Background:

Affective temperaments (depressive, cyclothymic, hyperthymic, irritable and anxious) are inherited stable parts of the personality and determine the emotional mood, activity and reactivity. There are few studies on the relationship and mediating factors between affective temperaments and metabolic control among patients with type 2 diabetes mellitus (T2DM).

Research questions:

We aimed to investigate the association between affective temperaments and glycemic control among patients with T2DM in general practice, and whether temperaments affect metabolic control through depression or through impairing self-care.

Method:

We included 338 patients with T2DM from six primary care practices in this cross-sectional study. A self-administered questionnaire (patient history, anthropometric, socioeconomic, laboratory parameters), the Beck Depression Inventory (BDI), the Hamilton Anxiety Scale and the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego Autoquestionnaire were used.

Results:

The mean age of the sample was 63.98 ± 11.51 (years±SD), 61.2% of participants were female. Cyclothymic affective temperament (p=0.002) and higher BDI score (p=0.048) were associated with worse HbA1c in univariate linear regression. Depressive, anxious, irritable, and hyperthymic affective temperaments were not associated directly with HbA1c, also, lifestyle factors, such as smoking, physical activity, and alcohol intake were not predicting HbA1c. In causal mediation analyses cyclothymic affective temperament was directly associated with higher HbA1c (p=0.008), with the effect not mediated by BDI. Hyperthymic affective temperament was indirectly associated with lower HbA1c, mediated by BDI (p=0.034). Depressive, anxious, and irritable affective temperaments were not associated with HbA1c neither directly nor indirectly.

Conclusions:

Among primary care patients with type 2 diabetes, cyclothymic temperament correlates with worse glycemic control independently of depressive symptoms. Hyperthymic temperament reduces depressive symptoms thereby improving glycaemic control. It is important to screen for affective temperaments in addition to depression among patients with type 2 diabetes in general practice.

Points for discussion: