Detecting motor vehicle travel in accelerometer data.

Chronic Obstructive Pulmonary Disease (COPD) frequently has a significant impact on patients' everyday activity. Because of this, accurate measurement of daily activity is of particular interest. Although accelerometers are an objective means of measuring daily activity, these devices sense vibrations and erroneously score motor vehicle travel (MVT) as moderate physical activity. It is the objective of this study to develop a new method to analyze accelerometry data that would accurately classify MVT as non-acceleration, or sitting/standing. As sitting/standing has a different pattern of count-to-count variability than walking, we hypothesized that a rolling standard deviation (RSD), which is a measurement of volatility in the data, would more accurately classify periods of MVT than analysis based on activity counts alone. Twenty-two subjects with COPD were studied. A training set of 15% of the dataset was used to establish an RSD-threshold during MVT based on the upper 95%-confidence interval. The accuracy of the RSD thresholds were tested and presented as sensitivity, specificity and receiver operating curves. Results demonstrated high sensitivity and specificity suggesting that the RSD not only accurately classified MVT, but had a low rate of misclassification. The RSD analysis scored more MVT as sitting/standing than assessment by VMU alone. The accuracy of accelerometers to define the profile of daily activity in sedentary populations, such as those with COPD, is greatly improved.

Gout and Progression of Aortic Stenosis.

BACKGROUND: Patients with aortic stenosis are nearly twice as likely to have a diagnosis of gout compared with individuals without aortic valve disease. METHODS: This retrospective study evaluated consecutive adults age ≥65 years with aortic stenosis between December 2012 and November 2016 who underwent at least 2 transthoracic echocardiograms (TTEs) separated by at least 1 year. Severe aortic stenosis was defined as any combination of an aortic valve peak velocity ≥4.0 m/sec, mean gradient ≥40 mm Hg, aortic valve area ≤1 cm2, or decrease in left ventricular ejection fraction as a result of aortic stenosis. RESULTS: Of the 699 study patients, gout was present in 73 patients (10%) and not found in 626 patients (90%). Median follow-up was 903 days [552-1302] for patients with gout and 915 days [601-1303] for patients without gout (P = 0.60). The presence of severe aortic stenosis on follow-up transthoracic echocardiogram was more frequent in patients with gout compared to those without gout (74% vs 54%, P = 0.001; hazard ratio [HR] 1.45 [1.09-1.93]), even among the 502 patients without severe aortic stenosis at baseline (63% vs 39%, P = 0.003; hazard ratio 1.43 [1.07-1.91]). Gout remained associated with the development of severe aortic stenosis after multivariable adjustment (adjusted hazard ratio [aHR] 1.46 [1.03-2.08], P = 0.03). The annualized reduction in aortic valve area was numerically greater in the group with gout compared with the group without gout (-0.10 cm2/y [-0.18, -0.03] vs -0.08 cm2/y [-0.16, -0.01], P = 0.09); annualized change in peak velocity and mean gradient did not differ between groups. CONCLUSIONS: Progression to severe aortic stenosis was more frequent in patients with gout compared with those without gout, supporting the hypothesis that gout is a risk factor for aortic stenosis.

Colchicine Use and Incident Coronary Artery Disease in Male Patients With Gout.

BACKGROUND: Inflammation is associated with coronary artery disease (CAD) and myocardial infarction (MI). Patients with gout are at increased risk of MI, and colchicine is associated with a reduced risk of MI. The objective of this study was to determine whether colchicine prevents incident development of CAD in patients with gout. METHODS: This retrospective study followed a cohort of male patients with gout without known CAD at the time of diagnosis of gout in the VA New York Harbor Healthcare System. The association between colchicine use and development of incident CAD, defined as evidence of ischemia or obstructive CAD on stress test or angiography, was determined using an inverse probability weighted (IPW) Cox proportional hazard model. RESULTS: Among 178,877 patients, 1638 met criteria of gout, of whom 722 without known CAD at baseline (446 colchicine users and 276 nonusers) were followed for a median of 96 months (57 to 117). A trend toward association between use of colchicine and reduced incident CAD was observed but not statistically significant (IPW hazard ratio [HR], 0.49; 0.23-1.05). In patients without chronic kidney disease, use of colchicine was associated with a lower rate of incident CAD (interaction P = 0.005, IPW HR, 0.31; 0.14-0.70). Colchicine was also associated with a lower rate of the composite of incident CAD and MI (IPW HR, 0.37; 0.16-0.83). CONCLUSIONS: In male patients with gout and no known CAD, a trend of reduced incident CAD was observed with use of colchicine that was not statistically significant. Larger, prospective studies will be required to assess the primary prevention benefit of colchicine definitively.