The associations of anxiety, depression and personal illness representations with glycaemic control and health-related quality of life in patients with type 2 diabetes mellitus.

OBJECTIVE

This study examined the interrelationships of anxiety, depression and personal illness representations with glycaemic control and health-related quality of life in adults with Type 2 diabetes.

METHODS

One hundred eighty-four consecutive patients with Type 2 diabetes mellitus completed the Illness Perception Questionnaire (IPQ), the Well-Being Scale (WBQ) and the Short Form 36 Health Survey Questionnaire (SF-36). Demographic characteristics, details of diabetes status (duration of diabetes, treatments and complications) and glycosylated haemoglobin (HbA1c) were recorded.

RESULTS

Depression was correlated with greater perceived symptom load (r = .48, P < .01), worse anticipated consequences (r = -.41, P < .01) and perceived lack of control of diabetes (r = .28, P < .01). After controlling for demographic and illness characteristics, personal illness representations relating to symptom load and anticipated consequences were independently associated with the SF-36 physical functioning score, contributing an additional 15% to the variance. WBQ depression and anxiety scores, along with IPQ control and consequences, were independently associated with SF-36 mental function score, contributing a further 51% to the variance after controlling for demographic and illness details. Neither IPQ nor WBQ scales were associated with HbA1c after controlling for demographic and medical illness details.

CONCLUSION

Anxiety, depression and negative beliefs about illness influence physical and mental functioning, but not metabolic control in patients with diabetes.