THE KIDNEY FUNCTION IN PATIENTS WITH RHEUMATOID ARTHRITIS IN RELATION TO THE COMMENCEMENT OF THE DISEASE. VI.

Abstract

SummaryThe purpose of this work is to evaluate the kidney function in patients with rheumatoid arthritis in relation to the time of the commencement of the disease.The kidney function is examined by three 24-hour endogenous creatinine clearances, and clearance is expressed as the average of three 24-hour clearances and corrected for body surface (ml/min./1.73 m2).The material consists of 244 patients with rheumatoid arthritis and 247 patients with other diseases in a control group. No patient in the rheumatoid arthritis group has had a definitely identified renal disease before the disease started, and no patient in the control group has had symptoms from the urinary tract, arterial hypertension or osteoarthrosis.All the patients have been examined by the author, and the material is statistically prepared.In the introduction a short outline is given as to renal changes in systemic lupus erythematosus, polyarteritis nodosa, progressive scleroderma and dermatomyositis, just as references are given to previous investigations of the kidney in rheumatoid arthritis.The relationship between the rheumatoid arthritis and the commencement of the disease, especially in relation to the menstrual cycle, is discussed.With regard to the kidney function in patients with rheumatoid arthritis, there is, in women, found a constant relationship between the severity of the disease and the kidney function regardless of the time of the commencement of the disease, so that patients with a severe disease have lower kidney function than patients with a mild disease, and likewise lower than the kidney function of the patients in the control group. No relationship has been found between kidney function and duration of disease within each stage of the disease. The kidney function in men shows another pattern. There is no difference in the kidney function in patients with a mild and with a severe disease, if the disease has started at an early date, before the age of 51 years. When the disease has set in at a late date, after the age of 51 years, then there is, as in women, lower kidney function in the severe stages than in the milder stages. No certain relationship has been found between the kidney function and duration of the disease within each stage.If no regard is paid to the stages of the disease, then there is found relationship between the duration of the disease and kidney function in women with commencement of the disease in the preclimacteric age and in men with commencement of the disease at an advanced age.