Validation of the Composite Autonomic Symptom Score 31 (COMPASS 31) for the assessment of symptoms of autonomic neuropathy in people with diabetes.

AIM: To validate the Composite Autonomic Symptom Score (COMPASS) 31, in its Italian version, for the diagnosis of diabetic cardiovascular autonomic neuropathy in a clinic-based, single-centre study. METHODS: A total of 73 participants with diabetes (age 55 ± 14 years) completed the COMPASS 31 questionnaire before undergoing cardiovascular autonomic neuropathy and diabetic polyneuropathy assessment according to cardiovascular reflex tests, neuropathic symptoms and signs, and vibration and thermal thresholds. RESULTS: The COMPASS 31 total weighted score differed between participants with and without cardiovascular autonomic neuropathy (29.9 ± 19.5 vs 16.1 ± 14.7; P = 0.003) and with and without diabetic polyneuropathy (28.9 ± 19.1 vs 12.7 ± 11.3; P < 0.0001). It was related to cardiovascular reflex tests score (rho = 0.38, P = 0.0013) as well as diabetic polyneuropathy symptoms (rho=0.61, P < 0.0001) and signs scores (rho = 0.49, P < 0.0001). Receiver-operating curve analysis showed a fair diagnostic accuracy of total score for cardiovascular autonomic neuropathy (area under the curve 0.748 ± 0.068, 95% CI 0.599-0.861) and diabetic polyneuropathy (area under the curve 0.742 ± 0.061, 95% CI 0.611-0.845). The best score thresholds were 16 for early cardiovascular autonomic neuropathy (sensitivity 75.0%, specificity 64.9%, positive predictive value 37.5% and negative predictive value 90.2%), and 17 for both confirmed cardiovascular autonomic neuropathy and diabetic polyneuropathy (sensitivity 70.0% and 65.5%, respectively; specificity 66.7% and 79.5%, respectively; positive predictive value 25.0% and 67.9%, respectively; and negative predictive value 93.0% and 77.8%, respectively). COMPASS 31 had a good internal consistency according to Cronbach's α coefficient of 0.73. CONCLUSIONS: COMPASS 31 can represent a valid, easy-to-use, quantitative assessment tool for autonomic symptoms in diabetic neuropathy, with a fair diagnostic accuracy for both cardiovascular autonomic neuropathy and diabetic polyneuropathy.

Hippocampal volume and cognitive performance in long-standing Type 1 diabetic patients without macrovascular complications.

AIMS: Hippocampal atrophy and memory deficits have been reported in Type 2 diabetes. Whether similar alterations occur in Type 1 diabetes is currently unknown. METHODS: In a case-control design, 13 Type 1 diabetic patients with at least 10 years' duration of disease, but free from clinical signs of macrovascular disease, were compared with age- and gender-matched control subjects. Hippocampal volume and measures of global cerebral cerebrospinal fluid (CSF) were determined from magnetic resonance imaging (MRI) scans. Cognitive functions were assessed using four neuropsychological tests. Mood and depression were measured by questionnaires. RESULTS: Hippocampal volume and memory did not differ between Type 1 diabetic patients and control subjects. However, a significantly increased amount of cerebral CSF suggestive of mild cerebral atrophy was observed in the patients. In addition, deficits in psychomotor speed and selective attention were apparent. Eleven of 13 patients had retinopathy and/or nephropathy. Findings were unrelated to cerebrovascular disease, white matter disease or silent strokes. CONCLUSIONS: Results from our small study in Type 1 diabetic patients do not support findings from previous studies of Type 2 diabetic patients demonstrating reductions in hippocampal volume and impaired memory. On the contrary, we observed evidence for mild cerebral atrophy and impaired psychomotor speed and selective attention. This is in line with some previous studies in Type 1 diabetes. If replicated in larger studies, our findings would support the idea that the effects on brain function and structure differ between Type 1 and Type 2 diabetes.