Hyperaldosteronism in ketoacidosis and in poorly controlled non-ketotic diabetes

Spontaneous intracerebral hematomas in juvenile diabetic ketoacidosis

Ketoacidosis is one of the common complications of Type I insulin-dependent diabetes mellitus. Several neurologic (cerebral) deficiencies have been associated with diabetic ketoacidosis, including cerebral edema with increased intracranial pressure resulting in coma; partial and generalized seizures; and cerebrovascular occlusive disease resulting in motor and/or sensory dysfunction. Intracerebral hematomas have not been reported. A child is described who had insulin-dependent diabetes mellitus with hyperglycemic ketoacidosis who developed multiple spontaneous intracerebral hematomas. Possible mechanisms are discussed.

Diabetic control and the renin-angiotensin system, catecholamines, and blood pressure

Diabetic ketoacidosis is usually associated with marked secondary hyperaldosteronism. Plasma levels of renin, angiotensin II, and aldosterone are markedly raised before treatment in most patients, with values falling rapidly toward normal as metabolic control is restored. In a few patients, mostly those with long-term complications of diabetes, plasma levels of renin, angiotensin II, and aldosterone before treatment remain within the normal range. In moderately hyperglycemic patients who have glycosuria but not ketonuria, plasma levels of all three substances are significantly higher than when control is improved. Occasionally, moderately hyperglycemic patients have mild secondary hyperaldosteronism. Improved metabolic control in such patients causes a rise in plasma volume and a rise in total exchangeable sodium, the latter to levels significantly above normal. Plasma catecholamine levels are markedly elevated in diabetic ketoacidosis, probably as a consequence of the ketoacidotic state. In nonketotic patients with moderate hyperglycemia, basal plasma norepinephrine levels are normal; catecholamine responses to exercise may be exaggerated, however. Epidemiological and animal studies suggest a relationship between blood pressure and blood glucose levels. There are few clinical studies of the effects of altering metabolic control of diabetes on blood pressure, and this is an important area for further study.

Factors in the control of plasma renin activity and concentration in Type 1 (insulin-dependent) diabetes

Possible factors involved in the control of plasma renin activity (PRA) and concentration (PRC) have been analysed in 49 patients with long-standing Type 1 diabetes and in 40 healthy controls matched for age and sex. Eighteen of the diabetic subjects were clinically free of all microvascular and macrovascular complications of their disease (Group A); 31 had proliferative retinopathy (Group B). Both lying and standing PRA and PRC were similar in Group A and healthy controls. Mean PRA was 50-115% higher in Group B diabetics than in controls (P less than 0.001 supine and erect) and 50-70% higher than in Group A diabetics (P less than 0.05 supine and erect); PRC also was 60% higher in Group B than in Group A (P less than 0.05 supine and erect). Control subjects showed significant falls in both PRA and PRC with increasing age, while Groups A and B showed significant falls in PRA or PRC with age. Group A showed a significant inverse correlation between systolic blood pressure and supine PRC (r = -0.57), but this was not significant in the controls and was completely absent in Group B. With correction for the effect of age there were significant relationships of PRA and PRC with sodium excretion in the controls and in Group A, but not in Group B. PRA and PRC are thus normal in uncomplicated long-standing Type 1 diabetes, but regulation of renin secretion appears to be impaired in patients with microvascular disease. Renin secretion inappropriate to their blood pressure and sodium status may contribute to maintenance of their relative hypertension.