Concurrent Indicators of Gait Velocity and Variability Are Associated with 25-Year Cognitive Change: A Retrospective Longitudinal Investigation.

Background/Objectives: Physical function indicators, including gait velocity, stride time and step length, are linked to neural and cognitive function, morbidity and mortality. Whereas cross-sectional associations are well documented, far less is known about long-term patterns of cognitive change as related to objective indicators of mobility-related physical function. Methods: Using data from the Victoria Longitudinal Study, a long-term investigation of biological and health aspects of aging and cognition, we examined three aspects of cognition-physical function linkages in 121 older adults. First, we examined a simple marker of physical function (3 m timed-walk) as a predictor of cross-sectional differences and up to 25-year change for four indicators of cognitive function. Second, we tested associations between two markers of gait function derived from the GAITRite system (velocity and stride-time variability) and differences and change in cognition. Finally, we evaluated how increasing cognitive load during GAITRite assessment influenced the associations between gait and cognition. Results: The simple timed-walk measure, commonly used in clinical and research settings, was a minor predictor of change in cognitive function. In contrast, the objectively measured indicator of walking speed significantly moderated long-term cognitive change. Under increasing cognitive load, the moderating influence of velocity on cognitive change increased, with increasing variability in stride time also emerging as a predictor of age-related cognitive decline. Conclusion: These findings: (a) underscore the utility of gait as a proxy for biological vitality and for indexing long-term cognitive change; and (b) inform potential mechanisms underlying age-related linkages in physical and cognitive function.

Older Driver Safety: A Survey of Psychologists' Attitudes, Knowledge, and Practices.

Using an online survey, we examined the knowledge, attitudes, and practices with respect to older driver safety concerns of clinical psychologists from across Canada who self-identified as working with at least some drivers over 60 years of age. Eighty-four psychologists completed the survey, and many were aware of the issues relevant to older driver safety, although only about half reported that assessing fitness to drive was an important issue in their practice. The majority (75%) reported that they would benefit from education concerning evaluation of fitness to drive. The primary recommendation emerging from this investigation is to increase efforts to inform and educate psychologists about driving-related assessment and regulatory issues in general, and specifically with respect to older adults. As the population ages, it is of growing importance for all health care providers to understand the influence of mental health conditions-including cognitive impairment and dementia-on driving skills.

Just the facts: changes in older driver attitudes after exposure to educational interventions.

OBJECTIVES: To examine the change in cognitive processing as measured by consciousness raising and attitudes toward driving following educational interventions for older adults. METHODS: Older adults who viewed a research-based applied theater production about older driver safety (n = 110) were compared to those who were exposed to a print-based publication available to all drivers (n = 100). RESULTS: After viewing the play developed with input from older adults and others, older adult viewers' attitudes toward driving shifted in a manner consistent with an increased openness or willingness to consider changing their driving behavior. Conversely, after reading the print-based materials, the older adults felt more empowered to continue drive. CONCLUSIONS: Demonstrating that an intervention that takes into account the views of older drivers can lead to attitudinal outcomes that differ from those achieved with typical "just the facts" programs is an important step in understanding how program content and format affect outcomes. Future interdisciplinary work such as this may enhance our capabilities to understand more about the processes involved in influencing change in attitudes and behaviors.

The influence of cognitive impairment with no dementia on driving restriction and cessation in older adults.

Cognitively impaired older adults may be at increased risk of unsafe driving. Individuals with insight into their own impairments may minimize their risk by restricting or stopping driving. The purpose of this study was to examine the influence of cognitive impairment on driving status and driving habits and intentions. Participants were classified as cognitively impaired, no dementia single (CIND-single), CIND-multiple, or not cognitively impaired (NCI) and compared on their self-reported driving status, habits, and intentions to restrict or quit driving in the future. The groups differed significantly in driving status, but not in whether they restricted their driving or reduced their driving frequency. CIND-multiple group also had significantly higher intention to restrict/stop driving than the NCI group. Reasons for restricting and quitting driving were varied and many individuals reported multiple reasons, both external and internal, for their driving habits and intentions. Regardless of cognitive status, none of the current drivers were seriously thinking of restricting or quitting driving in the next 6 months. It will be important to determine, in future research, how driving practices change over time and what factors influence decisions to restrict or stop driving for people with cognitive impairment.

Conservative outpatient renoprotective protocol in patients with low GFR undergoing contrast angiography: a case series.

BACKGROUND: The correct strategy to prevent radiocontrast-induced nephropathy (CIN) in high-risk patients going for cardiac angiography is widely debated in the literature. It is well known that chronic kidney disease (CKD) patients with lower estimated glomerular filtration rates (eGFRs) at baseline are at the greatest risk for a significant loss in kidney function, or even dialysis after a contrast load. For this reason potentially life-saving procedures such as angiography are sometimes withheld or delayed. METHODS: We describe a case series of 31 well-characterized patients with CKD who underwent cardiac or peripheral vessel angiography, and patients with renal artery stenosis (RAS) who underwent angioplasty and stenting. All were treated with a standardized outpatient protocol of withholding their diuretics and angiotensin-converting enzyme (ACE) inhibitors (ACEs)/angiotensin receptor blockers (ARBs) the day prior to and 2 days after the procedure, restarting the diuretic the day after the procedure and the ACE inhibitor/ARB after 2 days. Calcium channel blockers were prescribed for the 2 days prior to and 2 days after the procedure. Patients had bloodwork on days 2-3 and days 7-10 post-procedure. RESULTS: The patients had a mean baseline creatinine of 214 micromol/l (SD = 123), ranging from 87 to 535 micromol/l. This corresponded to a mean baseline eGFR of 34 ml/min (SD = 15.8), ranging from a minimum of 12-59 ml/min. The mean age was 64 +/- 13.8 years; 48% were male and 11 (35.5%) were diabetic. All patients enrolled had a baseline eGFR of less than 60 ml/min as calculated by the Modification of Diet in Renal Disease (MDRD) formula. Based on pre-procedure CKD stage, 21 (68%) were stage 3 (eGFR 30-60 ml/min), 5 (16%) were stage 4 (eGFR 15-30 ml/min), and 6 (19%) were stage 5 (eGFR < 15 ml/min). No patient required urgent hemodialysis following their angiography. All patients have had a longitudinal follow up of 26 months, and none developed any change in the rate of progression from prior to procedure. CONCLUSIONS: This case series provides data in support of a conservative, outpatient-based approach for high-risk CKD patients going for cardiac angiography. This protocol warrants further study in randomized control trials.

Successful reintroduction of a different erythropoiesis-stimulating agent after pure red cell aplasia: relapse after successful therapy with prednisone.

We report a 3-year case history that describes a 78-year-old woman with recurrent transfusion-dependent pure red cell aplasia (PRCA) secondary to recombinant epoetin use that was responsive to immunosuppressant therapy. The patient had kidney disease of unknown aetiology (estimated glomerular filtration rate of 13 ml/min/1.73 m2) and was not on dialysis. After 16 months of therapy with subcutaneous Eprex, she developed anti-erythropoietin antibody-confirmed PRCA and was started on high dose prednisone (50 mg per day). Within 5 months, the patient's serum was clear of antibodies and, under the cover of low dose prednisone (5-7.5 mg per day), therapy with a different erythropoiesis-stimulating compound (Aranesp) was initiated due to persistent fatigue and anaemia. At 3 months of therapy, the serum anti-erythropoietin antibodies remained negative and, due to the patient's requests, and after discussion, prednisone therapy was discontinued. Unfortunately, 3 months after cessation of prednisone, a recurrence of PRCA was confirmed by the development of profound anaemia and reappearance of anti-erythropoietin antibodies in the patient's serum. High dose prednisone (50 mg per day) was reinstituted, whereupon, 2 months later, antibodies were again confirmed to be negative. This case report demonstrates the responsiveness of PRCA to simple immunosuppressive therapy, and the ability to introduce different erythropoiesis-stimulating agents in the presence of such therapy. It appears that there may be problems associated with discontinuation of immunosuppressive therapy in the presence of sustained erythropoiesis-stimulating agent therapy in those in whom the condition has occurred previously.

Stage of chronic kidney disease predicts seroconversion after hepatitis B immunization: earlier is better.

BACKGROUND: Hepatitis B virus (HBV) infection remains a concern in dialysis populations, and vaccination programs have been less successful than those in the general population. Reasons for poor response include malnutrition, uremia, and the generalized immunosuppressive state of patients with chronic kidney disease (CKD). This prospective cohort study evaluated factors impacting on the effectiveness of a vaccination program before dialysis therapy initiation, including level of kidney function. METHODS: All patients receiving care in the Kidney Function Clinic (St Paul's Hospital, Vancouver, Canada) were screened for previous HBV infection or vaccination. Those who were marker negative were administered a standardized hepatitis B vaccination schedule recommended for patients with CKD. The primary outcome measure, seroconversion, is defined as hepatitis B surface antibody titer greater than 10 IU 3 months after completion of the vaccination schedule. RESULTS: The study population of 165 patients included 64% men with a mean age of 60 years, mean serum creatinine level of 3.4 +/- 1.5 mg/dL (300 +/- 133 micromol/L), and median estimated glomerular filtration rate (GFR) of 20 mL/min (interquartile range, 14 to 20). Seroconversion rate was 82%. Multivariate analyses showed the independent predictive value of level of GFR. The model showed that patients with the lowest level of kidney function and who were older and had diabetes were less likely to seroconvert (P < 0.05). CONCLUSION: This is the largest study to show in a well-characterized cohort that patients with higher GFR levels are more likely to respond to hepatitis B vaccination programs with seroconversion, independent of other factors. Future studies will explore specific mechanisms to explain this phenomenon.

Association of forced expiratory volume with disease duration and sputum neutrophils in chronic asthma.

Some patients with chronic asthma develop irreversible airflow obstruction. Our aim was to assess whether reported duration of asthma and induced sputum cell counts were associated with pulmonary function in patients with asthma who did not smoke. Maximal forced expiratory volume in the first second (FEV(1)) was determined following a steroid trial (oral prednisolone, 30 mg/d [n = 92 patients]; or inhaled fluticasone, 2000 microg/d [n = 5]; for 2 weeks) and 2.5 mg of nebulized albuterol. Asthma history was recorded with duration from first diagnosis. All subjects were nonsmokers, or were to have stopped smoking > or =5 years previously and smoked < or =5 pack-years (n = 12). Induced sputum was obtained from 59 subjects for analysis of airway cell counts. Maximal FEV(1) was inversely associated with asthma duration (r = -0.47, P <0.0001), age (r = -0.40, P <0.0001), and the proportion of sputum neutrophils (r(s) = -0.50, P = 0.00004). After adjusting for age, both duration of disease and sputum neutrophils were independently associated with maximal FEV(1). Neutrophil activation, as measured by sputum myeloperoxidase levels, was positively associated with the proportion of sputum neutrophils (r(s) = 0.45, P = 0.0004) and inversely associated with maximal FEV(1) (r(s) = -0.59, P <0.0001). Long disease duration may be a predisposing factor for the development of irreversible airflow obstruction in patients with chronic asthma. The negative associations of sputum neutrophil count and activation with maximal FEV(1) suggest that neutrophils may be involved in the pathophysiology of irreversible airflow obstruction in asthma.