Genetic polymorphisms associated with smoking behaviour predict the risk of surgery in patients with Crohn's disease

BACKGROUND

Smoking is a strong environmental factor leading to adverse outcomes in Crohn's disease, but a more benign course in ulcerative colitis. Several single nucleotide polymorphisms (SNPs) are associated with smoking quantity and behaviour.

AIM

To assess whether smoking-associated SNPs interact with smoking to influence the clinical course of inflammatory bowel diseases.

METHODS

Genetic and prospectively obtained clinical data from 1434 Swiss inflammatory bowel disease cohort patients (821 Crohn's disease and 613 ulcerative colitis) were analysed. Six SNPs associated with smoking quantity and behaviour (rs588765, rs1051730, rs1329650, rs4105144, rs6474412 and rs3733829) were combined to form a risk score (range: 0-12) by adding the number of risk alleles. We calculated multivariate models for smoking, risk of surgery, fistula, Crohn's disease location and ulcerative colitis disease extent.

RESULTS

In Crohn's disease patients who smoke, the number of surgeries was associated with the genetic risk score. This translates to a predicted 3.5-fold (95% confidence interval: 2.4- to 5.7-fold, P<.0001) higher number of surgical procedures in smokers with 12 risk alleles than individuals with the lowest risk. Patients with a risk score >7 had a significantly shorter time to first intestinal surgery. The genetic risk score did not predict surgery in ulcerative colitis or occurrence of fistulae in Crohn's disease. SNP rs6265 was associated with ileal disease in Crohn's disease (P<.05) and proctitis in ulcerative colitis (P<.05).

CONCLUSIONS

SNPs associated with smoking quantity is associated with an increased risk for surgery in Crohn's disease patients who smoke. Our data provide an example of genetics interacting with the environment to influence the disease course of inflammatory bowel disease.

Physician speciality and pain reduction in patients with depressive symptoms under treatment with venlafaxine

OBJECTIVES

Excessive pain perception may lead to unnecessary diagnostic testing or invasive procedures resulting in iatrogenic complications and prolonged disability. Naturalistic studies on patients with chronic pain and depressive symptoms investigating the impact of medical speciality on treatment outcome in a primary care setting are lacking.

METHODS

In this observational study, we examined whether the magnitude of pain reduction in 444 patients with depressive symptomatology under venlafaxine would relate differently to the medical speciality of the 122 treating physicians, namely psychiatrists (n=110 patients), general practitioners (n=236 patients), and internists (n=98 patients).

RESULTS

Independent of age, gender, patient's region of origin, comorbidity, severity and duration of pain, and depressive symptoms at study entry, patients seemed to benefit significantly less in terms of pain reduction (p<0.001) and of reduction in severity of depressive symptomatology by psychiatrists as compared to general practitioners (p<0.019) and internists (p<0.002).

CONCLUSIONS

The findings suggest that patients referred to psychiatrists are more difficult to treat than those referred to general practitioners and internists, and might not have been adequately prepared for psychiatric interventions. A supporting cooperation and networking between psychiatrists and primary care physicians may contribute to an integrated treatment concept and therefore, may lead to a better outcome in this challenging patient group.

Regional Origin and Decrease of Pain in Patients with Depressive Symptoms Under Treatment with Venlafaxine

Aims:

Worldwide data are extensively lacking in regard to patients with depressive symptoms under therapy with antidepressants in the primary care setting. We hypothesized that the magnitude of pain reduction under treatment with venlafaxine differently relates to regional origin of patients.

Methods:

We conducted a prospective naturalistic observational trial on 420 pain sufferers with depressive symptoms from all over Switzerland who were treated with venlafaxine by 122 physicians in primary care. Previous and additional antidepressant medication was not taken into account. Physicians rated illness severity using the Clinical Global Impression severity scale and pain intensity by means of visual analogue scales.

Results:

Compared with Middle European patients (ME), those from Eastern Europe (EE), and Southern Europe (SE) were younger and presented more intense overall pain mainly affecting the head, extremities and back. In addition, SE patients suffered more intense thoracic pain than ME patients, and EE patients suffered less frequently from abdominal pain compared to their ME and SE counterparts. Furthermore, 3 months after study entry, ME patients were found to profit more from treatment with venlafaxine in terms of overall illness severity and pain intensity than patients from EE and SE.

Physician Speciality and Pain Reduction in Patients with Depressive Symptoms Under Treatment with Venlafaxine

Aims:

Excessive pain perception may lead to unnecessary diagnostic testing or invasive procedures to result in iatrogenic complications and prolonged disability. Naturalistic studies on depressed patients with chronic pain investigating the impact of medical speciality on treatment outcome in a primary care setting are lacking.

Methods:

In this observational study, we examined whether the magnitude of pain reduction in 444 depressed patients under venlafaxine would differently relate to the medical speciality of the 122 treating physicians, namely psychiatrists (n=110 patients), general practitioners (n=236 patients), and internists (n=98 patients).

Results:

Independent of demographic factors, comorbidity, severity of pain and illness at study entry, and the duration of pain and depression, patients seemed to profit significantly less in terms of pain reduction (p< .001) and of reduction in severity of their illness by psychiatrists as compared to general practitioners (p< .019) and internists (p< .002).

Increased NoGo-anteriorisation in first-episode schizophrenia patients during Continuous Performance Test

OBJECTIVE

NoGo-stimuli during a Continuous Performance Test (CPT) activate prefrontal brain structures such as the anterior cingulate gyrus and lead to an anteriorisation of the positive electrical field of the NoGo-P300 relative to the Go-P300, so-called NoGo-anteriorisation (NGA). NGA during CPT is regarded as a neurophysiological standard index for cognitive response control. While it is known that patients with chronic schizophrenia exhibit a significant reduction in NGA, it is unclear whether this also occurs in patients undergoing their first-episode. Thus, the aim of the present study was to determine NGA in a group of patients with first-episode schizophrenia by utilizing a CPT paradigm.

METHODS

Eighteen patients with first-episode schizophrenia and 18 matched healthy subjects were investigated electrophysiologically during a cued CPT, and the parameters of the Go- and NoGo-P300 were determined using microstate analysis. Low resolution tomography analysis (LORETA) was used for source determination.

RESULTS

Due to a more posterior Go- and a more anterior NoGo-centroid, NGA was greater in patients than in healthy controls. LORETA indicated the same sources for both groups after Go-stimuli, but a more anterior source in patients after NoGo-stimuli. In patients P300-amplitude responses to both Go- and NoGo-stimuli were decreased, and P300-latency to NoGo-stimuli was increased. After the Go-stimuli false reactions and reaction times were increased in patients.

CONCLUSIONS

Attention was reduced in patients with first-episode schizophrenia, as indicated by more false reactions, prolongation of reaction time, P300-latencies and by a decrease in P300-amplitude. Significantly however, the NGA and prefrontal LORETA-sources indicate intact prefrontal brain structures in first-episode schizophrenia patients. Previously described changes in this indicator of prefrontal function may be related to a progressive decay in chronic schizophrenia.

SIGNIFICANCE

The results support the idea of a possible new biological marker of first episode psychosis, which may be a useful parameter for the longitudinal measurement of changing prefrontal brain function in a single schizophrenia patient.

Cerebral Disconnectivity: An Early Event in Schizophrenia

Neuroimaging and electrophysiological investigations have demonstrated numerous differences in brain morphology and function of chronic schizophrenia patients compared to healthy controls. Studying patients at the beginning of their disease without the confounding effects of chronicity, medication, and institutionalization may provide a better understanding of schizophrenia. Recently, at many institutions around the world, special projects have been launched for specialized treatment and research of this interesting patient group. Using the PubMed search engine in this update, the authors summarize recent investigations between January 2002 and September 2006 that focus on whether signs of disconnectivity already exist early in the disease process. They discuss gray and white matter changes, their impact on symptomatology, electroencephalogram-based studies on connectivity, and possible influences of medication. NEUROSCIENTIST 14(1):19—45, 2008. DOI: 10.1177/1073858406298391