INTRODUCTION: National objectives recommend healthcare professionals provide physical activity advice. This study examined health and demographic characteristics associated with receipt of medical advice to increase physical activity among U.S. health care-utilizing adults and differences in associations by age group. METHODS: Analyses included 8,410 health care-utilizing adults aged >/=20 years from the 2013-2016 National Health and Nutrition Examination Surveys (analyzed in 2018). Logistic regression was used to examine associations between receipt of medical advice to increase physical activity in the past year and measured health conditions, reported health behaviors, and demographic characteristics. Models were stratified by age group (20-39, 40-59, and >/=60 years). RESULTS: Physical activity medical advice was received by 42.9% (95% CI=40.8, 44.9) of adults overall. By age group, 32.7% of younger adults, 46.7% of middle-aged adults, and 48.9% of older adults received advice. Among all adults and across all age groups, receipt of advice was higher among adults with chronic health conditions: obesity (63.0%, 95% CI=60.3, 65.7), hypertension (56.5%, 95%=CI 53.8, 59.2), diabetes (69.8%, 95% CI=66.5, 72.8), hypercholesterolemia (55.6%, 95% CI=52.3, 59.0), and low high-density lipoprotein cholesterol (53.8%, 95% CI=50.1, 57.4). Among all adults, those with obesity, hypertension, and diabetes had significantly greater odds of receipt of advice after adjustment. Stronger associations between diabetes and hypercholesterolemia and receiving physical activity advice were observed among younger adults. CONCLUSIONS: Receipt of physical activity medical advice was highest among adults with specific chronic health conditions, and this pattern was stronger among younger adults with diabetes and hypercholesterolemia. However, most health care-utilizing adults did not receive physical activity medical advice.

Active transportation (AT), or walking or bicycling for transportation, represents one way individuals can achieve recommended physical activity (PA) levels. This study describes AT prevalence and temporal trends, and examines associations between AT levels and measured CVD risk factors (hypertension, hypercholesterolemia, low high-density [HDL] cholesterol, diabetes, and obesity) among U.S. adults. National Health and Nutrition Examination Survey (NHANES) 2007-2016 data (analyzed in 2017) were used to conduct overall trend analyses of reported AT in a typical week [none (0-9min/week); low (10-149min/week); or high (>/=150min/week)]. Logistic regression was used to examine associations between AT level and each CVD risk factor from NHANES 2011-2016 (n=13,943). Covariates included age, sex, race/Hispanic origin, education, income, smoking, survey cycle, non-transportation PA, and urbanization level. U.S. adults who engaged in high AT levels increased from 13.1% in 2007-2008 to 17.9% in 2011-2012, and then decreased to 10.6% in 2015-2016 (p for quadratic trend=0.004). Over the same period, the quadratic trend for low AT was not significant. During 2011-2016, 14.3% of adults engaged in high AT, 11.4% in low AT, and 74.4% in no AT. High AT levels were associated with decreased odds of each CVD risk factor assessed, compared to no AT. Low AT (versus no AT) was associated with decreased odds of hypertension (aOR=0.77, 95% CI 0.64, 0.91) and diabetes (aOR=0.68, 95% CI 0.54, 0.85). AT prevalence among adults has fluctuated from 2007 to 2016. Despite favorable associations between AT and CVD risk factors, most U.S. adults do not engage in any AT.

BACKGROUND: Obesity is a risk factor for asthma. However, it is unclear if increased obesity prevalence contributed to rising childhood asthma prevalence. OBJECTIVE: To assess if population-level changes in weight status impacted asthma prevalence over time. METHODS: Using nationally representative 1988-2014 National Health and Nutrition Examination Survey data for 40 644 children aged 2-19 years, we analyzed asthma trends by weight status (body mass index age-specific percentiles determined using measured weight and height). Logistic regression and population attributable fraction were used to assess the association between obesity and asthma prevalence. RESULTS: Although obesity was a risk factor for asthma throughout the period, asthma prevalence increased only among children with normal weight; there was no interaction between weight status and time. The population attributable fraction for overweight/obesity rose from 8.5% in 1988-1994 to 11.9% in 2011-2014, but this increase was not significant (P = 0.44). CONCLUSIONS: Together, these data do not support a contribution of obesity trends to asthma prevalence trends.

PURPOSE: Racial disparities in childhood asthma prevalence increased after the 1990s. Obesity, which also varies by race/ethnicity, is an asthma risk factor but its contribution to asthma prevalence disparities is unknown. METHODS: We analyzed nationally representative National Health Examination and Nutrition Survey data for 2-19 year olds with logistic regression and decomposition analyses to assess the contributions of weight status to racial disparities in asthma prevalence, controlling for sex, age, and income status. RESULTS: From 1988-1994 to 2011-2014, asthma prevalence increased more among non-Hispanic black (NHB) (8.4% to 18.0%) than non-Hispanic white (NHW) youth (7.2% to 10.3%). Logistic regression showed that obesity was an asthma risk factor for all groups but that a three-way "weight status-race/ethnicity-time" interaction was not significant. That is, weight status did not modify the race/ethnicity association with asthma over time. In decomposition analyses, weight status had a small contribution to NHB/NHW asthma prevalence disparities but most of the disparity remained unexplained by weight status or other asthma risk factors (sex, age and income status). CONCLUSIONS: NHB youth had a greater asthma prevalence increase from 1988-1994 to 2011-2014 than NHW youth. Most of the racial disparity in asthma prevalence remained unexplained after considering weight status and other characteristics.