Autonomic dysfunction in primary biliary cirrhosis correlates with fatigue severity.

BACKGROUND AND AIMS

Autonomic dysfunction has previously been described in primary biliary cirrhosis patients. In nonhepatic diseases, fatigue is associated with autonomic dysfunction and impaired baroreflex sensitivity. Here, we investigate the prevalence of autonomic dysfunction using highly sensitive detection modalities and its relationship with fatigue in both noncirrhotic and cirrhotic primary biliary cirrhosis patients.

METHODS

Autonomic reflex tests were performed, using continuous blood pressure and electrocardiograph measurement in 47 primary biliary cirrhosis patients and age and sex-matched controls. Fatigue was measured using the primary biliary cirrhosis-40.

RESULTS

In all, 100% of precirrhotic and 81% of cirrhotic primary biliary cirrhosis patients exhibited autonomic dysfunction. Valsalva ratio and 30 : 15 ratio (measures of parasympathetic autonomic dysfunction) were significantly lower in primary biliary cirrhosis patients than in controls (valsalva ratio: 1.42 vs. 1.57; P=0.01, 30 : 15: 1.1 vs. 1.2; P=0.01). Blood pressure drop on standing (sympathetic autonomic dysfunction) was greater in the primary biliary cirrhosis group (31+/-22 vs. 23+/-15 mmHg; P=0.03). Valsalva phase IV size was similar between primary biliary cirrhosis patients and controls, however, time to phase IV was significantly longer (P=0.01), suggesting adrenergic failure. Increasing fatigue was associated with impaired baroreflex sensitivity and an earlier, bigger phase IV (sympathetic overactivity). No significant differences were seen, between cirrhotic and noncirrhotic patients.

CONCLUSION

The prevalence of autonomic dysfunction in primary biliary cirrhosis patients is significantly higher than has previously been thought to be the case. Indeed, when sensitive detection modalities are used, it is found to be almost universal at all stages of the disease process. Fatigue in primary biliary cirrhosis is associated with abnormalities of autonomic function.