A longitudinal investigation of inflammatory biomarkers, vitamin D, and physical fitness in trained and untrained elderly men and women
Increases in chronic inflammation and decreases in muscular strength and aerobic capacity occur as individuals age. Additionally, vitamin D levels in the blood have been positively associated with increases in strength and lower levels of inflammatory cytokines. Individuals who have participated in a training study may be more likely to continue structured exercise programs and thus maintain their strength, aerobic capacity and inflammatory levels. Subjects from previous studies were recruited to visit the lab so that measurements could be taken for inflammation, strength, aerobic capacity, and 25-hydroxy vitamin D. Comparisons were made over 7 year (G7Y), 4 year (G4Y), and 3 year (G3Y) time periods. CRP did not increase over 3 years among subjects who remained physically active. There was a positive correlation (r=.47, p<.05) between vitamin D and 8 RM seated row. G4Y subjects were able maintain their strength for 8 RM leg press and 8 RM chest press. However, 8 RM seated row and 8 RM lat pull down decreased significantly (p<.01, p=.01, respectively). There was only a significant increase in 8 RM chest press for G7Y. BMI increased significantly (p<.005) for G3Y, but not G7Y or G4Y; however, body fat decreased for both G4Y (p<.005) and G3Y (p<.001). Both systolic and diastolic blood pressure decreased for G7Y (p<.05) and systolic blood pressure decreased for G4Y (p<.01). These results show that remaining active appears to blunt inflammatory increases that occur with age. Additionally, participating in an exercise training study may educate subjects on how to properly exercise in order to allow them to maintain strength and aerobic measures which literature has shown are expected to decline. No significant decreases in physical activity in any group may have contributed to decreases in body fat percentage, no change in BMI for G7Y and G4Y, and minimal decreases in strength. Different seasonal time-points may have had an effect on the level of 25-hydroxy vitamin D and associated lack of significance when correlated with all variables except seated row. Blood pressure may have decreased as a result of medications prescribed after their participation in the original study. No subjects reported taking blood pressure medication in the original study, but eleven people were taking medications to control blood pressure at follow up in 2007.^
Michael G. Flynn, Purdue University.
Health Sciences, Recreation|Biology, Physiology