced a 2-fold and 1.6-fold increased risk of dyslipidaemia, respectively, in the 2006 study. The increased risk of low HDL-C dyslipidaemia for overweight participants was 2.6-fold and 7.2-fold in boys and girls, respectively. In 2006, each unit increment of BMI was associated with 28%, 13% and 13% risk of hypertriglyceridaemia, low HDL-C and dyslipidaemia for boys, and 25% risk of low HDL-C dyslipidaemia in girls.

CONCLUSIONS

The prevalence of dyslipidaemia had increased significantly for boys and girls in normal weight and overweight adolescents. Early screening of dyslipidaemia and weight intervention programmes in adolescents will be the key to prevent dyslipidaemia and cardiovascular-related comorbidities.

Alarming rise in prevalence of atherogenic dyslipidaemia in the black population of Cape Town: the Cardiovascular Risk in Black South Africans (CRIBSA) study

OBJECTIVES

To determine the prevalence, determinants, and management of dyslipidaemia in the 25-74-year-old urban black population of Cape Town and examine the changes between 1990 and 2008/09 in the 25-64-year-old sample.

METHODS

In 2008/09, a representative cross-sectional sample, stratified for age and sex, was randomly selected from the same townships sampled in 1990. Cardiovascular disease (CVD) risk factors were determined by questionnaires, clinical measurements, and fasting biochemical analyses. Survey logistic regression analysis assessed the determinants of raised low-density lipoprotein cholesterol (LDL-C).

RESULTS

There were 1099 participants in 2008/09 (392 men and 707 women; response rate 86%). The prevalence of raised total cholesterol (TC), raised LDL-C, and reduced high-density lipoprotein cholesterol (HDL-C) were 25.2% (95% confidence interval, CI, 20.0-31.3), 37.8% (95% CI 32.5-43.4), and 55.2% (95% CI 49.9-60.4) in men and 23.1% (95% CI 20.0-26.5), 47.0% (95% CI 43.1-50.9), and 66.8% (95% CI 62.9-70.5) in women, respectively. Between 1990 and 2008/09, raised LDL-C and reduced HDL-C prevalence increased significantly with no change for raised TC. Among participants with raised LDL-C, only 2.6% were aware of their diagnosis, 2.7% were on treatment, and 1.5% had LDL-C <3 mmol/l. In the logistic model, increasing age (odds ratio, OR, 1.04, 95% CI 1.03-1.05; p < 0.001), rising body mass index (OR 1.03, 95% CI 1.01-1.05; p = 0.003), and fat intake ≥30% of diet (OR 1.37, 95% CI 1.02-1.85; p = 0.035) were significantly associated with LDL-C ≥3 mmol/l but not sex, physical activity, or urbanization.

CONCLUSIONS

The dyslipidaemia pattern in this population requires full lipogram screening in high-risk individuals and demands improved management using a total CVD risk approach.

HDL-C Response Variability to Niacin ER in US Adults

Background. Niacin is the most effective treatment currently available for raising HDL-C levels. Objective. To evaluate if gender and baseline lipid levels have an effect on the HDL-C response of niacin ER and to identify factors that predict response to niacin ER at the 500 mg dose. Material and Methods. The change in HDL-C effect between baseline and follow-up levels was quantified in absolute change as well as dichotomized into high versus low response (high response was defined as an HDL-C effect of >15% increase and low response was HDL-C <5%) in a sample of 834 individuals. Results. Both males and females with low HDL-C levels at baseline exhibited a response to treatment in the multivariate model (males, HDL-C <40 mg/dL: OR = 5.18, 95% CI: 2.36–11.39; females, HDL-C <50 mg/dL: OR = 5.40, 95% CI: 1.84–15.79). There was also a significant difference in the mean HDL-C effect between baseline and follow-up HDL-C levels in the 500 mg niacin ER dose group for both males (mean HDL-C effect = 0.08, P < 0.001) and females (mean HDL-C effect = 0.10, P = 0.019). Conclusion. Baseline HDL-C levels are the biggest predictor of response to niacin ER treatment for both males and females among the factors evaluated.

Serum high-density lipoprotein cholesterol levels as a prognostic indicator in patients with idiopathic pulmonary arterial hypertension

High-density lipoprotein (HDL) cholesterol levels are a strong, independent inverse predictor of cardiovascular disease. The present study aimed to determine whether serum HDL cholesterol levels correlated with disease severity and clinical outcomes in patients with idiopathic pulmonary arterial hypertension (IPAH). The serum HDL cholesterol levels were measured in 76 Chinese patients with IPAH and 45 healthy controls, together with other clinical variables. Univariate and multivariate Cox proportional hazards analysis was performed to assess the prognostic value of HDL cholesterol and event-free survival. Event-free survival was estimated using the Kaplan-Meier method. Serum HDL cholesterol levels were significantly decreased in patients with IPAH compared with controls (1.0 ± 0.3 vs 1.5 ± 0.3 mmol/L; p <0.001). The serum HDL cholesterol levels decreased in proportion to the severity of World Health Organization functional class. Compared to the high HDL cholesterol group, the low HDL cholesterol group demonstrated a significantly lower 6-minute walking distance, cardiac index, mixed venous saturation, and arterial carbon dioxide pressure but significantly greater pulmonary vascular resistance and serum uric acid levels. The serum HDL cholesterol levels correlated positively with the cardiac index (r = 0.42; p = 0.002) and negatively with the pulmonary vascular resistance (r = -0.25; p = 0.04). Serum HDL cholesterol was independently related to event-free survival on multivariate Cox proportional hazards analysis. Kaplan-Meier survival curves according to the median HDL cholesterol value showed that lower HDL cholesterol levels were associated with lower event-free survival. In conclusion, serum HDL cholesterol levels might serve as an indicator of disease severity and prognosis in patients with IPAH.