Inga Bikulčienė

Despite increasing efforts to improve cardiovascular disease (CVD) risk evaluation and management, it remains a leading cause of mortality and morbidity worldwide. This has driven interest in high-density lipoprotein (HDL)-related biomarkers as indicators of oxidative stress and atherogenic processes not fully captured by traditional lipid measurements. In this study, we examined specific paraoxonase 1 (PON1) activity and its relationship with anthropometric, blood pressure, and lipid metabolism measures in 100 middle-aged Lithuanian individuals at high cardiovascular risk. HDL fractions were isolated using iodixanol-based density gradient centrifugation. PON1 concentration and arylesterase activity were measured, and specific activity was defined as arylesterase activity normalized to PON1 concentration. No significant associations were observed between specific PON1 activity and age, body mass index, waist circumference, blood pressure, smoking status, or statin use. Specific PON1 activity was independently associated with lower risk-weighted apolipoprotein B and lower low-density lipoprotein cholesterol levels. These exploratory findings suggest that higher specific PON1 activity may reflect a less atherogenic lipid profile in individuals at high cardiovascular risk, as indicated by its association with LDL-C and with risk-weighted apolipoprotein B. Because direct oxidative stress and inflammatory markers were not measured, interpretations regarding oxidative burden should be considered indirect and hypothesis-generating. Given the cross-sectional nature of the study and the relatively small sample size, these results should be interpreted as exploratory and hypothesis-generating. Further longitudinal studies in larger populations are needed to confirm these observations.

Background and Objectives: Midlife represents a critical window for the emergence of metabolic risk factors. This study aimed to investigate age- and sex-related changes in lipid profiles, body composition, oxidative stress, and fatty acid content. Materials and Methods: This cross-sectional study included adults grouped by age: Results: In total, 169 adults took part in this study (60 men and 109 women), aged 36.30 ± 6.25 years. Fat mass and its regional distribution were higher after age 40, especially in females. In women, fat mass was lower in the thirties and higher again in the forties, while, in men, fat accumulation was progressive. Participants aged 40–49 had a significantly worse metabolic profile than younger individuals. Statistically significant higher total cholesterol, LDL cholesterol, triglycerides, and glucose were shown in the 40–49-years group when compared to younger groups. Malondialdehyde was higher in the 40–49-years vs. 30–39-years group (105.83 vs. 99.72, p = 0.034). In women aged 40–49, a more adverse lipid and glycemic profile was observed compared to younger groups. Platelet fatty acids in the 40–49-years group showed higher polyunsaturated fatty acids and ω6 percentages (12.85% vs. 10.14%, p = 0.046 and 11.44% vs. 8.79%, p = 0.031), including higher linoleic (8.80 ± 5.18 vs. 6.97 ± 5.05, p = 0.045), arachidonic (2.64 ± 2.64 vs. 1.82 ± 1.73, p = 0.030), and docosahexaenoic (0.61 ± 0.86 vs. 0.31 ± 0.49, p = 0.008) acids, when compared to younger groups. Fat mass strongly correlated with insulin resistance, triglycerides, and CRP, and inversely with HDL-C. Conclusions: Significant age-related changes in body composition, metabolic biomarkers, and platelet fatty acid profiles occur after the age of 40, with distinct gender-specific patterns. The fifth decade of life is a transitional period characterized by central adiposity, deteriorating metabolic profiles, and altered fatty acid composition, especially in women.

Chronic stress and diabetes mellitus are highly associated with oxidative stress and inflammation, resulting in cell membrane disruption and platelet activity. This study aims to evaluate the impact of chronic psychological stress on the composition of the platelet phospholipid membrane and platelet activation in type 1 diabetes mellitus (T1DM). We enrolled 35 mature healthy female Wistar rats and randomly divided them into 4 groups, namely the control group (n = 9), stress group (n = 10), T1DM group (n = 8), and T1DM + Stress group (n = 8). The Wistar rats were treated in different experimental conditions for 28 days while being provided free access to feed and water. The concentration of corticosterone in blood serum and hair samples was measured using a competitive enzyme-linked immunosorbent assay. Gas chromatography-mass spectrometry was conducted to identify the methyl esters of fatty acids (FAs) in the platelet phospholipid membrane. A quantitative determination of 11-dehydro-thromboxane B2 in the blood serum was also performed using a competitive enzyme-linked immunosorbent assay. After 28 days, the concentration of corticosterone in blood serum (ng/mL) was observed to be higher in the stress group as compared to the T1DM and T1DM + Stress groups (P = 0.031 and P = 0.008, respectively). The percentage of C 16:0 FA in the platelet membrane was greater in the T1DM + Stress group, but its levels of C 20:1 omega (ω) 9 FA, including C 18:3ω3 FA, C 20:5ω3 FA, and the total sum of ω3 FAs, were lower as compared to the control group (P = 0.016; P = 0.016; P = 0.031; P = 0.016, P = 0.031). The concentration of 11-dehydro-thromboxane B2 in blood serum (pg/mL) was observed to be higher in the stress group than in rats with T1DM (P = 0.063). Chronic psychological stress is related to higher levels of corticosterone, saturated FAs acids in the platelet membrane, and greater platelet activation. This study proves how a low percentage of unsaturated fatty acids in the DM and stress groups indicates the disturbing impact of the oxidative/inflammatory environment to lipid metabolism and neuroendocrine response.

BACKGROUND:Oxidative stress (OS) is known to be extremely damaging for phospholipids in cell membranes, especially their polyunsaturated fatty acids (PUFAs). OS is known to be associated with increased platelet activation and thrombosis, which lead to cardiovascular lesions. The aim of this study was to investigate how changes in the composition of fatty acids (FAs) in the platelet phospholipid membrane correlate with OS in healthy men and in men who have experienced a myocardial infarction (post-MI men). MATERIAL AND METHODS:FA methyl esters from the platelet phospholipid membrane of 79 apparently healthy and 20 post-MI men were identified using gas chromatography/mass spectrometry. Malondialdehyde (MDA) was measured in the blood serum using high-performance liquid chromatography, and platelet-white blood cell aggregates (PWAs) were analysed based on whole-blood flow cytometry. The composition of platelet membrane FAs was compared to MDA concentration (µg/l) and the percentage of PWA formation between healthy men and individuals who had suffered a myocardial infarction (MI). RESULTS:Statistically, post-MI patients had a significantly higher concentration of blood serum MDA than those in the control group (p=0.000). The level of PUFAs was also higher in the platelet phospholipid membrane of post-MI patients than in healthy individuals (p=0.016). However, the percentage of PWA formation was lower in patients compared with the control group (p<0.05). CONCLUSIONS:A higher level of blood serum MDA concentration due to OS stimulates platelets to incorporate more PUFAs into the phospholipid membrane, thereby affecting platelet activation. This may lead the individual to develop cardiovascular diseases in the future.

BACKGROUND:Platelet membranes are extremely susceptible to peroxidation, forming a variety of lipid peroxides, including malondialdehyde (MDA), which has been implicated in the etiology of cardiovascular diseases. Moreover, platelet-leukocyte aggrega...

BACKGROUND:Fatty acids (FA) and their metabolites are closely related to some mechanisms involved in the development of uronephrolithiasis. The aim of this study was to evaluate the relationship between FA composition and type of kidney stones. MATER...