Zinc status and its relation to growth retardation in children with chronic inflammatory bowel disease

Abstract

Zinc status was studied in 30 patients with chronic inflammatory bowel disease (CIBD) as well as in 17 normal children, 13 primordial short stature, and 17 anorexia nervosa patients. Basal serum and urinary excretion levels of zinc were measured in all patients. In addition, a zinc loading test was performed in 16 CIBD patients, 21 normal and/or short stature children, and nine patients with anorexia nervosa. Eleven of 30 patients with CIBD had serum zinc values less than 0.7 microgram/ml, whereas none of the other patients had hypozincemia. In addition, the mean urinary zinc excretion of CIBD patients was significantly lower than that of patients with primordial short stature and with anorexia nervosa. An altered response to oral zinc load was the most frequent abnormality in CIBD patients. Those with moderate and severe clinical disease activity had a decreased serum rise of zinc after the oral load of this ion. Urinary excretion of zinc after oral load was also marked by deficiency in all CIBD patients. The abnormalities of zinc metabolism were more frequent among the CIBD patients with growth abnormalities, although they were also found in patients who had normal growth. Among the 14 patients with CIBD and growth abnormalities, seven were hypozincemic and four hypozincuric. Hypozincemia was only found in four patients who had normal height; however, the growth velocity was not known. The zinc tolerance test revealed abnormalities in four of five CIBD patients with short stature and in two of three patients with slow growth. On the other hand, similar alterations in zinc tolerance tests were seen in three of seven CIBD patients with normal height and growth.

Zinc Metabolism in Adolescents with Crohn's Disease

“…Fasting plasma zinc was lower in the CD subjects than the controls, consistent with other studies in CD with (19) or without gut resection (6,8,14,16,17,42). It has been suggested that the lower plasma (or serum) zinc in CD might result from a lower serum albumin concentration (12,13).…”

“…Several studies have suggested that urinary zinc excretion is lower in CD patients (17,(42)(43)(44), presumably as an adaptation to suboptimal zinc status. In our study, urinary zinc excretion was similar in the CD subjects and the controls.…”

“…The incidence of milder forms of zinc deficiency has been difficult to assess. Although several investigators have reported low plasma zinc concentrations in patients with CD (8,(12)(13)(14)(15)(16)(17)(18), very little body zinc is in the plasma and it is a poor measure of zinc status (2). Some studies have also demonstrated decreases in zinc-dependent enzymes [such as thymulin in the plasma (19) and metallothionein in the gut mucosa (20)], reduction in muscle zinc concentration (19), and poor taste acuity (6,21) in patients with CD.…”

“…A number of studies have examined zinc absorption in CD and have shown either normal (23,24) or low zinc absorption (17,18,25). However, we are unaware of any study that has measured endogenous fecal zinc excretion in CD.…”

Crohn's Disease Associated with Growth Hormone Secretory Dysfunction.

“…Juvenile-onset Crohn's disease reportedly causes marked growth retardation or results in the delay of secondary sexual maturation (5, 6), whereas colitis ulcerosa, also a nonspecific inflammatory disease, rarely is accompanied by severe growth retardation. Growth retardation associated with chronic inflammatory bowel disease is probably caused by malnutrition (2,7,8), endocrine abnormalities (9, 10), use of steroid hormones (1 1) and deficiency of trace elements, such as zinc (12). Some reports contradict the theory that endocrine function related to GHsecretion is impaired in the presence of Crohn's disease; normal GHsecretion has been reported in Crohn's disease patients (13,14).…”