Published online Feb 7, 2019. doi: 10.3748/wjg.v25.i5.600
Peer-review started: December 6, 2018
First decision: December 28, 2018
Revised: January 10, 2019
Accepted: January 14, 2019
Article in press: January 14, 2019
Published online: February 7, 2019
Processing time: 55 Days and 20.1 Hours
Zinc is a key element in numerous proteins and plays an important role in essential cell functions such as defense against free radicals and DNA damage repair. Chronic pancreatitis (CP) is a chronic inflammation with progressive fibrosis of pancreas ultimately resulting in pancreatic exocrine insufficiency (PEI), which is associated with malnutrition. Studies analyzing zinc levels in patients with CP are sparse and lead to conflicting results.
To investigate serum zinc levels in patients with CP of various etiologies.
Between October 2015 and March 2018, patients with a diagnosis of CP were identified and recruited from the Pancreatic Outpatient Clinic at the Karolinska University Hospital in Stockholm, Sweden. Demographic, clinical and laboratory data were analyzed. Etiology of CP was determined according to the M-ANNHEIM classification system into the following etiological subcategories: alcohol consumption, nicotine consumption, hereditary factors, efferent pancreatic duct factors and immunological factors. Pancreatic exocrine function was defined as normal (fecal elastase 1 > 200 μg/g), mildly reduced (100-200 μg/g) and severely reduced (fecal elastase 1 < 100 μg/g).
A total of 150 patients were included in the analysis. Zinc deficiency (< 11 μmol/L) was present in 39 (26.0%) of patients: 22 females and 17 males. In the group of patients with zinc deficiency, 76.7% of patients had an exocrine pancreatic insufficiency (FE-1 < 200 μg/g). Older age was significantly associated with low zinc levels. Following a univariate analysis, patients aged 60-69 and patients ≥ 70 years of age had a significantly higher prevalence of zinc deficiencies compared to patients < 40 years of age [OR: 3.8, 95%CI (1.08-13.4); P = 0.04]; [OR 6.26, 95%CI (1.94-20.2), P > 0.002]. Smoking and number of pack-years were additionally associated with low zinc levels. The risk of zinc deficiency in current smokers and smokers with ≥ 20 pack-years was approximately three times higher compared to those who had never smoked. Gender, body mass index, etiology of CP, presence of diabetes mellitus, levels of glycated hemoglobin (HbA1c), bone mineral density, alcohol intake and presence of PEI were not associated with low zinc levels.
Zinc deficiency is common in patients with CP and is significantly associated with age ≥ 60, smoking and the number of pack-years, but not with PEI.
Core tip: Normal levels of zinc are pivotal to maintain a homeostasis in a wide variety of important cellular systems and immune response. Chronic pancreatitis (CP) is a chronic inflammation of the pancreas resulting in pancreatic exocrine insufficiency, which is associated with malnutrition. There are conflicting published results of zinc levels in patients with CP. Most of the studies were restricted to patients with alcoholic etiology of CP and had limitations due to the small number of studied patients. We are presenting the results of the largest study so far comparing serum zinc levels in relation to different etiological groups of CP.