Cardiovascular events such as myocardial infarction and stroke are life-threatening complications associated with Neurofibromatosis type 1 (NF1). As previous studies observed an association between cardiovascular events and the loss of circadian variations of blood pressure, we investigated the 24 h circadian rhythm of blood pressure (BP) in 24 NF1 patients (10 males and 14 females, with a mean age of 39.5 years ± 14 years) by using ambulatory blood pressure monitoring (ABPM).
Only one-third of the patient were dippers, 50% were non-dippers, and 17% were risers. Reduced variability of systolic and diastolic nocturnal blood pressure was observed in NF1 patients compared with several studies of normotensive individuals (p = 0.024). In NF1 patients, the blunted systolic nocturnal decline was significantly associated with the number of neurofibromas (p = 0.049) and the presence of a plexiform neurofibroma (p = 0.020).
Most NF1 patients in this study showed a "non-dipper" pattern with a blunted nocturnal BP decline, which is considered an independent risk factor for cardiovascular events in normotensive and hypertensive individuals. Periodic monitoring of BP should be included in NF1 follow-up guidelines to diagnose masked hypertension or a non-dipper/riser pattern which would significantly increase the morbidity and mortality of NF1 patients to implement therapeutic strategies.