Clinical associations of total kidney volume: The Framingham Heart Study

Abstract

Total kidney volume (TKV) is an imaging biomarker that may have diagnostic and prognostic utility. The relationships between kidney volume, renal function and cardiovascular disease (CVD) have not been characterized in a large community-dwelling population. This information is needed to advance the clinical application of TKV. Methods We measured TKV in 1852 Framingham Heart Study participants (mean age 64.1 ± 9.2 years, 53% women) using magnetic resonance imaging. A healthy sample was used to define reference values. The associations between TKV, renal function and CVD risk factors were determined using multivariable logistic regression analysis. Results Overall, mean TKV was 278 ± 54 cm 3 for women and 365 ± 66 cm 3 for men. Risk factors for high TKV (>90% healthy referent size) were body surface area (BSA), diabetes, smoking and albuminuria, while age, female and estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m 2 were protective. Participants with high TKV had higher odds of diabetes [odds ratio (OR) 2.15, P < 0.001] and lower odds of eGFR <60 mL/min/1.73 m 2 (OR 0.32, P = 0.007). Risk factors for low TKV (<10% healthy referent size) were age, female and eGFR <60 mL/min/1.73 m 2, while BSA and diabetes were protective. Participants with low TKV had higher odds of eGFR <60 mL/min/1.73 m 2 (OR 6.12, P < 0.001) and albuminuria (OR 1.56, P = 0.03). Conclusions Low TKV is associated with markers of kidney damage including albuminuria and eGFR <60 mL/min/1.73 m 2, while high TKV is associated with diabetes and decreased odds of eGFR <60 mL/min/1.73 m 2. Prospective studies are needed to characterize the natural progression and clinical consequences of TKV.