Ethnicity and social deprivation independently influence metabolic control in children with type 1 diabetes

Aims/hypothesis This study was performed to evaluate the influence of ethnicity and socioeconomic status (SES) on metabolic control in a population-based cohort of children with type 1 diabetes mellitus, and to evaluate whether any relationship between ethnicity and HbA(1c) is mediated by SES. Methods We performed a retrospective review of all patients under age 16 years with type 1 diabetes (n = 555) from 1995 to 2005 in the greater Auckland region, New Zealand. Diabetes care variables and HbA(1c) values were collected prospectively, during clinic visits. Results The mean population HbA(1c) was 8.3 +/- 1.3%. Maori and Pacific patients had poorer metabolic control than their European counterparts (9.1% and 9.3% vs 8.1%, p < 0.001) and higher rates of moderate to severe hypoglycaemia (31.1 and 24.8 vs 14.9 events/100 patient-years, p = 0.03). In multiple linear regression analysis, both ethnicity and SES were independently associated with HbA(1c) (p < 0.001). Other factors associated with higher HbA(1c) level were longer duration of diabetes, higher insulin dose, lower BMI z score and less frequent blood glucose monitoring (p < 0.001). Conclusions/interpretation Both ethnicity and SES independently influenced metabolic control in a large, unselected population of children with type 1 diabetes. Irrespective of SES, Maori and Pacific youth with type 1 diabetes were at greater risk of both moderate to severe hypoglycaemia and long-term complications associated with poor metabolic control.