Ambulatory Blood Pressure Profiles in Children With Primary Headache Disorders Despite Normal Office Blood Pressure

ABSTRACT

Objectives

Headache is a common complaint in children and may indicate early hypertension (HT), an emerging concern in pediatrics. Children with primary headache (PH) may exhibit elevated blood pressure (BP) load or impaired nocturnal dipping despite normal office BP. This study aimed to evaluate the utility of ambulatory blood pressure monitoring (ABPM) in children with PH.

Methods

A case–control study was conducted including 37 children aged 8–17 years diagnosed with PH according to the International Classification of Headache Disorders (ICHD‐3) criteria, all with office BP below the 95th percentile. Thirty‐seven age‐ and sex‐matched healthy subjects served as controls. Demographic, office BP, and ABPM parameters were compared between groups.

Results

Of the PH group, 81% (n = 30) had migraines and 19% (n = 7) had tension‐type headache. No significant differences were found between groups regarding age, BMI SDS, or office systolic BP SDS. However, ABPM revealed significantly higher total, daytime, and nocturnal systolic BP, and increased nocturnal systolic and diastolic BP loads in the PH group (all p < 0.05). No differences were noted between headache subtypes.

Conclusion

Children with PH may exhibit increased BP loads and disrupted BP patterns despite normal office measurements. ABPM appears to be a useful tool for accurately detecting subtle BP alterations in this population.

1. Introduction

The most common types of primary headache (PH) in late childhood and adolescence are tension‐type headache (TTH) and migraine [1]. PH is a prevalent public health issue that significantly affects daily functioning and quality of life. Its prevalence is rising in the pediatric population as well [2]. In Turkey, the prevalence of migraine among children aged 8–17 years has been reported as 29.2%, while that of TTH is 12.9% [3].

Childhood hypertension (HT) is also an increasingly recognized health concern and has been identified as a risk factor for developing HT in adulthood [4, 5]. Several studies suggest shared pathophysiological mechanisms between PH and HT, including the involvement of central regulatory areas such as the hypothalamus and insula, overactivation of the sympathetic nervous system, and dysregulation of the renin–angiotensin system [6, 7, 8, 9, 10]. Although headache is a well‐known symptom of HT, it can also occur in individuals classified as having PH according to the International Classification of Headache Disorders, 3rd edition (ICHD‐3) [11, 12].

Ambulatory blood pressure monitoring (ABPM) is a non‐invasive, reliable method for diagnosing HT and identifying at‐risk individuals. It has been proposed that children with PH may exhibit increased BP load and inadequate nocturnal BP dipping, even in the presence of normal office BP readings, potentially contributing to PH pathogenesis. However, pediatric studies exploring this relationship are limited [13]. The aim of this study was to evaluate ABPM findings in children diagnosed with PH to better understand the potential association between PH and BP abnormalities.

2. Material and Methods

This prospective case–control study included 37 children aged 8–17 years who were diagnosed with PH according to the criteria outlined in the ICHD‐3 [14]. All patients were evaluated in pediatric neurology outpatient clinics and had office BP readings below the 95th percentile. A control group of 37 age‐ and sex‐matched healthy children was also included. At the time of ambulatory monitoring, none of the participants were experiencing a headache episode.

Demographic and anthropometric data—including age, sex, height, and weight—were recorded. Standard deviation scores (SDS) for height, weight, and body mass index (BMI) were calculated. Comparisons were made between the patient and control groups regarding age, sex, height, weight, and BMI SDS. Office BP values were assessed based on the 2017 American Academy of Pediatrics guidelines [15].

To determine BP percentiles and anthropometric parameters, the childmetrics online software (www.ceddcozum.com), which provides reference values for Turkish children, was used [16]. ABPM was conducted using Mobil‐O‐Graph devices, calibrated individually for each participant according to the manufacturer's guidelines, with data processed using HMS Client software. Participants were instructed to use the day/night button to indicate their sleep–wake times. BP measurements were taken automatically every 20 min during the day and every 40 min at night. After 24 h, the device was removed and the data were uploaded for analysis.

The following parameters were recorded: total systolic blood pressure (SBP), daytime SBP, nocturnal SBP, total diastolic blood pressure (DBP), daytime DBP, nocturnal DBP, total mean arterial pressure (MAP), daytime MAP, nocturnal MAP, daytime and nocturnal SBP and DBP loads, and systolic/diastolic dipping percentages. BP load was defined as the percentage of measurements exceeding the age‐ and height‐adjusted thresholds, with values > 25% considered abnormal. BP dipping was calculated as the percentage reduction in BP from daytime to nocturnal, with ≥ 10% considered normal.

Demographic characteristics, office BP, and ABPM parameters were compared between the PH and control groups. The control group included healthy children without acute infection, chronic disease, or long‐term medication use who voluntarily participated in the study.

Exclusion criteria were presence of any secondary cause of headache (e.g., papilledema, epilepsy, intracranial mass, hydrocephalus, vasculitis), use of medications associated with headache (e.g., corticosteroids), presence of chronic illnesses that may contribute to HT (e.g., obesity, type 1 diabetes mellitus, chronic kidney disease), office BP > 95th percentile or > 130/80 mmHg. Informed consent was obtained from all participants and their legal guardians.

Data were analyzed using IBM SPSS Statistics for Windows, Version 24.0 (IBM Corp., Armonk, NY). The normality of data distribution was assessed using the Shapiro–Wilk test. Continuous variables were expressed as mean ± standard deviation (SD), and categorical variables as frequencies and percentages. Comparisons of continuous variables between the PH and control groups were performed using the Independent Samples t‐test for normally distributed data, and the Mann–Whitney U test for non‐normally distributed data. Categorical variables, including dipping status and sex, were compared using the Chi‐square test or Fisher's exact test, as appropriate. A two‐sided p‐value of < 0.05 was considered statistically significant. Based on prior studies evaluating nocturnal systolic BP load differences, a minimum sample size of 35 participants per group was required to achieve 80% power at a 5% significance level. The ethical committee of University of Health Sciences Tepecik Training and Research Hospital approved the study (2019/11‐15).

3. Results

The study included 37 children diagnosed with PH and 37 healthy controls. Among the PH group, 81% (n = 30) were diagnosed with migraine, and 19% (n = 7) with TTH. A positive family history of HT was noted in 43.2% (n = 16), and a history of headache in 81.1% (n = 30) of the PH group. Detailed family history data regarding headache and HT were not systematically collected for the healthy control group.

There were no significant differences between the PH and control groups in terms of age, BMI SDS, or mean office SBP SDS (p = 0.86, p = 0.35, and p = 0.14, respectively) (Table 1). Similarly, no significant differences were found in office BP values between patients with migraine and those with TTH.

TABLE 1.

Demographic data and office blood pressure measurement of the patient and control group.

	Patient group (N = 37)	Control group (N = 37)	p
Age (year)	14.7 ± 2.1	14.6 ± 2.1	0.86
Body weight SDS	−0.63 ± 1.44	−0.25 ± 1.25	0.53
Height SDS	−0.12 ± 1.01	0.02 ± 0.97	0.52
BMI SDS	−0.02 ± 1.40	−0.30 ± 1.23	0.35
OfficeSBP (mmHg)	111 ± 8.9	113.6 ± 9.9	0.22
OfficeSBP SDS	0.2 ± 0.9	0.5 ± 0.9	0.14
OfficeDBP (mmHg)	68.9 ± 6.4	70.7 ± 7.7	0.28
OfficeDBP SDS	0.5 ± 0.6	0.7 ± 0.7	0.25

Abbreviations: BMI, Body Mass Index; BP, blood pressure; DBP, diastolic blood pressure; MAP, mean arterial pressure; SBP, systolic blood pressure; SDS, standard deviation score.

ABPM revealed that total SBP, daytime SBP, and nocturnal SBP values were significantly higher in the PH group compared to controls (all p < 0.05) (Table 2). Nocturnal SBP and DBP loads were also significantly elevated in the PH group (all p < 0.05) (Table 3). There were no significant differences in ABPM parameters between patients with migraine and those with TTH. Mean systolic and diastolic dipping percentages were not significantly different between the groups (p = 0.98 and p = 0.73, respectively). In terms of dipping status, systolic dipping was observed in 9 patients (24.3%) in the PH group and 9 (24.3%) in the control group. Diastolic dipping was present in 27 patients (73.0%) in the PH group and 26 (70.3%) in the control group (p = 1.00), as shown in Table 3.

TABLE 2.

Ambulatory blood pressure monitoring data of the patient and control groups.

	Patient group (N = 37)		Control group (N = 37)		p
	Mean	SD	Mean	SD
Total SBP	107.05	7.19	102.08	7.83	< 0.05
Total SBP SDS	0.87	0.83	−1.10	0.86	0.24
Total DBP	64.32	4.41	62.70	4.86	0.23
Total DBP SDS	0.53	0.80	−0.84	0.83	0.10
Daytime SBP	108.72	7.15	103.35	8.82	< 0.05
Daytime SBP SDS	−1.15	0.74	−1.35	0.93	0.08
Daytime DBP	66.72	4.50	65.24	5.26	0.19
Daytime DBP SDS	−0.91	0.73	−1.24	0.81	0.06
Nocturnal SBP	101.45	7.76	96.81	6.44	< 0.05
Nocturnal SBP SDS	−0.03	0.89	−0.34	0.70	0.09
Nocturnal DBP	57.67	5.40	55.75	4.25	0.09
Nocturnal DBP SDS	0.38	0.88	0.05	0.72	0.08
Total MAP	83.83	5.24	81.75	5.15	0.08
Total MAP SDS	0.41	0.77	0.07	0.85	0.07
Daytime MAP	85.81	5.16	84.13	5.46	0.18
Daytime MAP SDS	−0.03	0.67	−0.26	0.80	0.19
Nocturnal MAP	77.83	6.07	75.72	4.65	0.09
Nocturnal MAP SDS	1.13	0.99	0.74	0.70	0.056

Note: Bold values indicate statistical significance (p < 0.05).

Abbreviations: BP, blood pressure; DBP, diastolic blood pressure; MAP, mean arterial pressure; SBP, systolic blood pressure; SDS, standard deviation score.

TABLE 3.

Blood pressure loads and dip rates of patient and control group.

	Patient group (N = 37)		Control group (N = 37)		p
	Mean	SD	Mean	SD
Daytime SBP load	6.16	7.15	5.27	5.51	0.55
Nocturnal SBP load	13.29	17.86	5.81	7.84	< 0.05
Daytime DBP load	7.24	7.10	7.05	7.01	0.90
Nocturnal DBP load	19.45	19.45	6.21	7.55	< 0.05
Systolic dipping	6.83	4.42	6.81	4.63	0.98
Diastolic dipping	13.48	6.73	14.04	7.57	0.73

Note: Bold values indicate statistical significance (p < 0.05).

Abbreviations: BP, blood pressure; DBP, diastolic blood pressure; MAP, mean arterial pressure; SBP, systolic blood pressure; SDS, standard deviation score.

4. Discussion

Headache is one of the principal symptoms of HT. Nevertheless, elevated BP may also occur in individuals diagnosed with PH, as defined by the ICHD‐3 criteria [13]. Most studies exploring the relationship between PH and HT focus on adults, particularly those with migraine. In a study involving 104 adults (28 hypertensive, 76 normotensive), Babayan et al. reported impaired vasomotor reactivity and other markers of circulatory dysregulation in migraine patients compared to controls [7]. In the present study, although all participants had normal office BP measurements, total, daytime, and nocturnal SBP, as well as nocturnal SBP and DBP loads, were significantly elevated in the PH group. These findings may reflect early vascular dysregulation, potentially preceding the development of sustained HT. Gardener et al. conducted a population‐based survey in Northern Manhattan and found that systolic HT was significantly more prevalent in individuals with migraine than in controls [8]. The association was particularly strong in patients with uncontrolled HT lasting longer than 9 years. Although our study focused on children, the elevated nocturnal BP loads observed in the PH group may represent early signs of future HT. A large adult cohort study from the Federico University Headache Clinic, which included 399 males and 944 females aged 15–64 years, also found significantly higher BP in individuals with PH compared to a control group of 3784 participants [10]. This difference was consistent across all age groups and both sexes. Although this study did not find differences in HT prevalence among different headache types, it revealed that PH may be a risk factor for elevated BP in adolescents and young adults—a finding that aligns with our results.

Most prior studies assessing the PH–HT relationship relied on office BP measurements. With the advent of ABPM, which enables 24‐h BP tracking and assessment of circadian variation, a more nuanced understanding of BP regulation in headache disorders has emerged. While PH has been associated with elevated office BP in adults, ABPM has been shown to be useful for detecting early alterations in BP profiles in children, even when office BP is normal [17]. Therefore, we specifically included children with normotensive office BP in our study to focus specifically on ABPM‐related findings. In our study, total SBP, daytime SBP, nocturnal SBP, and nocturnal SBP and DBP loads were significantly higher in the PH group than in controls. These results are partially consistent with a study conducted in Turkey that evaluated ABPM in children with migraine, which found significantly higher nocturnal DBP, nocturnal MAP, and nocturnal BP loads in the case group [11]. While diastolic abnormalities were more pronounced in that study, systolic parameters were more prominently affected in our cohort.

Lovati et al. reported that nocturnal BP dipping was more frequent among individuals with headaches than among those without (46.6% vs. 32.8%) [18]. In contrast, Muiesan et al. found no significant difference in ABPM parameters between individuals with and without headaches, regardless of hypertensive status [19]. In our study, systolic and diastolic BP dipping percentages did not differ significantly between the groups. However, total and nocturnal SBP values and BP load percentages were consistently higher in the PH group. A Japanese study comparing circadian BP rhythms in 13 migraine patients and 11 healthy controls demonstrated disrupted circadian BP variation in migraine patients, potentially due to serotonergic system involvement—suggesting a pathophysiological link between migraine and BP regulation [20]. In our study, conducted during the COVID‐19 pandemic when school closures altered sleep–wake schedules, we also observed delayed sleep onset and waking times, which may have contributed to the relatively low dipper rates in both groups.

In addition to these findings, another aspect supporting a potential pathophysiological link between PH and BP regulation is the pharmacological overlap in their clinical management. Prophylactic agents commonly used in pediatric PH, such as beta‐blockers (e.g., propranolol) and calcium channel blockers (e.g., flunarizine), also have established antihypertensive effects. Their efficacy in reducing headache frequency and severity may reflect shared underlying mechanisms, including vascular tone dysregulation and increased sympathetic activity. From a clinical perspective, the identification of subclinical BP alterations via ABPM may assist in more individualized treatment decisions, potentially addressing both vascular dysregulation and headache burden simultaneously.

Lifestyle, environmental, and genetic factors may also contribute to the migraine–HT relationship [21]. Psychosocial stress, including academic pressure, has been associated with both impaired ABPM parameters and migraine in pediatric populations [22]. In this context, it is important to consider whether these two conditions share a direct pathophysiological link—such as sympathetic nervous system overactivation or endothelial dysfunction—or whether they co‐occur as parallel responses to common external stressors. In our study population of children and adolescents, the stress related to developmental factors and pandemic‐related disruptions may have influenced both BP regulation and headache presentation. Notably, as the study was conducted during the COVID‐19 pandemic, school closures and altered sleep–wake patterns, along with increased anxiety, may have acted as external exacerbating factors for both BP dysregulation and headache symptoms. Therefore, although our findings demonstrate an association between PH and altered ABPM parameters, further studies that adequately control for psychological variables are needed to clarify whether this relationship reflects a direct causal link or parallel responses to shared environmental stressors.

Despite all patients fulfilling the strict ICHD‐3 criteria for PH and having normal office BP, our ABPM findings raise an important diagnostic consideration. It remains challenging to ascertain whether these headaches are purely primary or represent early symptomatic manifestations of subclinical BP dysregulation detected only through ambulatory monitoring. Given that headache is a recognized symptom of HT, the elevated nocturnal systolic and DBP loads observed in the PH group may indicate that some cases classified as PH could, in fact, represent early clinical expressions of underlying vascular dysregulation. These findings underscore the added value of ABPM in detecting subtle hemodynamic alterations that are not captured by office measurements.

Several limitations should be acknowledged. First, reduced hospital admissions during the pandemic and alterations in sleep–wake patterns may have influenced ABPM parameters in both groups. Additionally, pandemic‐related psychological stress may have acted as a confounding factor affecting both BP regulation and headache characteristics, thereby limiting the generalizability of our findings. Furthermore, detailed family history data regarding headache and HT were only systematically collected for the patient group and not for the healthy controls, limiting our ability to comparatively evaluate genetic predisposition between groups.

The coexistence of HT and PH may be underestimated in clinical practice, potentially leading to underrecognition of early BP dysregulation. However, the growing body of evidence highlighting their potential association underscores the importance of early identification. In our study, children and adolescents with PH exhibited elevated BP loads and impaired BP regulation despite having normal office BP measurements. Specifically, ABPM revealed significantly higher total, daytime, and nocturnal SBP, as well as increased nocturnal systolic and DBP loads in the PH group compared to controls. These findings suggest that subclinical BP abnormalities may contribute to the pathophysiology of PH and could represent early markers of future HT. Therefore, ABPM may serve as a valuable clinical tool in the evaluation and follow‐up of pediatric patients with PH, particularly for identifying those at increased risk of developing sustained HT. Further large‐scale, prospective longitudinal studies are needed to further clarify the clinical significance of these findings and to guide evidence‐based strategies for early detection and management.

Author Contributions

Study concept and design: S.A.‐Ç., P.G., and B.K.D.; data collection: A.B., G.E., Ö.Ö.Ş., G.B., F.M., and D.A.; analysis and interpretation of the results: A.B., S.A.‐Ç., and C.B.; draft manuscript preparation: A.B., S.A.‐Ç., P.G., N.O.D., and B.K.D. All authors reviewed the results and approved the final version of the manuscript.

Ethics Statement

The ethical committee of University of Health Sciences Tepecik Training and Research Hospital approved the study (2019/11‐15).

Conflicts of Interest

The authors declare no conflicts of interest.

Bolca A., Arslansoyu Çamlar S., Başaran C., et al., “Ambulatory Blood Pressure Profiles in Children With Primary Headache Disorders Despite Normal Office Blood Pressure,” Pediatrics International 68, no. 1 (2026): e70495, 10.1111/ped.70495.

Data Availability Statement

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.