BACKGROUND

Delirium is common after cardiac surgery and may be associated with long-term changes in cognitive function. We examined postoperative delirium and the cognitive trajectory during the first year after cardiac surgery.

METHODS

We enrolled 225 patients 60 years of age or older who were planning to undergo coronary-artery bypass grafting or valve replacement. Patients were assessed preoperatively, daily during hospitalization beginning on postoperative day 2, and at 1, 6, and 12 months after surgery. Cognitive function was assessed with the use of the Mini–Mental State Examination (MMSE; score range, 0 to 30, with lower scores indicating poorer performance). Delirium was diagnosed with the use of the Confusion Assessment Method. We examined performance on the MMSE in the first year after surgery, controlling for demographic characteristics, coexisting conditions, hospital, and surgery type.

RESULTS

The 103 participants (46%) in whom delirium developed postoperatively had lower pre-operative mean MMSE scores than those in whom delirium did not develop (25.8 vs. 26.9, P<0.001). In adjusted models, those with delirium had a larger drop in cognitive function (as measured by the MMSE score) 2 days after surgery than did those without delirium (7.7 points vs. 2.1, P<0.001) and had significantly lower postoperative cognitive function than those without delirium, both at 1 month (mean MMSE score, 24.1 vs. 27.4; P<0.001) and at 1 year (25.2 vs. 27.2, P<0.001) after surgery. With adjustment for baseline differences, the between-group difference in mean MMSE scores was significant 30 days after surgery (P<0.001) but not at 6 or 12 months (P = 0.056 for both). A higher percentage of patients with delirium than those without delirium had not returned to their preoperative baseline level at 6 months (40% vs. 24%, P = 0.01), but the difference was not significant at 12 months (31% vs. 20%, P = 0.055).

CONCLUSIONS

Delirium is associated with a significant decline in cognitive ability during the first year after cardiac surgery, with a trajectory characterized by an initial decline and prolonged impairment. (Funded by the Harvard Older Americans Independence Center and others.)

OBJECTIVES

Although several studies suggest that slow gait speed is a predictor of falls, it may also be a protective mechanism to prevent falls. Further, fast walking may precipitate falls. Therefore, we examined the relationship between gait speed and falls risk.

DESIGN

Longitudinal analysis of the association between gait speed and subsequent falls and analysis of gait speed decline as a predictor of future falls

SETTING

Population-based cohort study

PARTICIPANTS

763 community-dwelling elders underwent baseline assessments and were followed for falls. Of these, 600 completed an 18-month follow-up assessment to determine change in gait speed and were followed for subsequent falls.

MEASUREMENTS

Gait speed was measured during a 4-meter walk, falls data were collected from monthly post-card calendars, and covariates were collected from in-home and clinic visits.

RESULTS

There was a U-shaped relation between gait speed and falls with faster (≥1.3 m/s, incident rate ratio (IRR) = 2.12, 95% CI = 1.48 – 3.04) and slower speeds (<0.6 m/sec, IRR = 1.60, CI = 1.06 – 2.42) at highest risk compared to normal gait speeds (≥1.0 and < 1.3 m/sec). In adjusted analyses, slower gait speeds were associated with an increased risk ratio for indoor falls (for <0.6 m/sec, IRR = 2.17, CI = 1.33 – 3.55 and for ≥0.6 and <1.0 m/sec, IRR = 1.45, CI = 1.08 – 1.94). Faster gait speed was associated with an increased risk ratio for outdoor falls (IRR = 2.11, CI = 1.40 – 3.16). A gait speed decline of >0.15 m/sec/year predicted an increased risk for all falls (IRR = 1.86, CI = 1.15 – 3.01).

CONCLUSION

There is a non-linear relation between gait speed and falls with a greater risk of outdoor falls in faster walkers and greater risk of indoor falls in slow walkers.

OBJECTIVES

To investigate the relationships between uncontrolled and controlled hypertension, orthostatic hypotension (OH), and falls in participants of the Maintenance of Balance, Independent Living, Intellect, and Zest in the Elderly of Boston Study (N = 722, mean age 78.1).

DESIGN

Prospective population-based study.

SETTING

Community.

PARTICIPANTS

Seven hundred twenty-two adults aged 70 and older living within a 5-mile radius of the study headquarters at Hebrew Rehabilitation Center in Boston.

MEASUREMENTS

Blood pressure (BP) was measured at baseline in the supine position and after 1 and 3 minutes of standing. Systolic OH (SOH) and diastolic OH at 1 and 3 minutes were defined as a 20-mmHg decline in systolic BP and a 10-mmHg decline in diastolic BP upon standing. Hypertension was defined as BP of 140/90 mmHg or greater or receiving antihypertensive medications (controlled if BP < 140/90 mmHg and uncontrolled if ≥140/90 mmHg). Falls data were prospectively collected using monthly calendars. Fallers were defined as those with at least two falls within 1 year of follow-up.

RESULTS

OH was highest in participants with uncontrolled hypertension; SOH at 1 minute was 19% in participants with uncontrolled hypertension, 5% in those with controlled hypertension, and 2% in those without hypertension (P≤.001)). Participants with SOH at 1 minute and uncontrolled hypertension were at greater risk of falls (hazard ratio = 2.5, 95% confidence interval = 1.3–5.0) than those with uncontrolled hypertension without OH. OH by itself was not associated with falls.

CONCLUSION

Older adults with uncontrolled hypertension and SOH at 1 minute are at greater risk for falling within 1 year. Hypertension control, with or without OH, is not associated with greater risk of falls in older community-dwelling adults.

Background

Our objective was to investigate the association between hypertension and concurrent impairments in mobility, cognition and mood; the role of brain white matter hyperintensities in mediating this association; and the impact of these impairments on disability and mortality in elderly hypertensive individuals.

Methods and Results

Blood pressure, gait speed, digit symbol substitution test, and the Center for Epidemiologic Studies Depression Scale were measured yearly (1992-1999) on 4700 participants in the Cardiovascular Health Study (age: 74.7, 58% women, 17% African Americans, 68% hypertension, 3600 had brain MRI in 1992-93, survival data 1992-2005). Using latent profile analysis at baseline, we found that 498 (11%) subjects had concurrent impairments and 3086 (66%) were intact on all three measures. Between 1992 and 1999, 651 (21%) became impaired in all three domains. Hypertensive individuals were more likely to be impaired at baseline (Odds ratio 1.23, 95% CI (1.04-1.42), p=0.01) and become impaired during the follow-up (Hazard Ratio (HR)= 1.3, 95% Confidence Interval (CI): 1.02 to 1.66, p=0.037). Greater degree of white matter hyperintensities was associated with impairments in the 3 domains (p=0.007) and mediated the association with hypertension (p=0.19 for hypertension after adjusting for white matter hyperintensities in the model, 21% HR change). Impairments in the three domains increased subsequent disability with hypertension (p<0.0001). Hypertension mortality also was increased in those impaired (compared to unimpaired hypertensive individuals HR=1.10, 95% CI (1.04-1.17), p=0.004).

Conclusions

Hypertension increases the risk of concurrent impairments in mobility, cognition and mood, which increases disability and mortality. This association is partly mediated by microvascular brain injury.

Objective

HIV-infected patients are at increased risk for cardiovascular disease, which may be mediated in part by inflammation. Surrogate marker studies suggest an increased prevalence of vascular abnormalities in HIV infection. We examined the association of all-cause mortality in HIV-infected patients with carotid artery intima-media thickness (cIMT) and high-sensitivity C-reactive protein (hsCRP).

Design and Methods

Baseline risk factors, cIMT and hsCRP were prospectively measured in 327 HIV-infected participants. Follow-up time with median of 3.1 years was calculated from baseline to death or censored dated 7/31/07. Cox Proportional Hazards models were used to study risk factors associated with mortality.

Results

Thirty eight (11.6 %) of participants have died since study enrollment. CIMT was significantly higher in those who died and decedents were significantly more likely to have cIMT above the 75th percentile. Those who died had higher hsCRP than those alive and more had hsCRP values above 3 mg/L. CD4 count was lower and log10 viral load was higher in decedents, but antiretroviral regimens were similar in both groups. CIMT and hsCRP levels were significantly associated with mortality (HR=2.74, 95% CI 1.26 to 5.97, p=0.01; HR=2.38, 95% CI 1.15 to 4.9, p=0.02).

Conclusions

Our study demonstrated a strong association of carotid IMT and hsCRP with all-cause death in this HIV-infected population despite being similar with respect to exposure to antiretroviral medications. Together these surrogate markers may be indices of chronic inflammation and unfavorable outcomes in HIV-positive patients.

Background

Poor nutritional status is often present among older adults who experience a fall. However, dietary intake and weight loss are often overlooked as potential factors. The objective of this study was to test the association between dietary protein intake and risk of subsequent falls in a population-based cohort of elderly men and women.

Methods

Dietary intake and clinic data from 807 men and women (ages 67–93 years) from the Framingham Original Cohort Study were analyzed. Protein intake (total, animal and plant) was assessed as a continuous variable and by tertile of intake. Falls were reported by participants using a validated questionnaire at two time points. Weight was ascertained at each examination to examine the effect of weight loss over follow-up.

Results

Higher dietary protein intakes were associated with a reduced odds of falling, although of borderline statistical significance (OR=0.80, 95% CI: 0.60–1.07) and were not associated with the rate of falls over follow-up (RR=0.93, 95%CI: 0.73–1.19). Tertile analyses tended towards a protective association, but most did not achieve statistical significance; there was no dose-response. For those who lost ≥ 5% of their baseline weight, higher intakes of total, animal and plant protein showed a significantly lower rate of subsequent falls.

Conclusion

This work highlights the importance of adequate protein intake as a potentially modifiable risk factor for fall prevention in older adults. Further exploration of the interaction of protein intake and weight loss as related to falls is needed.

OBJECTIVES

To identify risk factors for indoor and outdoor falls.

DESIGN

Prospective cohort study.

SETTING

MOBILIZE Boston, a study of falls etiology among community-dwelling older individuals.

PARTICIPANTS

765 women and men, mainly of age 70 years and older, from randomly sampled households in the Boston MA area.

MEASUREMENTS

Baseline data were collected by questionnaire and comprehensive clinic examination. During follow-up participants recorded falls on daily calendars. A telephone interview queried the location and circumstances of each fall.

RESULTS

598 indoor and 524 outdoor falls were reported over a median follow-up of 21.7 months. Risk factors for indoor falls included older age, being female, and various indicators of poor health. Risk factors for outdoor falls included younger age, being male, and being relatively physically active and healthy. For instance, the age- and gender-adjusted rate ratio (and 95% confidence interval) for having much difficulty or inability to perform activities of daily living relative to no difficulty was 2.57 (1.69–3.90) for indoor falls, but 0.27 (0.13–0.56) for outdoor falls. The rate ratio for gait speed of <0.68 m/sec relative to a speed of >1.33 m/sec was 1.48 (0.81–2.68) for indoor falls, but 0.27 (0.15–0.50) for outdoor falls.

CONCLUSION

Risk factors for indoor and outdoor falls differ. Combining these falls, as is done in many studies, masks important information. Prevention recommendations for non-institutionalized older people should be more effective if targeted differently for frail, inactive older people at high risk for indoor falls and relatively active, healthy people at high risk for outdoor falls.

Background.

Poor medication adherence is associated with negative health outcomes. We investigated whether poor medication adherence increases the rate of falls as part of Maintenance of Balance, Independent Living, Intellect, and Zest in the Elderly of Boston (MOBILIZE Boston), a prospective, community-based cohort recruited for the purpose of studying novel risk factors for falls.

Methods.

A total of 246 men and 408 women (mean age, 78 years) were followed for the occurrence of falls (median follow-up, 1.8 years). Adherence was assessed by the Morisky scale based on the following four questions: whether an individual ever forgets, is careless at times, stops taking medications when feels better, or stops taking medications when feels worse. Low adherence was defined as a “yes” answer to one or more questions. High adherence was defined as a “no” answer to every question.

Results.

Forty-eight percent of subjects were classified as having low medication adherence. The rate of falls in the low adherence group was 1.1 falls/person-year (95% confidence interval [CI]: 1.0–1.3) compared with 0.7 falls/person-year (95% CI: 0.6–0.8) in the high adherence group. After adjusting for age, sex, race/ethnicity, education, alcohol use, cognitive measures, functional status, depression, and number of medications, low medication adherence was associated with a 50% increased rate of falls compared with high medication adherence (rate ratio = 1.5, 95% CI: 1.2–1.9; p < .001).

Conclusions.

Low medication adherence may be associated with an increased rate of falls among older adults. Future studies should confirm this association and explore whether interventions to improve medication adherence might decrease the frequency of falls and other serious health-related outcomes.