Bone biopsy in renal osteodystrophy: continued insights into a complex disease.

PURPOSE OF REVIEW: The pathogenesis and optimal therapy of renal bone disease remains poorly understood in chronic kidney disease (CKD) and dialysis patients. Bone biopsy is thus far the only window into cellular and molecular events in bone. This review will focus on recent insights into the pathophysiology of renal bone disease, as highlighted by bone biopsy, and discuss implications for treatment. RECENT FINDINGS: Abnormalities in bone physiology start very early in children and adults with CKD, when most clinically measurable mineral metabolism parameters are normal. In addition, racial differences, known to exist in serum markers such as parathyroid hormone, also appear prominent in the bone, suggesting that clinical treatment guidelines may not address the needs of all patient populations. The effects of treatments for secondary hyperparathyroidism on bone may be unexpected. SUMMARY: With the help of bone biopsy studies, molecular insights into the pathogenesis of renal osteodystrophy are beginning to emerge. Current therapies may have unexpected effects on bone physiology.

Eight self-administered 24-hour dietary recalls using the Internet are feasible in African Americans and Whites: the energetics study.

OBJECTIVE: To support research and to provide food and nutrition practitioners with a strong foundation for nutrient-based counseling, there is a need for affordable automated 24-hour dietary recalls. Multiple days of intake, along with repeated reports over time, are needed to achieve stable indicators of individual intakes and to support evaluation of success in meeting dietary goals because of intraindividual intake variability. Little information has been published on subject responses, participation rates, and the perceived subject burden of repeated 24-hour recalls. Our aim was to determine the willingness of subjects to conduct eight 24-hour recalls via the Internet. DESIGN: A study to validate a Web-based, automated, self-administered 24-hour recall (DietDay, Centrax Corporation, Chicago, IL). SUBJECTS/SETTING: Two-hundred and sixty-one white and African-American subjects within 50 miles of the University of California-Los Angeles participated in the study. Subjects completed 3 DietDays at the study visits and another 5 days on their own. The last 2 DietDays were completed 1 and 2 months after the final clinic visit. Subjects were notified by automatic e-mail of the need for DietDay completion, and nonresponders were followed up with personalized e-mails and phone calls. RESULTS: The perceived subject burden was minimal and, even after completing six recalls, 92% were willing to continue reporting their daily diets 1 and 2 months later. White subjects had a slightly higher rate of return, with 94% completing all eight recalls, compared to 91% of African-American subjects. Participants were able to access the Internet in their homes, offices, library, or homes of friends or family. It is also of interest that 82% of subjects believed the 24-hour recall was superior to a diet history in reflecting their normal diet. CONCLUSION: These results open up new opportunities for food and nutrition practitioners to strengthen their nutritional counseling in an efficient and affordable manner without additional time investment.