Background: Metabolic complications including diabetes (DM) and insulin resistance have been conclusively associated with HIV infection.  The addition of HAART has had further deleterious effects on metabolic risk factors in this already vulnerable population, particularly among older patients.  Correlation to neurocognitive function is not well understood and is the objective of this analysis. 

Methods:  Participants were from one of two groups (under 40 or 50+ years old) within the seropositive arm of the Hawaii Aging with HIV Cohort. Evaluations included comprehensive neuropsychological testing. Three measures of cognitive functioning were constructed from combinations of scores on neuropsychological test results standardized within our sample: an overall measure of cognitive functioning, NPZ8; a measure of memory, NPZ3-memory; and a measure of psychomotor functioning, NPZ3-psychomotor. Trained personnel obtained medical histories including established diagnoses for diabetes (DM) using a structured interview.  Data from 169 participants (73 younger and 96 older) were available for these analyses. 

Results: Frequency of DM was 8.9% (15.6% among older and 0% among younger). DM was negatively associated with overall cognitive functioning (F = 19.15, p < 0.01), accounting for 11% of the variance in NPZ8 scores. DM was also negatively associated with psychomotor functioning (F = 14.16,pp < 0.01) accounting for 8% of the variance in NPZ3-psychomotor scores.  There was no association between DM and NPZ3-memory scores. Controlling for age, ARV, current hypertension, current hypercholesterolemia, pack-years of smoking, ethnicity, and duration of HIV infection, did not substantially alter these results.

Conclusions: These data suggest that diabetes is associated with decreased overall cognitive performance and specifically psychomotor performance in patients with HIV.   Our findings are driven exclusively by diabetes in older patients and thus, if confirmed, may represent a newly identified risk factor for older seropositive patients. This risk is independent of other vascular risk factors.  The underlying mechanism is not clear.  While speculative, this could be associated with metabolic dysfunction and abnormalities in glucose regulation.

Keywords: dementia; diabetes; aging