Physical exercise at midlife and risk of dementia three decades later: a population-based study of Swedish twins

BACKGROUND: With the number of people with dementia increasing, identifying potential protective factors has become more important. We explored the association between physical exercise at midlife and subsequent risk of dementia among members of the HARMONY study. METHODS: Measures of exercise were obtained by the Swedish Twin Registry an average of 31 years prior to dementia assessment. Dementia was diagnosed using a two-stage procedure--screening for cognitive impairment followed by full clinical evaluation. We used two study designs: case-control analyses included 264 cases with dementia (176 had Alzheimer's disease) and 2870 controls; co-twin control analyses included 90 twin pairs discordant for dementia. RESULTS: In case-control analyses, controlling for age, sex, education, diet (eating fruits and vegetables), smoking, drinking alcohol, body mass index, and angina, light exercise such as gardening or walking and regular exercise involving sports were associated with reduced odds of dementia compared to hardly any exercise (odds ratio [OR] = 0.63, 95% confidence interval [CI], 0.43-0.91 for light exercise; OR = 0.34, 95% CI, 0.16-0.72 for regular exercise). Findings were similar for Alzheimer's disease alone. In co-twin control analyses, controlling for education, the association between higher levels of exercise and lower odds of dementia approached significance (OR = 0.50, 95% CI, 0.23-1.06; p =.072). CONCLUSIONS: Exercise at midlife may reduce the odds of dementia in older adulthood, suggesting that exercise interventions should be explored as a potential strategy for delaying disease onset.     

The impact of the use of statins on the prevalence of dementia and the progression of cognitive impairment

BACKGROUND: Previous evidence suggests that treatment with 3-hydroxy-3-methylglutaryl-coenzyme-A reductase inhibitors (statins) has a positive impact on dementia. We decided to investigate the association between the use of statins and the prevalence of dementia and statins' impact on the progression of cognitive impairment. METHODS: This is a case-control and a retrospective cohort study of a community-based ambulatory primary care geriatric practice. We included a convenience sample of all patients (N = 655, mean age 78.7 +/- 0.3 years, 85% Caucasian, 74% women) with hypercholesterolemia or dementia, or using statins. We compared those using statins with those who do not with respect to the clinical diagnosis of dementia and its subtypes and the progression of cognitive impairment. RESULTS: At the initial visit, 35% had dementia, and 17% were using statins. After covariate adjustments, patients on statins were less likely to have dementia (odds ratio [OR] for dementia based on composite definition = 0.23; 95% confidence interval [CI] [0.1-0.56], p =.001, OR Alzheimer's disease = 0.37; 95% CI [0.19-0.74], p =.005, OR vascular dementia = 0.25; 95% CI [0.08-0.85], p =.027). At follow-up, patients on statins showed an improvement on their Mini-Mental Status Examination score by 0.7 +/- 0.4 compared to a decline by 0.5 +/- 0.3 in controls, p =.025 (OR for no change or improvement on statins = 2.81; 95% CI [1.02-8.43], p =.045) and scored higher on the Clock Drawing Test (difference of 1.5 +/- 0.1, p =.036). CONCLUSIONS: The use of statins is associated with a lower prevalence of dementia and has a positive impact on the progression of cognitive impairment.     

Sex differences in the effect of heart rate on mortality in the elderly

OBJECTIVES: To examine the association between heart rate and mortality risk in the elderly. DESIGN: Longitudinal cohort. SETTING: Outpatient. PARTICIPANTS: Four hundred twenty-two people, aged 70 upon entry, were surveyed and followed for 6 years. MEASUREMENTS: Pulse rate was measured manually, while sitting and standing, and heart rate was measured from electrocardiogram recordings. The population was divided into quartiles of heart rate, with the top quartile comprising those with heart rate greater than 77 beats per minute (bpm) and the bottom quartile those with heart rate less than 60 bpm. RESULTS: After controlling for possible confounders, there was a clear correlation (r) between heart rate and all-cause mortality in elderly women (r=0.25, P=.0003). The correlation in women was observed using the three different methods for measuring heart rate. Heart rate was associated with all-cause and cardiovascular mortality. There was no relationship between heart rate and level of exercise or smoking status. In multiple regression analysis, the increased risk of death in the women was independent of previous cardiovascular or cerebrovascular disease, hypertension, anemia, congestive heart failure, smoking, and level of exercise or activities of daily living (relative odds ratio (ROR)=3.37, 95% confidence interval (CI)=0.96-11.8). When women using beta-blockers were excluded, this relationship became even stronger (ROR=8.5, 95% CI=1.19-60.1). CONCLUSION: Elevated heart rate is related to increased mortality in elderly women, thus representing a simple index of general health status in this population. Elevated heart rate did not predict mortality in elderly men.     

Depression after stroke: a prospective epidemiological study

OBJECTIVES: To elucidate the relationship between stroke and depressive symptoms and to determine whether disability or cerebrovascular risk factors mediate that relationship. DESIGN: A prospective longitudinal epidemiological survey. SETTING: The mid-Monongahela Valley, a rural, nonfarm, low-socioeconomic-status community. PARTICIPANTS: Random sample of 1,134 subjects aged 65 and older. MEASUREMENTS: The dependent variable was clinically significant depressive symptoms, as defined by five or more symptoms on the modified Center for Epidemiological Studies Depression scale. The independent variables were demographics (age, sex, education), stroke, number of impaired instrumental activities of daily living (IADLs), diabetes mellitus, hypertension, atherosclerotic heart disease, and smoking. Logistic regression analyses were conducted for cross-sectional and longitudinal models examining whether stroke was associated with or predicted depressive symptoms, with other associated factors included as covariates. RESULTS: Clinically significant depressive symptoms were cross-sectionally associated with stroke (odds ratio (OR)=3.5, 95% confidence interval (CI)=1.4-8.3), diabetes mellitus (OR=2.8, 95% CI=1.7-4.6; P相似文献   

Plasma homocysteine and cognitive impairment in an older British African-Caribbean population

OBJECTIVES: To investigate the association between homocysteine concentrations and cognitive impairment in an older African-Caribbean population. To investigate other measures of risk for vascular disease and nutritional status as potential confounding factors. DESIGN: A secondary analysis from a cross-sectional community study. SETTING: The sample was drawn from registration lists for seven primary care services in south London, United Kingdom. PARTICIPANTS: Two hundred forty-eight individuals aged 55 to 75 who were born in a Caribbean nation and for whom homocysteine concentrations had been ascertained. MEASUREMENTS: Plasma homocysteine and serum folate were assayed from frozen samples. Cognitive impairment as a composite measure was derived from 11 psychometric tests. Other measures of risk for vascular disease were considered as potential confounding factors: diagnosed hypertension/diabetes mellitus; physical exercise; and concentrations of cholesterol, triglycerides, and fibrinogen. RESULTS: Cognitive impairment was classified in 68 (27%) participants. Raised homocysteine (highest quartile: >13.85 micromol/L) was significantly associated with cognitive impairment (odds ratio (OR)=2.50, 95% confidence interval (CI)=1.33-4.69). This association persisted after adjustment for age, occupation, other measures of vascular risk, folate, body mass index, and waist:hip ratio (OR=3.00, 95% CI=1.35-6.69). As with other risk factors for vascular disease in this sample, the association was significant only in those with less education (P-value for interaction=.049). CONCLUSION: Raised homocysteine was associated with cognitive impairment in this sample, but this was modified by previous educational attainment. This association was independent of other measures of vascular risk and was not explained by folate concentrations.     

Anticoagulant use for atrial fibrillation in the elderly

OBJECTIVES: To determine the influence of advanced age on anticoagulant use in subjects with atrial fibrillation and to explore the extent to which risk factors for stroke and contraindications to anticoagulant therapy predict subsequent use. DESIGN: Retrospective cohort study. SETTING: The Veterans Affairs Boston Healthcare System. PARTICIPANTS: A total of 2,217 subjects with nonvalvular atrial fibrillation. MEASUREMENTS: Administrative databases were use to identify subject's age, anticoagulant use, and the presence of a diagnosis of atrial fibrillation, cerebrovascular accident, hypertension, diabetes mellitus, congestive heart failure, or gastrointestinal or cerebral hemorrhage. RESULTS: Unadjusted analysis showed no difference in warfarin use between those aged 75 and older and younger subjects regardless of the presence (33.9% vs 35.7%, P=.37) or absence (33.4% vs 34.7%, P=.58) of contraindications to anticoagulant therapy. Multivariate modeling demonstrated a 14% reduction (95% confidence interval (CI)=4-22%) in anticoagulant use with each advancing decade of life. Intracranial hemorrhage was a significant deterrent (odds ratio (OR)=0.27 95% CI=0.06-0.85). History of hypertension (OR=2.90, 95% CI=2.15-3.89), congestive heart failure (OR=1.70, 95% CI=1.41-2.04), and cerebrovascular accident (OR=1.54, 95% CI=1.25-1.89) were significant independent predictors for anticoagulant use. CONCLUSION: Despite consensus guidelines to treat all atrial fibrillation patients aged 75 and older with anticoagulants, advancing age was found to be a deterrent to warfarin use. Better estimates of the risk:benefit ratio for oral anticoagulant therapy in older patients with atrial fibrillation are needed to optimize decision-making.     

Plasma Carboxymethyl-Lysine, an Advanced Glycation End Product, and All-Cause and Cardiovascular Disease Mortality in Older Community-Dwelling Adults

OBJECTIVES: To determine whether older adults with high plasma carboxymethyl-lysine (CML), an advanced glycation end product, are at higher risk of all-cause and cardiovascular disease (CVD) mortality.
DESIGN: Prospective cohort study.
SETTING: Population-based sample of adults aged 65 and older residing in Tuscany, Italy.
PARTICIPANTS: One thousand thirteen adults participating in the Invecchiare in Chianti study.
MEASUREMENTS: Anthropometric measures, plasma CML, fasting plasma total, high-density and low-density lipoprotein cholesterol, triglycerides, glucose, creatinine. Clinical measures: medical assessment, diabetes mellitus, hypertension, coronary heart disease, heart failure, stroke, cancer. Vital status measures: death certificates and causes of death according to the International Classification of Diseases . Survival methods were used to examine the relationship between plasma CML and all-cause and CVD mortality, adjusting for potential confounders.
RESULTS: During 6 years of follow-up, 227 (22.4%) adults died, of whom 105 died with CVD. Adults with plasma CML in the highest tertile had greater all-cause (hazard ratio (HR)=1.84, 95% confidence interval) CI)=1.30–2.60, P <.001) and CVD (HR=2.11, 95% CI=1.27–3.49, P =.003) mortality than those in the lower two tertiles after adjusting for potential confounders. In adults without diabetes mellitus, those with plasma CML in the highest tertile had greater all-cause (HR=1.68, 95% CI=1.15–2.44, P =.006) and CVD (HR=1.74, 95% CI=1.00–3.01, P =.05) mortality than those in the lower two tertiles after adjusting for potential confounders.
CONCLUSION: Older adults with high plasma CML are at higher risk of all-cause and CVD mortality.     

Participation in activity and risk for incident delirium

OBJECTIVES: To examine the mediating role between educational attainment and risk for incidence delirium of activity participation and to examine the contribution of participation in specific activities to the development of delirium. DESIGN: Prospective cohort study. SETTING: Urban teaching hospital in New Haven, Connecticut. PARTICIPANTS: Participants were drawn from two prospective cohort studies of 779 newly hospitalized patients aged 70 and older without dementia. MEASUREMENTS: The main outcome was delirium, measured using the full Confusion Assessment Method (CAM) algorithm, which consisted of acute onset and fluctuating course, inattention, and disorganized thinking or altered level of consciousness, as rated by trained clinical interviewers. RESULTS: Bivariable results indicated a significant relationship between education and the development of delirium (odds ratio (OR)=0.92, 95% confidence interval (CI)=0.88–0.97) and between activity and delirium (OR= 0.60, 95% CI=0.46–0.79). In multivariable analysis, activity mediated the relationship between education and risk for delirium. Considering each activity separately, multivariable logistic regression analysis showed that regular exercise significantly lowered the risk for developing delirium (OR=0.76, 95% CI=0.60–0.96). CONCLUSION: In older persons without dementia, activity participation before hospitalization is a mediator between education and incidence of delirium. Specifically, it was found that participation in regular exercise was found to be significantly protective against delirium.     

The effect of dementia on outcomes and process of care for Medicare beneficiaries admitted with acute myocardial infarction

OBJECTIVES: To determine differences in mortality after admission for acute myocardial infarction (AMI) and in use of noninvasive and invasive treatments for AMI between patients with and without dementia. DESIGN: Retrospective chart review. SETTING: Cooperative Cardiovascular Project. PATIENTS: Medicare patients admitted for AMI (N=129,092) in 1994 and 1995. MEASUREMENTS: Dementia noted on medical chart as history of dementia, Alzheimer's disease, chronic confusion, or senility. Outcome measures included mortality at 30 days and 1-year postadmission; use of aspirin, beta-blocker, angiotensin-converting enzyme (ACE) inhibitor, thrombolytic therapy, cardiac catheterization, coronary angioplasty, and cardiac bypass surgery compared by dementia status. RESULTS: Dementia was associated with higher mortality at 30 days (relative risk (RR)=1.16, 95% confidence interval (CI)=1.09-1.22) and at 1-year postadmission (RR=1.18, 95% CI=1.13-1.23). There were few to no differences in the use of aspirin and beta-blockers between patients with and without a history of dementia. Patients with a history of dementia were less likely to receive ACE inhibitors during the stay (RR=0.89, 95% CI=0.86-0.93) or at discharge (RR=0.90, 95% CI=0.86-0.95), thrombolytic therapy (RR=0.82, 95% CI=0.74-0.90), catheterization (RR=0.51, 95% CI=0.47-0.55), coronary angioplasty (RR=0.58, 95% CI=0.51-0.66), and cardiac bypass surgery (RR=0.41, 95% CI=0.33-0.50) than patients without a history of dementia. CONCLUSION: The results imply that the presence of dementia had a major effect on mortality and care patterns for this condition.     

Ethnic differences in the prevalence and pattern of dementia-related behaviors

OBJECTIVES: To determine the prevalence of dementia-related behaviors in a large, multiethnic sample of community-dwelling patients with moderate to severe dementia and to determine whether differences in patient or caregiver characteristics could explain any differences in prevalence of these behaviors between white and nonwhite patients. DESIGN: Cross-sectional study. SETTING: Community-based. PARTICIPANTS: A total of 5,776 Medicare patients (5,090 white, 469 black, 217 Latino; mean age 78.9) enrolled in the Medicare Alzheimer's Disease Demonstration and Evaluation study at eight sites across the United States between 1989 and 1991. MEASUREMENTS: Trained interviewers collected information on patient demographic characteristics, cognitive and functional status, and caregiver characteristics such as relationship to patient, functional status, depression, and burden. Ethnicity was obtained by self-report. Caregivers were asked if the patient typically demonstrated any of eight dementia-related behaviors. To determine the independent association between ethnicity and dementia-related behaviors, logistic regression models were developed for each of the behaviors, adjusting for patient and caregiver characteristics. RESULTS: Overall, 92% of patients had one or more dementia-related behaviors. Sixty-one percent of black and 57% of Latino patients were reported to have four or more behaviors, compared with 46% of white patients (P<.001). The prevalence of specific behaviors ranged from 24% for combativeness to 67% for wandering. After multivariate adjustment, black patients were significantly more likely than whites to be constantly talkative (odds ratio (OR)=1.41, 95% confidence interval (CI)=1.11-1.80), to have hallucinations (OR=1.89, 95% CI=1.49-2.40) and episodes of unreasonable anger (OR=1.70, 95% CI=1.34-2.15), to wander (OR=1.40, 95% CI=1.08-1.81), and to wake their caregiver (OR=1.33, 95% CI=1.04-1.69). Latinos had a significantly higher likelihood than whites of having hallucinations (OR=1.49, 95% CI=1.10-2.01), episodes of unreasonable anger (OR=1.59, 95% CI=1.18-2.16), combativeness (OR=1.59, 95% CI=1.17-2.17), and wandering (OR=1.59, 95% CI=1.21-2.26). For most behaviors, these adjusted ORs are similar in magnitude of effect and statistical significance to the unadjusted estimates. CONCLUSION: Black and Latino community-dwelling patients with moderate to severe dementia have a higher prevalence of dementia-related behaviors than whites. Therefore, as the aging minority population grows, it will be especially important to target caregiver education, in-home support, and resources to minority communities.     

A randomized, controlled trial of doxycycline and rifampin for patients with Alzheimer's disease

OBJECTIVES: To assess whether doxycycline and rifampin have a therapeutic role in patients with Alzheimer's disease (AD). DESIGN: Randomized, triple-blind, controlled trial. SETTING: Three tertiary care and two community geriatric clinics in Canada. PARTICIPANTS: One hundred one patients with probable AD and mild to moderate dementia. INTERVENTION: Oral daily doses of doxycycline 200 mg and rifampin 300 mg for 3 months. MEASUREMENTS: The primary outcome was a change in Standardized Alzheimer's Disease Assessment Scale cognitive subscale (SADAScog) at 6 months. Secondary outcomes were changes in the SADAScog at 12 months and tests of dysfunctional behavior, depression, and functional status. RESULTS: There was significantly less decline in the SADAScog score at 6 months in the antibiotic group than in the placebo group, (-2.75 points, 95% confidence interval (CI)=-5.28 to -0.22, P=.034). At 12 months, the difference between groups in the SADAScog was -4.31 points (95% CI=-9.17-0.56, P=.079). The antibiotic group showed significantly less dysfunctional behavior at 3 months. There was no significant difference in adverse events between groups (P=.34). There were no differences in Chlamydia pneumoniae detection using polymerase chain reaction or antibodies (immunoglobulin (Ig)G or IgA) between groups. CONCLUSION: Therapy with doxycycline and rifampin may have a therapeutic role in patients with mild to moderate AD. The mechanism is unlikely to be due to their effect on C. pneumoniae. More research is needed to investigate these agents.     

A pilot study of banxia houpu tang, a traditional Chinese medicine, for reducing pneumonia risk in older adults with dementia

OBJECTIVES: To evaluate whether the traditional Chinese herbal medicine Banxia Houpu Tang (BHT, formula magnolia et pinelliae) prevents aspiration pneumonia and pneumonia-related mortality in elderly people.
DESIGN: A prospective, observer-blinded, randomized, controlled trial.
SETTING: Two long-term care hospitals for handicapped elderly patients in Japan from March 2005 to February 2006.
PARTICIPANTS: One hundred four elderly patients (31 men and 73 women; mean age±standard deviation 83.5±7.8) with dementia and cerebrovascular disease, Alzheimer's disease, or Parkinson's disease.
INTERVENTION: Ninety-five participants (mean age 84.0, M:F=28:67) were randomly assigned to the BHT treatment group (n=47) or the control group (n=48) and took BHT or placebo for 12 months.
MEASUREMENTS: The occurrence of pneumonia, mortality due to pneumonia, and the daily amount of self-feeding.
RESULTS: Complete data were available for analysis on 92 of the 95 subjects randomized. Four patients in the BHT group developed pneumonia, and one of them died as a result. Fourteen patients in the control group developed pneumonia, and six of them died as a result. There was a significant difference between the two groups in pneumonia onset ( P =.008), and a tendency toward significance in pneumonia-related mortality ( P =.05). The relative risk of pneumonia in the BHT group compared with the control group was 0.51 (95% confidence interval (CI)=0.27–0.84, P =.008) and that of death from pneumonia was 0.41 (95% CI=0.10–1.03, P =.06) according to the Cox proportional hazards model. No adverse events were observed from treatment with BHT. The BHT group was able to maintain self-feeding better than the control group ( P =.006).
CONCLUSION: Treatment with BHT reduced the risk of pneumonia and pneumonia-related mortality in elderly patients with dementia.     

Obesity and health-related quality of life: a cross-sectional analysis of the US population

OBJECTIVE: To examine the relationship between body mass index (BMI) and health-related quality-of-life (HRQL), in the presence of dietary controls and/or exercise in a national sample in the United States. METHODS: BMI and its association with HRQL domains (physical, mental and activity limitations) were examined using the Centers' for Disease Control and Prevention's 2000 Behavioral Risk Factor Surveillence System (BRFSS) data, after adjusting for various sociodemographic factors, self-reported health-status, and diet/exercise behavior. RESULTS: Based on World Health Organization's (WHO) classification of obesity, the study sample (N=182 372) included approximately 43.7% nonoverweight, 36% overweight, 14% obese, and 7% severely obese respondents. Exercise and dietary modifications were used by 17.5% of overweight, 15.2% of obese, and 12.5% of severely obese individuals. Logistic regression results using nonoverweight BMI as the reference category showed that severely obese (OR=1.87, 95% CI 1.64-2.12) and obese (OR=1.21, 95% CI 1.09-1.33) were more likely to experience greater than 14 unhealthy days affecting the physical health domain. Severely obese (OR=1.41, 95% CI 1.26-1.59) and obese (OR=1.17, 95% CI 1.07-1.28) were also more likely to experience greater than 14 unhealthy days affecting the mental health domain. Similarly, severely obese (OR=1.73, 95% CI 1.50-1.99) and obese (OR=1.22, 95% CI 1.08-1.37) were more likely to experience greater than 14 days with activity limitations. Exercise and dietary controls were associated with better HRQL across all three domains. CONCLUSION: The study highlights the relationship between BMI and HRQL in the United States. The study also underlines the positive correlation of exercise and dietary modifications with HRQL.     

Why Would Caregivers Not Want to Treat Their Relative's Alzheimer's Disease?

OBJECTIVES: To determine family caregivers' willingness to use Alzheimer's disease (AD)-slowing medicines and to examine the relationships between this willingness, dementia severity, and caregiver characteristics. DESIGN: Cross-sectional survey. SETTING: In-home interviews of patients from the Memory Disorders Clinic of the University of Pennsylvania's Alzheimer's Disease Center. PARTICIPANTS: One hundred two caregivers of patients with mild to severe AD who were registered at an Alzheimer's disease center. MEASUREMENTS: Subjects participated in an in-home interview to assess their willingness to use a risk-free AD-slowing medicine and a medicine with 3% annual risk of gastrointestinal bleeding. RESULTS: Half of the patients had severe dementia (n=52). Seventeen (17%) of the caregivers did not want their relative to take a risk-free medicine that could slow AD. Half (n=52) did not want their relative to take an AD-slowing medicine that had a 3% annual risk of gastrointestinal bleeding. Caregivers who were more likely to forgo risk-free treatment of AD were older (odds ratio (OR)=1.7, P=.04), were depressed (OR=3.66, P=.03), had relatives living in a nursing home (OR=3.6, P=.02), had relatives with more-severe dementia according to the Mini-Mental State Examination (MMSE) (OR=2.29, P=.03) or Dementia Severity Rating Scale (DSRS) (OR=2.55, P=.002), and rated their relatives' quality of life (QOL) poorly on a single-item global rating (OR=0.25, P=.001) and the 13-item quality-of-life (QOL)-AD scale (OR=0.38, P=.002). Caregivers who were more likely to forgo a risky treatment were nonwhite (OR=6.53, P=.005), had financial burden (OR=2.93, P=.02), and rated their relative's QOL poorly on a single-item global rating (OR=0.61, P=.01) and the QOL-AD (OR=0.56, P=.01). CONCLUSION: These results suggest that caregivers are generally willing to slow the progression of their relative's dementia even into the severe stage of the disease, especially if it can be done without risk to the patient. Clinical trials and practice guidelines should recognize that a caregiver's assessment of patient QOL and the factors that influence it affect a caregiver's willingness to use AD-slowing treatments.     

Prognostic value of treadmill exercise echocardiography

INTRODUCTION AND OBJECTIVES: Exercise echocardiography (EE) is useful for diagnosing coronary disease, but little is known about its value for risk stratification. We aimed to determine: a) whether data from EE supplemented clinical data and data from exercise testing and resting echocardiography in predicting cardiac events; and b)whether the number and location of abnormal regions and their responses to exercise influenced risk stratification. PATIENTS AND METHOD: The 2,436 patients referred for EE were followed up for 2.1+/-1.5 years. Some 120 serious cardiovascular events (i.e., non-fatal myocardial infarction or cardiovascular death) occurred before revascularization. RESULTS: In 1203 patients (49%), EE gave abnormal results. There were 89 events in patients with an abnormal result (7.3%) and 31 in those with a normal result (2.5%; P<.0001). Multivariate analysis of clinical data, and data from exercise testing, resting echocardiography, and EE showed that male sex (RR=1.7; 95% CI, 1.1-2.8; P=.02), metabolic equivalents or METs (RR=0.9; 95% CI, 0.86-0.98; P=.01), peak heart rate x blood pressure (RR= 0.9;95% CI, 0.9; P=.002), resting wall motion score index (RR=2.5; 95% CI, 1.5-4.1; P<.0001), and number of abnormal regions at peak exercise (RR=1.4; 95% CI, 1.2-1.7; P<.0001) were independently associated with the risk of a serious event (final model chi2, 170; incremental P<.0001). The same variables, excluding sex, were independently associated with cardiovascular death (final model chi2, 169; incremental P=.01). CONCLUSIONS: Exercise echocardiography supplements clinical data and data from exercise testing and resting echocardiography in patients with known or suspected coronary artery disease.     

Folate, Vitamin B12, Homocysteine, and Depressive Symptoms in a Population Sample of Older Chinese Adults

OBJECTIVES: To investigate the independent associations between folate, B12, and homocysteine levels and depressive symptoms in older adults.
DESIGN: Cross-sectional study.
SETTING: Resident population in southeast Singapore.
PARTICIPANTS: Six hundred sixty-nine community-living noninstitutionalized Chinese adults aged 55 and older.
MEASUREMENTS: Laboratory values of folate, vitamin B12, and homocysteine were examined for their independent relationships with depressive symptoms (Geriatric Depression Scale (GDS) score ≥5).
RESULTS: Respondents with depression (n=178) had lower mean serum folate concentrations (21.5 nmol/L) than those without (n=491, 24.0 nmol/L, P =.04). There was a linear relationship between descending quartiles of folate concentrations and increasing odds of association with depressive symptoms, independent of other risk factors (demographic, psychosocial, alcohol and smoking, chronic morbidity, functional status, nutritional risk, albumin, anemia, depression-inducing medications, use of antidepressants and vitamin supplements), including B12 and homocysteine ( P for trend=.02). The odds ratio (OR) of association between low folate (lowest quartile: <14.6 nmol/L) and depressive symptoms independent of other risk factors, including homocysteine and B12, was 1.72 (95% confidence interval (CI)=1.11–2.66). Vitamin B12 across a range of values did not show a linear association, but B12 deficiency (<180 pmol/L) appeared to be significantly associated with depressive symptoms (OR=2.68, 95% CI=1.20–6.00), independent of folate and homocysteine.
CONCLUSION: Decreasing and low levels of serum folate and deficient levels of B12 were associated with greater risk of depressive symptoms in older Chinese adults.     

Serum folate and cardiovascular disease mortality among US men and women

BACKGROUND: Folate has been linked to cardiovascular disease (CVD) through its role in homocysteine metabolism. OBJECTIVE: To assess the relationship between serum folate and CVD mortality. DESIGN: In this prospective study, serum folate concentrations were measured on a subset of adults during the Second National Health and Nutrition Examination Survey (1976-1980) and vital status ascertained after 12 to 16 years. SETTING AND PATIENTS: A national probability sample consisting of 689 adults who were 30 to 75 years of age and did not have a history of CVD at baseline. MAIN OUTCOME MEASURE: Vital status was determined by searching national databases that contained information about US decedents. RESULTS: The associations between serum folate and CVD and all-cause mortality differed by diabetes status (P =.04 and P =.03, respectively). Participants without diabetes in the lowest compared with the highest serum folate tertile had more than twice the risk of CVD mortality after adjustment for age and sex (relative risk [RR], 2.64; 95% confidence interval [CI], 1.15-6.09). This increased risk for participants in the lowest tertile was attenuated after adjustment for CVD risk factors (RR, 2.28; 95% CI, 0.96-5.40). Serum folate tertiles were not significantly associated with total mortality, although the age- and sex-adjusted risk was increased for participants in the lowest compared with highest tertile (RR, 1.74; 95% CI, 0.96-3.15). Risk estimates for participants with diabetes were unstable because of the small sample size (n = 52). CONCLUSION: These data suggest that low serum folate concentrations are associated with an increased risk of CVD mortality among adults who do not have diabetes. Arch Intern Med. 2000;160:3258-3262.     

Risk factors for incident dementia in England and Wales: The Medical Research Council Cognitive Function and Ageing Study. A population-based nested case-control study

OBJECTIVE: To investigate a number of prospectively collected factors (sociodemographic, medical and behavioural) and their association with incident dementia in a population-based cohort. DESIGN: Nested case-control analysis (at 2 and 6 years) of a population-based cohort study. SETTING: Individuals aged 65 years and above from five centres in England and Wales: two rural (Cambridgeshire and Gwynedd) and three urban (Nottingham, Newcastle and Oxford). PARTICIPANTS: A total of 4,075 individuals from a detailed assessment group, with risk measured at baseline. MAIN OUTCOME MEASURE: Incident dementia at 2 and 6 years. METHODS: Logistic regression was used to calculate crude odds ratios (ORs) for various risk factors and ORs adjusted for age, sex, education and social class. RESULTS: Age (90+ versus 65-69 years OR = 25.6, 95% confidence interval (CI) = 11.6-56.9) and sex (women versus men OR = 1.6, 95% CI = 1.1-2.4) were directly associated with dementia, with a trend by years of education (P(trend) = 0.02) but not social class. Poor self-perceived health (versus good) increased the risk for incident dementia (OR = 3.9, 95% CI = 2.2-6.9). Alcohol and smoking (never, past and current) were neither strongly protective nor predictive. Stroke was strongly related to incident dementia (OR = 2.1, 95% CI = 1.1-4.2), as was Parkinson's disease (OR = 3.5, 95% CI = 1.3-9.3), and exposure to general anaesthesia (GA) was inversely associated with dementia development (OR = 0.6, 95% CI = 0.4-0.9, with a trend with increasing GA exposure; P = 0.003). CONCLUSION: In this large multicentre and long-term population-based study, some well-known risk factors for dementia, of vascular and Alzheimer's type, are confirmed but not others. The association between self-perceived health-a robust predictor of later health outcomes-and incident dementia, independently of other potential risks, warrants further study.     

Body mass index, physical activity and erectile dysfunction: an U-shaped relationship from population-based study

OBJECTIVE: To investigate the relationships between body mass index (BMI), physical activity and erectile dysfunction (ED). DESIGN AND SUBJECTS: A population representative cross-sectional analytic study of ED in Hong Kong, with two-stage stratified random sampling, and face-to-face interviews conducted by trained interviewers with structured questionnaires. Study subjects were 1506 men aged 26-70. RESULTS: Age (odds ratio (OR)=1.30; 95% confidence interval (CI) 1.20-1.40), physical activity (OR=0.91 per 500 kcal/week; 95% CI 0.84-0.98), and general psychological distress (OR=1.03 per GHQ score; 95% CI 1.00-1.06) were independently associated with ED after multivariate adjustments. An U-shaped relationship between BMI and ED was observed only among men with no exercise ( or =25.0 (OR=2.47; 95% CI 1.08-5.67) using BMI 21.0-21.9 as reference, adjusted for age, GHQ and smoking status. Being physically active (> or =1000 kcal/week) only reduced the risk of ED (OR=0.40, 95% CI 0.16-0.95) in men who were obese, adjusted for age, GHQ, smoking status and BMI. CONCLUSIONS: BMI and physical activity independently and differentially affected ED risk. BMI had greatest influence with low physical activity, and physical activity exerted greatest influence when BMI was high. This is the first study to demonstrate an U-shaped relationship between BMI and ED risk, but only in men with no exercise, and to identify underweight as a risk factor for ED. This relationship has clinical implications for obese as well as underweight individuals.