Lower-income youth with kidney disease, even when prescribed growth hormone, are less likely to grow to a normal height, U.S. researchers say. Dr. Susan Furth, a researcher at The Children's Hospital of Philadelphia and lead author of the Chronic Kidney Disease in Children study, the largest study of children with the ailment, said it is the first to examine the effects of income on kidney disease progression and complications in this population. This study examined growth failure, common in children with CKD, because the disease can interfere with the normal effect of a child's own growth hormone. "Since these lower socioeconomic status children received higher proportions of prescriptions for growth hormone, it's possible that these families are not filling all their prescriptions or are filling them but not sticking to their treatment regimen as closely as higher-income families are," Dr. Marva Moxey-Mims, a pediatric kidney specialist at the National Institute of Health's National Institute of Diabetes and Digestive and Kidney Diseases, said in a statement. "Although there also could be other issues like nutrition or household finances contributing to this difference, the main lesson is that we may need to learn how to help families better follow treatment plans for their children with CKD." Furth agreed. "More aggressive intervention or other programs to help support what's happening outside the doctor's office could help," Furth said. "For example, more frequent contact with nurses and other medical staff could help children and families understand and follow prescribed treatments." Also, blood pressure control -- a factor associated with kidney disease progression -- improved across the groups, though children with lower socioeconomic status took an average of 4.5 years to get their blood pressure down within the normal range, compared with two years for those with a higher income. However, the longer time period did not appear to result in more advanced CKD in children from low-income families, the study found. "Clearly, we need to find better ways to achieve good blood pressure control in all the children," she said. "Like the growth hormone question, blood pressure could be a matter of being able to afford or regularly take the medications prescribed, or genetics, or may involve factors like diet, interactions with other medications, or other exposures that could hinder the treatments from working as well for some children." The findings were published online ahead of the December print edition of the American Journal of Kidney Diseases.