Is the process of β-cell destruction in type 1 diabetes at time of diagnosis more extensive in females than in males?

Objective: To evaluate sex differences in patients with insulin-dependent diabetes mellitus (type 1 diabetes) by comparing the integrated parameters of metabolic control at the time of clinical diagnosis and 3 months after intensive insulin therapy in pre-pubertal, pubertal and post-pubertal patients. Design: A total of 331 consecutive patients with newly diagnosed type 1 diabetes were studied. The mean age of the group was 15 years (S.D. 8.1; range 5-23 years). Patients were stratified into three groups according to their age at disease onset: pre-pubertal (ages 5-9 years), pubertal (ages 10-18 years) and post-pubertal (ages 19-23 years). Methods: Glycated haemoglobin (HbA(1c)), insulin dose and both basal and glucagon-stimulated C-peptide were evaluated at diagnosis and after 3 months of insulin therapy. Results: We found that females diagnosed after puberty were those with the lowest basal C-peptide compared with males (P = 0.005). No statistically significant differences were observed for other metabolic parameters. When the entire group was evaluated, females at the time of diagnosis showed significant lower body mass index (P = 0.001), lower basal C-peptide (P = 0.021) and higher HbA(1c) (P = 0.023) and required more insulin than males (P < 0.001). After 3 months of therapy, only a significantly greater dose of insulin was observed in females compared with males (P = 0.001), with similar good metabolic control as assessed by HbA(1c). Conclusions: We conclude that the process of beta -cell destruction at diagnosis may be more extensive in post-pubertal females than in males. Moreover, after the introduction of insulin therapy, females and males show similar metabolic parameters, although females still require significantly more insulin than males to achieve good metabolic control, 3 months after diagnosis.