Disturbances of noradrenergic systems in normal weight bulimia: relationship to diet and menses

Several lines of evidence suggest that noradrenergic (NE) disturbances occur in normal-weight bulimic patients. The purpose of this study was to investigate factors that may be related to noradrenergic disturbances. First, we measured plasma NE during bingeing and vomiting. We found that this behavior activated the sympathetic nervous system. Bingeing produced a significant increase in the duration and the peak increase of plasma NE when compared with normal controls eating a large meal. Second, we assessed basal peripheral and central NE levels near in time (within several days of hospital admission) to chronic bingeing and vomiting. At this time, bulimics had normal basal plasma and CSF NE levels. Finally, we restudied the same patients after 30 days of inpatient hospitalization and observed abstinence from bingeing and vomiting. In this last state, bulimics had a reduction of basal plasma and cerebrospinal fluid (CSF) NE levels compared with themselves on admission and compared with healthy controls. This study confirms that reduced noradrenergic activity occurs in normal-weight bulimic women and suggests that this abnormality may emerge during abstinence from bingeing. We hypothesize that dietary intake is related to noradrenergic activity, but cause and effect remain uncertain. Noradrenergic disturbances did not appear to be related to weight, depression, physical activity, or amino acid precursors. Lower CSF NE levels were found in amenorrheic bulimic women in both states, suggesting that a noradrenergic disturbance may be associated with the frequent incidence of amenorrhea in bulimic women.