Aims: There is growing recognition of the clinical importance of cardiorenal syndrome-the bidirectional interplay between kidney and cardiac dysfunction. Yet, the role of kidney tubular damage in the development of heart failure is less studied. The objective of this study was to investigate whether urinary kidney injury molecule (KIM)-1, a specific marker of tubular damage, predisposes to an increased heart failure risk.
Methods and results: This was a community-based cohort study [Uppsala Longitudinal study of Adult Men (ULSAM)] of 565, 77-year-old men free from heart failure at baseline. Heart failure hospitalizations were used as outcome. During follow-up (median 8.0 years), 73 participants were hospitalized for heart failure. In models adjusted for cardiovascular risk factors (age, systolic blood pressure, diabetes, smoking, body mass index, LDL/HDL ratio, antihypertensive treatment, lipid-lowering treatment, aspirin treatment, LV hypertrophy, and prevalent cardiovascular disease) and markers of kidney dysfunction and damage [cystatin C-based glomerular filtration rate (GFR) and urinary albumin/creatinine ratio], a higher urinary KIM-1/creatinine ratio was associated with higher risk for heart failure (hazard ratio upper vs. lower tertile, 1.81; 95% confidence interval 1.01-3.29; P < 0.05). Participants with a combination of low GFR (<60 mL/min/1.72 m(2)) and high KIM-1/creatinine (>128 ng/mmol) had a 3-fold increase in heart failure risk compared with participants with normal GFR and KIM-1 (P < 0.001).
Conclusion: Our findings suggest that kidney tubular damage predisposes to an increased risk for heart failure in the community. Further studies are needed to clarify the causal role of KIM-1 in the development of heart failure, and to evaluate the clinical utility of urinary KIM-1 measurements.