Posthypoglycemic hyperglycemia in diabetic children

Fluctuations of Serum Phenobarbital and Phenytoin Concentrations during Two Acute Episodes of Diabetic Ketoacidosis

The details of two consecutive admissions of a diabetic, epileptic patient are presented. Anticonvulsant serum level monitoring documented a decline in both phenobarbital and phenytoin concentrations during both episodes of diabetic ketoacidosis. These periods of reduced serum anticonvulsant concentrations coincided with increased seizure activity. Urine analysis revealed a dramatic increase in the excretion rate of phenobarbital. The urinary excretion rate of unchanged phenytoin was also markedly increased by diuresis, but the percent of the dose removed via this pathway remained small. These results dictate frequent serum concentration monitoring in patients afflicted with both diabetes and epilepsy.

Studies of insulin resistance following hypoglycemia in insulin-dependent diabetes mellitus

Insulin resistance was assessed after a hypoglycemia induced by insulin (1.5 mU X kg-1 X min-1) between 7 and 8 a.m. in 10 well-insulinized patients with insulin-dependent diabetes mellitus (IDDM). Blood glucose levels during a somatostatin (100 micrograms X h-1)-insulin (0.4 mU X kg-1 X min-1)-glucose (4.5 mg X kg-1)-infusion test (SIGIT) performed between 11 a.m. and 3 p.m. served as an indicator of total body insulin resistance. Plasma epinephrine, growth hormone, and cortisol increased in response to hypoglycemia, while blunted responses of glucagon were simultaneously registered. At the start of the subsequent SIGIT, blood glucose and plasma-free insulin concentrations were similar to those obtained in the control study without preceding hypoglycemia, and at this point all counter-regulatory hormones had returned to basal. During the SIGIT close to identical levels of plasma-free insulin and counter-regulatory hormones were registered, despite which a significant hyperglycemia was seen 2 hours after the start of the SIGIT when preceded by hypoglycemia. In a separate study, the SIGIT was shown to have a good reproducibility in IDDM patients. We conclude that hypoglycemia evokes a state of insulin resistance for several hours, as demonstrated by elevated blood glucose levels during a somatostatin-insulin-glucose-infusion test.

Chronic poor metabolic control in the pediatric population: a stepwise intervention program

Improving metabolic outcomes in children and adolescents with IDDM who are in chronically poor metabolic control is one of the most difficult tasks confronting health care providers. These patients have clinical histories characterized by recurrent episodes of diabetic ketoacidosis and the persistance of acute disease symptoms. Complex psychosocial factors play a critical role in the genesis of chronic poor control, and patients are often resistant to standard interventions. To guide treatment of these difficult patients, we have developed a stepwise intervention program that addresses psycho social issues and provides strategies for improving metabolic control. The steps include documentation of patient response to insulin and the correction of educational deficiencies, defining and renegotiating the family care role, confronting families' inappropriate perceptions of care, and legal interventions. Previous evaluation has shown that appli cation of this approach can nearly eliminate recurrent episodes of diabetic ketoacidosis.

Exaggerated epinephrine responses to hypoglycemia in normal and insulin-dependent diabetic children

To determine whether children with insulin-dependent diabetes mellitus (IDDM) might have exaggerated hormonal responses to hypoglycemia, the euglycemic-hypoglycemic glucose clamp procedure was used to provide a uniform hypoglycemic stimulus (plasma glucose kept at 90 mg/dL for 2 hours, then reduced to 50 to 55 mg/dL for 1 hour) in children and adults with and without IDDM. The chidren with IDDM showed an exaggerated rise in plasma epinephrine levels (625 +/- 112 pg/mL) compared with adults with IDDM (259 +/- 57 pg/mL, P less than 0.02); the same was true for children and adults without IDDM (811 +/- 100 vs 458 +/- 85 pg/mL, P less than 0.05). Among the children, the increase in epinephrine during hypoglycemia was similar in prepubertal and pubertal patients. Children with IDDM showed a greater rise in plasma norepinephrine than did adults with IDDM (P less than 0.001), and both diabetic groups failed to mount a glucagon response. Growth hormone and cortisol responses were unaffected by either childhood or diabetes. Enhanced secretion of epinephrine, induced by mild reductions in plasma glucose, may contribute to the management difficulties characteristically observed in the young patient with diabetes.

Effect of intensive insulin treatment on linear growth in the young diabetic patient

Although impaired growth is a well-recognized complication of uncontrolled diabetes, it has not been established whether less severe metabolic derangements commonly seen with conventional treatment adversely affected growth potential. To examine this question, growth velocity was measured in nine type 1 diabetic patients (age 14 +/- 3 years) before and after six months of intensive insulin treatment either with the insulin pump or with multiple injections, which lowered mean plasma glucose concentration from 270 +/- 96 to 105 +/- 55 mg/dl and total glycosylated hemoglobin from 12.4 +/- 3.0 to 8.4 +/- 1.5% (mean +/- SD). During conventional treatment, growth velocity (5.3 +/- 2.2 cm/year) was within the range of normal despite elevations in plasma glucose concentrations. However, growth velocity increased sharply during intensive treatment (to 9.4 +/- 3.9 cm/year, P less than 0.005), reaching values in excess of normal in seven patients. The increase in growth velocity observed during intensive treatment was associated with a twofold rise in plasma somatomedin-C values. Skeletal maturation, previously normal or slightly delayed, did not advance excessively. These data indicate that the metabolic changes accompanying intensive treatment may enhance growth in diabetic children, even in those with apparently normal growth velocity during conventional therapy.

Comparison of single- and split-dose insulin regimens with 24-hour monitoring

It has been asserted that twice daily injections of mixed insulin provide better blood glucose control than one. To compare the two regimens we conducted a random-order, double-crossover trial in ten diabetic children. Each regimen lasted for six weeks, concluding with a hospital evaluation. Control at home was assessed by a urine log and determination of glycosylated hemoglobin. Control in the hospital was assessed with measurements of quantitative urinary glucose, serum lipids, and by 24-hour blood sampling for glucose, C-peptide, and counterregulatory hormones. For the group as a whole, none of the indices of control demonstrated a significant advantage for either regimen. Individually, several children did appear to achieve better control on one regimen than the other. Indices of control at home did not consistently predict control in the hospital. In the hospital, the largest increases in glucose concentration followed breakfast (mean rise 148 mg/dl), and standardized exercise invariably reduced plasma glucose values (mean decrement 60 mg/dl). C-Peptide concentrations were low, but higher values were associated with better control. Although a split insulin regimen may improve metabolic control in some patients, this study did not demonstrate a substantial advantage for the majority of subjects over the short period of the trials.

Profiles of metabolic control in diabetic children-frequency of asymptomatic nocturnal hypoglycemia

Twenty-four hr glucose and hormonal monitoring was conducted in 34 randomly selected children with insulin dependent diabetes. Asymptomatic nocturnal hypoglycemia was present in 18% (6/34). The nocturnal plasma glucose decline of 20-25 mg/dl/hr reached a mean nadir of 50 mg/dl. The mean rebound hyperglycemia of 300 mg/dl over the subsequent 6.4 hrs. was significantly greater than any glucose excursion in diabetic children with daytime, symptomatic hypoglycemia (n = 5) or in those with non-hypoglycemic profiles (n = 23). Coincident with the nocturnal decline, but preceding the glucose nadir, was a marked release of growth hormone which was significantly greater (p less than .05) than that observed in the other diabetic groups. This release of growth hormone, and the nocturnal hypoglycemia, were reflected in the ratio of awake/sleep mean concentrations of glucose and growth hormone. These data support the speculation that growth hormone release contribute to the hyperglycemic rebound observed. Mean 24 hr growth hormone concentrations varied considerably from patient to patient such that a generalization for growth hormone concentrations in insulin dependent diabetes cannot be made. Asymptomatic nocturnal hypoglycemia is a frequent complication of the therapy of insulin dependent diabetes. Subsequent hyperglycemic rebound (the "Somogyi Effect") is associated with exuberant counterregulatory release of growth hormone. The precise pathophysiological role of this growth hormone release is unclear.

In search of the Somogyi effect

Insulin-treated diabetic patients may show a rapid swing to hyperglycaemia after episodes of hypoglycaemia. This rebound hyperglycaemia, or Somogyi effect, is thought to be caused by the unopposed actions of hormonal antagonists to insulin secreted in response to hypoglycaemia. To test this theory a study was made of 15 patients who had 17 episodes of asymptomatic untreated hypoglycaemia (blood-glucose less than 2 mmol/l) between 11 P.M. and 3 A.M. After nocturnal hypoglycaemia, mean fasting blood-glucose concentrations at 7 A.M. ranged from 0.7-17 mmol/l and were over 7 mmol/l in 6 patients. These 6 patients with apparent rebound hyperglycaemia did not have higher levels of growth hormone, cortisol, or glucagon than those who had little or no recovery of blood-glucose. There was a close inverse correlation (r = -0.996, p < 0.001) between blood-glucose and free insulin, suggesting that hyperglycaemia, when present, was due to relative insulin deficiency in the latter part of the night. Early changes in blood-glucose after untreated hypoglycaemia seem to be primarily due to changes in free insulin rather than a response to antagonist hormones.

Unrecognised nocturnal hypoglycaemia in insulin-treated diabetics

Overnight metabolic studies in 39 poorly controlled insulin-treated diabetic patients aged 9 to 66 years showed hypoglycaemia (blood-glucose less than 2 mmol/1) in 22 patients; it lasted 3 h or more in 17. Hypoglycaemic symptoms were very mild or absent, but 19 patients had other features of overtreatment with insulin. These included lethargy, depression, night sweats, morning headaches, fits (3 patients), glycogen-laden hepatomegaly (3), and acquired tolerance to high doses of insulin (mean 1 u/kg/24 h). The best clinical clue to recurrent nocturnal hypoglycaemia was the intermittent occurrence of symptoms, however "mild" and infrequent these appeared to be. Reduction of insulin by a mean of 25% in these patients (without change of species) did not result in loss of overall control; 1 patient with recurrent ketoacidosis was stablished on 40% of his initial dose. It is difficult, sometimes impossible, to achieve good overnight control with conventional once or twice daily insulin therapy. Since patients readily become tolerant of low blood-glucose levels, reliance on urine tests and symptoms of hypoglycaemia as a guide to dosage easily produces a spiral of overtreatment.

Pediatrics: office management of diabetes mellitus in children

For children with diabetes and their families, education should start immediately upon diagnosis of the disease or recovery from the initial episode of ketoacidosis and should be directed specifically toward childhood diabetes. The physician or nurse should be accessible by phone at all times in case of severe hypoglycemia or ketoacidosis. Nonemergency problems are handled during routine office visits, which should be scheduled regularly every three months. Measures important to good control include accurate daily testing of urine, proper choice and careful regulation of insulin, and maintenance of a well-balanced diet consistent in total intake and meal and snack times. Children who stay involved with peer groups and activities maintain a healthier attitude toward living with their disease.

The Somogyi phenomenon. A short review

The Somogyi phenomenon or effect is a paradoxical situation of insulin-induced post-hypoglycemic hyperglycemia. The historical aspects of this phenomenon and the subsequent hypotheses and controversy are reviewed. The clinical situation is explained, with regard to its recognition, management and importance as an etiological factor in "brittle" diabetes. Hormone immunoassay techniques at present show human growth hormone (HGH) to be the major consequence of insulin-induced hypoglycemia leading to post-hypoglycemia glucose intolerance, but further studies will probably show glucagon to have a major role.