Relationship between serum zinc levels and clinical status in persons with severe motor and intellectual disabilities

Abstract

Objective: To investigate the relationship between serum zinc levels and clinical status in persons with severe motor and intellectual disabilities (SMID) living at our medical residential facility.

Subjects and Methods: A total of 301 persons with SMID were included in the study. The relationships of serum zinc levels with background factors and blood and urine test values were examined retrospectively.

Results: Of the 301 subjects, 115 (38.2%) presented with hypozincemia (zinc level <60μg/dL), whereas only 17 (5.6%) were within the Japanese standard reference range (80–130μg/dL). Serum zinc levels were positively and significantly correlated with body mass index (BMI), energy intake per body weight, and serum albumin and creatinine levels. The proportion of bedridden persons, those with tracheostomy, and users of antiepileptic drugs were significantly higher in the hypozincemia group. Multiple regression analysis revealed that motor function, BMI, tracheostomy, treatment with valproic acid, and serum albumin were significant factors associated with serum zinc levels.

Conclusion: Serum zinc levels in most subjects were below Japanese standard reference values. Bedridden status, low BMI, tracheostomy, valproic acid use, and low serum albumin seem to be risk factors for hypozincemia in persons with SMID.