Plasma lipoprotein (a), homocysteine, and other cardiovascular disease (CVD) risk factors in Nigerians with CVD

Analysis of Alterations in Intestinal Flora in Chinese Elderly with Cardiovascular Disease and Its Association with Trimethylamine

To investigate the changes in the intestinal flora in the Chinese elderly with cardiovascular disease (CVD) and its correlation with the metabolism of trimethylamine (TMA), the intestinal flora composition of elderly individuals with CVD and healthy elderly individuals was analyzed using 16S rRNA sequencing, the TMA levels in the feces of elderly were detected using headspace-gas chromatography (HS-GC), and four kinds of characterized TMA-producing intestinal bacteria in the elderly were quantified using real-time fluorescence quantitative polymerase chain reaction (qPCR). The results showed that Firmicutes, Actinobacteria, Proteobacteria, Bacteroidetes, and Verrucomicrobia are the dominant microorganisms of the intestinal flora in the Chinese elderly. And there were significant differences in the intestinal bacteria composition between healthy elderly individuals and those with CVD, accompanied by a notable difference in the TMA content. The richness and diversity of the intestinal flora in the elderly with CVD were higher than those in the healthy elderly. Correlation analysis indicated that certain significantly different intestinal flora were associated with the TMA levels. Our findings showed a significant difference in TMA-producing intestinal flora between healthy elderly individuals and those with CVD. The TMA levels were found to be positively and significantly correlated with Klebsiella pneumoniae, suggesting that this bacterium is closely linked to the production of TMA in the elderly gut. This may have implications for the development and progression of CVD in the elderly population.

Is Lp(a) ready for prime time use in the clinic? A pros-and-cons debate

Lipoprotein (a) (Lp(a)) is a cholesterol-rich lipoprotein known since 1963. In spite of extensive research on Lp(a), there are still numerous gaps in our knowledge relating to its function, biosynthesis and catabolism. One reason for this might be that apo(a), the characteristic glycoprotein of Lp(a), is expressed only in primates. Results from experiments using transgenic animals therefore may need verification in humans. Studies on Lp(a) are also handicapped by the great number of isoforms of apo(a) and the heterogeneity of apo(a)-containing fractions in plasma. Quantification of Lp(a) in the clinical laboratory for a long time has not been standardized. Starting from its discovery, reports accumulated that Lp(a) contributed to the risk of cardiovascular disease (CVD), myocardial infarction (MI) and stroke. Early reports were based on case control studies but in the last decades a great deal of prospective studies have been published that highlight the increased risk for CVD and MI in patients with elevated Lp(a). Final answers to the question of whether Lp(a) is ready for wider clinical use will come from intervention studies with novel selective Lp(a) lowering medications that are currently underway. This article expounds arguments for and against this proposition from currently available data.

Plasma oxidized low density lipoprotein cholesterol correlates inversely with testosterone in young adult male smokers

INTRODUCTION

There are indications that oxidized low density lipoprotein cholesterol (Ox-LDLC) may play an important role in cardiovascular disease (CVD) events. In most developing countries, the interplay between the different lipid fractions and cigarette smoking has not been studied. This study assessed the effect of cigarette smoking on the alterations in plasma lipid fractions and their associations with the gonadal hormone, testosterone (T).

METHODS

One hundred and sixty male participants, consisting of eighty smokers and eighty apparently healthy non-smokers were recruited. Anthropometric indices and biochemical parameters were determined using standard procedures.

RESULTS

Significant increases were obtained in plasma total cholesterol (TC), triglyceride (TG), oxidized low density lipoprotein (Ox-LDLC) and Ox-LDLC/TT ratio (p<0.001) in smokers compared with the non-smokers. Plasma high density cholesterol (HDLC) (p<0.001) was significantly reduced in smokers compared with the non-smokers. The plasma mean T result was not significantly different from the non-smokers, but inversely correlated with Ox-LDLC and significantly correlated with the lipids and lipoproteins. Significantly high plasma TC, TG and LDLC (p<0.001) and low HDLC (p<0.001) were also obtained in smokers when co-founding factors such as duration and number of cigarette smoked per day were applied.

CONCLUSION

This study showed an inverse correlation between Ox-LDLC and testosterone as well as strong association between the number of tobacco and cigarettes usage per day. These changes in part, could be major causes of premature CVD and decreased fertility in young adults.

Moderate hyperhomocysteinemia provokes dysfunction of cardiovascular autonomic system and liver oxidative stress in rats

Hyperhomocysteinemia (HHcy) is associated with cardiovascular disease, atherosclerosis and reactive oxygen species generation. Thus, our aim was to investigate whether there was an association between HHcy, blood pressure, autonomic control and liver oxidative stress. Male Wistar rats were divided into 2 groups and treated for 8weeks: one group (control, CO) received tap water, while the other group (methionine, ME) was given a 100mg/kg of methionine in water by gavage. Two catheters were implanted into the femoral artery and vein to record arterial pressure (AP) and heart rate (HR) and drug administration. Signals were recorded by a data acquisition system. Baroreflex sensitivity was evaluated by HR responses to AP changes induced by vasoactive drugs. HR variability and AP variability were performed by spectral analysis in time and frequency domains to evaluate the contribution of the sympathetic and parasympathetic modulation. Lipid peroxidation and antioxidant enzyme activities were evaluated by measuring superoxide dismutase, catalase and glutathione peroxidase in liver homogenates. The ME group presented a significant increase in systolic arterial pressure (118±9 vs 135±6mmHg), diastolic arterial pressure (81±6 vs. 92±4) and mean arterial pressure (95±7 vs. 106±6). In addition, pulse interval variability presented a significant decrease (41%), while the low frequency component of AP was significantly increased (delta P=6.24mmHg(2)) in the ME group. We also found a positive association between lipid peroxidation and cardiac sympathetic modulation, sympathetic and vagal modulation ratio and systolic pressure variability. Collectively, these findings showed that HHcy induced dysfunction of cardiovascular autonomic system and liver oxidative stress.

The relationships between body composition and cardiovascular risk factors in young Australian men

INTRODUCTION

Cardiovascular (CV) disease is a leading cause of global mortality. Despite clear evidence of the coexistence of several risk factors in young people as children and an understanding of the importance of the health behaviors in controlling CV disease, there are limited data on the relationships between risk factors and CV disease in young people. Therefore further study is required.

OBJECTIVE

This study aimed to investigate associations among body composition, health behaviors and CV risk factors in young Australian men.

METHODS

Thirty five healthy men aged 18-25 years had their blood pressure (BP), blood lipids, body composition, resting metabolic rate (RMR), physical activity, dietary intake and cardiorespiratory fitness assessed.

RESULTS

Participants were categorised according to the percentage of body fat into two groups: lean and overweight men. There were no between-group differences in the biochemical indicators except that overweight men had lower HDL-C compared to lean men. Both groups had similar mean energy, protein, fat, carbohydrate and alcohol intake, RMR, physical activity level (PAL) and energy expenditure (EE). Most of the participants (65.7%) had LDL≥2.5 mmol/L. Other common individual risk factors were body fat≥20% (42.9%), waist circumference≥88 cm (28.6%), PAL<1.8 (22.9%) and systolic BP≥130 mmHg (20%). The mean number of CV risk factors was lower among men having a high intake of monounsaturated fatty acids (MUFA, >12% of the energy intake) regardless of whether they were overweight or lean and did not seem to differ according to the source of MUFA consumed.

CONCLUSIONS

It is a serious concern to observe such a high percentage of CV risk factors in a group of apparently healthy young men. The likelihood of multiple CV risk factors is greater among those with high body fatness and low MUFA intake. Intake of MUFA favorably affects CV risk factors regardless of the source.