Low Blood Pressure and Amyloidosis

Yahya Saḡliker, MD, Professor of Medicine, Head, Department of Medicine, Çukurova University School of Medicine, TR01330 Adana (Turkey) Dear Sir, Amyloidosis is a complex disease entity caused by deposition of amyloid substance in various organs or systems with resultant derangement in bodily functions. The symptomatology of the disease depends on the organ involved. Kidneys are known to be primarily affected and proteinuria due to glomerular permeability increase is usually the leading symptom in the patient with systemic amyloidosis. As the disease progresses renal functions further deteriorate and death is usually caused by renal complications [1-4]. Cardiovascular involvement is another frequent feature and cause of death in amyloidosis patients [1,5,6]. Hypotension is reported to be a common feature of the disease though the exact mechanism is not established. Autonomic neuropathy, suppression of the renin-angiotensin-aldosterone system due to juxtaglomerular apparatus involvement, adrenal insufficiency, low-cardiac output and secondary reasons like dehydration and malnutrition are some factors that are held responsible [ 1 ‚ 7-9]. For elucidating the incidence and etiology of low blood pressure in systemic amyloidosis, we conducted a study on 30 systemic amyloidosis patients diagnosed by renal biopsies. Two of the patients had primary, 16 patients had reactive and 12 patients had FMFrelated heredofamilial amyloidosis. The mean age of the patients was 35.6 ± 15.0 years. Sixteen of the patients were newly diagnosed while 14 had had the disease for an average duration of 42 + 33 months. The presenting symptoms were edema in 26, uremic complications in 2, gastrointestinal bleeding in 1 and restrictive cardiac failure in 1 of the patients. After a complete physical examination, blood pressure and heart rate was taken. Laboratory tests like a hemogram, biochemical tests and urinalysis were performed. Electrocardiographic, echocardiographic, ultrasono-graphic examinations were done. Blood pressure while standing was measured and autonomic tests like Valsalva maneuver, sub-maximal handgrip test were performed for evaluating the autonomic system involvement. The results of cardiac and autonomic tests were compared to those of a control group of 15 subjects. Average mean arterial blood pressure was 80.6 ± 13.7 mm Hg in the patients while it was 89.2 ± 12.7 mm Hg in the control group, the difference being statistically significant (p < O.02).