The association between age and nephrosclerosis on renal biopsy among healthy adults.

BACKGROUND: Chronic kidney disease is common with older age and is characterized on renal biopsy by global glomerulosclerosis, tubular atrophy, interstitial fibrosis, and arteriosclerosis.

OBJECTIVE: To see whether the prevalence of these histologic abnormalities in the kidney increases with age in healthy adults and whether histologic findings are explained by age-related differences in kidney function or chronic kidney disease risk factors.

DESIGN: Cross-sectional study.

SETTING: Mayo Clinic, Rochester, Minnesota, from 1999 to 2009.

PATIENTS: 1203 adult living kidney donors.

MEASUREMENTS: Core-needle biopsy of the renal cortex obtained during surgical implantation of the kidney, and medical record data of kidney function and risk factors obtained before donation.

RESULTS: The prevalence of nephrosclerosis (> or =2 chronic histologic abnormalities) was 2.7% (95% CI, 1.1% to 6.7%) for patients aged 18 to 29 years, 16% (CI, 12% to 20%) for patients aged 30 to 39 years, 28% (CI, 24% to 32%) for patients aged 40 to 49 years, 44% (CI, 38% to 50%) for patients aged 50 to 59 years, 58% (CI, 47% to 67%) for patients aged 60 to 69 years, and 73% (CI, 43% to 90%) for patients aged 70 to 77 years. Adjustment for kidney function and risk factor covariates did not explain the age-related increase in the prevalence of nephrosclerosis.

LIMITATION: Kidney donors are selected for health and lack the spectrum or severity of renal pathologic findings in the general population.

CONCLUSION: Kidney function and chronic kidney disease risk factors do not explain the strong association between age and nephrosclerosis in healthy adults.

PRIMARY FUNDING SOURCE: National Institutes of Health, U.S. Public Health Service.