The risk of fibromyalgia in patients with iron deficiency anemia: a nationwide population-based cohort study.

Since iron is essential for neurotransmitter synthesis, decreased iron stores might lead to reduced production of biogenic amines which phenomenon was shown in Fibromyalgia (FM) patients. The aims are to investigate the association of iron deficiency anemia (IDA) and FM and to find the effects of different interventions. We conducted a study using the Taiwan National Health Insurance Research Database. The IDA cohort consisted of 13,381 patients with newly diagnosed IDA between 2000 and 2008. Each patient with IDA was frequency-matched with one people without IDA, by sex, age and index year. The Cox proportional hazards regression analysis was conducted to estimate the association between IDA and FM risk. The event was the occurrence of FM. The overall incidence density rate of FM in the IDA cohort was higher than in the non-IDA cohort with a multivariable Cox proportional hazards model measured adjusted hazard ratio [HR], 1.19; 95% confidence interval [CI], 1.13-1.25). When using non-IDA group as reference, we compared with different therapies for IDA. The adjusted HRs of FM were 1.38 (95% CI = 1.30-1.47), 1.10 (95% CI = 1.03-1.16), 1.18 (95% CI = 0.98-1.43) and 0.73 (95% CI = 0.58-0.90) for IDA patient without therapy, iron supplement alone, blood transfusion alone and both iron supplement and blood transfusion respectively. Our results suggest IDA is associated with an increased risk of FM. All patients should have iron supplementation both to correct anemia and replenish body stores.

The impact of timing and modalities of dental prophylaxis on the risk of 5-fluorouracil-related oral mucositis in patients with head and neck cancer: a nationwide population-based cohort study.

PURPOSE: This study investigated the impact of dental prophylaxis on 5-fluorouracil (5-FU)-related oral mucositis (OM) according to the head and neck cancer (HNC) locations and treatment times. METHODS: A total of 13,969 HNC participants, including 482 5-FU-related OM subjects and 13,487 comparisons were enrolled from the Longitudinal Health Insurance Database for Catastrophic Illness Patients of Taiwan between 2000 and 2008. All subjects were stratified into subgroups based on the times to perform chlorhexidine use, scaling, and fluoride application before 5-FU administration. The dental prophylaxis related to 5-FU-related OM was estimated by multiple logistic regression and represented with odds ratio (OR) and 95% confidence interval (CI). RESULTS: Fluoride gel application and scaling significantly impacted on OM development (p < 0.001), and the joint effect of fluoride gel and scaling induced 5-FU-related OM (OR = 3.46, 95% CI = 2.39-5.01). The risk of OM was raised 2.25-fold as scaling within 3 weeks before 5-FU-related chemotherapy (95% CI = 1.81-2.81), and a 3.22-fold increased risk of OM while fluoride gel was applied during 5-FU-related treatment (95% CI = 1.46-7.13). CONCLUSION: Dental prophylaxis significantly affected 5-FU-related OM in the HNC population. A short interval between dental scaling or fluoride application and 5-FU administration may be associated with higher prevalence of OM. Scaling simultaneously combined with chlorohexidine promoted 5-FU-related OM in specific HNC patients excluding the oral cancer and nasopharyngeal cancer population. Proper timing of the prophylactic dental treatments prior to 5-FU therapy could reduce the risk to develop 5-FU-related OM.

Response to iron overload in cultured hepatocytes.

Iron is essential for a variety of physiological processes. Hepatic iron overload acts as a trigger for the progression of hepatic steatosis to nonalcoholic steatohepatitis and hepatocellular carcinoma. In the present study, we aimed to study the effects of iron overload on cellular responses in hepatocytes. Rat primary hepatocytes (RPH), mouse primary hepatocytes (MPH), HepG2 human hepatoma cells and Hepa1-6 mouse hepatoma cells were treated with FeCl3. Treatment with FeCl3 effectively increased iron accumulation in primary hepatocytes. Expression levels of molecules involved in cellular signaling such as AMPK pathway, TGF-ß family pathway, and MAP kinase pathway were decreased by FeCl3 treatment in RPH. Cell viability in response to FeCl3 treatment was decreased in RPH but not in HepG2 and Hepa1-6 cells. Treatment with FeCl3 also decreased expression level of LC-3B, a marker of autophagy in RPH but not in liver-derived cell lines. Ultrastructural observations revealed that cell death resembling ferroptosis and necrosis was induced upon FeCl3 treatment in RPH. The expression level of genes involved in iron transport varied among different liver-derived cells- iron is thought to be efficiently incorporated as free Fe2+ in primary hepatocytes, whereas transferrin-iron is the main route for iron uptake in HepG2 cells. The present study reveals specific cellular responses in different liver-derived cells as a consequence of iron overload.

Type 1 diabetes is associated with an increased risk of venous thromboembolism: A retrospective population-based cohort study.

BACKGROUND: It has been unclear whether diabetes mellitus (DM) is positively associated with a risk of venous thromboembolism (VTE). In addition, whether the risk of VTE is altered in patients with type 1 diabetes (T1DM) has rarely been explored. AIM: We investigated whether patients with T1DM are at a relatively high risk of VTE development. METHODS: We retrieved data from the National Health Insurance Research Database of Taiwan to conduct this retrospective cohort study. The T1DM group consisted of 4967 patients diagnosed as having T1DM before 2003. The non-T1DM group comprised 19 868 age- and sex-matched enrollees without T1DM. Cox proportional hazard regression analysis was used to investigate the hazard ratio of VTE in patients with T1DM relative to those without T1DM. RESULTS: During a mean follow-up period of 8.61 years, the risk of VTE in the T1DM group was 5.33-fold higher than in the non-T1DM group after adjusting for dyslipidemia, hypertension, stroke, lower leg fracture or surgery, and obesity. Further stratified analysis revealed that the risk of VTE was significantly high in both sexes and in all age groups below the age of 60. CONCLUSION: T1DM appears to be an independent risk factor for VTE development.

Association between asthma and risk of benign prostatic hyperplasia: a retrospective population-based study.

OBJECTIVE: The association between asthma and benign prostatic hyperplasia (BPH) has rarely been explored. We investigated whether male asthmatic patients had an increased risk of BPH by conducting this retrospective nationwide population-based study. METHODS: We utilized data derived from the National Health Insurance Research Database (NHIRD) in Taiwan. A total of 9778 male patients aged >40 years who were newly diagnosed with asthma between 2000 and 2006 were included in the asthma group. Male enrollees without asthma were selected as the non-asthma group from the same database. Both the groups were followed up until the end of 2013. We performed Cox proportional hazard regression analysis to estimate the risk of BPH and transurethral resection of the prostate (TURP) in the male patients with asthma compared with that in those without asthma. RESULTS: The risk of BPH and TURP in the asthma group was 1.40-fold (95% confidence interval [CI] = 1.30-1.42) and 1.30-fold (95% CI= 1.31-1.50) higher than that in the non-asthma group, respectively, after adjusting for comorbidities, relevant medications and number of annual outpatient visits. CONCLUSIONS: The male patients with asthma were found to have a higher risk of BPH than did those without asthma.

Increased risk of chronic fatigue syndrome following psoriasis: a nationwide population-based cohort study.

BACKGROUND: The onset of chronic fatigue syndrome (CFS) has been shown to be associated with several immunological conditions such as infections or atopy. The aim of this study was to clarify the risk of chronic fatigue syndrome following the diagnosis of psoriasis, an immune-related dermatological disease, by analyzing the National Health Insurance Research Database of Taiwan. METHOD: 2616 patients aged 20 years or older with newly diagnosed psoriasis during 2004-2008 and 10,464 participants without psoriasis were identified. Both groups were followed up until the diagnoses of CFS were made at the end of 2011. RESULTS: The relationship between psoriasis and the subsequent risk of CFS was estimated through Cox proportional hazards regression analysis, with the incidence density rates being 2.27 and 3.58 per 1000 person-years among the non-psoriasis and psoriasis populations, respectively (adjusted hazard ratio [HR] = 1.48, with 95% confidence interval [CI] 1.07-2.06). In the stratified analysis, the psoriasis group were consistently associated with a higher risk of CFS in male sex (HR = 2.05, 95% CI 1.31-3.20) and age group of ≥ 60 years old (HR = 2.32, 95% CI 1.33-4.06). In addition, we discovered that the significantly increased risk of CFS among psoriasis patients is attenuated after they receive phototherapy and/or immunomodulatory drugs. CONCLUSIONS: The data from this population-based retrospective cohort study revealed that psoriasis is associated with an elevated risk of subsequent CFS, which is differentiated by sex and age.

Incidence of stroke in patients with HIV infection: A population-based study in Taiwan.

BACKGROUND: Few studies have evaluated whether people infected with human immunodeficiency virus (HIV) are at an increased risk of stroke in an Asian population. We investigated the association between HIV infection and the risk of developing stroke by age, calendar year of HIV diagnosis, and follow-up duration in Taiwan. METHODS: Using the claims data of a universal health insurance program, we identified 5,961 patients with HIV and 23,844 matched non-HIV subjects without previous stroke from 1998 to 2005 and followed them up until the end of 2011 to measure the incidence of stroke. Cox proportional hazards models adjusted for potential confounders were used to estimate hazard ratios (HR) and 95% confidence intervals (CI), with the non-HIV group as reference. RESULTS: During a median follow-up of 8 years, the incidence rates for total, ischemic, and hemorrhagic stroke per 1000 person-years were 2.12, 1.22, and 0.60, respectively, in patients with HIV infection, and 1.98, 1.14, and 0.54, respectively, in the comparison group. HIV infection was associated with an elevated risk of developing total stroke (adjusted HR [95% CI], 1.57 [1.15-2.14]) and ischemic stroke (1.91 [1.25-2.91]) in patients aged less than 45 years, but no association was observed in other age groups (P for interaction with age, p = 0.048 and 0.024, respectively). Patients diagnosed with HIV infection in 1998-1999 had a greater HR for total stroke and ischemic stroke than those diagnosed in 2000-2002 and 2003-2005 (P for interaction, for total stroke p = 0.034, for ischemic stroke p = 0.056). The HRs did not differ by follow-up duration. CONCLUSIONS: HIV infection among a young age group is associated with increased risk of developing overall and ischemic stroke. The findings highlight the importance of screening and correcting risk factors for young stroke prevention immediately and aggressively.

Increased risk of chronic fatigue syndrome in patients with inflammatory bowel disease: a population-based retrospective cohort study.

BACKGROUND: Similarities in the symptoms of chronic fatigue syndrome (CFS) and inflammatory bowel disease (IBD) have been observed as follows: severe disease activity in IBD correlates with severe fatigue, major psychiatric signs, the common use of medication, and bacterial translocation. One of several hypotheses for explaining the mechanisms underlying CFS suggests a similarity to the impaired intestinal mucosa of IBD. "This study investigated the risk of incident CFS among patients with IBD". METHODS: We conducted a population-based retrospective cohort study by using Taiwan's National Health Insurance Research Database to evaluate the subsequent risk of CFS in patients with IBD, according to demographic characteristics and comorbidities. The exposure cohort comprised 2163 patients with new diagnoses of IBD. Each patient was randomly selected and frequency matching according to gender and age with four participants from the general population who had no history of CFS at the index date (control cohort). Cox proportional hazards regression analysis was conducted to estimate the relationship between IBD and the subsequent risk of CFS. RESULTS: The exposure cohort had a significantly higher overall risk of subsequent CFS than that of the control group [adjusted hazard ratio (Christophi in Inflamm Bowel Dis 18(12):2342-2356, 2012) = 2.25, 95%, confidence interval (Aaron and Buchwald in Ann Intern Med 134(9 Pt 2):868-881, 2001; Farraye et al. in Am J Gastroenterol 112:241, 2017) 1.70-2.99]. Further analysis indicated a significantly higher risk of CFS in patients who were male (HR = 3.23, 95% CI 2.12-4.91), were older than 35 years, and had IBD but without comorbidity status, e.g. Cancers, diabetes, obesity, depression, anxiety, sleep disorder, renal disease (HR = 2.50, 95% CI 1.63-3.84) after adjustment. CONCLUSION: The findings from this population-based retrospective cohort study suggest that IBD, especially Crohn's disease, is associated with an increased risk of subsequent CFS.

Increased Risk for Hip Fractures among Patients with Cholangitis: A Nationwide Population-Based Study.

BACKGROUND: Cholangitis is the infectious disease involving the biliary tract, which may induce systemic inflammation. Bone loss is a well-known sequelae after systemic inflammatory disease, and one grave complication after osteoporosis is hip fracture. We want to know whether cholangitis can contribute to increased risk of hip fracture. METHODS: All the patients diagnosed with cholangitis since January 1, 2001, to December 31, 2009, were assessed. All the subjects with cancer history, traumatic accident, and previous fracture were excluded. We selected the controls without cholangitis and matched the controls to cholangitis patients by age, sex, osteoporosis, and the use of steroid for more than 30 days by approximately 1:4 ratio. RESULTS: There were 2735 subjects in the cholangitis cohort and 10915 in the noncholangitis cohort. There were 101 hip fractures in the cholangitis cohort with the incidence density of 7.58 per 1000 person-years. As for the noncholangitis cohort, 366 individuals suffered from hip fracture with the incidence density of 5.86 per 1000 person-years. The risk of hip fracture was higher in the cholangitis cohort with a 1.29-fold increased risk than the noncholangitis cohort (hazard ratio = 1.29, 95% confidence interval = 1.03-1.61). The association between cholangitis and the hip fracture was more prominent among subjects less than 65 years (hazard ratio = 2.65, 95% confidence interval =1.30-5.39) and the subjects without comorbidities (hazard ratio = 3.01, 95% confidence interval = 1.42-6.41). CONCLUSIONS: Cholangitis is associated with higher risk for hip fracture, especially among young subjects free from medical comorbidities.

Is Fibromyalgia Risk Higher Among Male and Young Inflammatory Bowel Disease Patients? Evidence from a Taiwan Cohort of One Million.

BACKGROUND: Prior literatures have shown inflammatory bowel disease (IBD) could increase fibromyalgia (FM) risk. However, studies about gender and age distributions of FM risk among patients with IBD are rare. With large study samples, this study aimed to evaluate the FM risk among IBD patients with different gender and different age. OBJECTIVE: We aim to estimate the FM risk among male and younger IBD patients with a large patient sample. STUDY DESIGN: A retrospective cohort study was arranged in this research. SETTING: The data used in this research were selected from the Taiwan National Health Insurance Research Database (NHIRD). METHODS: From the Taiwan NHIRD, we selected 4,510 patients with IBD and 18,040 randomly gender- and age-matched patients without a history of IBD from the beginning of 2000 to the end of 2005 to analyze the development of FM over a 12-year follow-up period (2000-2011). The Cox regression model was used to assess the effects of IBD on the risk of FM by adjusting for gender, age, and comorbidities, including hypertension, diabetes, hyperlipidemia, depression, anxiety, and sleep disorder. RESULTS: After adjusting suitable covariates, the IBD patients had a greater FM risk (adjusted hazard ratio [aHR] 1.70, 95% confidence interval [CI] 1.59-1.83) than the controls. Male IBD patients had a higher FM risk than female IBD patients did (aHR 2.00, 95% CI 1.79-2.23 and aHR 1.52, 95% CI 1.38-1.67, respectively). The greatest age-specific FM risk occurred in the youngest IBD subgroup (= 39 years old) (aHR 1.92, 95% CI 1.68-2.19). LIMITATIONS: The information about personal behaviors was unobtainable in the Taiwan NHIRD. Other risk factors for cardiovascular disease that might augment FM cannot be excluded entirely in this study. CONCLUSION: IBD is disclosed to be correlated with an enhanced risk to develop FM, particularly in male and younger IBD patients. For preventing FM, it is necessary to pay more attention to the management of the IBD patients. Future researches are needed to further confirm the findings in this study. KEY WORDS: Inflammation, inflammatory bowel disease, fibromyalgia, Taiwan National Health Insurance Research Database.

Zinc(II)-Histidine Induced Collagen Peptide Assemblies: Morphology Modulation and Hydrolytic Catalysis Evaluation.

Collagen-related materials have many potential biomedical applications because of their high biocompatibility and biodegradability. Designed collagen-mimetic peptides (CMPs) could self-assemble into supramolecular structures via a variety of interactions. In particular, metal-ligand interactions can induce microscale sizes of collagen assemblies. Our previous study also successfully applied metal-histidine coordination method to promote the self-assembly of CMPs into micrometers of constructs. In an effort to broaden the metal-induced strategies on assembling designed CMPs and explore the new insights into their assembly process, herein we designed and synthesized a series of short CMPs with one or more histidine residues incorporated into the peptides and used Zn(II) to induce the formation of collagen assembled microstructures. By altering the location and the number of histidine residues, we found that the assembly rate was significantly affected as well as the morphology of the assembled architectures. The CMPs containing terminal histidine residues were found to assemble into less ordered granulated and spherical microstructures while that with only one single histidine in its middle site could form pinwheel or floret-like constructs, showing that we could modulate the morphology of collagen assemblies by changing the location and number of Zn(II)-His coordination sites. Additionally, these CMPs also exhibited catalytic activities on ester hydrolysis in the presence of Zn(II) ions, which suggested that Zn(II)-CMP assemblies could be potentially applied to the development of artificial enzymes.

Allergic Conjunctivitis-induced Retinal Inflammation Promotes Myopia Progression.

Myopia is a highly prevalent eye disease. There is limited information suggesting a relationship between myopia and inflammation. We found children with allergic conjunctivitis (AC) had the highest adjusted odds ratio (1.75, 95% confidence interval [CI], 1.72-1.77) for myopia among the four allergic diseases. A cohort study was conducted and confirmed that children with AC had a higher incidence and subsequent risk of myopia (hazard ratio 2.35, 95%CI 2.29-2.40) compared to those without AC. Lower refractive error and longer axial length were observed in an AC animal model. Myopia progression was enhanced by tumor necrosis factor (TNF)-α or interleukin (IL)-6 administration, two cytokines secreted by mast cell degranulation. The TNF-α or IL-6 weakened the tight junction formed by corneal epithelial (CEP) cells and inflammatory cytokines across the layer of CEP cells, which increased the levels of TNF-α, IL-6, and IL-8 secreted by retinal pigment epithelial cells. The expression levels of TNF-α, IL-6, IL-8, monocyte chemoattractant protein-1, and nuclear factor kappa B were up-regulated in eyes with AC, whereas IL-10 and the inhibitor of kappa B were down-regulated. In conclusion, the experimental findings in mice corroborate the epidemiological data showing that allergic inflammation influences the development of myopia.

Hypothyroidism is associated with all-cause mortality in a national cohort of chronic haemodialysis patients.

AIM: The prevalence of hypothyroidism is high in haemodialysis (HD) patients and hypothyroidism increases all-cause mortality in HD patients. Comorbidities are common in HD patients and are associated with both mortality and hypothyroidism. The aim of the study is to explore the effect of the interactions of comorbidities and hypothyroidism on all-cause mortality in HD patients. METHOD: Patients with hypothyroidism (ICD-9-CM 244.0, 244.1, and 244.9) and matched patients without hypothyroidism in the Registry for Catastrophic Illness Patient Database of Taiwan Health Insurance from 2000 to 2010 were analyzed. The association of hypothyroidism and risk of all-cause mortality was analyzed using Cox proportional hazard regression. RESULT: Nine hundred and eight HD patients with hypothyroidism and 3632 sex-, age-, gender- matched HD patients without hypothyroidism were analyzed. Hypothyroidism was associated with increased all-cause mortality with an adjusted hazard ratio of 1.22 [95% confidence interval (CI): 1.10-1.36, P < 0.001]. TRT may decrease mortality associated with hypothyroidism (P < 0.001). There was a significant interaction (P = 0.04) between diabetes and hypothyroidism. There was no significant interaction found in hypothyroidism and the following comorbidities: hyperlipidaemia, hypertension, chronic obstructive pulmonary disease, coronary artery disease, stroke, peripheral arterial disease, asthma, congestive heart failure and cancer. CONCLUSION: Hypothyroidism is associated with increased all-cause mortality in chronic HD patients. The interaction of hypothyroidism and diabetes, but not other common comorbidities in HD patients, has an effect on mortality risks.

Asthma is associated with endometriosis: A retrospective population-based cohort study.

BACKGROUND: Evidence regarding the association between asthma and endometriosis is limited and inconsistent. The goal of the study was to investigate whether women diagnosed as having asthma were at a greater risk of endometriosis than age-matched unaffected women. METHODS: We conducted a nationwide population-based retrospective study by using data retrieved from the Taiwan National Health Insurance Research Database during the period of 2000-2005 with follow-up through 2013. The current analysis included 7337 women aged 12-50 years with newly diagnosed asthma and using asthma-related medications and 29,348 age-matched women without asthma. A Cox proportional hazards regression model was used to estimate the risks of endometriosis in women with asthma as compared with those without asthma. RESULTS: The overall risk of endometriosis in the asthma group was 1.50-fold higher (95% confidence interval = 1.33-1.70) than that in the nonasthma group. A stratified analysis by age further revealed that patients with asthma were associated with a higher risk of endometriosis in age groups of 21-50 years. CONCLUSION: Compared with women without asthma, women with asthma of reproductive age are at a higher risk of endometriosis. Additional studies are warranted to elucidate the mechanism(s) underlying the association between asthma and a higher risk of endometriosis.

Does pyogenic liver abscess increase the risk of delayed-onset primary liver cancer?: Evidence from a nationwide cohort study.

Delayed-onset primary liver cancer (PLC) including hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC) in patients with pyogenic liver abscess (PLA) is not common. The relationship between PLA and delayed-onset PLC is unclear. We investigated the association in a nationwide cohort study.From Taiwan National Health Insurance claims data, a cohort of 17,531 patients with PLA was generated after excluding patients with a history of cancer (n = 2034) and those diagnosed with PLC (n = 572) and other cancers (n = 627) within 1 year of a diagnosis of PLA. An age-, sex-, index year-, and diabetes mellitus (DM)-matched control cohort of 70,124 persons without PLA was selected from the same dataset. Both cohorts were followed up until the end of 2011. The risk of PLC was estimated for both cohorts.The incidence of PLC was nearly 2-fold greater in the PLA group than in the control cohort (29.3 per 10,000 person-years vs. 16.2 per 10,000 person-years). The incidences of HCC and ICC were 1.5- (22.1 per 10,000 person-years vs. 15.0 per 10,000 person-years) and 11-fold greater (6.73 per 10,000 person-years vs. 0.62 per 10,000 person-years), respectively, in the PLA group than in the control cohort. The PLA cohort also had high risks of PLC (adjusted hazard ratio [aHR] = 1.56; 95% confidence interval [CI] = 1.35-1.81), HCC (aHR = 1.34; 95% CI = 1.15-1.57), and ICC (aHR = 6.94; 95% CI = 4.23-11.57).In conclusion, in this nationwide cohort study, PLA increased the risk of delayed-onset PLC.

Association between chronic obstructive pulmonary disease and increased risk of benign prostatic hyperplasia: a retrospective nationwide cohort study.

OBJECTIVE: Chronic obstructive pulmonary disease (COPD) and benign prostatic hyperplasia (BPH) are common disorders in ageing male populations. Nevertheless, the relationship between the two diseases has rarely been explored. The objective of this study was to examine whether patients with COPD are at an increased risk of BPH. DESIGN: Retrospective nationwide cohort study. SETTING: Data retrieved from the Taiwan National Health Insurance Research Database. PARTICIPANTS: Overall, 19 959 male patients aged 40 years and over with newly diagnosed COPD between 2000 and 2006 were included as the COPD group, and 19 959 sex-matched and age-matched enrollees without COPD were included as the non-COPD group. Both groups were followed-up until the end of 2011. OUTCOME MEASURES: A Cox proportional hazards regression model was used to compute the risk of BPH in patients with COPD compared with enrollees without COPD. RESULTS: The overall incidence rate of BPH was 1.53 times higher in the COPD group than that in the non-COPD group (44.7 vs 25.7 per 1000 person-years, 95% CI 1.46 to 1.60) after adjusting for covariates. An additional stratified analysis revealed that this increased risk of BPH in patients with COPD remained significantly higher than that in enrollees without COPD in all men aged 40 years and over. CONCLUSION: After adjustment for covariates, male patients with COPD were found to be at a higher risk of BPH. We suggest that clinicians should be cautious about the increased risk of BPH in male patients with COPD.

Risk of osteoporosis and pathologic fractures in cancer patients who underwent hematopoietic stem cell transplantation: a nationwide retrospective cohort study.

BACKGROUND: Long-term data on post-hematopoietic stem cell transplantation (HSCT) osteoporosis and fracture are limited. This study evaluated the long-term risk of osteoporosis and fracture in cancer patients who underwent HSCT. RESULTS: The incidence density rate of osteoporosis was 12.5 per 1000 person-years in the HSCT group, which was significantly higher than that in the non-HSCT group (5.65 per 1000 person-years) after adjustment for associated factors and consideration of competing risk factors (adjusted subhazard ratio, 1.48; 95% confidence interval, 1.06-2.07). The incidence density rate of fracture was 4.89 per 1000 person-years in the HSCT group, and the risk of fracture was 1.40 times higher in the HSCT group than in the non-HSCT group (95% confidence interval, 0.83-2.40). The vertebra was the most common site of fracture after HSCT (68.4%). The risk of osteoporosis and fracture significantly increased in post-HSCT patients with both hematological malignancies and solid tumors. Both autologous and allogeneic HSCTs increased the risk of osteoporosis, whereas only autologous HSCT recipients had an increased risk of fracture. MATERIALS AND METHODS: This nationwide retrospective cohort study analyzed data from Taiwan's National Health Insurance Research Database. We identified an HSCT group comprising 1040 cancer patients who underwent HSCT during 2000-2008 and a non-HSCT group comprising 4160 propensity score-matched cancer patients who did not undergo HSCT. All patients were followed up until the occurrence of osteoporosis; fracture; December 31, 2011; or withdrawal from the insurance program. CONCLUSIONS: HSCT recipients have an increased risk of osteoporosis.