Association between ferritin, transferrin receptor and retinol biomarkers obtained from dried blood spots and anthropometric measures in Kenyan children

Micronutrient deficiencies continue to be a problem in Africa and  dried   blood  spot (DBS) specimens provide a practical means to explore their causes. This study examined the  association  of DBS biomarker data with age and  anthropometric  measurements. DBS specimens were collected from 369  children  aged 0–59 months residing in four randomly selected locations in the Ukambani region of Kenya. A 0.635 cm disk was punched from the DBS on the collection card and extracted with buffer.  Ferritin  and  transferrin   receptor  were assayed by ELISA and  retinol  by HPLC.  Anthropometric   measures   obtained  on site were used to compute malnutrition indices (z-scores) using EPI INFO 2000. With increasing age, DBS concentration of  ferritin  decreased ( P =0.02),  transferrin   receptor increased ( P <0.001) and  retinol  showed no change. There were significant positive correlations between  ferritin  and weight-for-height, weight-for-age and height-for-age z scores, whereas  transferrin   receptor  was negatively correlated to weight-for-height and height-for-age z scores ( P <0.05). In conclusion, values for  ferritin and  transferrin   receptor  varied with age and were correlated to  anthropometric   measures  whereas those of  retinol  did not show similar outcomes.