DETERMINANTS OF BLOOD-GLUCOSE VARIABILITY IN ADOLESCENTS WITH INSULIN-DEPENDENT DIABETES-MELLITUS

Metabolic control and blood glucose variability in children with insul in-dependent diabetes mellitus (IDDM) during and after puberty were st udied. Seventy-two children (43M, 29F), aged 10-19 years, with a 2-16- year duration of IDDM participated in the study. Fourteen of the patie nts were prepubertal (Tanner stage 1), 27 pubertal (Tanner 2-4) and 31 postpubertal (Tanner 5). They performed self-monitoring of blood gluc ose (SMBG) five times daily, every 2 days for 4 weeks. The SD (SDbg) f or all values in each patient was calculated as a measure of blood glu cose variability. Weight-length index, linear growth velocity and Tann er stage were recorded. Hemoglobin (Hb)AI,, alkaline phosphatase and s ex hormone levels in serum were analyzed. Subjectively experienced hyp oglycemic episodes were recorded. HbA(1c) levels showed no relation to Tanner stage. SDbg was lower in stage 5 than in stages 2-4 (p = 0.02) . There was no significant correlation between HbA(1c) and SDbg, but t he variability was significantly lower in individuals with mean blood glucose in the lower quartile compared with those in the upper three q uartiles (p < 0.001). Alkaline phosphatase concentration, as a measure of growth velocity, was the main independent determinant of SDbg (r = 0.35, p < 0.005). There was an inverse correlation between levels of sex hormones and SDbg. We conclude that blood glucose variability is l ower after than during puberty. This variability seems to be related t o linear growth velocity or its biochemical marker.