***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Summary Back pain due to vertebral collapse is the main symptom of postmenopausal osteoporosis . The clinical picture in these crush fractures varies , depending on the type and the location of fracture , but in general , a new vertebral crush fracture gives rise to severe pain that immobilizes the patient and necessitates bedrest . In this double-blind controlled clinical trial , 56 patients who had recently ( within the last 3 days ) suffered an osteoporotic vertebral fracture were hospitalized for a period of 14 days .  Salmon calcitonin ( 100 IU ) or placebo injections were given daily . Pain was rated daily on a 10-point scale by the same observers . Blood and urinary parameters were also evaluated . The results showed a significant ( P<0.001 ) difference in pain intensity between the calcitonin group and the placebo group . This beneficial effect was generally apparent from the second day of treatment onward , and over the following 2 weeks , the patients were able to sit and st and , and gradually started to walk again . A significant decrease in urinary hydroxyproline and urinary calcium was also noted in the calcitonin group . It is concluded that calcitonin exerts a beneficial effect on back pain following a vertebral crush fracture The aim of this study was to investigate the effect of nasal calcitonin on  chronic back pain and disability attributed to  osteoporosis .  The study design involved three groups of osteoporotic postmenopausal women suffering from chronic back pain . Group I consisted of 40 women with vertebral fractures , group II of 30 women with degenerative disorders and group III of 40 patients with non specific chronic back pain and without abnormality on plain X-rays .  Pain intensity was measured using a numerical rating scale ( NRS ) and disability due to back pain was measured using the Oswestry disability question naire . The patients were r and omly assigned to receive , for three months , either 200 IU intranasal salmon calcitonin and 1,000 mg of oral calcium daily ( groups IA , IIA , IIIA ) or 1,000 mg of oral calcium daily ( groups IB , IIB , IIIB ) . Repeated measures ANOVA showed that there were no significant time , group or interaction effects for pain intensity and disability in any of the groups studied . Mean Oswestry and NRS scores were reduced during the follow-up period in the groups IA , IIIA , but the differences between the two time points were not statistically significant . Intranasal calcitonin has no effect on chronic back pain intensity and functional capacity of osteoporotic women regardless of the presence of fractures , degenerative disorders or chronic back pain of non-specific etiology The purpose of this study was to evaluate the efficacy of calcitonin on β-endorphin levels in female patients experiencing back pain associated with postmenopausal osteoporosis . The secondary purpose was to assess the pain and quality of life in these patients . There were 30 patients with a mean age of 58.2±5.4 years in the treatment group and 26 patients with a mean age of 58.8±5.2 years in the placebo group in this r and omized , placebo-controlled study . The patients subcutaneously received 100 IU salmon calcitonin or placebo injections and 1,000 mg elementary calcium for 2 weeks . Baseline plasma β-endorphin levels were measured and repeated after 2 weeks . Patients ’ pain and quality of life ( QOL ) were evaluated by using the Visual Analogue Scale , Modified Face Scale , Beck Depression Index , and Nottingham Health Profile . Patients ’ global assessment of disease activity was also performed at baseline and at the end of the first and second week . We found that plasma β-endorphin levels in the treatment group were significantly higher than the placebo group at the end of the second week ( p<0.001 ) . Although pain and QOL scores were improved at the end of the second week in both groups ( p<0.05 ) , the improvement in the treatment group was more significant when compared with the placebo group ( p<0.05 ) . Therefore , calcitonin is an analgesic agent , as it increases the plasma β-endorphin levels in patients with postmenopausal osteoporosis , which consequently improves QOL Our aim was to compare the analgesic efficacy of pamidronate ( PAM ) and synthetic human calcitonin ( CT ) in intravenous infusion for recent painful benign vertebral compression in a r and omised prospect i ve double-blind study . Twenty-seven patients aged 49–85 years with painful benign non-traumatic vertebral compression were included in the study . They received either PAM ( 1 mg/kg ) or synthetic human CT ( 1.5 mg ) as an intravenous infusion . Pain and functional disability were evaluated before infusion , and 4 and 30 days afterwards . The pain score assessed on a visual analogue scale at day 0 was 5.94±2.47 in patients treated with PAM and 6.27±2.50 in patients treated with CT ( p=0.74 ) ; at day 4 , 4.8±2.80 with PAM vs 3.9±2.68 with CT ( p=0.37 ) ; and at day 30 , 3.6±3.13 with PAM vs 3.10±2.76 with CT ( p=0.70 ) . Spinal function scores were 18.21±3.17 at day 0 in patients treated with PAM vs 17.23±4.42 in patients treated with CT ( p=0.69 ) and at day 30 , 13.7±5.36 with PAM vs 12.33±3.22 with CT ( p=0.68 ) . We found no advantage  of PAM over CT in a single intravenous infusion for the treatment of painful recent benign vertebral compression . Since CT is ten times less costly , its use should be preferred Summary A placebo-controlled , double-blind study was carried out over 4 months to evaluate two doses of synthetic human calcitonin ( 0.25 and 0.125 mg ) given s.c . three times per week . Enrolled were 60 women , aged 56–82 years , who had experienced a vertebral fracture due to low-energy trauma within the preceding year . During active treatment there was within the first month a dose-dependent decrease of the indices of bone resorption ( fasting urinary calcium and hydroxyproline excretions ) , whereas only the higher dose and a treatment period of 4 months produced a reduction of bone formation ( serum osteocalcin ) . The bone mineral content ( BMC ) of the nondominant forearm was unchanged . Treatment with calcitonin also had significant , dosedependent , analgetic effects . The amelioration of pain was , in multivariate analyses , related to a reduction in parameters felt to be markers for bone resorption . In the placebo group there was a significant reduction of the BMC of the forearm but no changes of any of the biochemical markers for bone turnover and no improvement of pain . In conclusion , treatment with two low doses of calcitonin induced changes of the biochemical markers of bone turnover in a dosedependent manner . The analgetic properties of calcitonin were also of salient clinical importance . The knowledge derived from this study could be adapted to the dosage schedule in long-term trials in osteoporosis Radiographically detected vertebral fractures ( hereafter referred to as vertebral fractures ) are a hallmark of postmenopausal osteoporosis and an important end point in clinical trials of osteoporosis treatment . Women with vertebral fractures have low bone mass compared with women without these fractures and , independently of bone mass , have an increased risk for additional vertebral and other fractures [ 1 - 4 ] . Vertebral fractures are common : Five percent of 50-year-old white women and 25 % of 80-year-old women have had at least one vertebral fracture [ 5 ] . Surprisingly , however , the manner in which vertebral fractures affect health remains uncertain . Cross-sectional studies in community-derived sample s of older women have demonstrated only a modest association [ 6 - 8 ] or no association [ 9 - 11 ] between prevalent vertebral fractures and back pain or disability . Cross-sectional studies do not distinguish more recent fractures from older vertebral fractures and may fail to capture transient increases in pain or disability [ 12 ] , a limitation that may underestimate the clinical effect of these fractures [ 13 ] . Back pain is common among elderly women [ 14 ] , and frequent causes of back pain , such as degenerative disc disease , facet joint osteoarthritis , spinal stenosis , and scoliosis , may obscure the impact of vertebral fracture . Only about one third of new vertebral fractures come to medical attention [ 15 , 16 ] , suggesting that most vertebral fractures are asymptomatic . However , attitudes toward back pain in older women and access to health care may also play a role in determining whether vertebral fractures come to medical attention . We examined the effect of incident vertebral fractures on back pain and back-related functional limitations in a large community-based sample of elderly women who underwent serial spinal radiography and annual assessment s of back pain and disability over the same period . Methods Participants Study patients were participants in the Study of Osteoporotic Fractures , a cohort recruited from population -based listings in four U.S. metropolitan areas . Details of the design of this study are published elsewhere [ 17 ] .  Lateral spine radiographs were obtained for 9677 white women between the ages of 65 and 99 years ( median age , 70 years ) who underwent baseline examination between 1986 and 1988 . Repeated spinal radiographs suitable for morphometry were obtained for 7223 women ( 75 % of the original cohort ) at a follow-up clinic visit held an average of 3.7 years ( range , 1.3 to 5.1 years ) later . All participants gave informed consent . Vertebral Morphometry Lateral radiographs of the thoracic and lumbar spine were obtained in accordance with current guidelines [ 18 ] . Quantitative vertebral morphometry was performed using six-point digitization as described elsewhere [ 3 , 19 ] to calculate the anterior ( Ha ) , mid- ( Hm ) , and posterior ( Hp ) height for each vertebral body from T4 to L4 . A system of triage of radiographs , described elsewhere [ 3 , 20 ] , was used to reduce the number of radiographs requiring morphometric measurements . Briefly , trained technicians separated sets of radiographs into normal , uncertain , or probably fractured groups on the basis of a limited semiquantitative grading scheme that categorized women by the most abnormal vertebral level [ 20 ] . Uncertain grade s were further categorized by the study radiologist as normal or probably fractured . Morphometry was done on the radiograph pairs that were categorized as probably fractured ( 42 % ) . In a r and om sample of 503 women whose radiographs were triaged and then digitized , triage missed no incident fractures according to the study definition . Definition of Vertebral Fracture A vertebra was classified as having a prevalent fracture on the baseline radiograph if any of the following ratios were more than 3 SDs ( > 4 SDs for severe fractures ) below the normal mean for that vertebral level : ( Ha/Hp ) , ( Hm/Hp ) , or a combination of ( H/H [ ] 1 ) and ( Hai/Hai 1 ) [ 3 , 21 ] . A new ( incident ) fracture was identified if any of the three vertebral heights ( Ha , Hm , or Hp ) on follow-up radiographs decreased by 20 % or more and by at least 4 mm compared with the baseline height . Incident fractures identified by morphometry were review ed by a radiologist to exclude imaging artifacts or such conditions as osteophytosis and Scheuermann disease ; 7 % of vertebrae meeting the morphometric criteria for incident fracture were reclassified as not fractured . Incident Clinical Fractures We used previously described methods [ 22 ] to assess the occurrence of clinical fractures of any bone during follow-up . Women were considered to have a clinical vertebral fracture if they reported a new diagnosis of spinal fracture and a clinical radiology report confirmed that a vertebral fracture was present . Measurements of Pain , Disability , and Limited Activity We evaluated outcome measures by using a previously described question naire [ 7 , 23 ] that asked about back pain and back-related disability in the past 12 months and the number of days of limited activity due to back pain . The question naire was administered at baseline and at three annual follow-up contacts held before assessment of vertebral fractures . The third follow-up contact coincided with follow-up radiography . Back pain was assessed on scales of frequency ( 0 , never or rarely ; 1 , some of the time ; 2 , most of the time ; or 3 , all of the time ) and severity ( 0 , no pain ; 1 , mild pain ; 2 , moderate pain ; or 3 , severe pain ) . The two pain questions had high internal consistency ( Cronbach = 0.81 ) and were summed for a total score that could range from 0 to 6 . We defined clinical ly significant back pain as pain that was experienced most or all of the time or pain that was moderate or severe . Women without significant back pain at baseline were considered to have increased back pain if clinical ly significant pain had developed between any follow-up contacts . For women with clinical ly significant back pain at baseline , increased back pain was defined as an increase in total pain score of at least two points . Both types of increase had a similar association with incident fractures and thus were combined for a single outcome . Back-related disability was assessed with questions about the 
    Output:
    
The combined results from 13 trials ( n = 589 ) determined that calcitonin significantly reduced the severity of acute pain in recent OVCFs .
Side effects were mild , with enteric disturbances and flushing reported most frequently .
Although calcitonin has proven efficacy in the management of acute back pain associated with a recent OVCF , there is no convincing evidence to support the use of calcitonin for chronic pain associated with older fractures of the same origin