Increased plasma levels of total homocysteine but not asymmetric dimethylarginine in Hispanic subjects with ischemic stroke FREC-VI sub-study.

BACKGROUND AND PURPOSE: Despite sharing some metabolic and pathological mechanisms, the reported association between total homocysteine (tHcy), asymmetric dimethylarginine (ADMA) and stroke remains controversial, particularly in Hispanic populations from developing countries in which genetic, socioeconomic, and nutritional factors are different to those described in developed countries. Our objectives were to determine the relationships of these factors to stroke and to each other independent of other cardiovascular risk factors, and to explore potential sex differences. METHODS: This national (Colombia) multicenter case-control study included 238 cases and 238 controls to evaluate traditional and emerging risk factors for ischemic stroke including tHcy and ADMA plasma levels. RESULTS: The median plasma levels of tHcy were 8.48 µM for controls and 10.01 µM for cases (P<0.0001). Plasma levels of tHcy between 12 and 50µM were considered moderate hyperhomocysteinemia (HtHcy). There were no differences in plasma ADMA concentration between groups (P=0.40). Plasma levels of ADMA and creatinine were not correlated (P=0.47). After adjusting for confounding factors, the presence of HtHcy was strongly associated with stroke (OR 8.97; P<0.0001). The adjusted association between HtHcy and stroke in men (OR 9.98) was comparable to that in women (OR 8.98) (P=0.41). CONCLUSIONS: In this Hispanic population, with relatively normal renal function, plasma levels of tHcy but not ADMA were associated with stroke independent of other cardiovascular risk factors.

Sex differences in cardiac autonomic function of depressed young adults.

BACKGROUND: Cardiac autonomic dysfunction has been proposed as an important contributing factor to the increased cardiovascular risk observed in major depression (MDD). However, the evidence regarding alterations in heart rate variability (HRV) in otherwise healthy depressed subjects has been inconclusive. METHODS: A case-control study in 50 treatment-naïve young adults with a first MDD episode without comorbid psychiatric disorders and 50 healthy control subjects was conducted. Time- and frequency-domain indexes of HRV were determined at baseline supine and after 5-min of orthostatic stress at 60°. RESULTS: There were no significant differences in the time- or frequency-domain variables of HRV between depressed patients and controls. However, a random-effect ANOVA model showed that during orthostatic stress depressed men had a reduced HRV and decreased parasympathetic activity compared to control subjects, while no differences were found between depressed women and controls. CONCLUSION: These results suggest a sex-dependent relationship between major depression and cardiac autonomic dysfunction and provide one potential explanation for sex differences in the association of depressive symptoms with cardiovascular morbidity.