News & Views from the Editor-in-Chief - L. Bruce Gladden
Please direct your attention particularly to three articles in the June 2018 issue of MSSE®. First, Parry and Hayward investigated whether exercise could protect against cancer-induced cardiac cachexia in a rodent mammary tumor model. Sedentary tumor-bearing animals showed signs of cardiac cachexia including reduced cardiac mass, cardiac dysfunction, unfavorable shifts in cardiac myosin heavy chain, and excessive maladaptive autophagy. Chronic exercise induced cardioprotective effects that were evidenced by a preservation of cardiac mass and function, along with a normalization of myosin heavy chain distribution and autophagic flux. Although the fatigue and weakness associated with cachexia are primarily attributed to skeletal muscle wasting, it is possible that cardiac insufficiency may be an equally contributing factor. These new findings demonstrate that exercise may be one effective strategy to offset the debilitating effects of cardiac cachexia and is yet another example highlighting the benefits of structured exercise in cancer survivors.
In another high-quality study, Yan et al. investigated, using microdialysis, whether acute and chronic exercise training alters subcutaneous abdominal adipose tissue metabolic and circulatory responses to standardized meals in lean and obese children. Poor suppression of lipolysis and a blunted increase in adipose tissue nutritive blood flow in response to breakfast was associated with obesity. Interestingly, an acute bout of exercise normalized the antilipolytic and blood flow responses to a subsequent identical, lunchtime, meal in obese children but not in nonexercise control obese children. Unfortunately, a 16-wk exercise intervention did not produce a significant impact on meal-induced suppression of lipolysis or nutritive blood flow. These findings indicate the importance of encouraging daily physical activity in obese children and also demonstrates the utility of microdialysis to continuously monitor metabolism and blood flow over many hours in children.
Finally, Kallio et al. investigated how persistent physical inactivity during transition between childhood and adulthood is associated with glucose metabolism in adulthood. Data were drawn from the ongoing Cardiovascular Risk in Young Finns Study with repeated follow-ups between 1980 and 2011. Impaired glucose metabolism was defined as having impaired fasting glucose or type 2 diabetes in adulthood. Leisure-time physical activity (PA) habits were repeatedly collected with a standardized questionnaire and expressed as a PA index. Using PA index, four groups were formed: persistently low PA, decreasingly active, increasingly active, and persistently active subjects. Persistently physically inactive lifestyle from youth to adulthood was associated with increased risk of impaired glucose metabolism in adulthood. Importantly, a moderate increase in PA lowered the risk. These results highlight the importance of avoiding a physically inactive lifestyle at all stages of life.
L. Bruce Gladden
School of Kinesiology