RESISTANCE TRAINING AND MEASURES OF INFLAMMATION IN RELATION TO BONE MINERAL DENSITY IN POSTMENOPAUSAL WOMEN

Abstract

The purpose of this study was to determine the role of body composition and fat distribution on C-reactive protein (CRP) and interleukin-6 (IL-6); determine the differences in CRP and IL-6 among HT users and non-users; determine the effect of 12-months of resistance training and resulting body composition changes on IL-6 and CRP; determine the relationship between BMD and IL-6, CRP and creatine kinase (CK). Sedentary women (N=208, age 44-66, 3-10 years postmenopausal) taking HT (N=106) or not taking HT (N=102) were randomly assigned to resistance training: HTexercise (N=55), HT-no exercise (N=45), no HT-exercise (N=53), and no HT-no exercise (N=49). The program included three weekly 60-75 minute sessions of 8 exercises performed in 2 sets of 6-8 repetitions at 70-80% of 1RM. Total fat mass (TFM), lean soft tissue mass (LSTM) and BMD were assessed by dual-energy X-ray absorptiometry (DXA). Abdominal fat mass (AFM) was assessed using DXA region of interest. For each subject, baseline and 1- year IL-6, CRP and CK were measured. High TFM, high IL-6 and HT use were independently associated with high CRP levels. A stronger relationship between IL-6 and AFM compared to TFM was found in HT users. High TFM and LSTM were significantly related to higher IL-6 levels. A stronger relationship between CRP and AFM compared to TFM was found in HT non-users. CRP was higher in HT users (5.47±5.40 mg/L) compared to non-users (2.70±3.05 mg/L) and was higher in oral (5.76±5.29 mg/L opposed; 6.14±5.97 mg/L unopposed) compared to transdermal HT users (2.65±4.44 mg/L). CRP increased slightly (p=0.077) in exercisers (0.54 ± 0.34 mg/L) not taking HT compared to controls (-0.39 ± 0.35 mg/L). Reductions in TFM were associated with reductions in IL-6 and CRP in HT users. CK was positively associated to all BMD sites at baseline. IL-6 change was positively associated with change in femur neck BMD. CRP change was inversely correlated with change in lumbar spine BMD. CK change was directly related to change in total body and femur trochanter BMD. In conclusion, reductions in TFM were accompanied by reductions in IL-6 and CRP; AFM was more strongly correlated with inflammation than TFM; 12-months of resistance training did not decrease IL-6 or CRP; IL-6 and CK were positively related to BMD, and CRP was inversely associated with BMD.