Hypertension and microalbuminuria in diabetes mellitus: local experience - abstract

ABSTRACT

Both hypertension and diabetes mellitus are common diseases, affecting approximately 20 percent and 10 percent of the adult population, respectively, and together they are the largest contributor to the group of patients with end-stage renal failure. Gross proteinuria (dipstick) predicts the onset of inexorable decline in renal function in diabetes mellitus and, to a lesser extent, in hypertension. Microalbuminuria (immunoassay) is an early warning sign of impending renal failure in diabetes mellitus, and might occur while the process is reversible. In hypertension, the natural history of patients with microalbuminuria is unclear. This study was designed to compare the clinical progress of hypertensives and hypertensive diabetics with and without microalbuminuria, and to relate this to their haemodynamics. Patients were selected from the University Hospital of the West Indies Hypertensive Clinic on the basis of urinary albumin excretion 20-200 mg/l microalbuminuric and less than 20 mg/l normalbuminuric. Controls were matched hypertensives and hypertensive diabetics without microalbuminuria. All measurements were made of glomerular filtration rate and renal plasma flow (clearance of 51 Cr EDTA and 125 I Iodohippurate, respectively). Microalbuminuric hypertensives were older, had lower renal flow, higher filtration fraction and renal vascular resistance than controls. Haemodynamic variables were similar in the microalbuminuric diabetics and their controls. After one year, three cardiovascular events occurred among the diabetics with microalbuminuria, supporting the view that microalbuminuria is a marker for widespread vascular pathology. The fourth event occurred in the microalbuminuric hypertensive group (AU)