Plasma total homocysteine level and its association with carotid intima-media thickness in obesity

Comprehensive transcriptomics and metabolomics analyses reveal that hyperhomocysteinemia is a high risk factor for coronary artery disease in a chinese obese population aged 40-65: a prospective cross-sectional study

BACKGROUND

Clinical observations suggest a complex relationship between obesity and coronary artery disease (CAD). This study aimed to characterize the intermediate metabolism phenotypes among obese patients with CAD and without CAD.

METHODS

Sixty-two participants who consecutively underwent coronary angiography were enrolled in the discovery cohort. Transcriptional and untargeted metabolomics analyses were carried out to screen for key molecular changes between obese patients with CAD (CAD obese), without CAD (Non-CAD obese), and Non-CAD leans. A targeted GC-MS metabolomics approach was used to further identify differentially expressed metabolites in the validation cohorts. Regression and receiver operator curve analysis were performed to validate the risk model.

RESULTS

We found common aberrantly expressed pathways both at the transcriptional and metabolomics levels. These pathways included cysteine and methionine metabolism and arginine and proline metabolism. Untargeted metabolomics revealed that S-adenosylhomocysteine (SAH), 3-hydroxybenzoic acid, 2-hydroxyhippuric acid, nicotinuric acid, and 2-arachidonoyl glycerol were significantly elevated in the CAD obese group compared to the other two groups. In the validation study, targeted cysteine and methionine metabolomics analyses showed that homocysteine (Hcy), SAH, and choline were significantly increased in the CAD obese group compared with the Non-CAD obese group, while betaine, 5-methylpropanedioic acid, S-adenosylmethionine, 4-PA, and vitamin B2 (VB2) showed no significant differences. Multivariate analyses showed that Hcy was an independent predictor of obesity with CAD (hazard ratio 1.7; 95%CI 1.2-2.6). The area under the curve based on the Hcy metabolomic (HCY-Mtb) index was 0.819, and up to 0.877 for the HCY-Mtb.index plus clinical variables.

CONCLUSION

This is the first study to propose that obesity with hyperhomocysteinemia is a useful intermediate metabolism phenotype that could be used to identify obese patients at high risk for developing CAD.

Association between homocysteine and obesity: A meta-analysis

According to previous studies of obesity, we found that the association between homocysteine concentrations and obesity was reported controversially. Thus, we carried out this meta-analysis to investigate this association. We searched PubMed, The Cochrane library, and EMBASE database for studies that evaluate the relationship between homocysteine concentrations and obesity from inception to March, 2019. The quality of all included studies was assessed by the Newcastle Ottawa Scale (NOS) and the Agency for Healthcare Research Quality (AHRQ). The RevMan5.3 software and Stata12.0 software were used for conducting all data analyses. Standardized mean differences (SMD) with the corresponding 95% confidence intervals (95% CIs) were used as a measure of effect size to assess the relationship between homocysteine concentrations and obesity through a meta-analysis. The level of significance was set at P < .05. A total of 14 studies were ultimately included in our meta-analysis. Meta-analysis of the 14 studies found remarkable lower homocysteine concentrations in controls than in obese patients (SMD = 0.76, 95% CI = 0.25-1.27, P < .01; I²  = 94% and P < .01 for heterogeneity), regardless of nutritional status, dietary habit, insulin resistance (IR) status, special disease history, history of medicine taken, genetic background, and so on. Homocysteine concentrations in nonobese patients with polycystic ovarian syndrome (PCOS) were lower than obese patients with PCOS (SMD = 0.48, 95% CI = 0.20-0.77, P < .01; I²  = 39% and P = .18 for heterogeneity). The result of our meta-analysis showed that homocysteine concentrations were significantly elevated among obese patients.

Sex differences in the prevalence and clinical correlates of hyperhomocysteinemia in patients with bipolar disorder

OBJECTIVE

Sex differences in bipolar disorder are well recognized but little attention has been paid to sex differences in homocysteine or hyperhomocysteinemia in bipolar patients. This study compared gender differences in homocysteine levels and rates of hyperhomocysteinemia in Chinese inpatients with bipolar disorder.

METHODS

A total of 198 BD patients and 84 healthy controls were enrolled. The Young Mania Rating Scale, Hamilton Depression Rating Scale, and the Clinical Global Impressions-Severity scale were used to assess the affective symptomatology. Fasting plasma Hcy levels were measured by high-performance liquid chromatography.

RESULTS

Men had higher homocysteine levels than women and the prevalence of hyperhomocysteinemia in male patients was approximately twice that in female patients. Logistic regression analyses showed that HHcy was associated with less frequent use of valproate in males and being overweight in females. Further correlation analysis and multivariate regression analysis demonstrated that Hcy levels were inversely correlated with valproate treatment in men and positively associated with overweight in women.

CONCLUSIONS

In bipolar patients, there are significant differences between sexes in the levels of homocysteine and prevalence of hyperhomocysteinemia. This appears to be associated with lower prevalence of valproate prescribing in men and with being overweight in women.

Short Sleep Duration Is Associated With Increased Serum Homocysteine: Insights From a National Survey

STUDY OBJECTIVES

Both short sleep duration and increased serum homocysteine levels are associated with cardiovascular events. However, research on the relationship between sleep duration and serum homocysteine levels is sparse. The aim of this study is to examine the association between sleep duration and serum homocysteine levels from a national database.

METHODS

In total, 4,480 eligible participants older than 20 years who had serum homocysteine data and reported sleep duration were enrolled from the US National Health and Nutrition Examination Survey of 2005 to 2006. The association between sleep duration and serum homocysteine levels was analyzed using multivariate regression models for covariate adjustment.

RESULTS

Serum homocysteine level was lowest in individuals with a sleep duration of 7 hours and increased in those with both shorter and longer self-reported total sleep time (groups were categorized into ≤ 5 hours, 6 hours, 7 hours, 8 hours, and ≥ 9 hours). After adjustment for covariates, those in the group sleeping ≤ 5 hours had significantly higher serum homocysteine levels than the reference group (sleep duration of 7 hours). In subgroup analyses by sex, body mass index (BMI), and ethnicity, the association between short sleep duration (≤ 5 hours) and higher serum homocysteine levels persisted in women, individuals with obesity (BMI ≥ 30 kg/m²), and non-Hispanic whites.

CONCLUSIONS

This study highlighted that short sleep duration was associated with higher serum homocysteine levels in women, individuals with obesity (BMI ≥ 30 kg/m²), and non-Hispanic whites; this finding might suggest increased vulnerability to cardiovascular risk or other atherothrombotic events in these groups in the context of short sleep.

Fruit vinegars attenuate cardiac injury via anti-inflammatory and anti-adiposity actions in high-fat diet-induced obese rats

CONTEXT

Fruit vinegars (FVs) are used in Mediterranean folk medicine for their hypolipidemic and weight-reducing properties.

OBJECTIVE

To investigate the preventive effects of three types of FV, commonly available in Algeria, namely prickly pear [Opuntia ficus-indica (L.) Mill (Cectaceae)], pomegranate [Punica granatum L. (Punicaceae)], and apple [Malus domestica Borkh. (Rosaceae)], against obesity-induced cardiomyopathy and its underlying mechanisms.

MATERIALS AND METHODS

Seventy-two male Wistar rats were equally divided into 12 groups. The first group served as normal control (distilled water, 7 mL/kg bw), and the remaining groups were respectively treated with distilled water (7 mL/kg bw), acetic acid (0.5% w/v, 7 mL/kg bw) and vinegars of pomegranate, apple or prickly pear (at doses of 3.5, 7 and 14 mL/kg bw, acetic acid content as mentioned above) along with a high-fat diet (HFD). The effects of the oral administration of FV for 18 weeks on the body and visceral adipose tissue (VAT) weights, plasma inflammatory and cardiac enzymes biomarkers, and in heart tissue were evaluated.

RESULTS

Vinegars treatments significantly (p < .05) attenuated the HFD-induced increase in bw (0.2-0.5-fold) and VAT mass (0.7-1.8-fold), as well as increase in plasma levels of CRP (0.1-0.3-fold), fibrinogen (0.2-0.3-fold), leptin (1.7-3.7-fold), TNF-α (0.1-0.6-fold), AST (0.9-1.4-fold), CK-MB (0.3-1.4-fold) and LDH (2.7-6.7-fold). Moreover, vinegar treatments preserved myocardial architecture and attenuated cardiac fibrosis.

DISCUSSION AND CONCLUSION

These findings suggest that pomegranate, apple and prickly pear vinegars may prevent HFD-induced obesity and obesity-related cardiac complications, and that this prevention may result from the potent anti-inflammatory and anti-adiposity properties of these vinegars.

Decreased serum betaine concentrations in patients after bariatric surgery

Bariatric surgery significantly reduces the risk of cardiovascular diseases but has no effects on hyperhomocysteinemia, the risk factor for atherogenesis. We hypothesize that the decrease in serum betaine (involved in homocysteine metabolism) concentrations, after bariatric surgery, impairs conversion of homocysteine to methionine, leading to hyperhomocysteinemia. If this is true, it may be desirable to supply patients after bariatric surgery with betaine. Serum betaine and homocysteine concentrations were measured by liquid chromatography/mass spectrometry, in 16 obese patients, before and 6 months after bariatric surgery. Ten healthy individuals with normal body mass index served as controls. Serum betaine concentrations decreased to the values lower than in controls after bariatric surgery, whereas serum homocysteine concentrations remained elevated. In patients supplemented with B(12) and folate, no effect of bariatric surgery on serum concentrations of vitamins involved in homocysteine metabolism was observed. These results suggest that betaine deficit could be responsible for maintenance of hyperhomocysteinemia after bariatric surgery. We postulate that supplementation with betaine could be of therapeutic value for the treatment of hyperhomocysteinemia after bariatric surgery.

Cysteine and obesity: consistency of the evidence across epidemiologic, animal and cellular studies

PURPOSE OF REVIEW

The concentrations of several plasma amino acids increase in obesity. Notably, plasma total concentrations of the sulphur amino acid cysteine (tCys) are linearly associated with fat mass in large population studies. Animal and cellular experiments support the concept that cysteine may be obesogenic. Here we review experimental and epidemiologic findings linking cysteine and related compounds with fat regulation and obesity.

RECENT FINDINGS

tCys, and to a lesser extent cystathionine, are the only plasma sulphur amino acids consistently associated with human obesity, whereas glutathione is inversely associated with BMI. Supplementing cyste(i)ne in rodents decreases energy expenditure and promotes adiposity, whereas defects of cysteine-synthesizing enzymes decrease body weight. In adipocytes, cysteine inhibits lipolysis and promotes lipogenesis via H2O2 production. Unlike most plasma amino acids, tCys levels do not decrease with gastric bypass-induced weight loss, further supporting the concept that elevated cysteine may be a cause, not a consequence of obesity. Although cysteine products (glutathione, taurine and H2S) are altered in obesity, they do not appear to explain cysteine's effects on body weight.

SUMMARY

Cellular, animal and epidemiologic data are consistent with the view that cysteine is obesogenic. Targeted research linking in-vitro and in-vivo findings is needed to elucidate mechanisms involved.

High serum homocysteine levels correlate with a decrease in the blood flow velocity of the ophthalmic artery in highway toll collectors

Highway workers, such as policemen, automotive service companies, and toll collectors, are placed at risk of the accelerated atherosclerotic process, since recent studies have suggested that exposure to exhaust particles and ambient air pollution increases carotid intima-media thickness and reduces ocular blood flow velocity. Therefore, we assessed the relationship between serum homocysteine, a potential parameter for atherosclerosis, and the ocular blood flow velocity and the resistivity index in highway toll collectors. The peak systolic and end diastolic flow velocities and the resistivity index were measured in 22 toll collectors and 24 control subjects by color Doppler ultrasonography. The resistivity index, which is an indirect measure of the atherosclerotic process, was calculated: resistivity index = (peak systolic velocity - end diastolic velocity)/peak systolic velocity. Serum homocysteine levels were determined by fluorometric high-performance liquid chromatography. In the highway toll collectors, the serum homocysteine level (14.4 +/- 4.8 micromol/l; p < 0.005) and the resistivity index of the ophthalmic artery (0.741 +/- 0.015; p < 0.05) were higher and the ophthalmic blood flow velocity (33.0 +/- 3.0 cm/s; p < 0.001) was lower than those in the controls (10.6 +/- 3.1 micromol/l; 0.728 +/- 0.023; 36.8 +/- 2.2 cm/s; respectively). There were significant correlations between the serum homocysteine level and ophthalmic artery resistivity index in both highway toll collectors (p < 0.001) and controls (p < 0.005). Exposure to exhaust particles might increase the serum homocysteine level, which in turn could lead to the decreased ocular blood flow and the increased resistivity index.

Association between brachial-ankle pulse wave velocity and cardiovascular risk factors in healthy adolescents

OBJECTIVE

To investigate the associations between cardiovascular risk factors and arterial stiffness, measured as brachial-ankle pulse wave velocity (baPWV), in healthy adolescents.

STUDY DESIGN

In this cross-sectional study, 178 male and 84 female adolescents, aged 12 to 18 years, were recruited. Total homocysteine levels, serum lipid profiles, high-sensitivity C-reactive protein (hs-CRP) levels, fasting glucose levels, fasting insulin levels, and baPWV were measured.

RESULTS

baPWV was significantly higher in male adolescents than in female adolescents. In both sex groups, baPWV was positively correlated with body mass index (BMI), waist circumference, waist-hip ratio, systolic and diastolic blood pressures, fasting insulin levels, homeostatic model assessment of insulin resistance, triglyceride levels, hs-CRP levels, and total homocysteine levels. In male adolescents, age, total cholesterol level, low-density lipoprotein cholesterol levels, and white blood cell counts were positively correlated with baPWV, and, in female adolescents, high-density lipoprotein cholesterol levels were negatively correlated with baPWV. In multivariate analysis, sex, mean blood pressure, BMI, and total homocysteine levels were found to be independent factors associated with baPWV.

CONCLUSION

Blood pressure, BMI, sex, and total homocysteine levels were independently associated with arterial stiffness, measured as baPWV, in healthy adolescents, suggesting that these risk factors may be associated with an increased risk of atherosclerosis in adolescents.

The role of obesity and its bioclinical correlates in the progression of chronic kidney disease

In spite of a progressive fall in the incidence of traditional risk factors of cardiovascular morbidity (cigarette smoking, high blood pressure, and hyperlipidemia), there is an upward trend in the prevalence of obesity and chronic kidney disease (CKD). Furthermore, there is a strong correlation between body mass indices and the relative risk of progression of CKD. The close biophysiological interaction between obesity and CKD is evident by a similar occurrence of comorbidities including insulin resistance, hyperlipidermia, endothelial dysfunction, and sleep disorders. Truncal obesity is a primary component of metabolic syndrome; unlike peripheral fat, the visceral adipocytes are more resistant to insulin. In addition, lipolysis results in a release of free fatty acid and TG, whereas hypertriglycedemia is potentiated by uremic activation of fatty acid synthase. Hypertriglycedemia and low HDL cholesterol increase the relative risk of progression of CKD. Furthermore, endothelial inflammation and premature atherosclerosis are promoted by hyperhomocysteinemia and oxidation of LDL, both of which are commonly observed in CKD and obesity. Predominance of oxidative stress in both obesity and azotemia stimulate synthesis of angiotensin II, which in turn increases TGF-B and plasminogen activator inhibitor-1, thereby propagating glomerular fibrosis. Furthermore, local synthesis of angiotensinogen by adipocytes, leptin activation of sympathetic nervous system, and hyperinsulinemia contribute to the development of hypertension in obesity and CKD. In addition, increased renal tubular expression of Na-K-ATPase and a blunted response to natiuretic hormones in obesity promote salt and water retention. Glomerular hyperfiltration from systemic volume load and hypertension results in mesangial cellular proliferation and progressive renal fibrosis. In addition, maternal nutritional deprivation increases the incidence of obesity, hypertension, and diabetes in adulthood. Reduced fetal protein synthesis contributes to oxidative glomerular injury and impairment of renal morphogenesis. Thus, kidneys are poorly equipped to handle physiologic stress that may result from the rapid body growth and programmed metabolic dysfunction later in life. Finally, in order to minimize morbidity of obesity-related kidney disease, preventive strategy must include optimal maternal health care, promotion of healthy nutrition and routine physical exercise, and early detection of CKD.