Celiac disease (CD) affects predominantly the proximal small intestine where the absorption of zinc is most efficient(1). Few studies have been done to study the association between zinc and CD and their results have shown that CD patients are at risk of zinc deficiency(2-4). Hence this work was planned with the aim to determine the zinc levels in untreated and treated celiac disease.

The present study was conducted between June 2004 and June 2005. Patients attending Pediatric Gastroenterology clinic with chronic diarrhea, growth failure, abdominal distention and/or anemia were subjected to duodenal biopsy and anti-endomysial antibody (EMA). Diagnosis of CD was made as per modified ESPHGAN criteria(5). Duodenal biopsy was graded as per the Marsh classification(6). EMA (IgA) were done at a commercial laboratory (Lal Pathology labs, New Delhi) with the monkey esophagus as substrate. All children provisionally diagnosed as CD and previously diagnosed CD cases were included in the study. Demographical data, historical details and examination findings with special reference to clinical signs associated with CD, were recorded on a pre-designed proforma on inclusion. Nutrition status was assessed as per CDC norms. All patients with a provisional diagnosis of CD were put on gluten free diet (GFD). Blood sample was taken for zinc levels at inclusion. Zinc (2 mg/kg/day for 3 months) and iron supplementation were started at inclusion with doses being 12 hours apart. Prior to this study we were not advising zinc to all the celiac cases in the Pediatric Gastroenterology clinic. As per the protocol of this clinic, patients are called for 2 weekly follow up till the initial 8 weeks and later at 1-2 monthly intervals. At every visit history, dietary compliance and weight were recorded. Zinc levels and height measurements were repeated at 3 and 6 months after inclusion. All the patients showing unequivocal response to GFD within 8 weeks were confirmed to have CD. For each of these cases, anthropometry and serum zinc level of an age and sex matched healthy control was also done.

Estimation of serum zinc was done by atomic absorption spectro-photometry. Four mL blood was taken in an ion free vial, kept in water bath at 37°C for 1 hour and the serum was separated by centrifugation at 3000 rpm for 10 min. Serum was discarded, if there was any evidence of hemolysis. Samples were stored at –20°C and analyzed within one week of collection.

Data were processed with help of SPSS version 11. Student t test and Fischer's exact test were used to analyze the continuous and categorical variables, respectively.

Results

Of the 214 cases of chronic diarrhea reporting to the Pediatric Gastroenterology Clinic, 79 were clinically suspected to have celiac disease. Of the 79 clinically suspected, 21 were diagnosed as CD. Additionally, 7 old cases of CD (already on GFD for more than 3 months) were also included in the study. Two patients presenting with intractable iron deficiency anemia and recurrent abdominal pain were suspected and diagnosed as atypical celiac disease. Of these 30 celiac cases, 15, 9 and 6 had Marsh score IIIA, IIIB and IIIC, respectively. EMA was positive in 24 cases. Of the six cases where EMA was negative 2 each had Marsh IIIA, IIIB and IIIC respectively. Because of the logistics constraints we were able to take only 27 controls. There were 15 old cases of CD who did not attend Pediatric Gastroenterology clinic during the study period hence could not be included in the study.

There were 20 males (66.7%) with a male: female ratio of 2:1 among the 30 cases and age group ranged between 21 to 192 months. The majority of cases are in the age group of 6-10 years. The mean duration of diarrhea at presentation was 44.5±35.2 months in the 28 cases with chronic diarrhea. Abdominal distension and moderate to severe anemia was present in 18 (60%) cases each, respectively. Vitamin D and A deficiency were present in 7 (23.3%) and 4 (13.3%) cases, respectively. Rectal prolapse was present in 2 cases at presentation. Alopecia, and dermatitis herpetiformis were present in 1 case each at presentation. Other clinical characteristics and serum zinc levels of the cases and controls are presented in the Table I. The comparison of mean serum zinc levels of the patients with varying weight and height z-scores are presented in Table II. The mean serum zinc levels of children with partial villous atrophy (0.66±0.40 mg/mL) and subtotal as well as total villous atrophy (0.79±0.42 mg/mL) were comparable (95% CI for mean difference –0.47 to 0.21). On follow up at 3 and 6 months the serum zinc levels showed no significant difference.

TABLE I

Characteristics of the Children with Celiac Disease and Controls at Inclusion