Peginterferon alfa-2a and ribavirin for chronic hepatitis C genotype 1 infections in black patients: safety, tolerability and impact on sustained virologic response.

HCV infections are two-times more prevalent in black Americans than in whites. We previously reported that treatment with peginterferon alfa-2a plus ribavirin produced a sustained virologic response (SVR) rate of 26% in blacks, a lower efficacy compared with the SVR in whites. Here we detail the safety profile of peginterferon alfa-2a plus ribavirin and the relationship between treatment adherence, defined by cumulative drug exposure, and SVR in 78 black patients infected with HCV genotype 1. Sixty-two (79%) patients completed 48 weeks of combination treatment. Peginterferon alfa-2a dose was modified for neutropenia in 36 patients (46%), whereas ribavirin dose was modified due to anemia in 31 patients (40%). The SVR rate was related to medication exposure, based on the percentage of the planned doses of peginterferon and ribavirin that the patients received. The SVR rates were 33, 25 and 0% in patients who received >80, 61-80 and 80, 61-80 and 80% of the total planned doses of both peginterferon and ribavirin and 7% (1 of 14) in patients who received 60% exposure to both, and 0% in patients with 60% of the planned peginterferon alfa-2a and ribavirin doses for 48 weeks was associated with a greater SVR in black patients with HCV genotype 1 infections.

Vagal and cardiac reactivity to psychological stressors in trained and untrained men.

PURPOSE: The aim of this study was to determine whether higher aerobic fitness is associated with enhanced vagal influences on the myocardium, resulting in moderation of chronotropic cardiac activity during psychological stress and recovery. METHOD: Heart period (HP) and respiratory sinus arrhythmia (RSA) were obtained from 10 aerobically trained (AT) and 10 untrained (UT) college-aged men at rest and during three contiguous psychological challenges and 3 min of recovery. Ratings of perceived stress were obtained at the end of the rest period, at the midpoint of each stressor, and at 30 s into recovery. Time series methods were used to quantify RSA from the beat-to-beat HP series. Responsivity was assessed both in terms of absolute levels of activity and phasic changes in activity (task or recovery minus baseline). RESULTS: Both groups reported similar levels of subjective stress throughout the experiment. The AT exhibited longer HP at rest and during psychological stress and recovery than did the UT. However, the groups did not differ on RSA at rest or during psychological stress and recovery, nor did they differ on phasic changes in RSA or HP during stress or recovery. Additionally, aerobic capacity was not correlated with absolute levels or phasic changes in RSA during psychological challenge for either group and, except in Min 2 for the UT, similar results were obtained for recovery. CONCLUSIONS: The results supported the hypothesis that, among young men, higher aerobic fitness is associated with longer HP at rest and during psychological stress and recovery. However, the lower cardiac chronotropic activation observed among the AT relative to the UT was not paralleled by a group difference in the amplitude of RSA. These results suggest that the group difference in HP was not mediated directly by the vagal mechanisms manifested in the amplitude of RSA.