Aleš Žák

Background: Dyslipidemia and distorted fatty acid (FA) metabolism are frequent biochemical abnormalities associated with anorexia nervosa (AN). Gut microbiota is supposed to play an important role in the etiopathogenesis of AN. Apart from the digestive function of bile acids (BAs), these compounds have multiple metabolic functions due to the activation of specific receptors. Objective/aims: The aims of the study were to investigate biochemical measures, including plasma lipids (lipoproteins, respectively), fatty acid (FA) patterns, and the profile of plasma Bas, in AN patients and healthy controls (CON). Methods: Plasma phospholipid FA and BAs profiles were analyzed in 39 women with a restrictive type of AN (AN-R; median age 17 years) and in 35 CON women (median age 20 years). Results: Compared to CON, AN had an increased concentration of HDL-C, increased content of palmitic acid, and decreased proportion of linoleic acid. Moreover, AN had a drop in the level of the sum of PUFAn-6 and increased delta 9 desaturase activity for stearic acid. In AN, we found decreased levels of plasma tauroursodeoxycholic acid (TUDCA). In AN, concentrations of 22:5n-6, 16:0, 20:3n-6 and fat mass index were predic-tors of HDL-C levels (R² = 0.43). Conclusions: Patients with AN-R had an increased concentration of HDL-C, decreased levels of total PUFA n-6, and increased activity of D9D for stearic acid. Furthermore, AN exerted decreased levels of TUDCA. Therefore, a decreased level of TUDCA could potentially serve as a marker of AN.

Objectives: This study assessed the nutritional and clinical status of Czech adolescents with anorexia nervosa (AN) during the SARS-CoV-2 pandemic (3/2020–3/2022), comparing them with those diagnosed before the pandemic (3/2018–3/2020) and healthy controls. Methods: A single-center, retrospective, cross-sectional study involved AN patients diagnosed before (ANpreCov, N = 19) and during (ANCov, N = 18) the pandemic, along with a healthy control group (HC). Anthropometric, clinical, and laboratory parameters were compared across all groups. Results: Despite a 64% increase in AN cases, no significant differences were found in clinical symptoms, laboratory results, diagnostic delays, hospitalization length, weight gain during hospitalization, or relapse and remission rates between the AN groups. Compared to healthy controls, AN patients had higher ferritin levels (p < 0.01), higher ALT activity and vitamin B₁₂ levels (both p < 0.05), and lower levels of non-esterified fatty acids (NEFA) (p < 0.01). Conclusion: Although AN cases significantly increased during the pandemic, the clinical and nutritional status upon admission remained similar before and during the pandemic. Elevated ALT, B₁₂ and ferritin are considered markers of malnutrition-induced liver injury. Reduced NEFA levels may result from increased oxidation or suppressed lipolysis, linked to alterations in the "adiponectin-GLUT4-AMP-activated protein kinase" signaling cascade.

Long-chain polyunsaturated fatty acids (LC-PUFAs) play important roles in human health, from controlling inflammation to lipid and glucose homeostasis. In our previous study, which employed a cluster analysis of a plasma fatty acid (FA) pattern, we identified two clusters of metabolic syndrome (MetS) independent of clinical and biochemical parameters within the whole study group (controls together with metabolic syndrome (MetS) patients). FA desaturase (FADS) genes are the key regulators of LC-PUFA metabolism. The aim of this study was to analyze associations between FADS polymorphisms and clusters of MetS. The study group consisted of 188 controls and 166 patients with MetS. The first cluster contained 71 controls (CON1) and 109 MetS patients (MetS1). The second cluster consisted of 117 controls (CON2) and 57 MetS patients (MetS2). In comparison with MetS2, cluster MetS1 displayed a more adverse risk profile. Cluster CON1 had, in comparison with CON2, higher body weight and increased triacylglycerol levels (p < 0.05). We found that the FADS rs174537 (p < 0.001), rs174570 (p < 0.01), and rs174602 (p < 0.05) polymorphisms along with two inferred haplotypes had statistically significant genotype associations with the splitting of MetS into MetS1 and MetS2. Conversely, we observed no significant differences in the distribution of FADS polymorphisms between MetS and CON subjects, or between CON1 and CON2. These associations between FADS polymorphisms and two clusters of MetS (differing in waist circumference, HOMA-IR, lipolysis, and oxidative stress) implicate the important influence of genetic factors on the phenotypic manifestation of MetS.

Dyslipidemia is common among patients on hemodialysis, but its etiology is not fully understood. Although changes in cholesterol homeostasis and fatty acid metabolism play an important role during dialysis, the interaction of these metabolic pathways has yet to be studied in sufficient detail. In this study, we enrolled 26 patients on maintenance hemodialysis treatment (high-volume hemodiafiltration, HV HDF) without statin therapy (17 men/9 women) and an age/gender-matched group of 26 individuals without signs of nephropathy. The HV-HDF group exhibited more frequent signs of cardiovascular disease, disturbed saccharide metabolism, and altered lipoprotein profiles, manifesting in lower HDL-C, and raised concentrations of IDL-C and apoB-48 (all p < 0.01). HV-HDF patients had higher levels of campesterol (p < 0.01) and β-sitosterol (p = 0.06), both surrogate markers of cholesterol absorption and unchanged lathosterol concentrations. Fatty acid (FA) profiles were changed mostly in cholesteryl esters, with a higher content of saturated and n-3 polyunsaturated fatty acids (PUFA) in the HV-HDF group. However, n-6 PUFA in cholesteryl esters were less abundant (p < 0.001) in the HV-HDF group. Hemodialysis during end-stage kidney disease induces changes associated with higher absorption of cholesterol and disturbed lipoprotein metabolism. Changes in fatty acid metabolism reflect the combined effect of renal insufficiency and its comorbidities, mostly insulin resistance.

Elevated plasma concentration of apolipoprotein B-48 (apoB-48) is an independent risk factor of cardiovascular disease. Stearoyl-CoA desaturase-1 (SCD1) is a rate-limiting lipogenic enzyme and a key regulator of fuel metabolism. The aim of this study was to analyse associations between clinical, biochemical, and genetic factors and different apoB-48 levels in subjects at increased cardiometabolic risk. We examined 220 subjects exhibiting at least one metabolic syndrome (MetS) component. In conjunction with basic clinical, anthropometric and laboratory measurements, we analysed various polymorphisms of stearoyl-CoA desaturase-1 ( SCD1 ). Subjects were divided into two groups according to the median apoB-48 level: (1) high apoB-48 (≥ 7.9 mg/l, N = 112) and (2) low apoB-48 (< 7.9 mg/l, N = 108). Neither group differed significantly in anthropometric measures. High plasma apoB-48 levels were associated with increased systolic blood pressure (+3 %; P < 0.05), MetS prevalence (59.8 vs. 32.4 %; P < 0.001), small-dense LDL frequency (46.4 vs. 20.4 %; P < 0.001), triglycerides (+97 %; P < 0.001), non-HDLcholesterol (+27 %; P < 0.001), and lower concentrations of HDL-cholesterol (–11 %; P < 0.01). This group was further characterized by a higher HOMA-IR index (+54 %; P < 0.001) and increased concentrations of conjugated dienes (+11 %; P < 0.001) and oxidatively modified LDL (+ 38 %; P < 0.05). Lower frequencies of SCD1 minor genotypes (rs2167444, rs508384, P < 0.05) were observed in subjects with elevated plasma concentrations of apoB-48. Elevated plasma concentrations of apoB-48 are associated with an adverse lipid profile, higher systolic blood pressure, insulin resistance, and oxidative stress. Lower proportions of minor SCD1 genotypes (rs2167444, rs508384) implicate the role of genetic factors in the pathogenesis of elevated levels of apoB-48.

Background: Patients with end-stage renal disease (ESRD) exhibit high morbidity as well as mortality for atherosclerotic cardiovascular diseases (CVD). Therefore, we investigated differences in individual lipoprotein classes and subclasses in ESRD patients under chronic high volume hemodiafiltration (HV-HDF) in comparison with a control group. We also assessed the prognosis of these patients and analyzed these parameters after 5 years follow-up. Methods: 57 patients and 50 controls were enrolled. We analysed high density (HDL) and low density (LDL) lipoprotein subfractions using the Quantimetrix Lipoprint(R) system. Subfractions were correlated with selected clinical-biochemical parameters including risk factors for atherosclerotic CVD at the beginning of and after 5 years follow-up. Results: Fourteen patients survived the 5-year follow-up. Follow-up results revealed a shift toward smaller HDL subfractions. In lipoproteins carrying apolipoprotein B, there was a shift of cholesterol from very low density (VLDL) to intermediate density (IDL) lipoproteins and LDLs. Hypolipidaemic therapy did not influence lipoprotein profiles in HV-HDF patients. Conclusions: 1. HV-HDF patients exhibit specific lipid profiles with elevated triacylglycerol, low HDL and LDL and higher content of cholesterol in remnant particles (VLDL and IDL) at the expense of large LDL. HDL subfractions were linked to the number of risk factors for CVD in the control group only. 2. Baseline lipoprotein profiles did not differ between survivors and non-survivors. Non-survivors had higher CRP and lower HDL-C. 3. During the 5 year follow-up period, cholesterol in HDL particles and lipoproteins carrying apolipoprotein B redistributed in survivors towards smaller particles, thus resembling the profile of control patients.

Background: This study examines the associations of fatty acids (FAs) in plasma phosphatidylcholine (PC) with the anthropometrical and biochemical characteristic of patients with metabolic syndrome (MetS)-related traits. Methods: We analyzed the FA profiles of PC in 300 persons with MetS-related traits (152 M/148F, mean age 46.9 ± 9.0 years) and in 70 healthy controls of the same age using a balanced men/women ratio and gas–liquid chromatography. Multivariate linear regression analysis was performed to determine the coefficients of determination (R²) using FA proportions of the mentioned proband characteristics. Results: The FA composition of PC in patients with MetS traits was only associated with waist circumference (R² = 0.27), waist-to-hip ratio (WHR; R² = 0.41), body fat percentage (R² = 0.62), and fat mass (R² = 0.29). Positive associations were found for dihomo-γ-linolenic (DGLA), palmitic, stearic (SA), α-linolenic (ALA), and eicosapentaenoic acids, whereas negative associations were found for linoleic (LA), oleic, and docosapentaenoic acids. Palmitoleic acid (POA) was positively associated with waist circumference but negatively with fat percentage. In controls, significant associations were found for waist circumference (R² = 0.51), WHR (R² = 0.53), body fat percentage (R² = 0.60), and fat mass (R² = 0.34). DGLA and saturated FA (SFA) were positively associated, whereas docosahexaenoic, adrenic, and cis-vaccenic acids were negatively associated. The study group differed from controls as follows: lower concentrations of LA and total n-6 FA, higher indices of delta-9-desaturase and delta-6 desaturase activity and higher proportions of POA, SA, ALA, DGLA, and SFA. Conclusions: We found significant associations (R² >0.25) of FA in plasma PC with adiposity in middle-aged persons with MetS-related traits, but not with metabolic indices.