title: Sexual dimorphism in insulin sensitivity in adolescents with insulin-dependent diabetes mellitus.
abstract: Sex-related differences in insulin sensitivity were evaluated in male and female adolescents with insulin-dependent diabetes mellitus (IDDM). They were matched for age, pubertal staging, body mass index, and glycohemoglobin levels. During a 1.7 mU/kg.min hyperinsulinemic-euglycemic clamp, the insulin-mediated glucose disposal rate was lower (26.9 +/- 2.1 vs. 47.1 +/- 3.7 mumol/kg.min; P less than 0.001), and GH levels were higher (6.5 +/- 1.2 vs. 2.9 +/- 0.8 micrograms/L; P = 0.03) in females than in males. Plasma glucagon, cortisol, epinephrine, and norepinephrine levels during the clamp were similar in the two sexes, except for pancreatic polypeptide, which showed a tendency to be higher in females (19 +/- 4 vs. 11 +/- 1 pmol/L; P = 0.07). During insulin-induced hypoglycemia, the rate of drop in plasma glucose was faster (0.16 +/- 0.01 vs. 0.11 +/- 0.01 mmol/L.min; P = 0.001), and the rate of glucose recovery was slower in males than in females (0.04 +/- 0.01 vs. 0.06 +/- 0.01 mmol/L.min; P = 0.05). Plasma glucose concentrations were lower in males than in females (glucose nadir, 2.3 +/- 0.2 vs. 3.3 +/- 0.2 mmol/L; P = 0.002; glucose peak, 3.7 +/- 0.2 vs. 5.3 +/- 0.4 mmol/L; P = 0.002), with similar plasma free insulin concentrations. Despite a greater degree of hypoglycemia, GH responses were lower in males than in females. The remaining counterregulatory hormone responses were similar in both sexes. We conclude that there is a distinct sexual dimorphism in insulin sensitivity in adolescents with IDDM. This is likely to be due to sex-related differences in GH levels. Furthermore, male patients with IDDM are apt to develop greater degrees of hypoglycemia accompanied by lower GH responses.
authors.affiliation: Division of Pediatric Endocrinology, Metabolism, and Diabetes Mellitus, Children's Hospital, University of Pittsburgh, Pennsylvania 15213.
authors.forename: S A
authors.initials: SA
authors.lastname: Arslanian
authors.forename: B V
authors.initials: BV
authors.lastname: Heil
authors.forename: D J
authors.initials: DJ
authors.lastname: Becker
authors.forename: A L
authors.initials: AL
authors.lastname: Drash
mesh_terms: D000293:Adolescent; D001786:Blood Glucose / Q000032:analysis; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D015309:Glucose Clamp Technique; D013006:Growth Hormone / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood / Q000627:therapeutic use*; D007333:Insulin Resistance; D008297:Male; D009994:Osmolar Concentration; D010191:Pancreatic Polypeptide / Q000097:blood; D012727:Sex Characteristics
chemical_list: D001786:Blood Glucose; D007328:Insulin; D010191:Pancreatic Polypeptide; D013006:Growth Hormone