Abstract: SA-PO891

Relation of Dietary Acid Load to Bone Mineral Density (BMD) and Osteoporosis in Early CKD

Session Information

  • Mineral Disease: CKD-Bone
    November 04, 2017 | Location: Hall H, Morial Convention Center
    Abstract Time: 10:00 AM - 10:00 AM

Category: Mineral Disease

  • 1203 Mineral Disease: CKD-Bone

Authors

  • Banerjee, Tanushree, University of California, San Francisco, San Francisco, California, United States
  • Hsu, Chi-yuan, University of California San Francisco, San Francisco, California, United States
  • Stack, Austin G., Graduate Entry Medical School, University of Limerick, Limerick, Ireland
  • Burrows, Nilka Rios, Centers for Disease Control and Prevention, Atlanta, Georgia, United States
  • Saran, Rajiv, University of Michigan, Ann Arbor, Michigan, United States
  • Powe, Neil R., Priscilla Chan and Mark Zuckerberg San Francisco General Hospital & University of California SF, San Francisco, California, United States
Background

Acidosis is buffered by bone leading to the release of calcium and bone resorption. High dietary acid load (DAL) may contribute to low BMD with studies in the general population showing inconsistent results. Inconsistencies may be due to lack of consideration of protein intake in the etiology of bone loss. Further, it has not been explored whether high DAL is associated with a decrease in bone turnover in chronic kidney disease (CKD). We investigated the association between DAL and BMD/osteoporosis by gender in early CKD and explored whether higher protein intake modifies these associations.

Methods

We studied 1,580 participants aged>=20 years with early CKD (stages 1 and 2) from 1999-2006 National Health and Nutrition Examination Survey. Nutrient intake from 24-hour recall was used to calculate net endogenous acid production (NEAP) and potential renal acid load (PRAL) (mEq/d). BMD measurements were made at the lumbar spine or pelvis and osteoporosis was defined as a T-score≤−2.5 standard deviation. Linear and logistic regression analyses explored associations between energy-adjusted NEAP or PRAL and BMD (including osteoporosis) after adjustment for demographics, weight, height, physical activity, smoking, alcohol, estrogen use, total calories, dietary magnesium and calcium, eGFR, and protein intake.

Results

Mean age in men and women was 52.5±0.7 and 49.7±0.8 yrs. Among men, a statistically significant inverse association was observed between PRAL with either pelvis or lumbar BMD (β[95% CI]:-0.03[-0.05,-0.01],-0.12[-0.14,-0.09], respectively) as well as with NEAP (-0.03[-0.06,-0.003],-0.13[-0.15,-0.10], respectively). When adjusted for protein intake, the association was positively modified between PRAL or NEAP with BMD (all p>0.05). In women, PRAL was positively associated with pelvis BMD (0.03[0.01-0.06]) but not with lumbar BMD. NEAP was positively associated with both pelvis and lumbar BMD and was inversely modified by protein intake. Neither PRAL nor NEAP associated with osteoporosis and further adjustment for protein intake did not modify these null associations.

Conclusion

DAL was associated with reduced BMD in men and was positively associated with BMD in women. Protein intake modified the association in both genders. Additional studies could help explain the reasons underpinning these gender differences.

Funding

  • NIDDK Support