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.