Association of urinary cadmium excretion with feline hypertension

Fifty client-owned senior cats (32 normotensive and 18 hypertensive) with renal function ranging from normal to moderately reduced were recruited into a prospective cross-sectional study exploring the association of urinary cadmium excretion and hypertension in cats. Heparinised plasma samples were collected and analysed for routine biochemical parameters. Urine samples were collected via cystocentesis and were analysed for cadmium concentrations using inductively coupled plasma mass spectrometry (ICP-MS). Blood pressure was measured using the Doppler method. Urinary cadmium concentrations were indexed to urinary creatinineconcentration. Comparison of urinary cadmium excretion was made between hypertensive and normotensive cats.The median (range) urinary cadmium concentration standardised to urinary creatinine concentration (UCdCr) in the normotensive and hypertensive cats was 0.08 (0.02 to 0.37) and 0.12 (0.02 to 1.38) nmol/mmol creatinine. The UCdCr was significantly higher in hypertensive compared with normotensive cats (P=0.016). UCdCr and plasma creatinine concentration remained independent predictors of hypertensive status in a logistic regression model. UCdCr and plasma creatinine concentration were not correlated (r=-0.01, P=0.956). These data suggest cadmium exposure and accumulation in cats may play a role in the development of feline hypertension.