NEUROPSYCHOLOGICAL FUNCTION IN OLDER SUBJECTS WITH NON-INSULIN-DEPENDENT DIABETES-MELLITUS

Neuropsychological function was compared in three well-matched groups of subjects: Group 1, 20 diabetic patients with hypertension, mean age 69.1 +/- 4.8 years, 14 males and 6 females; Group 2, 20 normotensive diabetic patients, mean age 69.0 +/- 6.2 years, 14 male and 6 females; Group 3, 20 healthy community controls, mean age 68.1 +/- 4.5 years, 13 males and 7 females. There were no significant differences between the groups in education or estimated IQ using the NART (National Adult Reading Test). Groups 1 and 2 did not differ significantly in duratio n of diabetes (mean 10.6 and 9.5 years, respectively), or mean glycosy lated haemoglobin, HbA(1) (mean 9.8 and 10.6 %, respectively), or mean blood glucose before or after testing. On a battery of neuropsycholog ical tests, sensitive to cognitive impairment in older subjects, analy sis of covariance using estimated IQ as the covariate showed no signif icant differences between the groups on tests of recall, with (Brown-P eterson Test) and without (Kendrick Object Learning Test) interference , forward and backward digit span, concentration (serial subtraction), verbal fluency, immediate and delayed prose recall, digit symbol subs titution or psychomotor speed (Kendrick Digit Copying Test). These res ults provide no support for an association between cognitive deficits and Type 2 diabetes mellitus in older subjects or for the view that su ch deficits may also be mediated by hypertension.