In an attempt to define the long-term clinical course of systemic lupus erythematosus followed by end-stage renal disease, we studied 28 patients with lupus nephritis at Stanford University between January 1969 and December 1980. The clinical and serologic manifestations of both renal and nonrenal disease improved with long-term hemodialysis despite the withdrawal of immunosuppressive drugs in almost all the patients. Rehabilitation was excellent, and a return to normal physical activity was generally the rule. The mortality rate was low (6 of the 28 patients died), but death occurred primarily in patients receiving high doses of prednisone. Recovery from renal failure and discontinuation of dialysis were not rare (eight patients recovered) despite the reduction in immunosuppressive drugs. Renal transplantation was also well tolerated. We found the long-term clinical course of these patients to be comparable to that of patients with end-stage renal disease associated with disorders other than systemic lupus erythematosus.

Veterans Administration Hospital, Palo Alto, California 94305 AB S T R A C T Insulin-LuI was administered intravenously to normal subjects, to patients with maturityonset diabetes and normal renal function, and to nondiabetic patients with renal failure. The ensuing plasma disappearance curves of immunoprecipitable radioactive insulin were determined, and these data were analyzed in a variety of ways. Firstly, fractional irreversible loss rates of insulin from plasma were calculated and found to be greatly diminished in patients with renal failure (t4 = 39 min), as compared with normal (t4 = 15 min) and diabetic subjects (ti = 12 min). Secondly, plasma insulin-2'I disappearance curves were resolved into sums of three exponentials by the method of "peeling," and values for the resultant three slopes and half-lives were determined. Patients with normal renal function had similar values for all parameters, while those patients with renal failure were differentiated on the basis of the slope of the last component, with a prolongation of its half-life to 275 min (approximately twice normal). Finally, a three pool model was formulated to describe the kinetics of plasma insulin disappearance in man. representing plasma (pool 1), interstitial fluid (pool 2), and all tissues in which insulin is utilized and degraded (pool 3). The proposed model adequately describing the disappearance curves of insulin-'I observed in all patients indicated that volumes (per cent body weight) of pool 1 (4.04) and pool 2 (10.11), calculated on the basis of the model and the experimental data, corresponded closely to estimates of plasma and interstitial fluid vol- umes obtained by independent means. It also demonstrated that patients with renal failure were characterized by a decreased removal rate of insulin from pool 3 and an increased recycling rate of insulin from pool 3 to pool 2. It is concluded that the proposed model represents a reasonable description of the kinetics of insulin distribution and degradation, and that its use provides quantitative insights into the physiology of insulin metabolism.

Insulin resistance was measured in 16 normal dogs by a method involving the continuous intravenous infusion of epinephrine, propranolol, glucose and insulin. With this approach, endogenous insulin secretin is inhibited, similar steady state levels of exogenous insulin are achieved in all doags, and the resultant steady state plasma glucose level provides a direct estimate of the ability of insulin to dispose of the infused glucose load. Thus, the higher the steady state plasma glucose level, the more the insulin resistance. Different amounts of alloxan were then administered to these dogs in order to produce insulin deficiency of varying degrees. Insulin resistance was then measured again in each dog. The results indicated that insulin resistance did not develop in dogs with only a moderate degree of insulin deficiency (fasting plasma glucose levels less than 150 mg/100 ml). On the other hand, a significant degree of insulin resistance developed in dogs with severe insulin deficiency (fasting plasma glucose greater than 150 mg/100 ml). Furthermore, the insulin resistance that developed in dogs with severe insulin deficiency could be returned to normal with insulin replacement for one week. These results indicate that insulin resistance can occur as a secondary manifestation of insulin deficiency.

The response of plasma triglyceride levels to changes in the composition of meal formula diets was studied in 12 subjects who had moderate to severe chronic renal failure. Fasting hypertriglyceridemia (greater than 150 mg/100 ml) was present in seven of 12 subjects. Fasting plasma triglyceride levels decreased in all subjects in response to a reduction in the proportion of carbohydrate (from 50 to 35% of total daily calories) and an increase in the poly-unsaturated to saturated fat ratio (from 0.2 to 2.0) in an isocaloric diet. Fasting plasma cholesterol and postprandial triglyceride levels were unchanged. Both the triglyceride production rate and the insulin response were significantly lower on a diet in carbohydrate and higher in polyunsaturated fat. These data indicate that hypertriglyceridemia occurs in subjects with moderate to severe chronic renal failure, and that dietary modification promptly reduces triglycerides levels over an 11 day period. A long term study on a dietary program incorporating these changes is indicated to determine whether this effect is sustained.