migraine is a periodic , often pulsatile unilateral headache , which is common in all ranges of ages . migraine headaches usually begin in the early adulthood although it can begins as late as fifth decade of life . a mendelian pattern was not observed in both types of migraine but familial occurrence is common in both types and especially in patients with aura . migraine is a common disorder and prevalence of it is approximately 6.5 percent in men and 18 percent in women . in many women , migraine attacks tend to occur in premenstrual period and in some women migraine attacks occur solely in this period . episodes of headaches usually persists 472 hours and nausea , vomiting , photophobia , phonophobia and fatigue are common symptoms that are usually observed in this disorder . pain is usually severe and needs treatment with analgesics and sometimes bed rest is necessary . migraines have many risk factors , some patients experience severe attacks after especial foods such as cheese , chocolate , onion or especial foods rich in tyramine . obesity is a serious problem in our life which is growing more and more specially in city dwellers . obesity has lots of complications such as heart failure , sudden death , early fatigue ability and osteoarthritis . many methods are used for migraine headaches treatment such as chemical drugs , psychotherapy , injection of botulinum toxin , behavioral modifications , psychotherapy , chiropractic , acupuncture and biofeedback techniques . some of these treatments are not accepted by all experts but there is consensus upon drugs . treatment are divided into two phases , acute treatment of pain and preventive treatment . in the first phase , we usually use analgesics ( nsaids ) , serotonin agonists and ergots derivatives and in the second phase the most preferred drugs are beta blockers , tricyclic antidepressants and anticonvulsants . migraine is very important disease with high prevalence which makes many patients to spend a lot of time in bed for resting . although there are many various treatments , some of them are not tolerated in all patients . further investigation is recommended to find better options for the treatment of migraine headaches . in this study , we aimed to evaluate the effects of weight on the preventive treatment of migraine headaches . this was a prospective experimental study conducted on 203 patients who were referred for evaluation of headache to the neurology clinic in the period from 2009 to 2010 . subjects were categorized in four groups according to their body mass index ( bmi ) , < 24.9 , 24.9 - 29 , 29 - 34.9 and > 35 . after the description of methods and aims of study all patients who had more than 3 episodes of migraine headaches each month and voluntarily asked for preventing treatment were selected for study . all patients were adults between 18 to 45 years old who had migraine headaches according to international headache society criteria ( ihs ) . visual analogue scale ( vas ) and 6-point behavioral rating scale ( brs-6 ) were two standard international scales which were used for evaluation of the severity of pain . brs-6 is a standard score for pain based on clinical symptoms which is divided from 0 to 5 . all patients were evaluated for the frequency , duration and severity of pain in the beginning of study and at the end of 4 , 6 and 8 weeks . selected patients were treated with nortriptyline 0.6 mg / kg / d and propranolol 1mg / kg / d . dosage was increased gradually over four weeks from the beginning of study to the end of 4 week . individuals who had any contraindication for use of these drugs were not included in this study . mean age of the patients was 30.5  7.1 years ranged from 15 to 45 years . weight , height and bmi of participants were 80.4  14.1 kg , 1.67  0.07 meter and 28.5  4.1 , respectively . pain frequency decreased from 8.1  2.3 attacks per month at baseline to 2.9  2.6 attacks per month in 8th week . pain duration decreased from 16.1  6.1 hour at baseline to 11.7  5.2 , 7.2  5.8 and 6.6  5.8 in 4th , 6th and 8th weeks , respectively . vas also showed a decreasing pattern from 73.3  15.2 mm in 1st week to 56.8  16.2 mm , 40.3  20.9 mm and 32.7  23.9 mm in 4th , 6th and 8th weeks , respectively . it reduced to 2.72  1.04 in 4th week , 1.84  1.07 in 6th week and 1.40  1.20 in 8th week . different demographic characteristic of patients , pain duration , frequency and severity of pain measured with vas and brs-6 scales are summarized in tables 1 to 3 . variations of visual analogue scale in different body mass index groups during the weeks of intervention behavioral rating scale ( brs ) in different body mass index groups during eight weeks of intervention pain frequency and duration in different body mass index groups throughout the study period data are presented as mean  standard deviation visual analogue scale variations in different groups in different weeks of study data are presented as mean  standard deviation behavioral rating scale in different weeks of study in four groups of body mass index data are presented as mean  standard deviation the aim of this study was to evaluate the effects of bmi on the treatment of migraine headaches . as mentioned earlier , all patients were classified in four groups according to their bmi , and all were treated with the similar dosage of drugs . age , height and weight were different in all four groups and increased with different bmi in different groups . the mean frequency of pain was similar in all groups at the beginning but there was significant difference at the end of study . the mean duration of pain had significant difference in all groups at the beginning and at the end of 8 week . mean vas score did not show statistically significant difference between bmi groups at the beginning . however , the difference was statistically significant at the end of the study in favor of better response to treatment in lower bmi . brs-6 score showed similar pattern . in spite of direct influence of bmi on pain duration , it had no influence on pain frequency . however , comparing the influence of treatment on bmi in different groups showed that both frequency and duration had better outcome in patients with lower bmi . the findings of this study were in agreement with studies by bigal et al . and lipton et al . because their studies showed association between bmi and migraine headache , although these studies had different methods . the findings of this study did not support mattsson and tietjen et al . which did not find direct influence of bmi on migraine headaches . the mechanism by which obesity affects on migraine or its treatment is unknown but mechanism that influence on body weight may simultaneously influence on migraine . lower activity of sympathetic and higher activity of parasympathetic systems and secretion of special neuropeptides such as neuropeptide y or melanocortins might be common factors . this study showed that obesity has a direct influence on the treatment of migraine headaches . consequently , it should be recommended to patients to reduce their weight for better response to the treatment . in addition , physicians must be careful about migraine drugs which make a tendency for increased appetite .
backgroundmigraine is a prevalent disease which is classified into two groups of migraine with aura and without aura . 
 eighteen percent of women and 6.5 percent of men in united states have migraine headache . 
 migraine headache is prevalent in all age groups but it usually subsides in adults above fifty . 
 migraine has many risk factors such as stress , light , tiredness , special foods and beverages . 
 the aim of this study was the evaluation of the effects of body mass index ( bmi ) on the treatment of migraine headaches.methodsall patients assigned to four groups according to their bmi . 
 patients with more than three attacks per month received nortriptyline and propranolol for eight weeks . 
 the frequency , duration and severity of pain were measured by visual analogue scale ( vas ) and behavioral rating scale ( brs-6 ) in regular intervals.results203 patients completed the study . 
 153(75% ) subjects were women and 50(25% ) were men . 
 mean age of patients was 30.5  7.1 years . 
 mean weight was 80.4  14.1 kg and mean height was 1.67  0.07 m. pain frequency and duration showed statistically significant differences among four groups with better response in patients with lower bmi ( p < 0.0001 ) . 
 vas and brs-6 scales showed statistically significant differences among four groups in favor of patients with lower bmi ( p < 0.0001).conclusionthis study showed that obesity has a direct influence on the treatment of migraine headaches . 
 it could be recommended to patients to reduce their weight for better response to treatment . 
 in addition , care should be taken about migraine drugs which make a tendency for increased appetite .