Absent circadian variation of blood pressure in patients with anorexia nervosa

Objective: To examine whether circadian rhythm of blood pressure (BP) is altered in patients with anorexia nervosa (AN), and if so, to determine whether it is reversible after refeeding. Study design: Ambulatory BP monitoring was performed on 17 female inpatients with AN (mean age, 13.3 ± 1.9 years) at the time of admission and serially during refeeding; 17 age- matched normal weight, normotensive female inpatients served as control subjects. Results: Patients with AN had lost an average of 23.4% ± 11.5% of body weight before the illness. Weight after refeeding was 105.6% ± 9.2% of that before illness. Mean 24-hour systolic BP (SBP) (96.5 ± 8.6 mm Hg) and diastolic BP (DBP) (53.4 ± 5.8 mm Hg) were significantly lower in patients with AN compared with those of control subjects (SBP, 106.1 ± 6.5 mm Hg; DBP, 60.2 ± 5.8 mm Hg). Although awake SBP and DBP were also lower in patients with AN, asleep SBP and DBP were not statistically different from those of control subjects. Night/day BP ratio in the control group was 0.93 ± 0.06 in systolic and 0.92 ± 0.09 in diastolic. Those values were significantly elevated in patients with AN (systolic 1.00 ± 0.09 and diastolic 1.00 ± 0.09). After refeeding, the ratio decreased to 0.88 ± 0.09 and 0.90 ± 0.08, respectively (both P < .05 vs baseline). Conclusions: In patients with AN, circadian variation of BP is absent. This reverts to normal after refeeding.