PURPOSE: Reduced heart rate variability significantly increases cardiovascular mortality. Metabolic syndrome increases the cardiac autonomic dysfunction. Recently, increasing cardiovascular mortality has been reported in patients with schizophrenia. This study was done to compare heart rate variability between adults with and without schizophrenia and to compare the relationship of heart rate variability to metabolic syndrome in hospitalized patients with schizophrenia. METHODS: This was a descriptive and correlational study in which 719 adults without schizophrenia and 308 adults with schizophrenia took part between May and June 2008. We measured the following: five-minute heart rate variability; high-frequency, low-frequency, the ratio of low-frequency to high-frequency, and the Standard Deviation of all the normal RR intervals. Data was also collected on metabolic syndrome, abdominal obesity, triglycerides, HDL cholesterol, blood pressure and fasting glucose. RESULTS: The Standard Deviation of all the normal RR intervals values of heart rate variability indices were 1.53+/-0.18. The low-frequency and high-frequency values of heart rate variability indices were significantly higher in hospitalized patients with schizophrenia (3.89+/-1.36; 3.80+/-1.20) than those in the healthy participants (2.20+/-0.46; 2.10+/-0.46). There were no significant differences between the schizophrenic patients with and without metabolic syndrome. CONCLUSION: The results of this study indicate that schizophrenia patients have significantly lower cardiac autonomic control, but they have significantly higher low-frequency and high-frequency values than those of healthy adults. Use of antipsychotic drug may affect the autonomic nervous system in schizophrenic patients. Metabolic syndrome was not associated with cardiac autonomic control in schizophrenia patients.
Adult ; Autonomic Nervous System/physiopathology ; Blood Glucose/analysis ; Blood Pressure ; Cardiovascular Diseases/complications/diagnosis/mortality ; Cholesterol, HDL/blood ; Female ; *Heart Rate ; Hospitalization ; Humans ; Male ; Metabolic Syndrome X/*complications/*physiopathology ; Middle Aged ; Obesity/etiology ; Schizophrenia/*complications/mortality/*physiopathology ; Triglycerides/blood

BACKGROUND/AIMS: Osteoprotegerin (OPG) and fetuin-A are vascular calcification regulators that may be related to high cardiovascular (CV) mortality in hemodialysis (HD) patients. We evaluated the relationship between OPG, fetuin-A, and pulse wave velocity (PWV), a marker of vascular stiffness, and determined whether OPG and fetuin-A were independent predictors of CV events in HD patients. METHODS: We conducted a prospective observational study in 97 HD patients. OPG and fetuin-A were measured at baseline and arterial stiffness was evaluated by PWV. All patients were stratified into tertiles according to serum OPG levels. RESULTS: A significant trend was observed across increasing serum OPG concentration tertiles for age, HD duration, systolic blood pressure, cholesterol, triglycerides, and PWV. Multiple linear regression analysis revealed that diabetes (beta = 0.430, p = 0.000) and OPG levels (beta = 0.308, p = 0.003) were independently associated with PWV. The frequency of new CV events was significantly higher in the upper OPG tertiles compared with those in the lower OPG tertiles. In Cox proportional hazards analysis, upper tertiles of OPG levels were significantly associated with CV events (hazard ratio = 4.536, p = 0.011). CONCLUSIONS: Serum OPG, but not fetuin-A, levels were closely associated with increased vascular stiffness, and higher OPG levels may be independent predictors of new CV events in HD patients.
Adult ; Aged ; Biological Markers/blood ; Cardiovascular Diseases/blood/diagnosis/*etiology/mortality/physiopathology ; Female ; Humans ; Kaplan-Meier Estimate ; Linear Models ; Male ; Middle Aged ; Multivariate Analysis ; Osteoprotegerin/*blood ; Predictive Value of Tests ; Prognosis ; Proportional Hazards Models ; Prospective Studies ; Pulse Wave Analysis ; *Renal Dialysis/adverse effects/mortality ; Renal Insufficiency, Chronic/complications/diagnosis/mortality/*therapy ; Risk Factors ; Up-Regulation ; *Vascular Stiffness ; alpha-2-HS-Glycoprotein/analysis