# Chronic kidney disease effects on cortical bone porosity and mechanics with age

> **NIH NIH F31** · INDIANA UNIVERSITY INDIANAPOLIS · 2021 · $39,072

## Abstract

ABSTRACT
Chronic kidney disease (CKD) affects one in seven individuals in the US and significantly increases fracture risk.
While CKD occurs in patients of all ages, the prevalence is highest in the aged, with nearly 40% of individuals
over age 65 having some form of CKD yet the interaction of CKD and aging is understudied. CKD primarily
affects cortical bone in the form of cortical porosity, which is inversely related to bone mechanical properties and
fracture. In CKD and aging, mechanical properties of bone are also compromised at the tissue level. Targeting
both cortical porosity and material properties will be important for reducing bone fragility in CKD. Previous
research on cortical porosity has focused on preventing pore formation while research on porosity reversal
(infilling) is lacking. We have shown that pore infilling occurs following potent suppression of parathyroid hormone
(PTH) in young animals with CKD-induced cortical porosity. Because osteoblast function is known to be
compromised with age, it is unclear whether infilling would be compromised in aged CKD or if it would necessitate
anabolic drug treatment with an agent such as anti-sclerostin antibody (romosozumab). Further, it remains
unknown if the bone that forms during pore infilling, in either young or aged animals, is of sufficient quality to
improve bone mechanical properties. Thus, the global hypothesis of this proposal is that PTH suppression alone
is insufficient to promote cortical pore infilling with normal bone matrix in aging bone and that it will require both
PTH suppression and anabolic stimulation. This hypothesis will be assessed in two Aims: Specific Aim 1.
Determine the isolated effect of PTH suppression or anabolic drug therapy compared to their combination for
promoting cortical pore infilling in young and aged CKD. Young and aged (16 and 66 weeks of age) male and
female C57BL/6J mice will be fed a diet containing adenine to induce CKD and cortical porosity. Animals will
then serve as untreated (controls) or receive 4 weeks of PTH-suppression drug treatment (cinacalcet, in diet),
anabolic drug treatment (romosozumab), or both combined. Key outcomes will include high-resolution computer
tomography imaging, histology, and gene expression. Specific Aim 2. Define the mechanical and material
properties of the infilled bone. Tissue from Aim 1 will be assessed for mechanical properties of the newly formed
bone within the cortical pores using Raman spectroscopy and nanoindentation. Whole bone mechanical
properties will be assessed by multiple testing methods. Importantly, the proposed studies provide a fertile
training environment in which the applicant can expand understanding of bone, aging, and chronic kidney
disease within an existing translational collaborative team. The mentoring team of Dr. Allen (skeletal biology),
Dr. White (mineral metabolism), Dr. Wallace (bone mechanics), and Dr. Moe (nephrology) have an established
track record of mentorship to augment...

## Key facts

- **NIH application ID:** 10314593
- **Project number:** 1F31DK130603-01
- **Recipient organization:** INDIANA UNIVERSITY INDIANAPOLIS
- **Principal Investigator:** Samantha P Tippen
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $39,072
- **Award type:** 1
- **Project period:** 2021-06-23 → 2024-06-22

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10314593

## Citation

> US National Institutes of Health, RePORTER application 10314593, Chronic kidney disease effects on cortical bone porosity and mechanics with age (1F31DK130603-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10314593. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*
