Friday, January 16, 2015 Study: Physical Inactivity Responsible for Twice as Many Deaths as Obesity A study of 334,000 European men and women over 12 years concludes that physical inactivity is responsible for more than twice as many deaths as obesity, and that even small changes in activity levels can make a significant difference in life expectancy regardless of BMI. In an article e-published ahead of print in the American Journal of Clinical Nutrition (.pdf), researchers compared individual BMI, waist circumference (WC), and self-reported physical activity (PA) levels with all-cause mortality data for 116,980 men and 217,181 women in Sweden, Denmark, The Netherlands, United Kingdom, France, Germany, Spain, Italy, and Greece. Individuals with baseline heart disease, cancer, or stroke history were excluded from the analysis, as were individuals who were in the top or bottom .5th percentile of the energy intake-to-estimated basal metabolic ratio rate. Researchers then created a 4-level activity designation based on daily kilojoule-per-kilogram rates: inactive (36 kJ/kg), moderately inactive (41 kJ/kg), moderately active (46 kJ/kg), and active (51 kJ/kg). After adjusting for sex, educational level, and lifestyle (alcohol intake and smoking), researchers found that within all BMI groupings, mortality rates for moderately inactive individuals were 20%-30% lower than rates of inactive individuals. The reductions in mortality increased as activity levels increased, but only among normal and overweight individuals—rates for individuals with a BMI of 30 or higher did not drop when activity was recorded as more than "moderately inactive." Researchers found a similar relationship between physical activity and WC, with decreased mortality rates in the moderately inactive individuals across adiposity groupings, and little additional effect for abdominally obese individuals who had PA levels beyond "moderately inactive." According to the study's authors, the findings make a strong case for the effect of increased PA on mortality. "Physical inactivity may theoretically be responsible for twice as many deaths as high BMI … in this population, similar to the number of deaths averted if abdominal adiposity were eliminated," they write. "If all inactive individuals were at least moderately inactive, the number of deaths would theoretically be reduced by 7.5%." Authors estimate that in 2008, 676,000 deaths among Europeans may have been attributable to physical inactivity, compared with 337,000 deaths attributable to obesity. Authors of the study believe that achieving a level of moderate inactivity among those who are currently inactive may be more easily reached than one might imagine. "This amount of energy expenditure can be achieved by a [physical activity energy expenditure] equivalent to 20 minutes of brisk walking per day, which is lower than the current PA recommendations for public health," they write. "Our results suggest that the influence of physical inactivity on mortality appears to be greater than that of high BMI and similar to that of high [waist circumference] in European men and women," authors write. "From a public health perspective, it is therefore encouraging that our results suggest that small increases in PA in those who are currently categorized as inactive appear to be associated with significant reductions in all-case mortality at all levels of BMI and WC." APTA is a strong and vocal advocate for the ability of physical activity to transform society through its effects on public health. The association offers a prevention and wellness webpage with resources on how physical therapists and physical therapist assistants can help individuals become more physically active. Additionally, the association's MoveForwardPT.com website stresses the importance of physical activity in ways designed to be easily understood by the general public. The association is also on the board of the National Physical Activity Plan alliance, a high-profile effort to create a comprehensive set of policies, programs, and initiatives to increase physical activity in all segments of the American population. Research-related stories featured in PT in Motion News are intended to highlight a topic of interest only and do not constitute an endorsement by APTA. For synthesized research and evidence-based practice information, visit the association's PTNow website.