HDL cholesterol efflux capacity and cholesterol loading capacity in long-term fasting: Evidence from a prospective, single-arm interventional study in healthy individuals.

BACKGROUND AND AIMS: Long-term fasting (LF) is increasingly emerging as a non-pharmacological approach to modulate risk factors associated with the development of atherosclerotic cardiovascular diseases (ASCVD). However, protection from ASCVD is more tied to the functionality of high-density lipoprotein (HDL) than its plasma levels. Our prospective interventional study focuses on the functional properties of lipoproteins in modulating cholesterol homeostasis on peripheral cells and examines how LF may influence this and lipoprotein subclass composition. For that purpose, we investigated its impact on HDL-cholesterol efflux capacity (CEC), and on serum cholesterol loading capacity (CLC). METHODS: Forty healthy subjects (50 % females) underwent medically supervised 9-day fasting (250 kcal/day) in a specialised facility. Thirty-two subjects had a follow-up examination after one month of food reintroduction. RESULTS: LF was well tolerated and increased self-reported energy levels. Fasting reduced triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and HDL cholesterol (HDL-C). Very-low-density lipoprotein cholesterol (VLDL-C) and LDL3-C showed sustained reductions at follow-up. Only HDL-C, specifically HDL2-C levels, increased at follow-up. Total HDL-CEC decreased during LF and increased above baseline at follow-up. Fasting decreased ATP binding cassette (ABC)A1-mediated HDL-CEC whereas ABCG1-mediated HDL-CEC remained unaffected. Aqueous diffusion increased at follow up. LF decreased serum CLC and then returned to baseline levels. CONCLUSIONS: LF not only maintains lipoprotein functionality but also contributes to a favorable shift in the atherogenic risk profile, which persists even after food reintroduction. This further emphasizes the importance of considering HDL functionality alongside traditional lipid measurements to understand the potential for non-pharmacological interventions like LF to promote cardiovascular prevention and health. TRIAL REGISTRATION NUMBER: NCT05031598.

Long-term fasting improves lipoprotein-associated atherogenic risk in humans.

PURPOSE: Dyslipidemia is a major health concern associated with an increased risk of cardiovascular mortality. Long-term fasting (LF) has been shown to improve plasma lipid profile. We performed an in-depth investigation of lipoprotein composition. METHODS: This observational study included 40 volunteers (50% men, aged 32-65 years), who underwent a medically supervised fast of 14 days (250 kcal/day). Changes in lipid and lipoprotein levels, as well as in lipoprotein subclasses and particles, were measured by ultracentrifugation and nuclear magnetic resonance (NMR) at baseline, and after 7 and 14 fasting days. RESULTS: The largest changes were found after 14 fasting days. There were significant reductions in triglycerides (TG, - 0.35 ± 0.1 mmol/L), very low-density lipoprotein (VLDL)-TG (- 0.46 ± 0.08 mmol/L), VLDL-cholesterol (VLDL-C, - 0.16 ± 0.03 mmol/L) and low-density lipoprotein (LDL)-C (- 0.72 ± 0.14 mmol/L). Analysis of LDL subclasses showed a significant decrease in LDL1-C (- 0.16 ± 0.05 mmol/L), LDL2-C (- 0.30 ± 0.06 mmol/L) and LDL3-C (- 0.27 ± 0.05 mmol/L). NMR spectroscopy showed a significant reduction in large VLDL particles (- 5.18 ± 1.26 nmol/L), as well as large (- 244.13 ± 39.45 nmol/L) and small LDL particles (- 38.45 ± 44.04 nmol/L). A significant decrease in high-density lipoprotein (HDL)-C (- 0.16 ± 0.04 mmol/L) was observed. By contrast, the concentration in large HDL particles was significantly raised. Apolipoprotein A1 decreased significantly whereas apolipoprotein B, lipoprotein(a), fibrinogen and high-sensitivity C-reactive protein were unchanged. CONCLUSION: Our results suggest that LF improves lipoprotein levels and lipoprotein subclasses and ameliorates the lipoprotein-associated atherogenic risk profile, suggesting a reduction in the cardiovascular risk linked to dyslipidemia. TRIAL REGISTRATION: Study registration number: DRKS-ID: DRKS00010111 Date of registration: 03/06/2016 "retrospectively registered".

SARS-CoV-2-IgG response is different in COVID-19 outpatients and asymptomatic contact persons.

Commercially available immunoassays have been developed for sensitive and specific detection of antibodies against SARS-CoV-2. While a fast and reliable IgG response has been reported for samples from hospitalized COVID-19 patients, less is known about ambulatory patients. We evaluated the SARS-CoV-2-IgG response by the Anti-SARS-CoV-2-ELISA IgG (Euroimmun) in a defined cohort of SARS-CoV-2-PCR-confirmed outpatients and asymptomatic contact persons including 137 serum samples from PCR-confirmed outpatients (n = 111) and asymptomatic but PCR-positive contact persons (n = 26) sent to our laboratory as part of routine diagnostics for determination of SARS-CoV-2-IgG. Overall positivity rate for SARS-CoV-2-IgG was 81.1 % in outpatients (irrespective of sampling before or after day 21 after onset of symptoms) but significantly lower in asymptomatic contact persons (15.4 %, p < 0.0001). In contact persons without symptoms the ct values of the PCR assays were significantly higher (5-7 threshold cycles) than in outpatients, and ct values were significantly negative correlated to the SARS-CoV-2-IgG ratio, suggesting a lower viral load as a possible explanation for lower rate of seropositivity. In summary, our study shows that serological response to SARS-CoV-2 in outpatients including asymptomatic persons is less pronounced than in hospitalized patients. Further controlled studies are urgently needed to determine serological response in outpatients and asymptomatic persons since this is the main target population for seroepidemiological investigations.

Association of mitotane with chylomicrons and serum lipoproteins: practical implications for treatment of adrenocortical carcinoma.

OBJECTIVE: Oral mitotane (o,p'-DDD) is a cornerstone of medical treatment for adrenocortical carcinoma (ACC). AIM: Serum mitotane concentrations >14  mg/l are targeted for improved efficacy but not achieved in about half of patients. Here we aimed at a better understanding of intestinal absorption and lipoprotein association of mitotane and metabolites o,p'-dichlorodiphenylacetic acid (o,p'-DDA) and o,p'-dichlorodiphenyldichloroethane (o,p'-DDE). DESIGN: Lipoproteins were isolated by ultracentrifugation from the chyle of a 29-year-old patient and serum from additional 14 ACC patients treated with mitotane. HPLC was applied for quantification of mitotane and metabolites. We assessed NCI-H295 cell viability, cortisol production, and expression of endoplasmic reticulum (ER) stress marker genes to study the functional consequences of mitotane binding to lipoproteins. RESULTS: Chyle of the index patient contained 197  mg/ml mitotane, 53  mg/ml o,p'-DDA, and 51  mg/l o,p'-DDE. Of the total mitotane in serum, lipoprotein fractions contained 21.7±21.4% (VLDL), 1.9±0.8% (IDL), 8.9±5.5% (LDL1), 18.9±9.6% (LDL2), 10.1±4.0% (LDL3), and 26.3±13.0% (HDL2). Only 12.3±5.5% were in the lipoprotein-depleted fraction. DISCUSSION: Mitotane content of lipoproteins directly correlated with their triglyceride and cholesterol content. O,p'-DDE was similarly distributed, but 87.9±4.2% of o,p'-DDA found in the HDL2 and lipoprotein-depleted fractions. Binding of mitotane to human lipoproteins blunted its anti-proliferative and anti-hormonal effects on NCI-H295 cells and reduced ER stress marker gene expression. CONCLUSION: Mitotane absorption involves chylomicron binding. High concentrations of o,p'-DDA and o,p'-DDE in chyle suggest intestinal mitotane metabolism. In serum, the majority of mitotane is bound to lipoproteins. In vitro, lipoprotein binding inhibits activity of mitotane suggesting that lipoprotein-free mitotane is the therapeutically active fraction.

Hepcidin/Ferritin Quotient Helps to Predict Spontaneous Recovery from Iron Loss following Blood Donation.

BACKGROUND: Iron supplementation is generally recommended for blood donors even though there are inter-individual differences in iron homeostasis. METHODS: Ferritin levels of repeat donors were compared with first-time donors, retrospectively. Prospectively, we tested 27 male repeat donors for the following parameters at the day of blood donation as well as 1, 3, 7, 10, and 56 days thereafter: ferritin, hepcidin, transferrin, transferrin receptor, hemoglobin, erythropoietin, reticulocytes, hemoglobin in reticulocyte, twisted gastrulation protein homolog 1, and growth differentiation factor-15. RESULTS: 56 days after blood donation, donors' average ferritin dropped to 55% (range 30-100%) compared to the initial value. Of all tested parameters hepcidin showed the highest and most significant changes beginning 1 day after donation and lasting for the whole period of 56 days. Along with ferritin, there was a high variation in hepcidin levels indicating inter-individual differences in hepcidin response to iron loss. Donors with a hepcidin/ferritin quotient < 0.3 regained 60% of their initial ferritin after 56 days, while those with a quotient ≥ 0.3 reached less than 50%. CONCLUSION: As hepcidin appears to integrate erythropoietic and iron-loading signals, clinical measurement of hepcidin (together with the hepcidin-ferritin ratio) may become a useful indicator of erythropoiesis and iron kinetics.

Decrease of carotid intima-media thickness in patients at risk to cerebral ischemia after supplementation with folic acid, Vitamins B6 and B12.

OBJECTIVE: Hyperhomocysteinemia is associated with atherosclerotic risk. Although vitamins can lower homocysteine (Hcy), information about effects on atherosclerosis is scarce. METHODS: We used carotid intima-media thickness (IMT) as an accepted marker of atherosclerotic changes. Fifty patients (60 +/- 8 years) with IMT> or =1 mm were included. In a double blind, randomized trial they received daily 2.5 mg folic acid, 25 mg Vitamin B6, and 0.5mg Vitamin B12 or placebo for 1 year. RESULTS: In the treatment group, Hcy decreased from 10.50 +/- 3.93 to 6.56 +/- 1.53 micromol/l (P < 0.0001), whereas it remained unchanged in the placebo group (10.76 +/- 2.36 versus 10.45+/-3.30 micromol/l). IMT decreased from 1.50 +/- 0.44 to 1.42 +/- 0.48 mm (P = 0.034) in the treatment group, whereas it increased from 1.47 +/- 0.57 to 1.54 +/- 0.71 mm in the placebo group. The mean individual changes of IMT between both groups differed significantly (-0.08 +/- 0.17 versus 0.07 +/- 0.25 mm, P = 0.019). Multiple regression analysis revealed that the observed effect on IMT depended only on medication. CONCLUSIONS: Vitamin supplementation significantly reduces IMT in patients at risk. This effect is independent of Hcy concentration.