Distinct Patterns of Daily Glucose Variability by Pubertal Status in Youth With Type 1 Diabetes.

OBJECTIVE: To evaluate glycemia and metrics of glucose variability in youth with type 1 diabetes, and to assess patterns of 24-h glucose variability according to pubertal status.

RESEARCH DESIGN AND METHODS: Metrics of glycemia, glucose variability, and glucose patterns were assessed by using 4 weeks of continuous glucose monitoring (CGM) data from 107 youth aged 8-17 years with type 1 diabetes for ≥1 year. Glucose values per hour were expressed as percentages relative to the mean glucose over 24 h for a 4-week period. Glucose data were compared on the basis of pubertal status-prepubertal (Tanner stage [T] 1), pubertal (T2-4), and postpubertal (T5)-and A1C categories (<7.5% [<58 mmol/mol], ≥7.5% [≥58 mmol/mol]).

RESULTS: Youth (50% female, 95% white) had a mean ± SD age of 13.1 ± 2.6 years, diabetes duration of 6.3 ± 3.5 years, and A1C of 7.8 ± 0.8% (62 ± 9 mmol/mol); 88% were pump treated. Prepubertal youth had a higher mean glucose SD (86 ± 12 mg/dL [4.8 ± 0.7 mmol/L]; 0.01) and coefficient of variation (CV) (43 ± 5%; 0.06) than did pubertal (SD 79 ± 13 mg/dL [4.4 ± 0.7 mmol/L]; CV 41 ± 5%) and postpubertal (SD 77 ± 14 mg/dL [4.3 ± 0.8 mmol/L]; CV 40 ± 5%) youth. Over 24 h, prepubertal youth had the largest excursions from mean glucose and the highest CV across most hours compared with pubertal and postpubertal youth. Across all youth, CV was strongly correlated with the percentage of time with glucose <70 mg/dL (<3.9 mmol/L) ( = 0.79; < 0.0001).

CONCLUSIONS: Prepubertal youth had greater glucose variability independent of A1C than did pubertal and postpubertal youth. A1C alone does not capture the full range of glycemic parameters, highlighting the added insight of CGM in managing youth with type 1 diabetes.