QT dispersion in mild cognitive impairment: a possible tool for predicting the risk of progression to dementia?

OBJECTIVE: The aim of this research was to investigate relationships between cognitive function and non-invasive, repeatable cardiac parameters in elderly subjects suffering from mild cognitive impairment (MCI) or Alzheimer's disease (AD). METHODS: Two hundred and twenty-four community-living elderly subjects, 31 AD patients, 77 MCI patients, and 116 cognitively normal subjects (CNS), were evaluated for cognitive abilities (Mini Mental State Examination score (MMSE)) and for electrocardiographic [corrected heart rate QT interval dispersion (QTcD)] and echocardiographic [Left ventricular ejection fraction (LVEF)] parameters. RESULTS: Mean values of LVEF were not significantly different between the three groups; QTcD mean values were significantly lower in CNS group than in subjects with MCI and AD. The Pearson Product Moment Correlation test, carried out in the three study groups, showed a significant inverse correlation between QTcD and MMSE score (r = -0.357; p < 0.01) in the group of MCI patients, only. In multivariable-adjusted linear regression tests, QTcD (p = 0.030) and education (p = 0.021) are associated with MMSE score in MCI group. Only the parameter of education appears to predict MMSE in CNS group; none of these parameters appear to predict MMSE in the group of patients with AD. CONCLUSION: The association between QTcD and MMSE requires cautious interpretation and further extensive investigation. However, if confirmed by longitudinal studies, the finding could play a role in the management of the subjects with MCI.

Effect of postprandial hyperglycaemia on blood viscosity in aged patients suffering from type 2 diabetes as compared with healthy volunteers.

Postprandial hyperglycaemia is an independent predictor of cardiovascular risk. Increased blood viscosity has been considered a major cardiovascular risk factor and may play a role in the vascular complications of diabetes. The present study aimed to verify whether blood viscosity is altered by the increased postprandial hyperglycaemia in aged type 2 diabetic patients. The whole blood viscosity, haematocrit, fibrinogen, glucose, insulin, total cholesterol, and triglyceride plasma levels, heart rate, and systolic and diastolic blood pressures were measured in 15 aged patients affected by type 2 diabetes and 15 healthy age-matched individuals before and 60 and 120 min after a test meal (670 kcal energy intake). In the basal condition, in both healthy control individuals and diabetic patients, the whole blood viscosity at higher shear rate (450/s) was significantly correlated in a negative way with the index of insulin resistance (P < 0.05), and in a positive way with the haematocrit value (P < 0.05) and the platelet count (P < 0.01). After the test meal, the whole blood viscosity significantly decreased (P < 0.01 or less) in aged healthy individuals, whereas it remained unchanged in type 2 diabetic patients. In conclusion, the negative action of postprandial hyperglycaemia in diabetes does not occur via a measurable increase of blood viscosity during that period. The decrease of blood viscosity observed during the postprandial period in normal individuals, however, points to the occurrence of alterations in the regulation of the haemorheological equilibrium in the postprandial period in aged type 2 diabetic patients.

Vigorous exercise acutely changes platelet and B-lymphocyte CD39 expression.

CD39/ATP diphosphohydrolase is expressed on B lymphocytes, cytotoxic T lymphocytes, monocytes, platelets, and endothelial cells, and it has a critical role in the inhibition of platelet responsiveness. To determine whether strenuous exercise could acutely change expression of CD39 in platelets and lymphocytes, eight healthy sedentary men, 34 yr old (SD 7), and eight physically active men, 34 yr old (SD 6), performed graded upright cycle ergometry to volitional exhaustion. Blood samples collected both at baseline and after exercise test were employed to measure CD39 expression in platelets and lymphocytes. The percentage of circulating platelet-platelet aggregates, the "in vitro" ADP and collagen-induced platelet aggregation, and the expression of both platelet glycoprotein IIb-IIIa (PAC-1) and P-selectin (CD62) were also considered markers of platelet activation. After strenuous exercise, all subjects demonstrated significant platelet activation as judged by the increased percentage of platelet-platelet aggregates. The in vitro ADP-induced platelet aggregation and the expression of CD62P on ADP-stimulated platelets significantly increased in sedentary but not in active subjects. After exercise, all of the subjects showed a significant reduction of CD39 expression in platelet [sedentary: from 2.2 (SD 0.8) to 1.1% (SD 0.8), P = 0.008; active: from 0.6 (SD 0.2) to 0.35% (SD 0.1), P = 0.009] and an increase of CD39 expression in B lymphocytes [sedentary: from 47 (SD 13) to 60% (SD 11), P = 0.0039; active: from 46 (SD 11) to 59% (SD 11), P = 0.0038]. Taken together, these findings confirm the critical role of this ADPase in inhibition of platelet responsiveness, also suggesting a possible role of B lymphocytes in thromboregulation mechanism.

Acute hyperglycemia alters von Willebrand factor but not the fibrinolytic system in elderly subjects with normal or impaired glucose tolerance.

To assess whether acute hyperglycemia affects fibrinolytic balance in elderly subjects with normal glucose tolerance (NGT) or impaired glucose tolerance (IGT), 40 non-obese elderly subjects (20 NGT, age 68 +/- 8 years; and 20 IGT, age 69 +/- 11 years) were studied. On two experimental days, randomly allocated and spaced 1 week apart, plasma concentrations of glucose, insulin, fibrinogen, tissue plasminogen activator, plasminogen activator inhibitor type 1 and von Willebrand factor (vWF) were measured in each subject at baseline (0) and 30, 60, 90, 120 min after the ingestion of 75 g glucose or a similarly sweet dose of aspartame (250 mg) (control test). In both NGT and IGT elderly subjects, tissue plasminogen activator, plasminogen activator inhibitor type 1 and fibrinogen plasma levels did not significantly change after both oral aspartame and glucose load. In IGT subjects, vWF plasmatic levels decreased after glucose (not aspartame) oral load, reaching the minimum level at 90 min after load (82.7 +/- 7.8 versus 93.7 +/- 10.2, P <0.01). These results demonstrate that acute hyperglycemia does not modify plasma fibrinolysis in elderly subjects. The decrease of plasma concentration of vWF in IGT elderly subjects requires cautious interpretation and further extensive investigations.

A 69-year-old woman with persistent iron deficiency anemia.

In women, iron deficiency anemia-a result of chronic iron loss-is most common during the reproductive years because of physiologic demands such as menstrual blood losses and pregnancy. In other cases, iron deficiency anemia is generally attributed to occult gastrointestinal bleeding. Common causes of chronic gastrointestinal blood loss include erosive esophagitis, gastric and duodenal ulcers, vascular ectasias, colon adenomas, and cancers. Bleeding from the small intestine at sites beyond the duodenal bulb is uncommon. The lesions of the small intestine are responsible for approximately 4% of gastrointestinal bleeding [7]. In this report we describe a case of persistent iron deficiency anemia due to carcinoid tumor of the small intestine.

Urinary incontinence in the elderly: relation to cognitive and motor function.

Urinary incontinence is a common problem in older subjects, very often wrongfully accepted as a normal part of the aging process. A total of 520 subjects (208 males and 312 females; mean age 74.8 +/- 11.8 years), from both private- and nursing-home dwelling populations, were included in this study aimed to estimate the incidence of urinary incontinence and identify factors associated with condition, in aged subjects. The incidence and type of urinary incontinence (stress, urge or mixed incontinence) were assessed by structured questionnaires and diagnosis was confirmed by a seven-day consecutive voiding diary. Assessment of physical, cognitive and emotional functions was performed on each subject using the Mini Mental State Examination (MMSE), Instrumental Activities of Daily Living Scale (IADL), Tinetti Scale (gait), Tinetti Scale (balance) and Geriatric Depression Scale (GDS) instruments. In the total population sample the incidence of urinary incontinence was 47.9%. The incontinence cases were classified, according to the different types, as: stress incontinence (males: 3.4%; females: 8.7%; males+females: 6.5%); urge incontinence (males: 27.4%; females: 31.4%; males+females: 29.8%); mixed incontinence (males: 20.2%; females: 5.8%; males+females: 11.5%). In the total population sample, no significant relationship was found between age and prevalence of urinary incontinence. In the elderly female group, age significantly correlated in a direct manner with urge incontinence (P<0.01) and inversely with stress incontinence (P<0.001). Only in the male sex group age significantly correlated with mixed incontinence (P<0.005). Multiple linear regression analysis showed that the dependent variable 'incontinence' could be predicted by MMSE (P<0.001) in the male sex group and by the Tinetti Scale (gait) (P<0.001) in the female sex group.