Introduction
Primary headache disorders, including migraine and tension-type headache (TTH), affect millions of people worldwide [
1]. The burden of headache has consequences for the individual and the society due to a reduced quality of life, absenteeism and lower performance at work, and increased disease-related costs [
2]. Although acute and prophylactic treatments are available, many frequent headache sufferers either do not seek treatment or do not respond satisfactory to these treatment strategies [
3]. Behaviour-dependent so-called lifestyle factors have been of interest for the onset of migraine and frequent headaches for a long time. Certain trigger factors for migraine and for TTH have been identified in the past [
4,
5]. These trigger factors include alcohol consumption and physical activity [
6,
7]. If lifestyle factors trigger specific headache attacks, then they might contribute to the high headache prevalence. In case of an existing association, modification of lifestyle habits would be a sufficient, feasible and cost-effective preventive strategy. Several studies have evaluated the role of lifestyle for the onset of headache in general and for specific headache types such as migraine and TTH [
8‐
19]. They report inconsistent findings. Data on the association between lifestyle factors and probable headache forms, introduced into the headache classification in 2004 by the International Headache Society (IHS) [
20], are lacking. The aim of our study was to evaluate the association between four common lifestyle factors including alcohol consumption, body mass index (BMI), physical activity and smoking and headache prevalence (migraine, probable migraine, TTH, probable TTH) in three different German studies applying the 2004 diagnostic criteria of the IHS.
Results
A total of 7,417 individuals participated in the three studies; 2,805 in KORA, 3,300 in SHIP and 1,312 in the DHS.
Baseline characteristics of participants according to the three different study regions are summarized in Table
1. Because of different age ranges in the three studies, we additionally present the common age group of 35–75 years old for all study regions and additionally all participants in the DHS and in KORA. To provide comparability among the three studies, further analyses (Tables
2,
3,
4,
5) were restricted to participants in the age range of 35–75 years yielding a total sample size of 1,134 in the DHS and 2,597 in SHIP. Due to missing values on one of the exposure status variables, we had to additionally exclude a total number of 7 participants in the DHS, 213 participants in SHIP and 7 participants in KORA.
Table 1
Characteristics of the regional study populations
Characteristic |
Age (range) | 35–75 (25–75) | 35–75 | 35–75 (25–80) |
Mean age (years) | 55.6 (52.1) | 54.6 | 54.9 (54.5) |
Women (%) | 52.4 (52.9) | 52.2 | 52.3 (51.9) |
School education ≤9 years (%) | 54.7 (49.5) | 57.6 | 40.7 (40.5) |
Current smoker (%) | 24.8 (25.5) | 20.3 | 25.7 (25.7) |
Physical activity >2 h/week (%) | 31.1 (32.1) | 36.3 | 22.4 (22.2) |
Median alcohol intake (g/d) | 2.9 (2.9) | 6.8 | 4.9 (4.4) |
BMI ≥ 30 kg/m2 (%) | 28.8 (26.4) | 25.9 | 32.4 (30.4) |
Mean systolic blood pressure (mmHg) | 143.0 (140.8) | 130.0 | 133.1 (132.5) |
Mean diastolic blood pressure (mmHg) | 87.9 (86.8) | 82.5 | 82.7 (81.4) |
History of hypertension (%) | 38.3 (35.2) | 44.2 | 51.6 (50.4) |
History of myocardial infarction (%) | 4.3 (3.7) | 3.1 | 4.0 (4.3) |
History of diabetes (%) | 8.7 (7.6) | 6.7 | 10.4 (11.2) |
History of stroke (%) | 2. 6 (2.2) | 1.7 | 2.7 (3.0) |
History of cancer (%) | 5.1 (4.6) | 5.0 | 5.4 (5.8) |
Any headache during the last 6 months (%) | 45.3 (48.6) | 54.6 | 45.0 (45.5) |
Migraine (%) | 12.7 (13.0) | 10.5 | 9.7 (9.5) |
Complete criteria (%) | 8.0 (8.5) | 7.9 | 4.4 (4.3) |
Probable criteria (%) | 4.7 (4.5) | 2.6 | 5.3 (5.2) |
Tension-type headache (%) | 24.2 (26.8) | 35.0 | 27.4 (27.7) |
Complete criteria (%) | 15.7 (17.5) | 23.6 | 15.5 (15.8) |
Probable criteria (%) | 8.5 (9.2) | 11.4 | 11.9 (11.9) |
Table 2
Age- and gender-adjusted associations between complete migraine prevalence and lifestyle variables, restricted to age groups 35–75 years
Smoking |
Never | 1.00 | 1.00 | 1.00 |
Past | 1.74 (1.03, 2.94) | 0.91 (0.65, 1.28) | 1.00 (0.62, 1.59) |
Current | 0.96 (0.53, 1.73) | 1.09 (0.76, 1.57) | 0.73 (0.44, 1.19) |
Physical activity |
None | 1.00 | 1.00 | 1.00 |
≤2 h/week | 0.95 (0.55, 1.62) | 0.98 (0.67, 1.43) | 1.10 (0.67, 1.80) |
>2 h/week | 0.67 (0.39, 1.15) | 1.25 (0.86, 1.81) | 1.28 (0.81, 2.02) |
Alcohol consumptiona |
None | 1.00 | 1.00 | 1.00 |
Moderate | 0.81 (0.48, 1.39) | 1.03 (0.74, 1.43) | 0.83 (0.52, 1.33) |
Increased | 0.75 (0.43, 1.31) | 0.58 (0.40, 0.84) | 0.60 (0.30, 1.20) |
Body mass index (kg/m2) |
<25 | 1.00 | 1.00 | 1.00 |
25.0–29.9 | 0.80 (0.47, 1.37) | 1.19 (0.85, 1.66) | 1.03 (0.64, 1.64) |
≥30.0 | 1.05 (0.59, 1.88) | 0.95 (0.64, 1.41) | 1.12 (0.68, 1.83) |
Health indexb | 0.93 (0.82, 1.05) | 1.02 (0.94, 1.11) | 1.05 (0.93, 1.18) |
Table 3
Age- and gender-adjusted associations between probable migraine prevalence and lifestyle variables, restricted to age groups 35–75 years
Smoking |
Never | 1.00 | 1.00 | 1.00 |
Past | 1.48 (0.77, 2.82) | 1.49 (0.85, 2.61) | 0.91 (0.57, 1.47) |
Current | 0.90 (0.42, 1.93) | 1.89 (1.03, 3.46) | 1.55 (1.02, 2.35) |
Physical activity |
None | 1.00 | 1.00 | 1.00 |
≤2 h/week | 2.10 (1.07, 4.12) | 0.99 (0.55, 1.76) | 1.03 (0.66, 1.61) |
>2 h/week | 1.31 (0.65, 2.66) | 0.74 (0.39, 1.38) | 0.81 (0.52, 1.27) |
Alcohol consumptiona |
None | 1.00 | 1.00 | 1.00 |
Moderate | 0.85 (0.44, 1.65) | 0.39 (0.21, 0.75) | 0.65 (0.42, 1.01) |
Increased | 0.75 (0.37, 1.52) | 0.60 (0.33, 0.99) | 0.50 (0.27, 0.94) |
Body mass index (kg/m²) |
<25 | 1.00 | 1.00 | 1.00 |
25.0–29.9 | 2.10 (1.00, 4.40) | 0.90 (0.50, 1.63) | 1.39 (0.91, 2.11) |
≥30.0 | 2.52 (1.15, 5.49) | 1.26 (0.68, 2.32) | 0.94 (0.58, 1.54) |
Health indexb | 0.94 (0.80, 1.10) | 0.80 (0.70, 0.92) | 0.94 (0.85, 1.05) |
Table 4
Age- and gender-adjusted associations between complete tension-type headache prevalence and lifestyle variables, restricted to age groups 35–75 years
Smoking |
Never | 1.00 | 1.00 | 1.00 |
Past | 1.05 (0.70, 1.55) | 0.86 (0.70, 1.06) | 1.34 (1.04, 1.74) |
Current | 1.25 (0.83, 1.89) | 0.81 (0.64, 1.03) | 0.91 (0.68, 1.21) |
Physical activity |
None | 1.00 | 1.00 | 1.00 |
≤2 h/week | 1.17 (0.78, 1.73) | 1.09 (0.87, 1.37) | 1.20 (0.91, 1.59) |
>2 h/week | 0.91 (0.61, 1.34) | 0.93 (0.74, 1.18) | 0.91 (0.69, 1.19) |
Alcohol consumptiona |
None | 1.00 | 1.00 | 1.00 |
Moderate | 0.98 (0.67, 1.45) | 1.03 (0.82, 1.29) | 1.35 (0.98, 1.86) |
Increased | 0.89 (0.60, 1.33) | 1.00 (0.80, 1.25) | 1.18 (0.80, 1.75) |
Body mass index (kg/m2) |
<25 | 1.00 | 1.00 | 1.00 |
25.0–29.9 | 0.64 (0.43, 0.94) | 0.96 (0.77, 1.19) | 0.96 (0.74, 1.25) |
≥30.0 | 0.74 (0.49, 1.14) | 1.07 (0.84, 1.36) | 0.83 (0.62, 1.10) |
Health indexb | 0.99 (0.91, 1.09) | 1.01 (0.96, 1.07) | 1.08 (1.01, 1.15) |
Table 5
Age- and gender-adjusted associations between probable tension-type headache prevalence and lifestyle variables, restricted to age groups 35–75 years
Smoking |
Never | 1.00 | 1.00 | 1.00 |
Past | 0.99 (0.59, 1.66) | 1.14 (0.87, 1.49) | 1.05 (0.78, 1.41) |
Current | 1.29 (0.75, 2.19) | 1.04 (0.75, 1.43) | 0.94 (0.69, 1.29) |
Physical activity |
None | 1.00 | 1.00 | 1.00 |
≤2 h/week | 1.08 (0.65, 1.79) | 1.02 (0.76, 1.37) | 0.84 (0.60, 1.17) |
>2 h/week | 0.78 (0.47, 1.30) | 0.81 (0.59, 1.10) | 0.93 (0.69, 1.25) |
Alcohol consumptiona |
None | 1.00 | 1.00 | 1.00 |
Moderate | 0.87 (0.53, 1.44) | 1.25 (0.93, 1.68) | 0.87 (0.63, 1.19) |
Increased | 0.86 (0.51, 1.44) | 0.92 (0.68, 1.24) | 0.64 (0.42, 0.98) |
Body mass index (kg/m2) |
<25 | 1.00 | 1.00 | 1.00 |
25.0–29.9 | 1.03 (0.61, 1.76) | 0.76 (0.57, 1.01) | 1.43 (1.05, 1.96) |
≥30.0 | 1.23 (0.70, 2.16) | 0.90 (0.66, 1.24) | 1.50 (1.08, 2.10) |
Health indexb | 0.92 (0.82, 1.04) | 1.01 (0.94, 1.08) | 0.97 (0.90, 1.04) |
We found regional variations concerning lifestyle habits and common chronic diseases. In KORA, participants were less likely to have a history of hypertension, diabetes, stroke or cancer compared to participants in SHIP or in the DHS. In contrast, the 6-month prevalence for any headache (54.55%) and for TTH was higher in KORA compared to the other study regions (Table
1).
In Tables
2,
3,
4, and
5, the association between lifestyle factors and headache subtypes is summarized. With regard to BMI and smoking status, we found inconsistent results for all headache types across the three studies and no clear pattern could be observed for the association between these two life style factors and headache prevalence (Tables
2,
3,
4,
5). Participants who exercised ≥2 h/week had a slightly decreased, but statistically non-significant risk of having complete and probable TTH in every study (Tables
4,
5). For migraine headache, we found inconsistent results across all three studies for physical activity as exposure variable (Tables
2,
3).
Increased alcohol consumption tended to be associated with a decreased risk of experiencing migraine and probable TTH, but without statistically significant results in all of the three studies (Tables
2,
3,
5). With regard to complete TTH, no clear pattern could be observed concerning the relationship with alcohol consumption (Table
4).
The association between the health index and headache is summarized in tables Tables
2,
3,
4,
5. The health index is a sum of risk factors representing an individual risk profile. There was no explicit association between the health index and headache subtypes in any of the three studies.
Discussion
In this cross-sectional analysis of data from three different studies in Germany, we found two noteworthy results. First of all, we found considerable variations in the distribution of lifestyle factors between the three regions. Second, there was no consistent association between migraine or TTH and the lifestyle factors smoking, alcohol consumption, physical activity and BMI irrespective of the prevalence of a specific lifestyle factor in one of the regions. In addition, a health index reflecting a sum score of four lifestyle factors was not associated with headache subtypes.
Several studies have evaluated a possible association between single lifestyle factors and headache with mostly conflicting results. A negative influence of alcohol consumption on headache occurrence, in general, and headache subtypes have been discussed for years with inconsistent findings. Several cross-sectional studies found no association between alcohol consumption and headache prevalence [
10,
13] as well as alcohol consumption and headache subtypes [
17]. In contrast, two large population-based studies reported a relationship, however, in opposing directions. In the first study, Aamodt et al. found a significant trend of decreasing prevalence of migraine with increasing amounts of alcohol consumption among 51,383 participants of the Head-HUNT Study. For non-migrainous headache, the inverse association between alcohol consumption and headache prevalence was weaker [
8]. In the second study, women but not men who sometimes to often consumed large amounts of alcohol reported more often recurrent headache and migraine [
14]. In contrast to our study, headache was not diagnosed according to the IHS criteria in this study. Thus, misclassification is possible and the comparability to other results is limited.
Inconsistency in published results also exists with regard to a possible relation between smoking and headache subtypes [
8,
14,
17,
27‐
31]. In a longitudinal study, Waldie et al. found that the risk of frequent headache was increased among smokers compared to non-smokers in childhood and adolescents. But during adulthood, smoking was not associated with frequent headache. The frequent headache group included migraine cases, TTH sufferers and those with coexisting migraine and TTH. In agreement with Waldie et al., we found no association between smoking status and headache subtypes in our adult population. Two additional cross-sectional studies support our findings [
17,
29]. In contrast, the prevalence of both, migraine and non-migrainous headache, increased with higher smoking levels in the Head-HUNT study in participants under the age of 40 years. No association was observed in higher age groups [
8]. Our results which were based on the older age range of 35–75 years are in line with the latter finding.
The association between physical activity and headache has gained popularity since case reports and small clinical-based studies suggested that physical activity may reduce headache severity, frequency and activity [
11,
12,
15,
32,
33]. Subsequently, several large-scale population studies have been conducted to evaluate the potential association between physical activity and headache prevalence, with mostly conflicting results [
14,
16,
18,
19,
29,
34,
35]. In a prospective study, low physical activity was associated with higher prevalences of migraine and non-migraine headache at baseline. After 11 years of follow-up, physically inactive persons were more likely to have non-migraine headache than active individuals [
18]. In contrary to these results and consistent with another cross-sectional study [
29], we found no significant association between physical activity and migraine prevalence.
Some studies suggested an association between obesity, a consequence of lifestyle, and headache [
36‐
38]. With regard to migraine status, results from several cross-sectional studies indicated that BMI and obesity are not related to migraine prevalence [
9,
39,
40]. In agreement with these results, we found no association between migraine fulfilling complete IHS criteria and BMI or probable migraine and BMI. There is increasing evidence that obesity is associated with migraine frequency and, therefore, a risk factor for chronic migraine. Only few studies have evaluated the association between BMI and TTH to date. In one of these studies conducted in 27 states in Brazil, Queiroz et al. found no significant association between TTH and BMI [
16].
A possible association between lifestyle factors and headache would have considerable consequences for the prevention of headache. By modifying their individual lifestyle habits, headache sufferers would have the opportunity to influence the occurrence, frequency and severity of headache. As presented before, the results of studies investigating the association between lifestyle factors and headache are not consistent. Methodological differences in the assessment of lifestyle factors and the headache case definition may be one cause for the observed inconsistency. The majority of studies including our own are cross-sectional studies. No assumptions regarding a causal relationship or a time sequence between lifestyle variables and headache are possible in this design. Thus, if, e.g., some headache patients report specific life style behaviours, especially alcohol consumption, to be trigger factors for their headache, they avoid the exposure. Also, patients with severe and frequent headache might not have the ability to exercise on a regular basis [
41]. A prospective study design with incident case assessment can better contribute to the clarification of a causal relationship. Nevertheless, our study suggests considerable regional variations with regard to life style habits within one country. The associations between the four lifestyle factors and headache types were negative in all three regions included, regardless of the absolute level of a specific behaviour. We interpret this as a support for a true negative finding.
Our study has several strengths including the large sample size, inclusion of participants from three different regions within one country and a standardized headache assessment by face-to-face interviews. In addition, we classified migraine and TTH and their probable forms using the diagnostic criteria of the 2004 edition of the IHS. Furthermore, information on a variety of lifestyle factors and cardiovascular disease risk factors was available. Several limitations should also be considered when interpreting our results. First, the information on lifestyle variables and headache symptoms is self-reported and we can not rule out potential underreporting, e.g. in alcohol consumption and smoking. Second, assessment of 2 lifestyle variables, physical activity and alcohol consumption, varied slightly between the three studies and we had to transform the information into uniform categories. However, evaluating the association with the original variables in each study yielded no different results (data not presented). Third, we had to exclude over 200 participants in SHIP due to missing data on the exposure status, mainly alcohol consumption. Therefore, we cannot rule out potential selection bias for this part of the analysis. Fourth, among headache sufferers, a higher percentage of participants in SHIP have been diagnosed with probable migraine and probable TTH compared to the DHS and KORA. Since the data collection and headache classification was completely standardized with trained interviewers across all studies, this is unlikely to be due to selection or recall bias. A potential explanation might be a difference in the perception of headache, including the questions from the headache module, in the north-eastern population compared to the two other studies. Fifth, because of the cross-sectional design of our study, a statement concerning a causal relationship or the time sequence of an association cannot be done. Sixth, the cohorts consisted of participants aged 35–75 years from three different regions in Germany which may limit the generalizability of our results to other populations. Lastly, headache is highly prevalent among subjects aged 18–35 years. Since we could not include subjects in this age range, our presented headache prevalence is lower compared to other studies assessing headache prevalence. However, we do not believe that the association between headache and lifestyle depends on headache prevalence and our population is suitable for studying the relationship between lifestyle factors and headache.
In summary, in this large study, we found variations in lifestyle factors in three regions in Germany, but no associations between single or combined life style factors and headache types were observed. Future research should focus on the association of lifestyle habits with first or recurrent headaches.
Acknowledgments
The German DMKG Headache Study was supported by the German Migraine & Headache Society (DMKG) and by unrestricted grants of equal share from Astra Zeneca, Berlin Chemie, Boots Healthcare, GlaxoSmithKline, McNeil Pharma (former Woelm Pharma), MSD Sharp & Dohme and Pfizer. SHIP and KORA additionally received funding from the following sources. SHIP was supported by the Community Medicine Research net (CMR) of the University of Greifswald, Germany, which is funded by the Federal Ministry of Education and Research (grants 01ZZ9603, 01ZZ0103, 01ZZ0403, 01ZZ0701), the Ministry of Cultural Affairs, and the Social Ministry of the Federal State of Mecklenburg-West Pomerania. The CMR encompasses several research projects that are sharing data of the population-based SHIP (
http://ship.community-medicine.de). The KORA research platform and the MONICA/KORA Augsburg studies are financed by the Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), which is funded by the German Federal Ministry of Education, Science, Research and Technology and by the State of Bavaria. Morbidity and Mortality follow-ups were in addition supported by grants from the Federal Ministry of Education, Science, Research and Technology (01 ER 9701/4) and the German Research Foundation (DFG) (TH 784/2-1).
Conflict of interest
Dr. Meisinger, K. Fendrich and S. Baumeister have nothing to disclose. Dr. Winter has received a postdoctoral fellowship of the American Association of University Women for the following project: associations between socioeconomic status and migraine. Dr. Hoffman has no financial relations with pharmaceutical companies in the context of headache research or therapy over the last 5 years. Dr. Vennemann worked at the Institute for Epidemiology at the University of Münster between 2003 and 2005. During that time she was paid by an unrestricted grant paid by several pharmaceutical companies. Dr. Vennemann never had contact with the companies nor received she any direct or indirect payments. Dr. Pfaffenrath received honoraria for participation in clinical trials, contribution to advisory boards or oral presentations from: Addex Pharma, Allergan, Almirall, AstraZeneca, Bayer Vital, Berlin Chemie, Boehringer Ingelheim, Bristol-Myers Squibb, GlaxoSmithKline, Janssen-Cilag, Lilly, 3 M Medica, MSD, Novartis, Pfizer, Shaper and Bruemmer, SanoviAventis, Weber & Weber. Financial support for research projects was provided by Allergan, Almirall, AstraZeneca, Bayer, GSK, Janssen-Cilag, Pfizer. Dr. Pfaffenrath has no ownership interest and does not own stocks of any pharmaceutical company. Dr. Evers has received grants and honorariers by GSK, Allergan, Berlin Chemie, Boehringer, MSD, Janssen-Cilag, Pfizer. Dr. Kurth has received investigator-initiated research funding from the French National Research Agency, the National Institutes of Health, Merck, the Migraine Research Foundation, and the Parkinson’s Disease Foundation. He is a consultant to i3 Drug Safety and World Health Information Science Consultants, LLC, and has received honoraria from Genzyme, Merck, and Pfizer for educational lectures. Dr. Berger has received research support for the conduction of DMKG Headache Study unrestricted grants of equal share from the German Migraine and Headache Society and a consortium formed by Allmiral, Astra-Zeneca, Berlin-Chemie, Boehringer Ingelheim Pharma, Boots Healthcare, GlaxoSmithKline, Janssen Cilag, McNeil Pharamceuticals, MSD Sharp & Dohme, Pfizer; for the ‘Course of Restless Legs Syndrome Study’ unrestricted grants from the German Restless Legs Society and a consortium formed by Boehringer Ingelheim Pharma, Mundipharma Research, Neurobiotec, UCB (Schwarz Pharma) and Roche Pharma; from the German Minister of Research and Education for several research projects within the German Competence Net Stroke and an ongoing cohort study on depression and subclinical arteriosclerosis.