Glomerulonephritis is inflammation of glomeruli (filters in the kidney) and is an immunological disease whereas hypertensive nephropathy is the result of kidney damage due to uncontrolled blood pressure of long duration.
These are different disease. CGN is not caused by hypertension however hypertension can occur in CGN. S. creatinine of 1.9 mg/dl is not normal for 62 years old.