Ideal cardiovascular health may reduce all-cause mortality associated with high-normal UACR: JAMA

The cohort study of 23 697 US adults with a UACR less than 30 mg/g showed a gradual increase in the risk of all-cause mortality associated with a high-normal UACR across CVH groups as delineated by Life’s Essential 8 scores. Participants with poor cardiovascular health status and high-normal UACR had the highest risk of all-cause mortality.

Cumulative evidence suggests that elevated UACR in the normal range may (<30 mg/g) be associated with an increased mortality risk, but only a few studies have investigated whether CVH modifies the harmful outcomes of high-normal UACR. Therefore, Nayili Mahemuti, Tianjin Medical University, Tianjin, China, and colleagues aimed to investigate associations of traditionally normal UACR and CVH with all-cause mortality.

The researchers analyzed seven continuous cycles of the National Health and Nutrition Examination Survey (NHANES) from 2005 through 2018 and linked mortality records up to 2019 for the nationally representative sample of U.S. adults who had supplied urine specimens at the time of survey completion.

The study cohort included 23,697 adults younger than 80 years (mean age: 45.6 years) with a normal UACR, and the cohort was roughly split between the sexes. UACR was treated as a continuous variable. They classified patients by tertiles of UACR: low-normal (<4.67 mg/g), medium-normal (4.67-7.67 mg/g), and high-normal (7.68-30 mg/g).

Cardiovascular health was assessed using Life’s Essential 8 scores and grouped as poor (0-49 points), moderate (50-79 points), and ideal (80-100 points).

Hazard ratios (HRs) were estimated for associations of UACR with all-cause mortality in total participants and as stratified by CVH groups using multivariable Cox proportional hazards regression.

The study revealed the following findings:

• During the median 7.8 years of follow-up, 1403 deaths were recorded.
• Near-linear associations were observed for continuous UACR and CVH with all-cause mortality.
• Compared with the low UACR group, high UACR in the normal range showed an increased mortality risk in the moderate and poor CVH groups (CVH [50-79]: HR, 1.54; CVH [0-49]: HR, 1.56), with a significant multiplicative interaction of UACR and CVH.

"The findings indicate that high UACR within the normal range is tied to a significantly increased all-cause mortality risk, with the association more pronounced in adults with poor CVH status," the researchers wrote.

"These findings highlight the importance of risk management for early kidney dysfunction, particularly among individuals with poor CVH," they concluded.

Reference:

Mahemuti N, Zou J, Liu C, Xiao Z, Liang F, Yang X. Urinary Albumin-to-Creatinine Ratio in Normal Range, Cardiovascular Health, and All-Cause Mortality. JAMA Netw Open. 2023;6(12):e2348333. doi:10.1001/jamanetworkopen.2023.48333