Hello and welcome,
It is highly likely he has renal parenchymal disease caused by hypertention.
Hypertension (HTN) starts with increased resistance to blood flow (
total peripheral resistance) that causes decreased blood flow to the kidneys. Kidneys start to produce renine which eventually converted to angiotensin to increase the blood flow. When the kidney is damaged (hypertension can be either a cause or a consequence) the kidney can not produce renin (low levels). Patients with kidney damage (renal parenchymal disease) have high
serum creatinine and decreased creatinine clearance which is diagnostic of the condition. The patient's
left ventricular hypertrophy, retinal hemorrages (end organ damage) shows uncontrolled HTN damaging those organs which might have affected his kidneys as well. Kidney damage can be diagnosed by studying serum creatinine, creatinine clearance and renal ultrasonography.
Other than kidney damage certain endocrine pathologies (very rare) may cause
high blood pressure and low renin. Adrenal gland problem (
hyperaldosteronism) causes HTN, low potassium, low renin and high aldosterone which can be initially diagnosed by obtaining renin and aldosteron levels.
I hope the above information will be helpful for you. Please, feel free to ask me if there is anything else you need to know.
Thank you,
Malik Amonov MD