Cognition in the Early Stage of Type 2 Diabetes

Abstract

OBJECTIVEType 2 diabetes is known to be associated with decrements in memory and executive functions and information-processing speed. It is less clear, however, at which stage of diabetes these cognitive decrements develop and how they progress over time. In this study, we investigated cognitive functioning of patients with recent screen-detected type 2 diabetes, thus providing insight into the nature and severity of cognitive decrements in the early stage of the disease. Possible risk factors were also addressed.RESEARCH DESIGN AND METHODSIncluded in this study were 183 diabetic patients from a previously established study cohort and 69 control subjects. A full neuropsychological assessment, addressing six cognitive domains, was made for each participant. Raw test scores were standardized into z scores per domain and compared between the groups. Possible risk factors for cognitive decrements were examined with multivariate linear regression.RESULTSRelative to scores for the control group, mean z scores were between 0.01 and 0.2 lower in the diabetic group across all domains, but after adjustment for differences in IQ between patients and control subjects, only memory performance was significantly reduced (mean difference −0.15 [95% CI −0.28 to −0.03]). A history of macrovascular disease and current smoking were significant determinants of slower information-processing speed in patients with diabetes.CONCLUSIONSThis study shows that modest cognitive decrements are already present at the early stage of type 2 diabetes. A history of macrovascular disease and smoking are significant risk factors for some early decrements.

Cognitive Dysfunction in Diabetic Patients with Special Reference to Age of Onset, Duration and Control of Diabetes

“…There was no significant positive correlation (p>0.05) between sex of patients and cognitive dysfunction in our study which is consistent with a previous syudy by Ruis et al (2009) Our study did not show any significant positive correlation (p>0.05) between dyslipidemia and BMI with cognitive dysfunction which was also observed in other studies.…”

“…Ruis et al (2009) had shown that diabetes duration was associated with the effect size (cognitive decline) of the study: the longer the known diabetes duration, the bigger the effect size which was substantiated by other studies. In the Study of Osteoporotic Fractures (Gregg et al, 2000), there was a trend of increasing risk of cognitive decline with increasing duration of diabetes, and in the Framingham study (Elias et al, 1997), each 5-year increment between diabetes diagnosis and cognitive assessment was associated with lower scores on tests of logical memory, word fluency, and similarities.…”

“…Ruis et al (2009) clearly showed that the age of diabetes onset was inversely related with performance of tasks for memory and information-processing speed in diabetic patients. Since we compared the cognitive score with age-adjusted normative data instead of taking a separate control group for comparison, we did not get any significant impact of age on cognitive function in our study.…”

“…Carla Ruis et al (2009) showed smoking to be a significant risk factor for some early decrements. Cigarette smoking is known to be associated with several harmful biological processes in addition to its effects on blood vessels, such as atherosclerosis and other changes in vessel wall morphology and function (Esen et al, 2004).…”

Impaired Word and Face Recognition in Older Adults with Type 2 Diabetes

“…Additionally, lower premorbid intelligence has been frequently reported in DM2 individuals (7,31), thus lower intelligence is an integral part of this condition which may in fact account for some of the cognitive deficits observed. Indeed, low intelligence is considered a risk factor for DM2 and a range of other chronic conditions, possibly in part because such individuals may be more inclined to engage in adverse health behaviours that increase the risk of disease (32).…”