5 research outputs found
Research in satellite-aided crop inventory and monitoring
Automated information extraction procedures for analysis of multitemporal LANDSAT data in non-U.S. crop inventory and monitoring are reviewed. Experiments to develope and evaluate crop area estimation technologies for spring small grains, summer crops, corn, and soybeans are discussed
WalkMore: a randomized controlled trial of pedometer-based interventions differing on intensity messages
Pedometer-based programs have elicited increased walking behaviors associated with improvements in blood pressure in sedentary/low active postmenopausal women, a population at increased risk of cardiovascular disease. Such programs typically encourage increasing the volume of physical activity with little regard for its intensity. Recent advances in commercially available pedometer technology now permit tracking of both steps/day and time in moderate (or greater) intensity physical activity on a daily basis. It is not known whether the dual message to increase steps/day while also increasing time spent at higher intensity walking will elicit additional improvements in blood pressure relative to a message to only focus on increasing steps/day. The purpose of this paper is to present the rationale, study design, and protocols employed in WalkMore, a 3-arm 3-month blinded and randomized controlled trial (RCT) designed to compare the effects of two community pedometer-based walking interventions (reflecting these separate and combined messages) relative to a control group on blood pressure in sedentary/low active post-menopausal women, a population at increased risk of cardiovascular disease. 120 sedentary/low active post-menopausal women (45-74 years of age) will be randomly assigned (computer-generated) to 1 of 3 groups: A) 10,000 steps/day (with no guidance on walking intensity/speed/cadence; BASIC intervention, n = 50); B) 10,000 steps/day and at least 30 minutes in moderate intensity (i.e., a cadence of at least 100 steps/min; ENHANCED intervention, n = 50); or a Control group (n = 20). An important strength of the study is the strict control and quantification of the pedometer-based physical activity interventions. The primary outcome is systolic blood pressure. Secondary outcomes include diastolic blood pressure, anthropometric measurements, fasting blood glucose and insulin, flow mediated dilation, gait speed, and accelerometer-determined physical activity and sedentary behavior. This study can make important contributions to our understanding of the relative benefits that walking volume and/or intensity may have on blood pressure in a population at risk of cardiovascular disease. ClinicalTrials.gov Record NCT01519583, January 18, 2012
Long-term weight loss with metformin or lifestyle intervention in the Diabetes prevention Program outcomes study
© 2019 American College of Physicians Background: Identifying reliable predictors of long-term weight loss (LTWL) could lead to improved weight management. Objective: To identify some predictors of LTWL. Design: The DPP (Diabetes Prevention Program) was a randomized controlled trial that compared weight loss with metformin, intensive lifestyle intervention (ILS), or placebo. Its Outcomes Study (DPPOS) observed patients after the masked treatment phase ended. (ClinicalTrials.gov: NCT00004992 and NCT00038727) Setting: 27 DPP and DPPOS clinics. Participants: Of the 3234 randomly assigned participants, 1066 lost at least 5% of baseline weight in the first year and were followed for 15 years. Measurements: Treatment assignment, personal characteristics, and weight. Results: After 1 year, 289 (28.5%) participants in the metformin group, 640 (62.6%) in the ILS group, and 137 (13.4%) in the placebo group had lost at least 5% of their weight. After the masked treatment phase ended, the mean weight loss relative to baseline that was maintained between years 6 and 15 was 6.2% (95% CI, 5.2% to 7.2%) in the metformin group, 3.7% (CI, 3.1% to 4.4%) in the ILS group, and 2.8% (CI, 1.3% to 4.4%) in the placebo group. Independent predictors of LTWL included greater weight loss in the first year in all groups, older age and continued metformin use in the metformin group, older age and absence of either diabetes or a family history of diabetes in the ILS group, and higher fasting plasma glucose levels at baseline in the placebo group. Limitation: Post hoc analysis; examination of nonrandomized subsets of randomized groups after year 1. Conclusion: Among persons with weight loss of at least 5% after 1 year, those originally randomly assigned to metformin had the greatest loss during years 6 to 15. Older age and the amount of weight initially lost were the most consistent predictors of LTWL maintenance
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Effect of Metformin and Lifestyle Interventions on Mortality in the Diabetes Prevention Program and Diabetes Prevention Program Outcomes Study
ObjectiveTo determine whether metformin or lifestyle modification can lower rates of all-cause and cause-specific mortality in the Diabetes Prevention Program and Diabetes Prevention Program Outcomes Study.Research design and methodsFrom 1996 to 1999, 3,234 adults at high risk for type 2 diabetes were randomized to an intensive lifestyle intervention, masked metformin, or placebo. Placebo and lifestyle interventions stopped in 2001, and a modified lifestyle program was offered to everyone, but unmasked study metformin continued in those originally randomized. Causes of deaths through 31 December 2018 were adjudicated by blinded reviews. All-cause and cause-specific mortality hazard ratios (HRs) were estimated from Cox proportional hazards regression models and Fine-Gray models, respectively.ResultsOver a median of 21 years (interquartile range 20-21), 453 participants died. Cancer was the leading cause of death (n = 170), followed by cardiovascular disease (n = 131). Compared with placebo, metformin did not influence mortality from all causes (HR 0.99 [95% CI 0.79, 1.25]), cancer (HR 1.04 [95% CI 0.72, 1.52]), or cardiovascular disease (HR 1.08 [95% CI 0.70, 1.66]). Similarly, lifestyle modification did not impact all-cause (HR 1.02 [95% CI 0.81, 1.28]), cancer (HR 1.07 [95% CI 0.74, 1.55]), or cardiovascular disease (HR 1.18 [95% CI 0.77, 1.81]) mortality. Analyses adjusted for diabetes status and duration, BMI, cumulative glycemic exposure, and cardiovascular risks yielded results similar to those for all-cause mortality.ConclusionsCancer was the leading cause of mortality among adults at high risk for type 2 diabetes. Although metformin and lifestyle modification prevented diabetes, neither strategy reduced all-cause, cancer, or cardiovascular mortality rates