Depression, anxiety, cognitive impairment and their association with clinical and demographic variables in people with type 2 diabetes: a 4-year prospective study

OBJECTIVE

To investigate depression, anxiety and cognitive impairment and their associations with clinical and socio-demographic variables in type 2 diabetes.

METHODS

The Zung Self-Rating Depression-Anxiety Scale and Mini-Mental State Examination (MMSE) were administered at baseline and after 4 years to 498 consecutive patients, 249 non-insulin treated (NIT) and 249 insulin treated (IT), aged 40-80 years.

RESULTS

At baseline, IT patients were older, had longer disease duration, higher HbA1c and did more glucose monitoring (p < 0.001, all) but their depression scores were lower than among NIT (p = 0.006), with no differences for anxiety or MMSE. After 4 years, 72 patients were lost to the follow-up, of whom 18 had died. 41 NIT had switched to insulin and increased BMI (p = 0.004), blood pressure (p < 0.001), retinopathy severity (p = 0.03) and microalbuminuria (p = 0.0045), but did not change their scores for depression, anxiety or MMSE. The remaining 171 NIT improved fasting glucose (p = 0.006), total cholesterol (p < 0.0001), triglyceride (p = 0.0026) and HbA1c (p = 0.0006). Despite increased prevalence of microalbuminuria and retinopathy (p < 0.0001, both), depression (p = 0.04) and MMSE (p = 0.0007) improved. Foot ulcers (p = 0.03), retinopathy (p < 0001), microalbuminuria (p = 0.0047) and hypertension (p < 0.0001) increased in the remaining 214 IT patients, in whom depression (p = 0.0005) and anxiety (p < 0.0001) worsened while MMSE improved slightly (p = 0.0002). On multivariate analysis, depression was associated with being a woman and anxiety with diabetes duration and lower schooling, which also affected MMSE scores.

CONCLUSIONS

Depression was associated with female gender and worsening complications but not modified by diabetes duration or switching to insulin therapy. Diabetes duration and lower schooling may affect anxiety and cognitive impairment.

A cross-sectional survey of depression, anxiety, and cognitive function in patients with type 2 diabetes

To evaluate the prevalence of depression in outpatients with type 2 diabetes and its possible correlation with anxiety, cognitive function, and clinical variables. The Zung Self-Rating Depression and Anxiety Scales and the Mini-Mental-State Examination were administered to 249 non-insulin-treated (NIT) and 249 insulin-treated (IT) outpatients with type 2 diabetes, aged 40-80, in a cross-sectional survey. Compared with a reported prevalence of 6-13% in the general population, 104 (20.9%) patients had either a score indicative of depression or were on anti-depressant medication. Assuming that medication might modify the responses to questionnaires, the latter patients were excluded from further analysis. IT patients had higher age, known duration of diabetes, HbA1c, more foot ulcers, retinopathy, microalbuminuria and practised more self-monitoring of blood glucose (P < 0.01 all) but a slightly lower mean depression score (P = 0.004) and similar anxiety or cognitive function. At multivariate analysis, depression was associated with anxiety (P < 0.001), age (P < 0.001), gender (men having lower scores than women, P = 0.042), and insulin treatment, IT patients being less depressed than NIT (P < 0.001), but none of the clinical variables. Anxiety correlated with age (P < 0.001). The association between depression and anxiety became progressively weaker with increasing age. These data confirm increased prevalence of depression in a population of patients with type 2 diabetes who did not show impaired cognitive function. The lack of correlation with disease duration, metabolic control, and complications suggests that depression may not appear/worsen with diabetes and/or its complications but rather supports suggestions that it might predate both.