Body mass index and its association with various features of migraine: A cross-sectional study from Saudi Arabia.

Introduction: Migraine is a highly prevalent condition, and prevalence of obesity is also increasing. Results of studies addressing association of body mass index (BMI) with migraine and its features are conflicting. In this cross-sectional study, we aim to assess association between BMI and various migraine features.
Methods: This study was conducted in the Headache Clinic of King Fahd Hospital of University, Al Khobar, Saudi Arabia. Interviews were conducted by three consultant neurologists. Migraine was defined according to the International Headache Society and BMI was calculated as weight (kilograms)/height (m2).
Results: Of total of 121 patients, 79% were female. Almost 87.6% of patients were taking prophylactic medications. Majority of patients had attack for more than 24 h (60.3%), pulsating character (81%), moderate-to-severe intensity (92.6%), associated with nausea and/or vomiting (75.2%), and photophobia/phonophobia (91.7%). About 29.8% of patients were normal weight, 28.1% were overweight, and 39.7% were obese and morbidly obese. There was insignificant association between various categories of BMI and features of migraine, that is, unilateral location (P = 0.385), pulsating character (P = 0.571), moderate-to-severe intensity (P = 0.187), nausea and/or vomiting (P = 0.582), and photophobia and/or phonophobia (P = 0.444).
Conclusion: In our study, we did not find an association between BMI and various features of migraine.

INTRODUCTION

Obesity and migraine are highly prevalent conditions in the general population.[12345] Obesity is a chronic, multifactorial disease with high prevalence in the general population and it is growing with time all over the world.[1234] Saudi Arabia is the 15th most obese country with an overall obesity rate of 33.7% and the prevalence of overweight and obese population is increasing in Saudi Arabia over time.[67] Obesity has been linked to pain disorders like migraine. On the other hand, migraine is a very common and disabling pain disorder with high prevalence in general population ranging from 5% to 35% in females and from 3% to 20% in males.[58]

Studies have focused on the association between obesity and migraine, but the results have been conflicting. Some studies have shown a relationship between obesity and various features of migraine including higher frequency, aura, and increased frequency of photophobia and phonophobia.[91011] Furthermore, obesity might have an association with various cardiovascular comorbidities seen with migraine.[1213141516] Positive association between migraine and obesity would be of great significance as it may lead to an increase in the prevalence of migraine and may be a possible target for preventive therapies of migraine.

In this study, we aim to evaluate the association between obesity as measured by body mass index (BMI) and various features of migraine.

METHODS

Methods and sample design

This cross-sectional study was conducted in the Headache Clinic of King Fahd hospital of University Al Khobar, Eastern region of Saudi Arabia from June 2018 to June 2019. The research protocol was approved by the institutional review board.

Migraine patients aged between 18 and 40 years were identified in the Headache Clinic. Informed consent was obtained from subjects before the interview. A trained neurologist conducted the interview. Migraine was defined according to the criteria by the International Headache Society as “At least five headache attacks, lasting 4–72 h and at least two of unilateral location, pulsating quality, moderate or severe intensity and aggravation by or causing avoidance of routine physical activity.” Questionnaire included questions pertaining to use of any prophylactic medications, duration (classified into <24 h, 24–48 h, and from 48 to 72 h or longer), unilateral location, pulsating character, intensity, avoidance of physical activity during attack, associated nausea and/or vomiting, photophobia and/or phonophobia, status of smoking, exercise, use of any hormonal therapy, and presence of any chronic medical illnesses. BMI was measured according to the formula: BMI = weight (kg)/height (m2). Body weight and height were measured on subjects with light dress and without shoes. According to the World Health Organization classification, BMI was classified into five categories: underweight (<18.5), normal weight (18.5–24.9), overweight (25–29.9), obese (30–34.9), and morbidly obese (>35).[2] Obese and morbidly obese patients were grouped together due to a very small number of morbidly obese patients.

Analysis

Descriptive statistics were used to assess frequencies and distributions. Proportions were compared with either χ2 test or Fisher's test. P < 0.05 was considered statistically significant. All analyses were performed using SPSS version 21.0 (IBM Corp., Armonk, NY, USA).

RESULTS

Patient's demographic characteristics and migraine features are given in Table 1. Of 121 patients, 96 (79.3%) were female. One hundred and six (87.6%) patients were taking prophylactic medications. Only 9.9% of patients were smoking at the time of enrollment, whereas 4.1% of patients were ex-smokers. The rest of the patients were nonsmokers. Only 29.8% of patients were doing exercise. Only 8.3% of patients were taking hormonal therapy. Regarding the history of chronic medical illness, 10.7% of patients had hypertension, 5% of patients had dyslipidemia, and 3.3% patients had hypothyroidism and diabetes each. Duration of headache was <1 day in 39.7% of patients, up to 48 h in 38% of patients, and up to 72 h or more than that in 22.3% of patients. Headache was unilateral in 67.8% of patients, of pulsating character in 81% of patients, and of moderate-to-severe intensity in 92.6% of patients. It was associated with nausea and/or vomiting in 75.2% of patients and photophobia and/or phonophobia in 91.7% of patients. Migraine led to avoidance of physical activity in 73.6%. Regarding categorization, according to the BMI, 2.5% of patients were underweight, 29.8% of patients were of normal weight, 28.1% of patients were overweight, and 39.7% were obese.

Table 1

Patient’s baseline characteristics

	Number of patients (%)
Gender
Females	96/121 (79.3)
Using prophylactic medications
Yes	106/121 (87.6)
Duration
<24 h	48/121 (39.7)
24- 48 h	46/121 (38)
48- 72 h or longer	24/121 (22.3)
Unilateral
Yes	82/121 (67.8)
Pulsating
Yes	98/121 (81)
Moderate/severe intensity
Yes	112/121 (92.6)
Avoidance of physical activity
Yes	89/121 (73.6)
Nausea and/or vomiting
Yes	91/121 (75.2)
Photophobia and/or phonophobia
Yes	111/121 (91.7)
Smoking
Never	104/121 (86)
Current	12/121 (9.9)
Ex-smoker	5/121 (4.1)
Exercise
No	85/121 (70.2)
Hormonal use
No	111/121 (91.7)
Chronic medical illness
None	77/121 (63.6)
Hypertension	13/121 (10.7)
Dyslipidemia	6/121 (5)
Hypothyroidism	4/121 (3.3)
Diabetes	4/121 (3.3)
Others	17/121 (14)
BMI
Underweight	3/121 (2.5)
Normal weight	36/121 (29.8)
Overweight	34/121 (28.1)
Obesity	48/121 (39.7)

BMI=Body mass index

Association of BMI with demographic characteristics and various migraine features is given in Table 2. Females made up 77.8%, 82.4%, and 79.2% of 36 normal weight, 34 overweight, and 48 obese patients, respectively. However, gender was not found to bear a significant association with different categories of BMI (P = 0.911). Prophylactic medications for migraine were being used by 83.3% of normal weight, 88.2% of overweight, and 89.6% of obese patients, but there was no significant association between use of prophylactic medication for migraine and various categories of BMI (P = 0.749). Similarly, duration of acute attack of migraine was not found to be significantly associated with different categories of BMI (P = 0.450). Unilateral location of migraine was found in 75% of normal weight, 64.7% of overweight, and 625.5% of obese patients, but the association between two was not significant (P = 0.385). Close to two-third of patients with a pulsating character of headache were either overweight or obese; however, the association was not found to be significant (P = 0.571). Again, 66% of patients with moderate-to-severe intensity of migraine were either overweight or obese, but the association of BMI with intensity of migraine was not found to be significant (P value = 0.187). About 68% of all patients with migraine who experienced nausea and/or vomiting were overweight or obese, but the association between nausea and/or vomiting and BMI was not significant (P = 0.582). Although 111 patients of 121 patients reported that they experienced photophobia and/or phonophobia during the attack, the association of photophobia and/or phonophobia with BMI was not statistically significant (P = 0.444). Association of BMI with avoidance of daily life activities during migraine attack was also found to be insignificant (P = 0.9). About 86% of patients were nonsmokers and only 9.9% of patients were smokers and insignificant association was found between smoking status and BMI (P = 0.496). Only one-third of patients were doing exercise, the association between BMI and exercise was insignificant (P = 0.706). Only 8.3% of patients reported use of hormones and association of hormonal use and BMI was found to be insignificant (P = 0.819). Nearly two-third of patients were free of any other medical illness, hypertension was the most prevalent condition in rest of the patients; however, BMI did not have a significant association with a history of medical illness (P = 0.113).

Table 2

Body mass index and various patient characteristics and features of migraine

	Underweight (%)	Normal weight (%)	Overweight (%)	Obesity (%)	Total (%)	P
Gender
Female	2 (66.7)	28 (77.8)	28 (82.4)	38 (79.2)	96 (79.3)	0.911
Male	1 (33.3)	8 (22.2)	6 (17.6)	10 (20.8)	25 (20.7)
Use of prophylactic medications
Yes	3 (100)	30 (83.3)	30 (88.2)	43 (89.6)	106 (87.6)	0.749
No	0 (0)	6 (16.7)	4 (11.8)	5 (10.4)	15 (12.4)
Duration
<24 h	1 (33.3)	19 (52.8)	14 (41.2)	14 (29.2)	48 (39.7)	0.450
24- 48 h	1 (33.3)	11 (30.6)	14 (41.2)	20 (41.7)	46 (38.0)
48- 72 h or longer	1 (33.3)	6 (16.7)	6 (17.6)	14 (29.2)	27 (22.3)
Unilateral
Yes	3 (100)	27 (75)	22 (64.7)	30 (62.5)	82 (67.8)	0.385
No	0 (0)	9 (25)	12 (35.3)	18 (37.5)	39 (32.2)
Pulsating
Yes	3 (100)	28 (77.8)	26 (76.5)	41 (85.4)	98 (81)	0.571
No	0 (0)	8 (22.2)	8 (23.5)	7 (14.6)	23 (19)
Moderate/severe
Yes	2 (66.7)	35 (97.2)	32 (94.1)	43 (89.6)	112 (92.6)	0.187
No	1 (33.3)	1 (2.8)	2 (5.9)	5 (10.4)	9 (7.4)
Nausea/vomiting
Yes	3 (100)	26 (72.2)	24 (70.6)	38 (79.2)	91 (75.2)	0.582
No	0 (0)	10 (27.8)	10 (29.4)	10 (20.8)	30 (24.8)
Photophobia/phonophobia
Yes	3 (100)	33 (91.7)	33 (97.1)	42 (87.5)	111 (91.7)	0.444
No	0 (0)	3 (8.3)	1 (2.9)	6 (12.5)	10 (8.3)
Avoidance of daily life activities
Yes	2 (66.7)	25 (69.4)	26 (76.5)	36 (75)	89 (73.6)	0.90
No	1 (33.31)	11 (30.6)	8 (23.5)	12 (12)	32 (26.4)
Smoking
Never	2 (66.7)	34 (94.4)	28 (82.4)	40 (83.3)	104 (86)	0.496
Current	1 (33.3)	2 (5.6)	4 (11.8)	5 (10.45)	12 (9.9)
Past	0 (0)	0 (0)	2 (5.69)	3 (6.3)	5 (4.1)
Exercise
Never	3 (100)	25 (69.4)	23 (67.6)	34 (70.8)	85 (70.2)	0.706
Yes	0 (0)	11 (30.6)	11 (32.4)	14 (29.2)	36 (29.8)
Hormonal use
Never	3 (100)	32 (88.9)	31 (91.2)	45 (93.8)	111 (91.7)	0.819
Yes	0 (0)	4 (11.1)	3 (8.8)	3 (6.3)	10 (8.3)
Medical illness
None	3 (100)	31 (86.1)	19 (55.9)	24 (50)	77 (63.6)	0.113
Hypertension	0 (0)	0 (0)	4 (11.8)	9 (18.8)	13 (10.7)
Dyslipidemia	0 (0)	0 (0)	3 (8.8)	3 (6.3)	6 (5)
Hypothyroidism	0 (0)	0 (0)	3 (8.8)	1 (2.1)	4 (3.3)
Other	0 (0)	4 (11.1)	4 (11.8)	9 (18.8)	17 (14.0)
Diabetes	0 (0)	1 (2.8)	1 (2.9)	2 (4.2)	4 (3.3)

DISCUSSION

In this clinic-based cross-sectional study, we did not find any significant association between BMI and various features of migraine including duration, laterality, intensity, nausea/vomiting, and photophobia/phonophobia.

There is considerable uncertainty about nature of the obesity/headache relationship and whether it is specific to migraine or chronic daily headache or headache in general.[17] Association of BMI with migraine has been studied previously, but the results are conflicting. Some studies did not find an association between BMI and migraine, whereas other studies have suggested an association between obesity and higher migraine frequency as well other migraine features such as severity and photophobia and/or phonophobia.

Similar to our study, Mattsson did not find a significant association between obesity and migraine in 684 females aged 40–74 years.[18] Similarly in a cross-sectional analysis of 11 datasets by Keith et al., migraine prevalence was not related to obesity, obese women had increased risk of headache (but not specifically migraine) as compared to those with normal BMI.[19] Téllez-Zenteno et al. did not find association between BMI and severity and disability caused by migraine.[20] Also, Winter et al. in their large prospective study about middle-aged women, they did not indicate a consistent association between migraine incidence and overweight, obesity or relevant weight gain.[21] In another recent study, any proportion of BMI was not associated with migraine, severity of pain in migraine, and duration of migraine.[22] Bigal et al. reported that although preventive therapy for migraine was effective, efficacy of preventive therapy for migraine did not differ with respect to different categories of BMI.[23]

Some studies have suggested that obesity is a comorbid with chronic pain syndromes including fibromyalgia and back and neck pain. Therefore, there was interest in the association between obesity and migraine. Several mechanisms supported that there may exist a possible link between BMI and headaches.[24] Concentrations of calcitonin gene-related peptide levels, which are elevated in obese individuals, are a very important mediators of migraine/chronic migraine.[24252627] Furthermore, migraines, like obesity, have been reported as a risk factor for cardiovascular disorders as well as stroke.[152829] Finally, preventive medications for migraine may also be a contributing reason for changes of BMI.[930] Some studies have suggested that obesity in patients with migraine is associated with aura, high-frequency migraines, greater severity, and with an increased frequency of photophobia and phonophobia and also with transformation of episodic migraine to chronic migraine.[103132333435] J-shaped association has been suggested between BMI and higher frequency of migraine.[32] It is also suggested that individuals with episodic headache and obesity are five times more likely to develop a chronic daily headache.[1115163637]

Main strengths of our study are (1) to our knowledge, this is the first study from Middle East region addressing association of BMI and migraine features. (2) Our study is mainly focused on the association of BMI with various features of migraine. (3) Most of our patients had moderate-to-severe intensity of migraine, hence most suitable population to assess the association of migraine and BMI.

Limitations of our study are small sample size and we did not assess the association of BMI with disability caused by migraine.

CONCLUSION

Although a large number of migraine patients might be overweight and obese, BMI does not bear association with migraine or its various features.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.