Lower serum bicarbonate levels are independently associated with rapid renal function decline in community-dwelling individuals with an estimated glomerular filtration rate (eGFR) above 60 mL/min/1.73 m2, according to a new study.
The study included 5,810 participants in the Multi-Ethnic Study of Atherosclerosis. Of these, 1,730 (33%) had a rapid kidney function decline, defined as an eGFR decline of more than 5% per year. Each 1 standard deviation lower baseline serum bicarbonate level was associated with a 12% increased risk of rapid kidney function decline and an 11% increased risk of incident reduced eGFR in adjusted analyses, Todd H. Driver, MD, of the University of California San Francisco, and colleagues reported online ahead of print in the American Journal of Kidney Diseases.
Compared with a bicarbonate level of 23-24 mEq/L, a level below 21 mEq/L was associated with a 35% increased risk of rapid kidney function decline and a 16% increased risk of incident reduced eGFR.
The association of low bicarbonate level with both renal outcomes was strongest among black subjects, the researchers observed.
“Our findings ultimately may have clinical implications,” the authors wrote, noting that “serum bicarbonate is an inexpensive laboratory test that is present on standard clinical chemistry panels; it may have the potential to identify persons at risk of developing CKD, perhaps in combination with other biomarkers, which could inform more aggressive management of kidney disease risk factors.”