Blood pressure is significantly higher in cats aged 11 years and over
In line with people, domestic cats who are 11-years-old or older have significantly higher blood pressure than cats of a younger age. A study found that blood pressure rises with age in domestic cats and this applies to systolic, diastolic, mean arterial and pulse pressure.
Systolic blood pressure is the pressure inside the artery when the heart contracts to force the blood around the arteries. It is the high blood pressure whereas diastolic pressure is the pressure of the blood in the arteries when the heart is between contractions i.e. when it is relaxed and the heart's ventricles are allowed to refill with blood.
Also, the study found that cats suffering from clinical renal disease, which I take to mean chronic kidney disease, a common disease in elderly cats, suffered from higher blood pressure than cats who did not have the disease. The same goes for cats with hypertensive retinopathy, which is when high blood pressure causes damage to the retina's blood vessels which limits the retina's function and puts pressure on the optic nerve which can cause vision problems.
The study is titled Epidemiological study of blood pressure in domestic cats published on June 28, 2008 on the Wiley Online Library.