Postprandial Lipid Metabolism in Normolipidemic Subjects and Patients with Mild to Moderate Hypertriglyceridemia: Effects of Test Meals Containing Saturated Fatty Acids, Mono-Unsaturated Fatty Acids, or Medium-Chain Fatty Acids

Fasting and postprandial hypertriglyceridemia are causal risk factors for atherosclerosis. The prevalence of hypertriglyceridemia is approximately 25–30% and most hypertriglyceridemic patients suffer from mild to moderate hypertriglyceridemia. Data regarding dietary interventions on postprandial triglyceride metabolism of mildly to moderately hypertriglyceridemic patients is, however, sparse. In a randomized controlled trial, eight mildly hypertriglyceridemic patients and five healthy, normolipidemic controls received three separate standardized fat-meals containing either saturated fatty acids (SFA), mono-unsaturated fatty acids (MUFA), or medium-chain fatty acids (MCFA) in a randomized order. Fasting and postprandial lipid parameters were determined over a 10 h period and the (incremental) area under the curve (AUC/iAUC) for plasma triglycerides and other parameters were determined. MCFA do not lead to a significant elevation of postprandial total plasma triglycerides and other triglyceride parameters, while both SFA (patients: p = 0.003, controls: p = 0.03 compared to MCFA) and MUFA (patients: p = 0.001; controls: p = 0.14 compared to MCFA) do lead to such an increase. Patients experienced a significantly more pronounced increase of plasma triglycerides than controls (SFA: patients iAUC = 1006 mg*h/dL, controls iAUC = 247 mg*h/dL, p = 0.02; MUFA: patients iAUC = 962 mg*h/dL, controls iAUC = 248 mg*h/dL, p = 0.05). Replacing SFA with MCFA may be a treatment option for mildly to moderately hypertriglyceridemic patients as it prevents postprandial hypertriglyceridemia.

Clinical review on triglycerides

Hypertriglyceridaemia is a common clinical problem. Epidemiologic and genetic studies have established that triglyceride-rich lipoproteins (TRL) and their remnants as important contributors to ASCVD while severe hypertriglyceridaemia raises risk of pancreatitis. While low-density lipoprotein is the primary treatment target for lipid lowering therapy, secondary targets that reflect the contribution of TRL such as apoB and non-HDL-C are recommended in the current guidelines. Reduction of severely elevated triglycerides is important to avert or reduce the risk of pancreatitis. Here we discuss interventions for hypertriglyceridaemia, including diet and lifestyle, established treatments such as fibrates and omega-3 fatty acid preparations and emerging therapies, including various biological agents.

Impact of perceptions of body size on obesity and weight management behaviour: a large representative population study in an African setting

BACKGROUND

Perception of body size is an important psycho-cultural cause of obesity with wide racial and ethnic variations.

METHOD

Cross-sectional household survey using multistage cluster-randomised sampling. Prevalence estimates were weighted. Logistic regressions were done to determine the impact of perception of large body size on obesity and the impact of perception of own body size on weight-management behaviour. Adjusted odds ratios (AOR) were reported.

RESULTS

The survey involved 6628 adults from 2843 households. More than a quarter of the population is either obese or overweight. Nearly half, 44.07% (95% confidence interval [CI]: 42.48-45.66%) of the population perceive large body size as desirable. Positive perception of large body size significantly increases the odds of obesity by 1.5 (AOR: 1.45; 95% CI: 1.09-1.9). Some 42.03% (95% CI: 35.52-48.55%) obese persons misperceive their weight to be normal. Perceiving own body size as normal decreases the odds of weight-losing behaviour (AOR: 0.019; 95% CI: 0.014-0.026).

CONCLUSION

There is a high level of veneration of large body size in southeast Nigeria, and this has a significant impact on obesity burden. Perception of own body size has a significant impact on weight-management behaviour. Health-promotion policies aimed at changing the social desirability of large body size and misperception of body size are recommended.

Anti-PCSK 9 antibodies increase the ratios of the brain-specific oxysterol 24S-hydroxycholesterol to cholesterol and to 27-hydroxycholesterol in the serum

AIMS

The serum ratios of the brain-specific oxysterol 24S-hydroxycholesterol (24S-OHC) to cholesterol and to 27-OHC reflect brain cholesterol turnover. We studied the effect of proprotein convertase subtilisin/kexin type 9 monoclonal antibodies (PCSK9ab) that enhance low-density lipoprotein receptor activity on serum cholesterol and oxysterol concentrations.

METHODS

Twenty-eight hypercholesterolaemic patients (15 males and 13 females) responding insufficiently to maximally tolerated statin and/or ezetimibe therapy were additionally subcutanously treated biweekly with either the PCSK9ab alirocumab (150 mg, n = 13) or evolocumab (140 mg, n = 15). Fasting serum cholesterol was measured by gas chromatography and the oxysterols 24S-OHC and 27-OHC using gas chromatography-mass spectrometry before, after 1-month (n = 28) and after 3-month (n = 13) treatment.

RESULTS

As expected, PCSK9ab treatment lowered serum cholesterol and oxysterol levels after 1 month. The serum ratio of 24S-OHC to cholesterol increased after 1 month by 17 ± 28% (mean ± standard deviation; 95% confidence interval [CI]: 5.8 to 28%; P < .01) and 24S-OHC to 27-OHC by 15 ± 39% (95% CI: 0.2 to 30%; P < .01). Within 3 months, 24S-OHC to cholesterol increased by 2.8 μg g^-1 mo^-1 (95% CI: 2.1 to 3.6; P < .01) and 24S-OHC to 27-OHC by 0.019 mo^-1 (95% CI: 0.007 to 0.032; P < .01).

CONCLUSION

The serum ratios of 24S-OHC to cholesterol and to 27-OHC increased after treatment with PCSK9ab. We hypothesize that this is caused by a reduced entrance of 27-OHC into the brain, increased synthesis of brain cholesterol, increased production of 24S-OHC and its secretion across the blood-brain barrier.

Social determinants and behaviors associated with overweight and obesity among youth and adults in a peri-urban area of Maputo City, Mozambique

BACKGROUND

Overweight and obesity are important risk factors for non-communicable diseases (NCDs) such as cardiovascular diseases (CVD), type 2 diabetes and certain cancers. NCDs are responsible for an increased number of deaths worldwide, including in developing countries. We aimed to determine the prevalence of overweight and obesity among youth and adults in a peri-urban area of Maputo city, Mozambique, and to assess their social and behavioral determinants.

METHODS

A cross-sectional study was conducted in a Health and Demographic Surveillance System (HDSS) area in Maputo city. We measured BMI and interviewed 15-64-year-old inhabitants to assess sociodemographic and behavioral characteristics using the STEPwise Approach methodology. A household wealth index was derived through Principal Component Analysis of various household assets and physical activity (PA) was measured using pedometers and accelerometers. Univariable and multivariable analyses were conducted to determine associations between overweight/obesity and social and behavioral determinants.

RESULTS

Among a total of 931 participants, the prevalence of overweight (BMI≥25 kg/m2) and obesity (BMI≥30 kg/m2) was 30.9% (95% confidence interval (CI) = 28.0, 33.9) and 12.6% (95% CI = 10.4, 14.7), respectively; one in every 10 youths and adults were underweight. Being female, older and living in a wealthier household were found to be significantly associated with overweight and obesity. Those with higher levels of education were found to have a reduced risk of being obese compared to those with no or lower levels of education. Behavioral risk factors (diet, alcohol and tobacco consumption and physical activity) did not significantly increase the risk of overweight and obesity.

CONCLUSIONS

Overweight and obesity are highly prevalent in this peri-urban part of the Mozambican capital, where underweight is still present in youth and adults, confirming that the country is facing a double burden of malnutrition. Social determinants of health should be taken into consideration in the design and implementation of NCD prevention programs.

Prevalence of the Metabolic Syndrome in Severely Obese Patients Presenting for Bariatric Surgery

OBJECTIVE

Although obesity is associated with metabolic changes, not all obese patients are characterized by the metabolic syndrome (MS). The goal of this study was to determine the prevalence of the MS, its characteristics, and the associated demographic factors in a large cohort of severely obese patients presenting for potential bariatric surgery.

METHODS

A total of 256 obese patients (68.7% female, 41.9 ± 11.6 years, BMI 49 ± 9.1 kg/m2) were evaluated using the harmonized criteria of the MS.

RESULTS

In this cohort, the prevalence of MS was 78.1% with no gender difference. The prevalence did not correlate with BMI, body weight, or waist circumference; however, the presence of MS and numbers of MS criteria met correlated with age. The prevalence of individual criteria varied considerably (central obesity [100%], hypertension [86.7%], elevated glucose (58.6%), low HDL-cholesterol [50%], and hypertriglyceridemia [43.7%]). On average, 3.4 ± 1.1 criteria were met, 3.5% fulfilled only one criterion (central obesity), and 16.4% met all 5 criteria. After adjusting for age and gender, hypertriglyceridemia and hypertension were more common in diabetic than in non-diabetic patients. Similarly, low HDL and elevated glucose were more common in hypertriglyceridemic individuals.

CONCLUSION

In severely obese patients, the prevalence of the MS and the number of criteria met was high. However, over 20% of severely obese individuals have no MS and thus may be at lower risk for cardiovascular complications of obesity. It is currently unclear whether treatment strategies with respect to obesity should differ between severely obese individuals with and without the MS.

Efficacy and safety of icosapent ethyl in hypertriglyceridaemia: a recap

Although low-density lipoprotein cholesterol lowering is effective in atherosclerotic cardiovascular disease (ASCVD) prevention, considerable ‘lipid-associated’ residual risk remains, particularly in patients with mild-to-moderate hypertriglyceridaemia (2–10 mmol/L; 176–880 mg/dL). Triglyceride (TG)-rich lipoproteins carry both TGs and cholesterol (remnant-cholesterol). At TG levels >5 mmol/L (440 mg/dL) vs. <1 mmol/L (88 mg/dL) or remnant-cholesterol >2.3 mmol/L (89 mg/dL) vs. <0.5 mmol/L (19 mg/dL), risk is ∼1.5-fold elevated for aortic stenosis, 2-fold for all-cause mortality, 3-fold for ischaemic stroke, 5-fold for myocardial infarction (MI), and 10-fold for acute pancreatitis. Furthermore, Mendelian randomization studies indicate that elevated TG-rich lipoproteins are causally related to increased risk of ASCVD and even all-cause mortality. While genetic and epidemiological data strongly indicate that TG-rich lipoproteins are causally linked to ASCVD, intervention data are ambiguous. Fibrates, niacin and low-dose omega-3 fatty acids have all been used in outcome trials, but have failed to demonstrate clear benefit in combination with statins. Whether the lack of additional benefit relates to methodological issues or true failure is indeterminate. Importantly, a recent intervention trial evaluating a high dose of eicosapentaenoic-acid showed clear benefit. Thus, REDUCE-IT evaluated the effect of icosapent ethyl (4 g/day) on cardiovascular outcomes in 8179 high-risk patients with moderate TG elevation on statin therapy. Over a median duration of 4.9 years, the relative risk for the primary endpoint (composite of cardiovascular death, non-fatal MI, non-fatal stroke, coronary revascularization, or unstable angina) was reduced by 25% (absolute risk 17.2% vs. 22.0%; P < 0.0001; number needed to treat 21). High-dose icosapent ethyl intervention therefore confers substantial cardiovascular benefit in high-risk patients with moderate hypertriglyceridaemia on statin therapy.

Everyday Life, Dietary Practices, and Health Conditions of Adult PKU Patients: A Multicenter, Cross-Sectional Study

BACKGROUND

Only few data on dietary management of adult phenylketonuria (PKU) patients are published.

OBJECTIVES

This study aimed to assess living situation, dietary practices, and health conditions of early-treated adult PKU patients.

METHODS

A total of 183 early-treated PKU patients ≥18 years from 8 German metabolic centers received access to an online survey, containing 91 questions on sociodemographic data, dietary habits, and health conditions.

RESULTS

144/183 patients (66% females) completed the questionnaire. Compared with German population, the proportion of single-person households was higher (22 vs. 47%), the rate of childbirth was lower (1.34 vs. 0.4%), but educational and professional status did not differ. 82% of the patients adhered to a low-protein diet, 45% consumed modified low-protein food almost daily, and 84% took amino acid mixtures regularly. 48% of the patients never interrupted diet, and 14% stopped diet permanently. 69% of the patients reported to feel better with diet, and 91% considered their quality of life at least as good. The prevalence of depressive symptoms was high (29%) and correlated significantly to phenylalanine blood concentrations (p = 0.046). However, depressive symptoms were only mild in the majority of patients.

CONCLUSION

This group of early-treated adult German PKU patients is socially well integrated, reveals a surprisingly high adherence to diet and amino acid intake, and considers the restrictions of diet to their daily life as low.

The Diagnosis and Treatment of Hypertriglyceridemia

BACKGROUND

Hypertriglyceridemia affects 15-20% of the adult population and is associated with overweight, metabolic syndrome, and diabetes mellitus. It is often discovered incidentally.

METHODS

This review is based on pertinent publications retrieved by a selective literature search, including current guidelines on hypertriglyceridemia.

RESULTS

Elevated triglyceride (TG) levels are causally linked to cardiovascular disease; TG levels above 1000 mg/dL (11.4 mmol/L) can induce acute pancreatitis. The individual risk of cardiovascular disease and of pancreatitis must be estimated in order to decide whether, and how, hypertriglyceridemia should be treated. Lifestyle modifications (cessation of alcohol consumption, reduced intake of rapidly metabolized carbohydrates), weight loss, and blood sugar control are the most effective ways to lower TG levels. The need to lower the low-density lipoprotein (LDL) concentration must be determined on the basis of the cardiovascular risk, independently of the success of the lifestyle changes. Few patients need specific drug treatment to lower the TG level. Fibrates can lower TG concentrations, but their efficacy in combination with statins has not been clearly shown in endpoint studies. A daily dose of 2-4 g omega-3 fatty acids can also lower TG levels. To date, only a single large-scale randomized, blinded trial has shown the efficacy of 4 g of eicosapentaenoic acid ethyl ester per day in lowering the risk in high-risk patients (number needed to treat = 21). Patients with the very rare purely genetic types of hypertriglyceridemia (familial chylomicronemia syndrome) should be treated in specialized outpatient clinics.

CONCLUSION

Hypertriglyceridemia is causally linked to cardiovascular disease and pancreatitis. Lifestyle modifications play a paramount role in its treatment.

Genetic determinants of blood lipids and cerebral small vessel disease: role of high-density lipoprotein cholesterol

Blood lipids are causally involved in the pathogenesis of atherosclerosis, but their role in cerebral small vessel disease remains largely elusive. Here, we explored associations of genetic determinants of blood lipid levels, lipoprotein particle components, and targets for lipid-modifying drugs with small vessel disease phenotypes. We selected genetic instruments for blood levels of high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides, for cholesterol and triglycerides components of size-defined lipoprotein particles, and for lipid-modifying drug targets based on published genome-wide association studies (up to 617 303 individuals). Applying two-sample Mendelian randomization approaches we investigated associations with ischaemic and haemorrhagic manifestations of small vessel disease [small vessel stroke: 11 710 cases, 287 067 controls; white matter hyperintensities (WMH): 10 597 individuals; intracerebral haemorrhage: 1545 cases, 1481 controls]. We applied the inverse-variance weighted method and multivariable Mendelian randomization as our main analytical approaches. Genetic predisposition to higher HDL-C levels was associated with lower risk of small vessel stroke [odds ratio (OR) per standard deviation = 0.85, 95% confidence interval (CI) = 0.78-0.92] and lower WMH volume (β = -0.07, 95% CI = -0.12 to -0.02), which in multivariable Mendelian randomization remained stable after adjustments for LDL-C and triglycerides. In analyses of lipoprotein particle components by size, we found these effects to be specific for cholesterol concentration in medium-sized high-density lipoprotein, and not large or extra-large high-density lipoprotein particles. Association estimates for intracerebral haemorrhage were negatively correlated with those for small vessel stroke and WMH volume across all lipid traits and lipoprotein particle components. HDL-C raising genetic variants in the gene locus of the target of CETP inhibitors were associated with lower risk of small vessel stroke (OR: 0.82, 95% CI = 0.75-0.89) and lower WMH volume (β = -0.08, 95% CI = -0.13 to -0.02), but a higher risk of intracerebral haemorrhage (OR: 1.64, 95% CI = 1.26-2.13). Genetic predisposition to higher HDL-C, specifically to cholesterol in medium-sized high-density lipoprotein particles, is associated with both a lower risk of small vessel stroke and lower WMH volume. These analyses indicate that HDL-C raising strategies could be considered for the prevention of ischaemic small vessel disease but the net benefit of such an approach would need to be tested in a randomized controlled trial.

Rapid hepatic metabolism blunts the endocrine action of portally infused GLP-1 in male rats

Glucagon-like peptide-1 (GLP-1) is an enteral peptide that contributes to the incretin effect. GLP-1 action is typically described as endocrine, but this mechanism has been questioned because rapid inactivation in the circulation by dipeptidylpeptidase 4 (DPP4) results in a short half-life, limiting the amount of the hormone that can reach the pancreatic islet. An alternative mechanism for GLP-1 to regulate insulin secretion through neuroendocrine signaling originating from sensors in the portal vein has been proposed. We hypothesized that portal infusion of GLP-1 would cause greater glucose-stimulated insulin secretion than equimolar administration into the jugular vein. To test this, hyperglycemic clamps with superimposed graded infusions of GLP-1 into the jugular or portal veins of male rats were performed. These experiments were repeated with pharmacologic DPP4 inhibition to determine the effect of GLP-1 metabolism in the jugular and portal venous beds. Contrary to our hypothesis, we found a higher insulinotropic effect with jugular compared with portal GLP-1, which was associated with higher plasma concentrations of intact GLP-1. The greater insulinotropic effect of jugular venous GLP-1 persisted even with pharmacological DPP4 inhibition. These findings do not support an important role of portal vein GLP-1 signaling for the incretin effect but highlight the hepatoportal bed as a major site of GLP-1 degradation that persists even with pharmacological inhibition. Together, these results support rapid inactivation of enterally released GLP-1 in the liver as limiting endocrine actions on the β-cell and raise questions about the conventional endocrine model of pharmacologic effects of DPP4 inhibitors.

Rare dyslipidaemias, from phenotype to genotype to management: a European Atherosclerosis Society task force consensus statement

Genome sequencing and gene-based therapies appear poised to advance the management of rare lipoprotein disorders and associated dyslipidaemias. However, in practice, underdiagnosis and undertreatment of these disorders are common, in large part due to interindividual variability in the genetic causes and phenotypic presentation of these conditions. To address these challenges, the European Atherosclerosis Society formed a task force to provide practical clinical guidance focusing on patients with extreme concentrations (either low or high) of plasma low-density lipoprotein cholesterol, triglycerides, or high-density lipoprotein cholesterol. The task force also recognises the scarcity of quality information regarding the prevalence and outcomes of these conditions. Collaborative registries are needed to improve health policy for the care of patients with rare dyslipidaemias.