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I B Hirsch

Publications and source records attributed to I B Hirsch.

49 records · Page 3Linked to original sources
PubMed1991

Catecholamines in prevention of hypoglycemia during exercise in humans.

To assess the role of catecholamines in the prevention of hypoglycemia during moderate exercise (approximately 60% peak O2 consumption for 60 min), normal humans were studied with combined alpha- and beta-adrenergic blockade and with adrenergic blockade while changes in insulin and glucagon were prevented with the islet clamp technique (somatostatin infusion with insulin and glucagon infused at fixed rates). The results were compared with those from an islet clamp alone study. In contrast to a comparison study (saline infusion), adrenergic blockade resulted in a small initial decrease in plasma glucose during exercise, from 5.0 +/- 0.2 to 4.4 +/- 0.2 mmol/l (P less than 0.01), but the level then plateaued. There was a substantial exercise-associated decrement in plasma glucose when insulin and glucagon were held constant, i.e., from 5.5 +/- 0.2 to 3.4 +/- 0.2 mmol/l (P less than 0.0001), but the level again plateaued. However, when insulin and glucagon were held constant and catecholamine actions were blocked simultaneously, progressive hypoglycemia, to 2.6 +/- 0.6 mmol/l (P less than 0.001), developed during exercise. Hypoglycemia was the result of an absent increase in glucose production and an exaggerated initial increase in glucose utilization. Thus we conclude that sympathochromaffin activation plays a minor role when insulin and glucagon are operative, but a catecholamine, probably epinephrine, becomes critical to the prevention of hypoglycemia during exercise when changes in insulin and glucagon do not occur.

3-Hydroxybutyric Acid↗
PubMed1991

Higher glycemic thresholds for symptoms during beta-adrenergic blockade in IDDM.

We tested the hypotheses that nonselective beta-adrenergic blockade does not cause absolute hypoglycemia unawareness but shifts the glycemic thresholds for symptoms to lower plasma glucose concentrations and that neither neuroglycopenic symptoms nor cognitive impairments during hypoglycemia are altered by beta-adrenergic blockade. To do so, we applied the euglycemic and stepped hypoglycemic clamp techniques to patients with moderately controlled insulin-dependent diabetes mellitus (IDDM) in the absence (n = 8) and presence (n = 9) of the nonselective beta-adrenergic antagonist propranolol. Compared with the corresponding euglycemic clamps, total symptom scores first increased at the 4.4-mM plasma glucose step (a higher level than that of 2.8 mM in nondiabetic subjects studied previously) in the absence of propranolol. Beta-adrenergic blockade did not produce absolute hypoglycemia unawareness. Indeed, at the frankly hypoglycemic step of 2.8 mM, total symptom scores tended to be higher in the presence than in the absence of propranolol. This was largely the result of greater (P less than 0.01) perception of diaphoresis. However, symptom scores did not increase until the 3.3-mM plasma glucose step during beta-adrenergic blockade. The perception of hunger, and perhaps that of tremulousness, was reduced by propranolol at the higher glucose steps. Neuroglycopenic symptoms were not reduced by propranolol. The cognitive function of memory, but not that of attention, was impaired, also starting at the 4.4-mM glucose step. This was not impaired further by propranolol. Thus, we formed the following conclusions. 1) Nonselective beta-adrenergic blockade does not cause absolute hypoglycemia unawareness but shifts the glycemic thresholds for symptoms to lower plasma glucose concentrations in patients with IDDM. 2) Beta-adrenergic blockade does not reduce neuroglycopenic symptoms, and it does not further impair cognitive function during hypoglycemia in IDDM patients.

Adult↗
PubMed1990

Intensive insulin therapy for treatment of type I diabetes.

Intensive insulin therapy is best defined as a comprehensive system of diabetes management with the patient and management team as partners. The system is directed at improvement of glycemia and patient well-being. Glycemic targets should be individually defined. Frequent self-monitoring of blood glucose, probably at least four times per day, is essential for meticulous control. The benefits include improved psychosocial functioning and the potential of lessening the risks of chronic complications of diabetes. The risks relate to problems associated with hypoglycemia, which are increased if meticulous glycemic control is sought. One of the important elements of intensive therapy is a multiple-component insulin program designed to provide effective insulinemia coinciding with each major meal and continuous basal insulinemia throughout the 24-h day. This may be achieved with continuous subcutaneous insulin infusion (CSII) or multiple injections with various insulin regimens, although CSII may offer real advantages in terms of the pharmacokinetics of insulin delivery. Other pharmacokinetic issues to be considered involve selection of injection sites, timing of premeal insulin, and mixing insulins. Many studies have shown that, albeit with effort, excellent glycemic control can be achieved by various intensive insulin-therapy regimens. The implementation of a program of intensive therapy involves patient self-management in terms of altering insulin dosages, food intake, and/or activity in an attempt to achieve the target level of glycemia selected. In motivated patients willing to embark on such a course of therapy, intensive insulin therapy can be worthwhile. It should be considered for all patients with type I (insulin-dependent) diabetes mellitus.

Diabetes Mellitus, Type 1↗
PubMed1990

Failure of nocturnal hypoglycemia to cause daytime hyperglycemia in patients with IDDM.

To test the hypothesis that nocturnal hypoglycemia causes postprandial hyperglycemia the next day (the Somogyi phenomenon) in patients with insulin-dependent diabetes mellitus (IDDM), we studied 10 moderately well controlled patients, who were on their usual therapeutic regimens, from 2000 to 2000 on three occasions. On a control day, samples were obtained without intervention. On another day, nocturnal hypoglycemia was prevented (by intravenous infusion of glucose, if necessary, from 2200 to 0400 to keep plasma glucose levels at greater than 5.6 mM). On another day, nocturnal hypoglycemia was induced (by stepped intravenous insulin infusions between 2200 and 0200 to reduce plasma glucose levels to less than 2.8 mM). After nocturnal hypoglycemia (1.9 +/- 0.2 mM), fasting (0800), morning (0800-1100), afternoon (1200-1500), evening (1600-2000), and entire-day (0800-2000) plasma glucose concentrations were no higher than those after prevention of nocturnal hypoglycemia or sampling only. On the control day, fasting and daytime plasma glucose levels were directly related to the preceding 2200 (r = 0.723, P less than 0.02, and r = 0.762, P = 0.01, respectively) and nocturnal nadir (r = 0.714, P less than 0.02, and r = 0.728, P less than 0.02) plasma glucose concentrations. Daytime plasma glucose levels were unrelated to peak nocturnal plasma glucagon, epinephrine, norepinephrine, growth hormone, or cortisol concentrations. We conclude that nocturnal hypoglycemia does not appear to cause clinically important daytime hyperglycemia in patients representative of most patients with IDDM.

3-Hydroxybutyric Acid↗
PubMed1990

Role of insulin in management of surgical patients with diabetes mellitus.

Because surgery is a likely event during the lifetime of patients with diabetes, health-care team members need to be aware of the metabolic problems that may occur during the perioperative period. Surgery, especially in the presence of general anesthesia, will produce a diabetogenic response. This is generally due to an elevation of counterregulatory hormones, although endogenous insulin is also suppressed. The excessive lipolysis and ketogenesis that can occur during surgery can have particularly deleterious effects for patients with diabetes. Thus, sufficient insulin must be provided during this period to suppress these catabolic processes. The major controversy regarding surgery and diabetes concerns the route of insulin administration. This article reviews the various treatment options for patients with insulin-dependent and non-insulin-dependent diabetes mellitus, with particular emphasis on the role of insulin. Special situations, e.g., outpatient surgery, coronary artery bypass, and emergency surgery, are also discussed.

Diabetes Mellitus, Type 1↗
PubMed1970

Feeding the poor.

Explore the source record for details and available documents.

Food Service, Hospital↗
PubMedDate not supplied

The effect of ejaculation on albumin excretion rate.

Microalbuminuria predicts the development of diabetic nephropathy. Large daily variations in albumin excretion rates are frequently observed. Because seminal fluid contains protein and albumin, we reasoned that sexual activity, ejaculation, or residual urethral semen could contribute to albumin content in urine and thus effect determination of albumin excretion rate. Our study was designed to determine the effect of ejaculation of albumin excretion rate and to ascertain if patients routinely should be advised to refrain from sexual activity during or before the urine collection period. Ten normotensive, nondiabetic men (age 31.0 +/- 2.3 years) collected 24-h urine specimens on three occasions: after 3 days of abstinence from sexual activity, during a 24-h period which included one ejaculatory episode, and on a day following sexual activity. Results for albumin excretion rate were: abstinence day: 4.8 +/- 0.7 micrograms/min; sex day: 6.3 +/- 1.1 microgram/min; post-sex day: 4.9 +/- 1.0 micrograms/min. There was no significant difference between these values when compared directly or after log transformation. There also were no differences in urinary creatinine excretion or clearance. We conclude that in nondiabetic individuals ejaculation does not influence albumin excretion rate.

Adult↗
PubMedDate not supplied

Ascorbic acid clearance in diabetic nephropathy.

The incidence of cardiovascular disease is increased in diabetic nephropathy. Increased oxidative stress in diabetes is believed to play an important role in the pathogenesis of atherosclerosis in diabetes. Since antioxidant vitamins, such as ascorbic acid, often are reduced in diabetes, we hypothesized that the renal clearance of ascorbic acid is increased in patients with diabetic nephropathy. Thirty-seven subjects with diabetic nephropathy were studies: 18 had microalbuminuria (30-300 mg/day albuminuria); the remainder had clinical nephropathy (> 300 mg/day albuminuria). Indices of glycemic control (glucose, hemoglobin A1C) and renal function (albuminuria and creatinine clearance) were measured in addition to serum and urinary ascorbic acid levels. Results showed that subjects with clinical nephropathy had lower mean plasma ascorbic acid (p=0.0009) and higher renal clearance of ascorbic acid (p=0.005) than those with microalbuminuria. Bivariate analysis revealed an inverse correlation between creatinine clearance and AA clearance (r=-0.42, p=0.009). There was a significant linear association between the quantity of albuminuria and ascorbic acid clearance (r=0.49, p=0.002). Thus, patients with diabetic nephropathy have reduced ascorbic acid levels due to increased ascorbic acid clearance. The decrease in antioxidant defense that arises from the low levels of vitamin C may contribute to the increased cardiovascular morbidity and mortality observed in this population.

Adult↗