Exercise and metabolic health in older adults

Introduction

Deterioration of the cardiovascular system and the metabolic profile tends to accompany aging. Although the effects of aerobic versus resistance training on cardiovascular risk factors have been compared, there is a need to further investigate the effects of the aerobic-based exercise versus strength-based exercise on body weight (BW), body mass index (BMI), waist circumference (WC), lipids, blood pressure, and walking distance in older women and men. Accordingly, in the current study we hypothesized that moderate intensity, progressive aerobic-based and strength-based training would improve metabolic health of older women and men.

Methods

Sixty three sedentary individuals (65-95 years old) volunteered to participate in this study (38 women, 25 men). Participants were randomized into two training groups and one control group. Venous blood samples were collected into EDTA containing tubes, after 12 hours fasting. Body weight, height, waist circumference, blood pressure, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, and 6-min walk distance were taken. Differences between evaluations were analyzed with a univariate analysis of variance for repeated measures. F and p values from the Pillai test were calculated for within participant’s comparisons. Bonferroni’s tests were used for multiple comparisons. Statistical significance was accepted at the p<0.05 level.

Results

The exercising group attained after treatment significant differences on BW (-1%), WC (-3%), BMI (-1%), diastolic blood pressure (DBP) (-4%), TG (-11%), TC (-6%), HDL-C (5%), LDL-C (-13%), TC/HDL-C relationship (-9%), and 6-minute walk distance (13%). The control group only had significant differences on waist circumference (-2%).
At baseline, BMI correlated with TC (r=0.35, p=0.007), and TG (r=0.38, p=0.004); WC correlated with TC (r=0.30, p=0.022), TG (r=0.35, p=0.010), and TC/HDL-C (r=0.38, p=0.005); BW also correlated with TC (r=0.33, p=0.011), TG (r=0.27, p=0.044), and TC/HDL-C (r=0.33, p=0.016).

Discussion

Our finding that TC, LDL-C, TG, and TC/HDL-C diminish with exercise is consistent with previous research (Kelley & Kelley, 2006) even some have failed to attain gains after strength training in women (Elliott et al., 2002) and in men (Sillampaa et al., 2009). A dose-response relationship between serum lipid levels (TC, TG, HDL-C, and TC/HDL-C) and levels of physical activity have been pointed to explain this absence of gains (Thune et al., 1998). Independent of the mechanism underlying lipid changes, a reduction of 1% on TC has been shown to reduce the risk for coronary artery disease by 2% (CDP, 1985), which implies that our exercising participants have reduced about 12% their risk. A 1% reduction in LDL-C reduces the risk of major coronary events by approximately 2% (Pedersen et al., 1998), which means that we have about a 26% gain. Moreover, a decrease of 1% on HDL-C has been associated with a 2-3% increase in the risk for CHD (Gordon et al., 1989), and assuming that the reverse is true, the 5% increase observed in our both programs should decrease CHD by 10-15%.
In conclusion, the training programs used in this study produced significant benefits on 6-minute walk distance, DBP, BW, WC, BMI, TG, TC, HDL-C, LDL-C, and TC/HDL-C. Accordingly, the results of the current study suggest that moderate intensity aerobic-based and strength-based programs are enough to positively influence the metabolic health indicators of sedentary older women and men.

References

Elliott KJ et al. Br J Sports Med 2002;36:340–345.
Kelley GA, Kelley KS. J Mens Health Gend 2006;3:61-70.
Sillanpaa E et al. Scand J Med Sci Sports 2009: 19: 885–895
Thune I et al. Arch Intern Med 1998;158:1633-40.
Consensus Development Panel. J Am Med Assoc 1985;253(14):2080–6
Pedersen TR et al. Circulation 1998;97(15): 1453–60.
Gordon DJ et al. Circulation 1989;79:8–15