Background: The link between glycaemic control of type 1 diabetes and family functioning is complex, with the existing literature largely focussing upon the association between clear patterns of disturbances in family functioning and suboptimal diabetic control. The more subtle changes to family function that might influence the degree of successful management of a child's diabetes have been less well studied. Methods: This study sought to explore whether suboptimal glycaemic control was associated with variations in family functioning that might not in themselves prompt concern in routine clinic review. The project focussed on families attending for routine follow-up in specialist paediatric diabetes clinics in the North East of England. Mother and child participants provided demographic information and completed the Family Adaptation and Cohesion Evaluation Scale (FACES IV), and the quality of their glycaemic control was assessed using the mean HbA1c value for each child over the last year. Families with clear emotional or family difficulties, or where the level of control was causing clear concern were excluded (as were families where there was major physical or a member with significant learning disabilities). The sample was divided into two groups; families whose children were in optimal glycaemic control of their diabetes, and families where the glycaemic control was suboptimal. Results: Whatever the degree of control, nearly all the mothers and index children reported functioning within the balanced range. The mothers of children with optimal glycaemic control reported their family to be more cohesive and expressed greater satisfaction with family life than mothers whose child's glycaemic control was suboptimal. The children with suboptimal diabetic control also tended to view their family life as more chaotic. Discussion: Despite the challenges most families cope reasonably well with the issues that managing type 1 diabetes in a child bring. However suboptimal control tends to be associated with some unhelpful family issues, and the implications for intervention are discussed. Conclusions: Suboptimal control, when it is present, prompts exploration of a wide range of factors. Assessment of family functioning should be part of this process, even if there is no evidence of major family difficulties because subtle distortions in functioning can significantly influence glycaemic control, especially in early adolescence.

The association between glycaemic control of type 1 diabetes and mental health issues within the family is well recognised, but the degree of difficulty that is associated with modest sub-optimal control is not. 66 families agreed to take part in the study, and they were divided into two groups according to the quality of metabolic control (good or sub-optimal). Of the 37 boys, 19 had suboptimal metabolic control, and of the 27 girls, 15 did not have a good control. Mother and child participants provided demographic information, and mothers completed the 28-item General Health Questionnaire (GHQ), the revised version of the Swanson, Nolan and Pelham Questionnaire (SNAP IV), elements of the Ontario Child Health Scale, and the Family Adaptation and Cohesion Evaluation Scale (FACES IV). The results from these scales were compared to the quality of the children's glycaemic control. Sub-optimal control was associated with the increased emotional symptoms and behavioural difficulties in the young person (p < 0.0001), and increased mental health difficulties in their mothers (p < 0.001). These elements had an adverse impact on the level of satisfaction with family life. Having sub-optimal glycaemic control is associated with an increased risk of having mental health symptoms, and a possible mechanism for this association is explored. Even modest deterioration in a family's mental health can have an adverse effect upon glycaemic control, and should be assessed as a routine in review clinics.