Role of Hyperhomocysteinemia and Hyperuricemia in Pathogenesis of Atherosclerosis

Homocysteine is Associated with Exaggerated Morning Blood Pressure Surge in Patients with Acute Ischemic Stroke

BACKGROUND

Considerable researches suggest that high level of homocysteine (Hcy) is associated with the risk of ischemic stroke. Ambulatory blood pressure monitoring (ABPM) parameters have also been confirmed associated with cardio-cerebrovascular events. However, the relationship between Hcy and ABPM parameters remains unclear in patients with acute ischemic stroke. In this study, we aim to investigate the association between Hcy level and ABPM parameters in patients with acute ischemic stroke.

METHODS

We enrolled 60 patients with acute ischemic stroke who received ABPM. We calculated ABPM parameters like morning blood pressure surge (MBPS), ambulatory arterial stiffness index, blood pressure variability, and night dipping patterns.

RESULTS

Multivariate logistic regression analysis indicated that patients in the top quartile of Hcy level tended to have a higher level of prewaking and sleep-trough MBPS compared with patients in the lower 3 quartiles after adjusted for age and gender (P = .028 and P = .030, respectively). When treating Hcy as a continuous variable, the linear regression showed the association between Hcy level and both MBPS parameters remained significant (prewaking MBPS, r = .356, P = .022; sleep-trough MBPS, r = .365, P = .017, respectively). However, there is no association between Hcy level and ambulatory arterial stiffness index, blood pressure variability or night dipping patterns (P = .635, P = .348 and P = .127 respectively).

CONCLUSIONS

There is a relationship between the 2 major cerebrovascular risk factors: MBPS and Hcy.

Causes of hyperhomocysteinemia and its pathological significance

In the last 10 years, homocysteine has been regarded as a marker of cardiovascular disease and a definite risk factor for many other diseases. Homocysteine is biosynthesized from methionine through multiple steps and then goes through one of two major metabolic pathways: remethylation and transsulfuration. Hyperhomocysteinemia is a state in which too much homocysteine is present in the body. The main cause of hyperhomocysteinemia is a dysfunction of enzymes and cofactors associated with the process of homocysteine biosynthesis. Other causes include excessive methionine intake, certain diseases and side effects of some drugs. Hyperhomocysteinemia is a trigger for many diseases, such as atherosclerosis, congestive heart failure, age-related macular degeneration, Alzheimer's disease and hearing loss. There are many studies showing a positive relationship between homocysteine level and various symptoms. We speculate that a high level of homocysteine can be the sole reason or an aggravating factor in numerous diseases for which causal links are not fully understood.

Association of prehypertension and hyperhomocysteinemia with subclinical atherosclerosis in asymptomatic Chinese: a cross-sectional study

OBJECTIVES

Comorbid hypertension and hyperhomocysteinemia is an important risk factor for carotid atherosclerotic plaque formation. We put forward the hypothesis that the subjects with comorbid prehypertension and hyperhomocysteinemia also had an increased risk of subclinical atherosclerosis, using carotid intima-media thickness (CIMT) as the marker of the atherosclerotic process.

METHODS

A total of 4102 asymptomatic Chinese subjects aged 18-60 years were divided into four groups according to blood pressure (BP) and homocysteine (HCY) level: the control group without prehypertension or hyperhomocysteinemia, isolated prehypertension group, simple hyperhomocysteinemia group and prehypertension with hyperhomocysteinemia group. Serum lipids, fasting blood glucose (FBG), HCY and CIMT were measured.

RESULTS

There was significant difference in the positive rates of increased CIMT among four groups. Compared with the controls, the subjects in the other three groups had a higher risk of increased CIMT (isolated prehypertension group, OR 2.049, 95% CI 1.525 to 2.754; simple hyperhomocysteinemia group, OR 2.145, 95% CI 1.472 to 3.125; prehypertension and hyperhomocysteinemia group, OR 3.199, 95% CI 2.362 to 4.332). However, by multiple logistic regression analysis, only comorbid prehypertension and hyperhomocysteinemia was independently associated with increased CIMT (OR 1.485, 95% CI 1.047 to 2.108, P<0.05).

CONCLUSIONS

Comorbid prehypertension and hyperhomocysteinemia was an independent risk factor of subclinical atherosclerosis in asymptomatic Chinese, but isolated prehypertension or hyperhomocysteinemia was not. Therefore, combined intervention for prehypertension and hyperhomocysteinemia may contribute to decrease the incident of cardiovascular disease.

Serum Homocysteine Levels in Men with and without Erectile Dysfunction: A Systematic Review and Meta-Analysis

OBJECTIVES

Elevated levels of serum homocysteine (Hcy) have been associated with cardiovascular diseases and endothelial dysfunction, conditions closely associated with erectile dysfunction (ED). This meta-analysis was aimed to assess serum Hcy levels in subjects with ED compared to controls in order to clarify the role of Hcy in the pathogenesis of ED.

METHODS

Medline, Embase, and the Cochrane Library were searched for publications investigating the possible association between ED and Hcy. Results were restricted by language, but no time restriction was applied. Standardized mean difference (SMD) was obtained by random effect models.

RESULTS

A total of 9 studies were included in the analysis with a total of 1320 subjects (489 subjects with ED; 831 subjects without ED). Pooled estimate was in favor of increased Hcy in subjects with ED with a SMD of 1.00, 95% CI 0.65-1.35, p < 0.0001. Subgroup analysis based on prevalence of diabetes showed significantly higher SMD in subjects without diabetes (1.34 (95% CI 1.08-1.60)) compared to subjects with diabetes (0.68 (95% CI 0.39-0.97), p < 0.0025 versus subgroup w/o diabetes).

CONCLUSIONS

Results from our meta-analysis suggest that increased levels of serum Hcy are more often observed in subjects with ED; however, increase in Hcy is less evident in diabetic compared to nondiabetic subjects. This study is registered with Prospero registration number CRD42018087558.