Cerebrospinal fluid pro-inflammatory cytokines differentiate parkinsonian syndromes.

INTRODUCTION: Neuroinflammation has been established to be part of the neuropathological changes in Parkinson's disease (PD) and atypical parkinsonism (APD). Activated microglia play a key role in neuroinflammation by release of cytokines. Evidence of the disparity, if any, in the neuroinflammatory response between PD and APD is sparse. In this study, we investigated CSF cytokine profiles in patients with PD, multiple system atrophy (MSA), or progressive supranuclear palsy (PSP). METHODS: On a sensitive electrochemiluminescence-based platform (Quickplex, Meso Scale Discovery®), we examined a panel of C-reactive protein (CRP) and eight selected cytokines, IFN-γ, IL-10, IL-18, IL-1ß, IL-4, IL-6, TGF-ß1, and TNF-α, among patients with PD (n = 46), MSA (n = 35), and PSP (n = 39) or controls (n = 31). Additionally, CSF total tau protein levels were measured as a marker of nonspecific neurodegeneration for correlation estimates. RESULTS: CRP and the pro-inflammatory cytokines TNF-α, IL-1ß, and Il-6 were statistically significantly elevated in MSA and PSP patients compared to PD patients but not compared to control patients. No analytes differed statistically significantly between MSA and PSP patients. The best diagnostic discrimination, evaluated by ROC curve (AUC 0.77, p = 007, 95% CI 0.660-0.867), between PD and MSA patients was seen for a subset of analytes: CRP, TNF-α, IL-1ß, and IFN-γ. CONCLUSION: Among the investigated cytokines and CRP, we found a statistically significant increase of microglia-derived cytokines in MSA and PSP patients compared to PD patients.

Hydrochlorothiazide use is strongly associated with risk of lip cancer.

BACKGROUND: The diuretic hydrochlorothiazide is amongst the most frequently prescribed drugs in the United States and Western Europe, but there is suggestive evidence that hydrochlorothiazide use increases the risk of lip cancer. OBJECTIVES: To study the association between use of hydrochlorothiazide and squamous cell carcinoma of the lip. METHODS: We conducted a case-control study using Danish nationwide registry data. From the Cancer Registry (2004-2012), we identified 633 case patients with squamous cell carcinoma (SCC) of the lip and matched them to 63 067 population controls using a risk-set sampling strategy. Hydrochlorothiazide use (1995-2012) was obtained from the Prescription Registry and defined according to cumulative use. Applying conditional logistic regression, we calculated odds ratios (ORs) for SCC lip cancer associated with hydrochlorothiazide use, adjusting for predefined potential confounders obtained from demographic, prescription and patient registries. RESULTS: Ever-use of hydrochlorothiazide was associated with an adjusted OR for SCC lip cancer of 2.1 (95% confidence interval (CI): 1.7-2.6), increasing to 3.9 (95%CI: 3.0-4.9) for high use (≥25 000 mg). There was a clear dose-response effect (P < 0.001), with the highest cumulative dose category of hydrochlorothiazide (≥100 000 mg) presenting an OR of 7.7 (95%CI: 5.7-10.5). No association with lip cancer was seen with use of other diuretics or nondiuretic antihypertensives. Assuming causality, we estimated that 11% of the SCC lip cancer cases could be attributed to hydrochlorothiazide use. CONCLUSIONS: Hydrochlorothiazide use is strongly associated with an increased risk of lip cancer.

Pain prevalence in hospitalized children: a prospective cross-sectional survey in four Danish university hospitals.

BACKGROUND: Pain management in hospitalized children is often inadequate. The prevalence and main sources of pain in Danish university hospitals is unknown. METHODS: This prospective mixed-method cross-sectional survey took place at four university hospitals in Denmark. We enrolled 570 pediatric patients who we asked to report their pain experience and its management during the previous 24 hours. For patients identified as having moderate to severe pain, patient characteristics and analgesia regimes were reviewed. RESULTS: Two hundred and thirteen children (37%) responded that they had experienced pain in the previous 24 hours. One hundred and thirty four (24%) indicated moderate to severe pain and 43% would have preferred an intervention to alleviate the pain. In children hospitalized for more than 24 hours, the prevalence of moderate/severe pain was significantly higher compared to children admitted the same day. The single most common painful procedure named by the children was needle procedures, such as blood draw and intravenous cannulation. CONCLUSION: This study reveals high pain prevalence in children across all age groups admitted to four Danish university hospitals. The majority of children in moderate to severe pain did not have a documented pain assessment, and evidence-based pharmacological and/or integrative ('non-pharmacological') measures were not systematically administered to prevent or treat pain. Thus, practice changes are needed.

Effects of nitrate supplementation in trained and untrained muscle are modest with initial high plasma nitrite levels.

Nitrate (NO3-) supplementation resulting in higher plasma nitrite (NO2-) is reported to lower resting mean arterial blood pressure (MAP) and oxygen uptake (VO2 ) during submaximal exercise in non-athletic populations, whereas effects in general are absent in endurance-trained individuals. To test whether physiologic effects of NO3- supplementation depend on local muscular training status or cardiovascular fitness, male endurance-trained cyclists (CYC, n=9, VO2 -max: 64±3 mL/min/kg; mean±SD) and recreational active subjects serving as a control group (CON, n=8, 46±3 mL/min/kg), acutely consumed nitrate-rich beetroot juice ([NO3-] ~9 mmol) (NIT) or placebo (PLA) with assessment of resting MAP and energy expenditure during moderate intensity (~50% VO2 -max) and incremental leg cycling (LEG-ex) and arm-cranking exercise (ARM-ex). NIT increased (P<.001) resting plasma NO3- by ~1200% relative to PLA. Plasma NO2- increased ~25% (P<.01) with a significant change only in CYC. LEG-ex VO2 (~2.60 L/min), ARM-ex VO2 (~1.14 L/min), and resting MAP (~87 mm Hg) remained unchanged for CYC, and similarly for CON, no changes were observed for LEG-ex VO2 (~2.03 L/min), ARM-ex VO2 (~1.06 L/min), or resting MAP (~85 mm Hg). VO2 -max was not affected by supplementation, but incremental test peak power was higher (P<.05) in LEG-ex for CYC in NIT relative to PLA (418±47 vs 407±46 W). In both CYC and CON, high initial baseline values and small increases in plasma NO2- after NIT may have lowered the effect of the intervention implying that muscular and cardiovascular training status is likely not the only factors that influence the physiologic effects of NO3- supplementation.

Inter-modal four-wave mixing study in a two-mode fiber.

We demonstrate efficient four-wave mixing among different spatial modes in a 1-km long two-mode fiber at telecommunication wavelengths. Two pumps excite the LP01 and LP11 modes, respectively, while the probe signal excites the LP01 mode, and the phase conjugation (PC) and Bragg scattering (BS) idlers are generated in the LP11 mode. For these processes we experimentally characterize their phase matching efficiency and bandwidth and find that they depend critically on the wavelength separation of the two pumps, in good agreement with the numerical study we carried out. We also confirm experimentally that BS has a larger bandwidth than PC for the optimum choice of the pump wavelength separation.

Statin use and risk for ovarian cancer: a Danish nationwide case-control study.

BACKGROUND: Limited data suggest that statin use reduces the risk for ovarian cancer. METHODS: Using Danish nationwide registries, we identified 4103 cases of epithelial ovarian cancer during 2000-2011 and age-matched them to 58,706 risk-set sampled controls. Conditional logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for epithelial ovarian cancer overall, and for histological types, associated with statin use. RESULTS: We observed a neutral association between ever use of statins and epithelial ovarian cancer risk (OR=0.98, 95% CI=0.87-1.10), and no apparent risk variation according to duration, intensity or type of statin use. Decreased ORs associated with statin use were seen for mucinous ovarian cancer (ever statin use: OR=0.63, 95% CI=0.39-1.00). CONCLUSIONS: Statin use was not associated with overall risk for epithelial ovarian cancer. The inverse association between statin use and mucinous tumours merits further investigation.

Statin use and risk of nonmelanoma skin cancer: a nationwide study in Denmark.

BACKGROUND: Evidence is conflicting regarding statin use and risk of basal cell (BCC) and squamous cell skin cancer (SCC). METHODS: Using Danish nationwide registries, we identified all patients with incident BCC/SCC during 2005-2009 and matched them to population controls. We computed odds ratios (ORs) for BCC and SCC associated with statin use. RESULTS: We identified 38,484 cases of BCC and 3724 cases of SCC. Statin ever use was associated with ORs of 1.09 (CI: 1.06-1.13) for BCC and 1.01 (CI: 0.91-1.11) for SCC. CONCLUSIONS: Statin use was not associated with risk of SCC. Residual confounding plausibly explains the marginally increased risk of BCC.

Low-dose aspirin use and the risk of ovarian cancer in Denmark.

BACKGROUND: A comprehensive body of evidence has shown that aspirin has cancer-preventive effects, particularly against gastrointestinal cancer, but its effects on the risk of ovarian cancer are less well established. This nationwide case-control study examined the association between low-dose aspirin and the risk of ovarian cancer. PATIENTS AND METHODS: We identified all patients in the Danish Cancer Registry aged 30-84 years old with a histologically verified first diagnosis of epithelial ovarian cancer during 2000-2011. Each patient was sex- and age-matched to 15 population controls using risk-set sampling. Prescription use, comorbidity, reproductive history, and demographic characteristics data were obtained from nationwide registries. The use of low-dose (75-150 mg) aspirin was defined according to the dose as well as the duration and consistency of use. Conditional logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for the association between low-dose aspirin use and the risk of epithelial ovarian cancer, both overall and for specific histological types. RESULTS: For 4103 ovarian cancer cases and 58 706 population controls, the adjusted OR for epithelial ovarian cancer associated with ever use (≥2 prescriptions) of low-dose aspirin was 0.94 (95% CI 0.85-1.05). ORs for epithelial ovarian cancer were lower with the use of 150 mg aspirin tablets (OR = 0.82; 95% CI 0.68-0.99) and with long-term use (≥5 years) of low-dose aspirin (OR = 0.77; 95% CI 0.55-1.08). Continuous long-term use of low-dose aspirin, defined as close consecutive prescriptions, was associated with a further reduction in OR (0.56; 95% CI 0.32-0.97). For histological types of epithelial ovarian cancer, the strongest inverse associations with low-dose aspirin use were seen for mucinous and endometrioid tumours. CONCLUSION: This nationwide case-control study indicates that low-dose aspirin use may be associated with a reduced risk of epithelial ovarian cancer.

Interference patterns and extinction ratio of the diatom Coscinodiscus granii.

We report experimental and theoretical verification of the nature and position of multiple interference points of visible light transmitted through the valve of the centric diatom species Coscinodiscus granii. Furthermore, by coupling the transmitted light into an optical fiber and moving the diatom valve between constructive and destructive interference points, an extinction ratio of 20 dB is shown.

Peripherally applied opioids for postoperative pain: evidence of an analgesic effect? A systematic review and meta-analysis.

BACKGROUND: Opioids applied peripherally at the site of surgery may produce postoperative analgesia with few side effects. We performed this systematic review to evaluate the analgesic effect of peripherally applied opioids for acute postoperative pain. METHODS: We searched PubMed (1966 to June 2013), Embase (1980 to June 2013), and the Cochrane Central Register of Controlled Trials (The Cochrane Library 2013, Issue 6). Randomized controlled trials investigating the postoperative analgesic effect of peripherally applied opioids vs. systemic opioids or placebo, measured by pain intensity scores, consumption of supplemental analgesics and time to first analgesic were included. Trials with sample sizes of fewer than 10 patients per treatment group or trials with opioids administered intra-articularly or as peripheral nerve blocks were excluded. RESULTS: Data from 26 studies, including 1531 patients and 13 different surgical interventions were included. Clinical heterogeneity of the studies was substantial. Meta-analysis indicated statistically significant, but not clinically relevant, reductions in VAS score at 6-8 h (mean difference -4 mm, 95% CI: -6 to -2) and 12 h postoperatively (mean difference -5 mm, 95% CI: -7 to -3) for peripherally applied opioids vs. placebo and statistically significant increased time to first analgesic (mean difference 153 min, 95% CI: 41-265). When preoperative inflammation was reported (five studies), peripherally applied opioids significantly improved postoperative analgesia. CONCLUSION: Evidence of a clinically relevant analgesic effect of peripherally applied opioids for acute postoperative pain is lacking. The analgesic effect of peripherally applied opioids may depend on the presence of preoperative inflammation.

Myasthenia and risk of cancer: a population-based case-control study.

BACKGROUND AND PURPOSE: To evaluate the association between having non-thymoma myasthenia and the risk of extra-thymic cancer in a population-based setting. METHODS: A nationwide case-control study was conducted in Denmark based on medical registries. The study included all cases with a first time diagnosis of cancer during 2000-2009. Each case was matched by birth year and gender with eight population controls using risk set sampling. Subjects with myasthenia were identified through a validated register-based algorithm. Conditional logistic regression was used to compute crude and adjusted odds ratios (ORs), with 95% confidence intervals (CIs), for cancer associated with a prior diagnosis of myasthenia. RESULTS: In all, 233 437 cases and 1 867 009 controls were identified. A total of 80 cases and 518 controls had a prior diagnosis of myasthenia. Myasthenia was not associated with an increased risk of overall cancer (OR 1.1; 95% CI 0.9-1.4). Adjusted ORs for major cancer sites were also close to unity, whereas an elevated risk of lymphomas was observed (OR 2.0; 95% CI 0.8-5.5). Early-onset myasthenia was associated with a slightly increased OR for overall cancer (1.5; 95% CI 1.0-2.3); however, this estimate was based on small numbers. CONCLUSIONS: Non-thymoma myasthenia was not associated with an increased risk of overall cancer. Larger studies are necessary to evaluate the association between myasthenia and risk of lymphoma and the potential effect modification by age of myasthenia onset in relation to cancer risk.

Risk of non-melanoma skin cancer in myasthenia patients treated with azathioprine.

BACKGROUND AND PURPOSE: The association between use of azathioprine and risk of non-melanoma skin cancer (NMSC) in patients with myasthenia was evaluated in a nationwide setting. Treatment of autoimmune myasthenia frequently involves long-term exposure to immunosuppressants, including azathioprine. Use of azathioprine increases the risk of NMSC in organ recipients and probably also in patients with other autoimmune disorders. No previous study has specifically investigated the risk of NMSC in myasthenia patients treated with azathioprine. METHODS: This is a case-control study based on Danish population-based registries. Cases were myasthenia patients with a first time diagnosis of NMSC during 2004-2009. Age- and sex-matched controls were selected amongst myasthenia patients with no history of cancer using incidence density sampling. Prior use of azathioprine in cases and controls was assessed through prescription records (1995-2009). Conditional logistic regression was used to calculate odds ratios (OR) with 95% confidence intervals (CI) for skin cancer associated with a high cumulative dose (≥150 g) or long-term use (≥5 years) of azathioprine, adjusted for confounders. RESULTS: Thirty NMSC cases and 360 matched controls were identified. Ever use of azathioprine was associated with a considerably increased risk of NMSC (OR 3.3, 95% CI 1.5-7.3) that was even more apparent in patients with high cumulative dose (OR 4.6, 95% CI 1.7-12.5) or long-term (OR 4.8; 95% CI 1.7-13.6) use of azathioprine. CONCLUSION: Azathioprine use in patients with myasthenia is associated with an increased risk of NMSC.

Use of statins and risk of glioma: a nationwide case-control study in Denmark.

BACKGROUND: Laboratory studies and a single case-control study have suggested a protective effect of statins on the risk of glioma. We wished to investigate the influence of statin use on the risk of glioma in a population-based setting. METHODS: We conducted a nationwide case-control study in Denmark based on population-based medical registries. We identified all patients aged 20 to 85 years with a first diagnosis of histologically verified glioma during 2000-2009. These cases were matched on birth year and sex with population controls. Prior use of statins since 1995 was classified into short-term use (<5 years) and long-term use (5+ years). We used conditional logistic regression to compute odds ratios (ORs), with 95% confidence intervals (CIs), for glioma associated with statin use, adjusted for potential confounders. RESULTS: A total of 2656 cases and 18,480 controls were included in the study. The risk of glioma was reduced among long-term statin users (OR=0.76; 95% CI: 0.59-0.98) compared with never users of statins, and was inversely related to the intensity of statin treatment among users (OR=0.71; 95% CI: 0.44-1.15 for highest intensity). The inverse association between long-term statin treatment and glioma risk was more pronounced among men aged ≤ 60 years (OR=0.40; 95% CI: 0.17-0.91) compared with men aged 60+ years (OR=0.71; 95% CI: 0.49-1.03). An inverse association was also observed among women aged ≤ 60 years (OR=0.28; 95% CI: 0.06-1.25), but not among women over age 60 years (OR=1.23; 95% CI: 0.82-1.85). CONCLUSION: Long-term statin use may reduce the risk of glioma.

Use of low-dose aspirin and non-aspirin nonsteroidal anti-inflammatory drugs and risk of glioma: a case-control study.

BACKGROUND: Few studies have examined the association between use of aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs) and risk of glioma and the results have been equivocal. We therefore investigated the influence of NSAID use on glioma risk in a nationwide setting. METHODS: We used national registries in Denmark to identify all patients aged 20-85 years with a first diagnosis of histologically verified glioma during 2000-2009. Each case was matched on birth year and sex to eight population controls using risk-set sampling. We used prescription data to assess NSAID use and classified exposure to low-dose aspirin or non-aspirin (NA) NSAIDs into ever use or long-term use, defined as continuous use for 5 years. Conditional logistic regression was used to compute odds ratios (ORs), with 95% confidence intervals (CIs), for glioma associated with NSAID use, adjusted for potential confounders. RESULTS: A total of 2688 glioma cases and 18,848 population controls were included in the study. Ever use of low-dose aspirin (OR=0.90; 95% CI: 0.77-1.04) or NA-NSAIDs (OR=1.05; 95% CI: 0.96-1.14) was not associated with glioma risk. Compared with never use, long-term use of low-dose aspirin or of NA-NSAIDs was associated with ORs of 0.80 (95% CI: 0.53-1.21) and 1.11 (0.57-2.17), respectively. We observed no clear patterns of risk in stratified analysis according to estimated doses of low-dose aspirin (≤ 100 mg, 150 mg). CONCLUSION: We did not find any apparent association between aspirin or NA-NSAID use and risk of glioma, although our results may be consistent with a slight reduction in glioma risk with long-term use of low-dose aspirin.

Raman and loss induced quantum noise in depleted fiber optical parametric amplifiers.

We present a semi-classical approach for predicting the quantum noise properties of fiber optical parametric amplifiers. The unavoidable contributors of noise, vacuum fluctuations, loss-induced noise, and spontaneous Raman scattering, are included in the analysis of both phase-insensitive and phase-sensitive amplifiers. We show that the model agrees with earlier fully quantum approaches in the linear gain regime, whereas in the saturated gain regime, in which the classical equations are valid, we predict that the amplifier increases the signal-to-noise ratio by generating an amplitude-squeezed state of light. Also, in the same process, we analyze the quantum noise properties of the pump, which is difficult using standard quantum approaches, and we discover that the pump displays complicated dynamics in both the linear and the nonlinear gain regimes.

Use of azathioprine for non-thymoma myasthenia and risk of cancer: a nationwide case-control study in Denmark.

BACKGROUND AND PURPOSE: To evaluate the association between the use of azathioprine and risk of cancer in patients with non-thymoma myasthenia gravis (MG) in a nationwide setting. METHODS: Case-control study based on population-based registries. Cases were patients with MG with a first time diagnosis of cancer (except non-melanoma skin cancer) registered during 2000-2009, and controls were patients with MG with no history of cancer. Prior use of azathioprine in cases and controls was assessed through prescription records (1995-2009). We used unconditional logistic regression to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for cancer associated with a high cumulative dose [≥ 1000 defined daily doses (DDD)] or long-term use (≥ 5 years) of azathioprine, compared with never use of the drug and adjusted for potential confounders. RESULTS: We identified 89 cases and 873 controls. The prevalence of ever use of azathioprine was similar among cases (39.3%) and controls (39.4%). We observed a slightly elevated OR for cancer overall associated with long-term use of azathioprine (1.22; 95% CI: 0.62-2.40, P = 0.56). The highest ORs were observed for use of 2000 DDD or more of azathioprine; however, these risk estimates were based on small numbers. CONCLUSIONS: Use of azathioprine in patients with non-thymoma MG may be associated with a slightly increased risk of cancer overall. Larger studies are necessary to address the risk of site-specific cancers.

Predictors of medication adherence in patients with schizophrenia and bipolar disorder.

OBJECTIVE: To investigate potential risk factors for medication non-adherence in patients with schizophrenia and bipolar disorder. METHOD: A total of 255 patients underwent clinical assessments, neurocognitive testing and blood sampling. The patients were divided into groups of 'No', 'Partial' or 'Full' adherence. Relationships to different risk factors were analyzed. RESULTS: In schizophrenia, use of illicit substances, alcohol and poor insight were related to worse adherence. Schizophrenia patients with No adherence did better on tests of executive functioning, verbal learning and memory and had higher IQ than patients with better adherence. There were higher levels of autonomic side effects in the non-adherence group, but body mass index was lower in the Partial adherence group than in the Full adherence group. In the bipolar disorder patients, there was an association between the use of illicit substances and alcohol and poor adherence. We found no relationship between adherence behavior and neurocognition in the bipolar disorder group. CONCLUSION: Substance use is an important risk factor for non-adherence in patients with schizophrenia and bipolar disorder. Poor insight is also a risk factor in schizophrenia. The results suggest that cognitive dysfunction is not a risk factor for non-adherence in these diagnostic groups.

Cancer occurrence in Danish diabetic patients: duration and insulin effects.

AIMS/HYPOTHESIS: Cancer is more frequent among diabetes patients, but it is unknown how this excess varies with duration of diabetes and insulin use. The aim of this study was to analyse disease data to examine this issue further. METHODS: We linked the Danish National Diabetes Register and Cancer Registry and performed a cohort analysis of the entire Danish population by diabetes status, duration of diabetes and insulin use, comparing cancer incidence rates in diabetic patients with the non-diabetic population for the 15 year period 1995-2009, using Poisson regression with natural splines to describe the variation by duration. RESULTS: We found 20,032 cancer cases among patients not using insulin and 2,794 cancer cases among diabetic patients using insulin. The cancer incidence rate ratio among non-insulin users relative to the non-diabetic population decreased from over 2 at diagnosis to 1.15 after 2 years of diabetes duration. The cancer incidence rate ratio was higher among patients using insulin, decreasing from 5 at the start of insulin treatment to about 1.3 [corrected] after 5 years of insulin use. Among non-insulin users, cancers of the stomach, colorectum, liver, pancreas, lung, corpus uteri, kidney and brain, and lymphomas were elevated. Among insulin users the rate ratio of prostate cancer was decreasing by duration whereas we found higher risk of cancer of the stomach, lung, liver, pancreas and kidney. Breast cancer incidence rates were not affected by either diabetes or insulin use. CONCLUSIONS: The observed duration effects suggest that both increased surveillance for cancer in the first years after diagnosis of diabetes, and reverse causation, where undiagnosed cancers increase the likelihood of diabetes diagnosis, play a role. For longer durations, a combination of common causes for diabetes and cancer, as well as the effects of diabetes and insulin exposure per se, may play a role in the association between diabetes and some cancers.

Comorbidity in elderly cancer patients in relation to overall and cancer-specific mortality.

BACKGROUND: Aims of this study were to describe the prevalence of comorbidity in newly diagnosed elderly cancer cases compared with the background population and to describe its influence on overall and cancer mortality. METHODS: Population-based study of all 70+ year-olds in a Danish province diagnosed with breast, lung, colorectal, prostate, or ovarian cancer from 1 January 1996 to 31 December 2006. Comorbidity was measured according to Charlson's comorbidity index (CCI). Prevalence of comorbidity in newly diagnosed cancer patients was compared with a control group by conditional logistic regression, and influence of comorbidity on mortality was analysed by Cox proportional hazards method. RESULTS: A total of 6325 incident cancer cases were identified. Elderly lung and colorectal cancer patients had significantly more comorbidity than the background population. Severe comorbidity was associated with higher overall mortality in the lung, colorectal, and prostate cancer patients, hazard ratios 1.51 (95% CI 1.24-1.83), 1.41 (95% CI 1.14-1.73), and 2.14 (95% CI 1.65-2.77), respectively. Comorbidity did not affect cancer-specific mortality in general. CONCLUSION: Colorectal and lung cancer was associated with increased comorbidity burden in the elderly compared with the background population. Comorbidity was associated with increased overall mortality in elderly cancer patients but not consistently with cancer-specific mortality.

Treatment for Helicobacter pylori infection and risk of Parkinson's disease in Denmark.

BACKGROUND AND PURPOSE: It has been speculated that gastrointestinal infection with Helicobacter pylori (HP) contributes to the development of Parkinson's disease (PD). We used nationwide Danish registers to investigate this hypothesis. METHODS: We identified 4484 patients with a first time PD diagnosis between 2001 and 2008 from the Danish National Patient Register (DNPR) and 22, 416 population controls from the Danish Civil Registration System (CRS). Information on drug use was obtained from the National Prescription Registry (NPR). We used logistic regression to compute odds ratios (OR) for the association between treatment for HP and risk of PD. RESULTS: Prescriptions for HP-eradication drugs and proton pump inhibitors (PPI) 5 or more years prior to the diagnosis of PD were associated with a 45% and 23% increase in PD risk, respectively. Hospitalizations and outpatient visits for gastritis and peptic/duodenal ulcers, however, were not associated with PD. CONCLUSIONS: Our population-based study suggests that chronic HP infections and/or gastritis contribute to PD or that these are PD-related pathologies that precede motor symptoms.