Ankle brachial index screening in asymptomatic older adults.

BACKGROUND: Screening for peripheral arterial disease (PAD) by measuring ankle brachial index (ABI) in asymptomatic older adults is currently recommended to improve cardiovascular disease risk assessment and establish early treatment, but it is not clear if the strategy is useful in all populations. We examined the prevalence and independent predictors of an abnormal ABI (<0.90), in an asymptomatic sample of 1,017 adults, 60 to 69 years old, enrolled in the ADVANCE study. METHODS: Baseline data collected between December 2001 and January 2004 among the healthy older controls enrolled in ADVANCE was examined. Frequency distributions and prevalence estimates of an abnormal ABI were calculated, using both standard and modified definitions of ABI. Stepwise logistic regression was used to examine independent predictors of ABI <0.90. Signal detection analysis using recursive partitioning was employed to explore potential demographic and clinical variables related to ABI <0.90. RESULTS: The prevalence of ABI <0.90 was 2% when using the standard definition and 5% when using a modified definition. ABI prevalence did not differ by gender (P > .05). Compared with subjects who had a normal ABI (0.90-1.39), subjects with an ABI <0.90 were more likely to currently smoke, be physically inactive, have a coronary artery calcium score >10, and an FRS >20% (P ≤ .02). Independent predictors of ABI <0.90 when using the standard definition included currently smoking, physical inactivity, and body mass index >30 (all P values ≤.03), and when using the modified definition included currently smoking, physical inactivity, and hypertension (all P values ≤.04). Currently, smoking was the only significant variable for ABI <0.90 derived through recursive partitioning (P = .02), and indicated that prevalence of ABI <0.90 was 1.5% for nonsmokers, while it was 6.6% for current smokers. CONCLUSIONS: ABI screening in generally healthy individuals 60 to 69 years old may result in lower prevalence rates of a positive result than estimates based on studies in clinical populations. The modified definition for calculating ABI captured more asymptomatic adults with suspected peripheral arterial disease. More evaluation of the appropriate role of ABI screening in unselected populations is needed before routine screening is implemented.

Incidental findings on cardiac multidetector row computed tomography among healthy older adults: prevalence and clinical correlates.

BACKGROUND: With the widespread use of cardiac multidetector row computed tomography (MDCT), the issue of incidental findings is receiving increasing attention. Our objectives were to evaluate the prevalence of incidental findings discovered during cardiac MDCT scanning and to identify clinical variables associated with incidental findings. METHODS: This cross-sectional analysis involved a population-based sample recruited from an integrated health care delivery system in Northern California as part of the Atherosclerotic Disease, Vascular Function and Genetic Epidemiology (ADVANCE) Study. Healthy men and women aged 60 to 69 years without diagnosed cardiovascular disease underwent cardiac MDCT for the detection and quantification of coronary artery calcification. The images were prospectively evaluated for incidental findings. RESULTS: A total of 459 participants underwent MDCT scanning, and the overall prevalence of any incidental finding was 41%. Of the 459 participants, 105 (23%) had at least 1 incidental finding that was recommended for clinical or radiological follow-up examination, the most common of which was single or multiple pulmonary nodules (18%). Participants with and without incidental findings had comparable baseline demographics and selected clinical variables, although there were significantly fewer men and a significantly lower prevalence of the metabolic syndrome in those with incidental findings. CONCLUSIONS: Incidental findings, especially pulmonary nodules, are common in cardiac MDCT performed to assess coronary artery calcification in older healthy adults. The net risks and benefits of looking for noncardiac abnormalities during cardiac MDCT should be rigorously evaluated.

Quantifying neurologic disease using biosensor measurements in-clinic and in free-living settings in multiple sclerosis.

Technological advances in passive digital phenotyping present the opportunity to quantify neurological diseases using new approaches that may complement clinical assessments. Here, we studied multiple sclerosis (MS) as a model neurological disease for investigating physiometric and environmental signals. The objective of this study was to assess the feasibility and correlation of wearable biosensors with traditional clinical measures of disability both in clinic and in free-living in MS patients. This is a single site observational cohort study conducted at an academic neurological center specializing in MS. A cohort of 25 MS patients with varying disability scores were recruited. Patients were monitored in clinic while wearing biosensors at nine body locations at three separate visits. Biosensor-derived features including aspects of gait (stance time, turn angle, mean turn velocity) and balance were collected, along with standardized disability scores assessed by a neurologist. Participants also wore up to three sensors on the wrist, ankle, and sternum for 8 weeks as they went about their daily lives. The primary outcomes were feasibility, adherence, as well as correlation of biosensor-derived metrics with traditional neurologist-assessed clinical measures of disability. We used machine-learning algorithms to extract multiple features of motion and dexterity and correlated these measures with more traditional measures of neurological disability, including the expanded disability status scale (EDSS) and the MS functional composite-4 (MSFC-4). In free-living, sleep measures were additionally collected. Twenty-three subjects completed the first two of three in-clinic study visits and the 8-week free-living biosensor period. Several biosensor-derived features significantly correlated with EDSS and MSFC-4 scores derived at visit two, including mobility stance time with MSFC-4 z-score (Spearman correlation -0.546; p = 0.0070), several aspects of turning including turn angle (0.437; p = 0.0372), and maximum angular velocity (0.653; p = 0.0007). Similar correlations were observed at subsequent clinic visits, and in the free-living setting. We also found other passively collected signals, including measures of sleep, that correlated with disease severity. These findings demonstrate the feasibility of applying passive biosensor measurement techniques to monitor disability in MS patients both in clinic and in the free-living setting.

Clinical utility of the Stanford brief activity survey in men and women with early-onset coronary artery disease.

PURPOSE: To determine the utility of the Stanford Brief Activity Survey (SBAS) as a quick screening tool in a clinical population, where no other measure of physical activity was available. METHODS: The SBAS was administered to 500 younger cases in the Atherosclerotic Disease Vascular Function and Genetic Epidemiology (ADVANCE) study, a case-control genetic association study, between December 2001 and January 2004. Younger cases in the ADVANCE study included men (<46 years old) and women (<56 years old) diagnosed with early-onset coronary artery disease. Frequency distributions of the SBAS and associations between SBAS activity categories and selected cardiovascular disease risk factors by sex were calculated. RESULTS: Subjects were 45.9 +/- 6.4 years old, 68% married, 61% women, 51% white, and 21% college graduates. Clinical diagnoses for early-onset coronary artery disease included 61% myocardial infarction, 23% coronary revascularization procedure, and 16% angina pectoris. In women, associations between all cardiovascular disease risk factors examined across SBAS categories were statistically significant (P trend < .01). In men, the associations across SBAS categories were statistically significant (P trend < .01), except for body mass index (P trend = .065). Adjustment for body mass index, age, ethnicity, and education with interactions by sex did not change the results. CONCLUSION: Subjects in the higher SBAS activity categories had more favorable cardiovascular disease risk profiles than did their less active counterparts, regardless of sex. The SBAS can be recommended for use in clinical populations providing immediate feedback on current physical activity level.

Validation of a new brief physical activity survey among men and women aged 60-69 years.

The Stanford Brief Activity Survey (SBAS), a new two-item physical activity survey, and the Stanford Seven-Day Physical Activity Recall (PAR) questionnaire were administered to men and women, aged 60-69 years, in the Atherosclerotic Disease VAscular functioN and genetiC Epidemiology (ADVANCE) Study. Frequency distributions of SBAS activity levels, as well as a receiver operating curve, were calculated to determine if the SBAS can detect recommended physical activity levels of 150 or more minutes/week at moderate or greater intensity, with PAR minutes/week. Data were collected between December 2001 and January 2004 from 1,010 participants (38% women) and recorded. Subjects were 65.8 (standard deviation: 2.8) years of age, 77% were married, 55% were retired, 23% were college graduates, and 68% were Caucasian. SBAS scores related significantly in an expected manner to PAR minutes/week (p < 0.01), energy expenditure (kcal/kg per day) (p < 0.01), and selected cardiovascular disease risk biomarkers (p < 0.01). The SBAS of physical activity at moderate intensity had a sensitivity of 0.73 and a specificity of 0.61. The SBAS is a quick assessment of the usual amount and intensity of physical activity that a person performs throughout the day. The SBAS needs further validation in other populations but demonstrated the potential of being a reasonably valid and inexpensive tool for quickly assessing habitual physical activity in large-scale epidemiology studies and clinical practice.