URINARY GROWTH-HORMONE EXCRETION IN CHILDREN AND ADOLESCENTS WITH INSULIN-DEPENDENT DIABETES-MELLITUS

Urinary growth hormone (uGH) excretion was evaluated in 96 type-1 insu lin-dependent diabetic patients and 37 age-matched healthy subjects. T he growth hormone concentration was measured by a solid-phase immunora diometric assay on 3 consecutive overnight urine collections. uGH excr etion was comparable between diabetic patients and healthy subjects: 1 0.9 (0.1-34.8) vs. 9.1 (2.6-34.5) pg/min. In both groups uGH excretion was lower in prepubertal than in pubescent or pubertal individuals (d iabetic patients, H = 29.7, p = 0.001; healthy subjects, H = 10.4, p = 0.006). In diabetic patients uGH excretion was related to Pz-microglo bulin excretion (r = 0.308; p = 0.005) and to urinary albumin excretio n (r = 0.230; p = 0.02) but it was independent of HbAlc and overnight glycemic values. The coefficient of variation of uGH excretion was hig her in diabetic patients with respect to healthy subjects: 50 (3-141) vs. 28 (3-100)% (p = 0.002). Among diabetic patients it was greater in prepubertal than in pubescent or pubertal patients (H = 13.7; p = 0.0 02); in contrast, it was independent of pubertal stage in healthy indi viduals (H = 2.4; NS). The coefficient of variation of uGH was not rel ated to HbAlc, the duration of diabetes, the coefficient of variation of urinary albumin excretion and the coefficient of variation of Pz-mi croglobulin excretion. In conclusion uGH excretion is comparable among diabetic patients and healthy subjects, but its day-to-day fluctuatio n is greater in the former than in the latter group. Renal function bu t not metabolic control can influence uGH excretion. The day-to-day fl uctuation in uGH excretion is independent of metabolic control and ren al function.