Michele D. Lewis

Alcohol and Smoking as Risk Factors in an Epidemiology Study of Patients With Chronic Pancreatitis

BACKGROUND & AIMS Alcohol has been implicated in the development of chronic pancreatitis (CP) in 60%-90% of patients, although percentages in the United States are unknown. We investigated the epidemiology of alcohol-related CP at tertiary US referral centers. METHODS We studied data from CP patients (n = 539) and controls (n = 695) enrolled in the North American Pancreatitis Study-2 from 2000 to 2006 at 20 US referral centers. CP was defined by definitive evidence from imaging or histologic analyses. Subjects and physicians each completed a study questionnaire. Using physician-assigned diagnoses, patients were assigned to an etiology group: alcohol (with/without other diagnoses), nonalcohol (any etiology of CP from other than alcohol), or idiopathic (no etiology identified). RESULTS The distribution of patients among etiology groups was: alcohol (44.5%), nonalcohol (26.9%), and idiopathic (28.6%). Physicians identified alcohol as the etiology more frequently in men (59.4% men vs 28.1% women), but nonalcohol (18% men vs 36.7% women) and idiopathic etiologies (22.6% men vs 35.2% women) more often in women (P < .01 for all comparisons). Nonalcohol etiologies were equally divided among obstructive, genetic, and other causes. Compared with controls, patients with idiopathic CP were more likely to have ever smoked (58.6% vs 49.7%, P < .05) or have a history of chronic renal disease or failure (5.2% vs 1.2%, P < .01). In multivariate analyses, smoking (ever, current, and amount) was independently associated with idiopathic CP. CONCLUSIONS The frequency of alcohol-related CP at tertiary US referral centers is lower than expected. Idiopathic CP and nonalcohol etiologies represent a large subgroup, particularly among women. Smoking is an independent risk factor for idiopathic CP.

Type of pain, pain-associated complications, quality of life, disability and resource utilisation in chronic pancreatitis: a prospective cohort study

Objective To compare patients with chronic pancreatitis (CP) with constant pain patterns to patients with CP with intermittent pain patterns. Methods This was a prospective cohort study conducted at 20 tertiary medical centers in the USA comprising 540 subjects with CP. Patients with CP were asked to identify their pain from five pain patterns (A–E) defined by the temporal nature (intermittent or constant) and the severity of the pain (mild, moderate or severe). Pain pattern types were compared with respect to a variety of demographic, quality of life (QOL) and clinical parameters. Rates of disability were the primary outcome. Secondary outcomes included: use of pain medications, days lost from school or work, hospitalisations (preceding year and lifetime) and QOL as measured using the Short Form-12 (SF-12) questionnaire. Results Of the 540 CP patients, 414 patients (77%) self-identified with a particular pain pattern and were analysed. Patients with constant pain, regardless of severity, had higher rates of disability, hospitalisation and pain medication use than patients with intermittent pain. Patients with constant pain had lower QOL (by SF-12) compared with patients who had intermittent pain. Additionally, patients with constant pain were more likely to have alcohol as the aetiology for their pancreatitis. There was no association between the duration of the disease and the quality or severity of the pain. Conclusions This is the largest study ever conducted of pain in CP. These findings suggest that the temporal nature of pain is a more important determinant of health-related QOL and healthcare utilisation than pain severity. In contrast to previous studies, the pain associated with CP was not found to change in quality over time. These results have important implications for improving our understanding of the mechanisms underlying pain in CP and for the goals of future treatments and interventions.

Combined Bicarbonate Conductance-Impairing Variants in CFTR and SPINK1 Variants Are Associated With Chronic Pancreatitis in Patients Without Cystic Fibrosis

BACKGROUND & AIMS Idiopathic chronic pancreatitis (ICP) is a complex inflammatory disorder associated with multiple genetic and environmental factors. In individuals without cystic fibrosis (CF), variants of CFTR that inhibit bicarbonate conductance but maintain chloride conductance might selectively impair secretion of pancreatic juice, leading to trypsin activation and pancreatitis. We investigated whether sequence variants in the gene encoding the pancreatic secretory trypsin inhibitor SPINK1 further increase the risk of pancreatitis in these patients. METHODS We screened patients and controls for variants in SPINK1 associated with risk of chronic pancreatitis and in all 27 exons of CFTR. The final study group included 53 patients with sporadic ICP, 27 probands with familial ICP, 150 unrelated controls, 375 additional controls for limited genotyping. CFTR wild-type and p.R75Q were cloned and expressed in HEK293 cells, and relative conductances of HCO(3)(-) and Cl(-) were measured. RESULTS SPINK1 variants were identified in 36% of subjects and 3% of controls (odds ratio [OR], 18.1). One variant of CFTR not associated with CF, p.R75Q, was found in 16% of subjects and 5.3% of controls (OR, 3.4). Coinheritance of CFTR p.R75Q and SPINK1 variants occurred in 8.75% of patients and 0.38% of controls (OR, 25.1). Patch-clamp recordings of cells that expressed CFTR p.R75Q showed normal chloride currents but significantly reduced bicarbonate currents (P = .0001). CONCLUSIONS The CFTR variant p.R75Q causes a selective defect in bicarbonate conductance and increases risk of pancreatitis. Coinheritance of p.R75Q or CF causing CFTR variants with SPINK1 variants significantly increases the risk of ICP.

Mechanisms of CFTR Functional Variants That Impair Regulated Bicarbonate Permeation and Increase Risk for Pancreatitis but Not for Cystic Fibrosis

CFTR is a dynamically regulated anion channel. Intracellular WNK1-SPAK activation causes CFTR to change permeability and conductance characteristics from a chloride-preferring to bicarbonate-preferring channel through unknown mechanisms. Two severe CFTR mutations (CFTRsev) cause complete loss of CFTR function and result in cystic fibrosis (CF), a severe genetic disorder affecting sweat glands, nasal sinuses, lungs, pancreas, liver, intestines, and male reproductive system. We hypothesize that those CFTR mutations that disrupt the WNK1-SPAK activation mechanisms cause a selective, bicarbonate defect in channel function (CFTRBD) affecting organs that utilize CFTR for bicarbonate secretion (e.g. the pancreas, nasal sinus, vas deferens) but do not cause typical CF. To understand the structural and functional requirements of the CFTR bicarbonate-preferring channel, we (a) screened 984 well-phenotyped pancreatitis cases for candidate CFTRBD mutations from among 81 previously described CFTR variants; (b) conducted electrophysiology studies on clones of variants found in pancreatitis but not CF; (c) computationally constructed a new, complete structural model of CFTR for molecular dynamics simulation of wild-type and mutant variants; and (d) tested the newly defined CFTRBD variants for disease in non-pancreas organs utilizing CFTR for bicarbonate secretion. Nine variants (CFTR R74Q, R75Q, R117H, R170H, L967S, L997F, D1152H, S1235R, and D1270N) not associated with typical CF were associated with pancreatitis (OR 1.5, p = 0.002). Clones expressed in HEK 293T cells had normal chloride but not bicarbonate permeability and conductance with WNK1-SPAK activation. Molecular dynamics simulations suggest physical restriction of the CFTR channel and altered dynamic channel regulation. Comparing pancreatitis patients and controls, CFTRBD increased risk for rhinosinusitis (OR 2.3, p<0.005) and male infertility (OR 395, p<<0.0001). WNK1-SPAK pathway-activated increases in CFTR bicarbonate permeability are altered by CFTRBD variants through multiple mechanisms. CFTRBD variants are associated with clinically significant disorders of the pancreas, sinuses, and male reproductive system.

Physical and mental quality of life in chronic pancreatitis: a case-control study from the North American Pancreatitis Study 2 cohort.

Objectives The objective of this study was to define the quality of life (QOL) in patients with chronic pancreatitis (CP). Methods We studied 443 well-phenotyped CP subjects and 611 control subjects prospectively enrolled from 20 US centers between 2000 and 2006 in the North American Pancreatitis Study 2. Responses to the SF-12 questionnaire were used to calculate the mental (MCS) and physical component summary scores (PCS) with norm-based scoring (normal ≥50). Quality of life in CP subjects was compared with control subjects after controlling for demographic factors, drinking history, smoking, and medical conditions. Quality of life in CP was also compared with known scores for several chronic conditions. Results Both PCS (38 [SD, 11.5] vs 52 [SD, 9.4]) and MCS (44 [SD, 11.5] vs 51 [SD, 9.2]) were significantly lower in CP compared with control subjects (P < 0.001). On multivariable analyses, compared with control subjects, a profound decrease in physical QOL (PCS 12.02 points lower) and a clinically significant decrease in mental QOL (MCS 4.24 points lower) was seen due to CP. Quality of life in CP was similar to (heart, kidney, liver, lung disease) or worse than (nonskin cancers, diabetes mellitus, hypertension, rheumatoid arthritis) other chronic conditions. Conclusions The impact of CP on QOL appears substantial. The QOL in CP subjects appears to be worse or similar to the QOL of many other chronic conditions.

Smoking is underrecognized as a risk factor for chronic pancreatitis

Background/Aims: Smoking is an established risk factor for chronic pancreatitis (CP). We sought to identify how often and in which CP patients physicians consider smoking to be a risk factor. Methods: We analyzed data on CP patients and controls prospectively enrolled from 19 US centers in the North American Pancreatitis Study-2. We noted each subject’s self-reported smoking status and quantified the amount and duration of smoking. We noted whether the enrolling physician (gastroenterologist with specific interest in pancreatology) classified alcohol as the etiology for CP and selected smoking as a risk factor. Results: Among 382/535 (71.4%) CP patients who were self-reported ever smokers, physicians cited smoking as a risk factor in only 173/382 (45.3%). Physicians cited smoking as a risk factor more often among current smokers, when classifying alcohol as CP etiology, and with higher amount and duration of smoking. We observed a wide variability in physician decision to cite smoking as a risk factor. Multivariable regression analysis however confirmed that the association of CP with smoking was independent of physician decision to cite smoking as a risk factor. Conclusions: Physicians often underrecognize smoking as a CP risk factor. Efforts are needed to raise awareness of the association between smoking and CP.

Use and perceived effectiveness of non-analgesic medical therapies for chronic pancreatitis in the United States

Aliment Pharmacol Ther 2011; 33: 149–159

Quality of Life in Chronic Pancreatitis is Determined by Constant Pain, Disability/Unemployment, Current Smoking, and Associated Co-Morbidities

Objectives:Chronic pancreatitis (CP) has a profound independent effect on quality of life (QOL). Our aim was to identify factors that impact the QOL in CP patients.Methods:We used data on 1,024 CP patients enrolled in the three NAPS2 studies. Information on demographics, risk factors, co-morbidities, disease phenotype, and treatments was obtained from responses to structured questionnaires. Physical and mental component summary (PCS and MCS, respectively) scores generated using responses to the Short Form-12 (SF-12) survey were used to assess QOL at enrollment. Multivariable linear regression models determined independent predictors of QOL.Results:Mean PCS and MCS scores were 36.7±11.7 and 42.4±12.2, respectively. Significant (P<0.05) negative impact on PCS scores in multivariable analyses was noted owing to constant mild–moderate pain with episodes of severe pain or constant severe pain (10 points), constant mild–moderate pain (5.2), pain-related disability/unemployment (5.1), current smoking (2.9 points), and medical co-morbidities. Significant (P<0.05) negative impact on MCS scores was related to constant pain irrespective of severity (6.8–6.9 points), current smoking (3.9 points), and pain-related disability/unemployment (2.4 points). In women, disability/unemployment resulted in an additional 3.7 point reduction in MCS score. Final multivariable models explained 27% and 18% of the variance in PCS and MCS scores, respectively. Etiology, disease duration, pancreatic morphology, diabetes, exocrine insufficiency, and prior endotherapy/pancreatic surgery had no significant independent effect on QOL.Conclusions:Constant pain, pain-related disability/unemployment, current smoking, and concurrent co-morbidities significantly affect the QOL in CP. Further research is needed to identify factors impacting QOL not explained by our analyses.

Racial Differences in the Clinical Profile, Causes, and Outcome of Chronic Pancreatitis.

OBJECTIVES:Racial differences in susceptibility and progression of pancreatitis have been reported in epidemiologic studies using administrative or retrospective data. There has been little study, however, on the clinical profile, causes, and outcome of chronic pancreatitis (CP) in black patients.METHODS:We analyzed data on black patients with CP prospectively enrolled in the multicenter North American Pancreatitis Studies from 26 US centers during the years 2000–2014. CP was defined by definitive evidence on imaging studies or histology. Information on demographics, etiology, risk factors, disease phenotype, treatment, and perceived effectiveness was obtained from responses to detailed questionnaires completed by both patients and physicians.RESULTS:Of the 1,159 patients enrolled, 248 (21%) were black. When compared with whites, blacks were significantly more likely to be male (60.9 vs. 53%), ever (88.2 vs. 71.8%), or current smokers (64.2 vs. 45.9%), or have a physician-defined alcohol etiology (77 vs. 41.9%). There was no overall difference in the duration of CP although for alcoholic CP, blacks had a longer duration of disease (8.6 vs. 6.97 years; P=0.02). Blacks were also significantly more likely to have advanced changes on pancreatic morphology (calcifications (63.3 vs. 55.2%), atrophy (43.2 vs. 34.6%), pancreatic ductal stricture or dilatation (72.6 vs. 65.5%) or common bile duct stricture (18.6 vs. 8.2%)) and function (endocrine insufficiency 39.9 vs. 30.2%). Moreover, the prevalence of any (94.7 vs. 83%), constant (62.6 vs. 51%), and severe (78.4 vs. 65.8%) pain and disability (35.1 vs. 21.4%) were significantly higher in blacks. Observed differences were in part related to variances in etiology and duration of disease. No differences in medical or endoscopic treatments were seen between races although prior cholecystectomy (31.1 vs. 19%) was more common in white patients.CONCLUSIONS:Differences were observed between blacks and whites in the underlying cause, morphologic expression, and pain characteristics of CP, which in part are explained by the underlying risk factor(s) with alcohol and tobacco being much more frequent in black patients as well as disease duration.

Spectrum of use and effectiveness of endoscopic and surgical therapies for chronic pancreatitis in the United States.

Objective This study aims to describe the frequency of use and reported effectiveness of endoscopic and surgical therapies in patients with chronic pancreatitis treated at US referral centers. Methods Five hundred fifteen patients were enrolled prospectively in the North American Pancreatitis Study 2, where patients and treating physicians reported previous therapeutic interventions and their perceived effectiveness. We evaluated the frequency and effectiveness of endoscopic (biliary or pancreatic sphincterotomy, biliary or pancreatic stent placement) and surgical (pancreatic cyst removal, pancreatic drainage procedure, pancreatic resection, surgical sphincterotomy) therapies. Results Biliary and/or pancreatic sphincterotomy (42%) were the most common endoscopic procedure (biliary stent, 14%; pancreatic stent, 36%; P < 0.001). Endoscopic procedures were equally effective (biliary sphincterotomy, 40.0%; biliary stent, 40.8%; pancreatic stent, 47.0%; P = 0.34). On multivariable analysis, the presence of abdominal pain (odds ratio, 1.82; 95% confidence interval, 1.15–2.88) predicted endoscopy, whereas exocrine insufficiency (odds ratio, 0.63; 95% confidence interval, 0.42–0.94) deterred endoscopy. Surgical therapies were attempted equally (cyst removal, 7%; drainage procedure, 10%; resection procedure, 12%) except for surgical sphincteroplasty (4%; P < 0.001). Surgical sphincteroplasty was the least effective (46%; P < 0.001) versus cyst removal (76% drainage [71%] and resection [73%]). Conclusions Although surgical therapies were performed less frequently than endoscopic therapies, they were more often reported to be effective.