Metabolically healthy obesity and risk of leukoaraiosis; a population based cross-sectional study

Metabolically healthy obese (MHO) individual is known to be defended from the metabolic complications of obesity. Leukoaraiosis, which is commonly detected on brain magnetic resonance imaging (MRI), is now recognized as a risk of stroke, dementia and death. However, the association between MHO and the prevalence of leukoaraiosis is unclear. In this cross-sectional study of 796 participants who received a medical examination program, we investigated the association between MHO and the prevalence of leukoaraiosis. We used common clinical markers for definition of metabolic healthy status: blood pressure, fasting plasma glucose, triglycerides and high-density lipoprotein cholesterol concentrations. Obesity was defined by body mass index ≥25.0 kg/m². We diagnosed leukoaraiosis by fluid-attenuated inversion recovery without hypointensity on T1-weighted images or the presence of a hyperintensity on T2-weighted images. The crude prevalence proportion of leukoaraiosis was 44.5% (case/n = 171/384) in metabolically healthy nonobese (MHNO) individual, 46.3% (44/95) in MHO individual, 62.3% (114/183) in metabolically unhealthy nonobese (MUNO) individual or 56.6% (77/136) in MUO individual. The odds ratios of prevalence of leukoaraiosis were 1.19 (95% CI 0.74-1.90, p = 0.471) for MHO, 1.79 (1.22-2.62, p = 0.003) for MUNO and 1.56 (1.03-2.37, p = 0.037) for MUO individuals after adjusting for sex, age, smoking statues, habit of exercise and alcohol, compared with MHNO individual. We revealed that MHO individuals were not related with the higher risk of leukoaraiosis, whereas MUNO and MUO individuals were.

Analysis of risk factors in patients with leukoaraiosis

To investigate the risk factors for leukoaraiosis (LA) and the correlation between risk factors and LA.The study comprised 92 patients with diagnoses of LA (LA group) and 56 non-LA individuals (control group). Data were collected for the following: age, gender, fasting blood glucose, total cholesterol, triglyceride, high- and low-density lipoprotein cholesterol, uric acid, creatinine, and histories of smoking, hypertension, and diabetes. Levels of serum asymmetric dimethylarginine (ADMA) were detected by enzyme-linked immunosorbent assay.Univariate analysis showed statistical significance between the 2 groups in age, histories of hypertension and smoking, uric acid, creatinine, and levels of serum ADMA (P < 0.05). Binary logistic analysis showed that age (P < 0.0001), hypertension (P = 0.0101), and serum ADMA (P = 0.0206) were related to LA. Pearson correlation analysis showed that levels of serum ADMA correlated with uric acid (r = 0.184, P = 0.025) and creatinine (r = 0.169, P = 0.04).Age, hypertension, and levels of serum ADMA were independent risk factors for LA. Serum ADMA levels may be related to uric acid and creatinine.

Asymmetric dimethylarginine in cerebral small vessel disease

BACKGROUND AND PURPOSE

Endothelial dysfunction may play a causal role in cerebral small vessel disease (SVD). Asymmetric dimethylarginine (ADMA), a circulating endogenous inhibitor of nitric oxide, has been implicated in endothelial dysfunction, particularly in hyperhomocystinemia, a known risk factor for SVD. We determined if ADMA was elevated in SVD, correlated with disease severity, and interacted with homocysteine.

METHODS

ADMA and homocysteine levels were determined in 47 consecutive symptomatic SVD patients and 38 controls. SVD was graded by leukoariosis severity and number of lacunar infarcts.

RESULTS

Mean (and SD) ADMA was higher in SVD patients compared with controls (0.814 [0.145] versus 0.747 [0.184] micromol/L; P=0.014) after controlling for age, gender, vascular risk factors, and creatinine clearance. Additionally controlling for homocysteine had only a small effect on this relationship (P=0.055). Mean homocysteine was higher in SVD cases compared with controls (15.14 [5.59] versus 12.49 [4.15] micromol/L; P=0.035). Leukoariosis grade correlated positively with ADMA (P=0.026) and homocysteine (P=0.003). Lacunar grade correlated with homocysteine (P=0.017), but not ADMA.

CONCLUSIONS

ADMA is independently associated with SVD and correlates with leukoariosis severity.

Plasma total homocysteine levels are associated with advanced leukoaraiosis but not with asymptomatic microbleeds on T2*-weighted MRI in patients with stroke

Both leukoaraiosis and asymptomatic microbleeds are associated with small-artery diseases. Although an association between hyperhomocysteinemia and leukoaraiosis has been reported, no studies have evaluated the association between total homocysteine (tHcy) level and presence of microbleeds in stroke patients. We evaluated the association between tHcy level and leukoaraiosis or microbleeds in stroke patients. In 102 patients with stroke (69.5 +/- 10.3 years old, 54 men and 48 women), microbleeds on T2*-weighted MR images were counted, leukoaraiosis on T2-weighted images was graded and fasting plasma tHcy concentrations were measured. Plasma tHcy level was significantly higher in patients with advanced leukoaraiosis than in those without advanced leukoaraiosis (13.9 +/- 4.6 micromol/l vs. 10.2 +/- 3.4 micromol/l, P < 0.0001). Plasma tHcy level was not significantly different in patients with microbleeds and those without microbleeds (11.3 +/- 4.1 micromol/l vs. 11.4 +/- 4.3 micromol/l, P = 0.9441). Elevated tHcy level is significantly and independently associated with advanced leukoaraiosis [odds ratio (OR), 1.330; 95% CI, 1.130-1.565] but not with the presence of microbleeds. Elevated tHcy level appears to be associated with ischemic small-artery disease rather than with bleeding-prone small-artery disease.