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Sir.—Hypertrophic cardiomyopathy in children has been described in association with insulin-sensitive hyperinsulinemic states,1most notably in infants of diabetic mothers.1-4A similar type of cardiomyopathy has been reported in certain rare, insulinresistant, hyperinsulinemic conditions, such as leprechaunism.5To emphasize these associations and their potential life-threatening severity, we describe two children with extreme hyperinsulinemia and hypertrophic cardiomyopathy. Patient Reports.—Patient1.—This infant girl was diagnosed as having islet-cell hyperplasia and nesidioblastosis at age 7 days. Her 27-year-old mother experienced a full-term pregnancy, and the infant's birth weight was 4.8 kg. The infant was delivered via emergency cesarean-section because of fetal distress and was immediately intubated. Apgar scores were 3, 5, and 7, at 1, 5, and 10 minutes, respectively. At age 30 minutes, she was found to have a serum glucose concentration of 0.33 mmol/L. The patient was given intravenous glucagon and an intravenous bolus of

• Germ cell tumors may cause various aberrations in pubertal development. In prepubertal boys, these tumors may secrete human chorionic gonadotropin, resulting in precocious puberty. Human chorionic gonadotropin and α-fetoprotein are both useful as germ cell tumor markers in the diagnosis and detection of recurrence. Pregnancyspecific β 1 -glycoprotein, another oncoplacental antigen, has been used as a tumor marker for trophoblastic neoplasms, but not previously for human chorionic gonadotropin—producing tumors associated with precocious puberty. Patients with germ cell tumors may also have abnormal karyotypes. Herein, we describe six male pediatric patients with germ cell tumors and pubertal derangements seen during an 8-year period. We confirm the high incidence of associated sexual precocity, the usefulness of α-fetoprotein, human chorionic gonadotropin, and pregnancy-specific β 1 -glycoprotein as tumor markers in the diagnosis and follow-up of these patients, and the occurrence of sex chromosomal abnormalities. ( AJDC . 1991;145:1294-1297)

\s=b\An 18-year-old man had cystic fibrosis (CF) and insulin-resistant carbohydrate intolerance characterized by (1) obesity, basal hyperinsulinemia, and hyperglucagonemia; (2) impaired oral glucose tolerance; (3) hyperinsulinemia in response to oral and intravenous (IV) administration of glucose and to IV administration of tolbutamide; (4) exaggerated gastric inhibitory polypeptide secretion following orally administered glucose; and (5) diminished sensitivity to insulin administered IV compared with other patients with CF. Both parents also demonstrate basal and stimulated hyperinsulinemia in response to orally administered glucose. The long-term outlook for patients with CF is improving, and more patients are surviving childhood. Thus, it should be recognized that an insulin-resistant form of carbohydrate intolerance may develop in patients with CF with obesity and/or genetic risk factors. (AJDC 1984;138:677-680)

To develop a simple test for pancreatic exocrine function in patients with cystic fibrosis, we compared serum pancreatic amylase isoenzyme (P isoamylase) activity with the more complex standard tests of pancreatic function. Twenty-seven patients with cystic fibrosis, newborn to 46 years of age, were studied. All patients over 17 months old with evidence of pancreatic exocrine insufficiency, as manifested by abnormal duodenal secretions and/or abnormal 72-hour fecal fat absorption, had serum P isoamylase activity below the age-matched normal range; patients with adequate pancreatic function (aged 2 to 46 years) had P isoamylase activity in or above the normal range. Although both normal neonates and neonates with cystic fibrosis have very low levels of serum P isoamylase activity, in patients over 1 1/2 years of age serum P isoamylase activity may serve as a simple and useful discriminator of pancreatic exocrine function in patients with cystic fibrosis.

In Reply.— Dr Baptist's letter interprets our report to indicate that multiple insulin injections are mandatory for good glycemic control. In fact, this is not necessarily implied. What is mandatory is that good control be achieved, and, as we indicated, in most patients this requires multiple injections. The group of patients in whom this may not be necessary, as implied by Dr Baptist, may be "protected" early in the course of their diabetes, when endogenous insulin secretion may still contribute to modulation of control. However, in our experience and that of others, 1 the vast majority of patients do not fall into this group. We would also prefer not to leave the reader with the idea that multiple insulin injections, as opposed to one, are necessarily more traumatic to parent or child. Depending on how the initial experience is handled, the number of injections usually is not a problem. Conversely

• A 7½-year-old boy with chronic renal failure (CRF) experienced transient central isosexual precocious puberty. Simultaneously, he demonstrated hyperprolactinemia with galactorrhea and apparent secondary or tertiary hypothyroidism. These findings could have been a consequence of an unexplained hypothalamic dysregulation. During this period, marked linear growth ensued (8.7 cm during nine months) associated with rapid bone age advancement (four years during a 21-month period). Whereas most boys with CRF demonstrate delayed pubertal development and suppressed linear growth, our patient's transient condition demonstrated that both growth and puberty can occur in the presence of uremia. ( Am J Dis Child 1983;137:956-958)

Prospective studies have shown that children and adolescents with diabetes have a high prevalence of serious complications and a sharp reduction in life expectancy. Recently, self-monitoring of blood glucose levels has become available and, for the first time, provides a method for determining the concentration of blood glucose with considerable accuracy. We have introduced this method of control assessment to our pediatric diabetic patient population in conjunction with a program of intensified insulin administration (two or more injections per day). This is a report of the ready acceptance of these methods by children and adolescents and their parents (53/63, or 84%). The effectiveness of this program is evidenced by a progressive and significant reduction in the percentage of glycosylated hemoglobin during a period of 18 months in a majority of the subjects. These observations suggest that improved glycemic control can be achieved in young diabetics by using multiple insulin injections and self-monitoring of blood glucose levels. Whether such control can lead to a better long-term outlook for diabetics remains to be seen. ( JAMA 1983;249:2913-2916)