Urinary growth hormone excretion in post-menarcheal adolescent girls with type 1 diabetes

Body composition and bone mineral density in long-standing type 1 diabetes

OBJECTIVES

To study body composition and bone mineral density (BMD) in adult patients with long-standing type 1 diabetes mellitus.

RESEARCH DESIGN AND METHODS

In a population-based study, body composition and BMD were evaluated by dual energy X-ray absorptiometry in 38 patients with type 1 diabetes since childhood, compared with 38 age- and sex-matched controls. The mean age was 43 years (range 33-55 years) and the mean duration of diabetes was 33 years (range 28-37 years).

RESULTS

Besides a tendency to a reduced abdominal fat mass in diabetic males, no difference was observed in fat mass, muscle mass, or BMD between the groups. Significant correlations were found between insulin dosage and whole body fat mass in diabetic females and between serum cholesterol levels and abdominal fat mass in diabetic males.

CONCLUSION

Patients with long-standing type 1 diabetes with onset in childhood and adolescence seem to show only minor differences in body composition and no difference in BMD compared with closely matched healthy controls.

Plasma and urinary GH following a standardized exercise protocol to assess GH production in short children

Plasma and urinary GH responses following acute physical exercise were evaluated in 19 short-statured children (12 males, 7 females, median age: 11.4 yr, age range: 6.1-14.5 yr, Tanner stage I-III, height < or = 3rd centile for age; 7 with familial short stature, FSS; 8 with constitutional growth delay, CGD; 4 with GH deficiency, GHD) and 7 normally growing, age- and sex-matched control children (4 males, 3 females, median age 11.0 yr, range: 7.2-13.1 yr, Tanner stage I-III). All patients and controls underwent a standardized exercise protocol (consisting of jogging up and down a corridor for 15 min, strongly encouraged to produce the maximum possible effort, corresponding to 70-80% of the maximal heart rate) after an overnight fasting. Samples for plasma GH determinations were drawn at 0 time (baseline), at 20 min (5 min after the end of exercise) and at 35 min (after 20 min of rest); urine samples were collected before (0 time) and at 40, 80 and 120 min after exercise. The distance covered by children with GHD during the test was significantly lower (p<0.05) than in the other groups of patients and controls. No differences in the pattern of plasma GH responses after physical exercise were found between children with FSS, CGD and healthy controls, the maximum percent increase (vs baseline) being evident at 20 min (median, FSS: +1125%; CGD: +1271%; controls: +571%). Children with GHD showed a smaller percent increase (+94%) of plasma GH, significantly lower (p<0.01) than those recorded in the other groups. A significant percent increase (p<0.01) of baseline urinary GH following exercise was found in children with FSS (median: +34%), CGD (+18%) and controls (+44%). Children with FSS and CGD showed a gradual increase of urinary GH, reaching the maximum at 80 min, while healthy controls had a more evident and precocious increase (maximum at 40 min). Urinary median GH levels did not change following physical exercise in children with GHD (-5%, not significant). A significant correlation was found between the maximal percent increase (vs baseline) of plasma and urinary GH following physical exercise (r=0.7, p<0.001). In conclusion, our results show that: 1) plasma and urinary GH responses (as well as the distance covered and the number of steps, i.e. the physical performance) to a standardized exercise protocol are similar in children with FSS, CGD and in normal-statured controls, being unable to differentiate among the "normal variants" of growth; 2) children with GHD, unable to accomplish the same performance of the other three groups, show significantly reduced plasma and urinary GH responses following physical exercise. Although the determination of GH responses to pharmacological stimuli remains the definitive tool for the diagnosis of GHD, these preliminary results seem to suggest a potential role of urinary (and plasma) GH response to a standardized exercise protocol as a safe, acceptable first screening test for GH sufficiency also in children, as previously reported in adults.