title: Inflammatory cytokine responses to progressive resistance training and supplementation with fortified milk in men aged 50+ years: an 18-month randomized controlled trial.
abstract: We examined the effects of progressive resistance training (PRT) and supplementation with calcium-vitamin D(3) fortified milk on markers of systemic inflammation, and the relationship between inflammation and changes in muscle mass, size and strength. Healthy men aged 50-79 years (n = 180) participated in this 18-month randomized controlled trial that comprised a factorial 2 × 2 design. Participants were randomized to (1) PRT + fortified milk supplement, (2) PRT, (3) fortified milk supplement, or (4) a control group. Participants assigned to PRT trained 3 days per week, while those in the supplement groups consumed 400 ml day(-1) of milk containing 1,000 mg calcium plus 800 IU vitamin D(3). We collected venous blood samples at baseline, 12 and 18 months to measure the serum concentrations of IL-6, TNF-α and hs-CRP. There were no exercise × supplement interactions, but serum IL-6 was 29% lower (95% CI, -62, 0) in the PRT group compared with the control group after 12 months. Conversely, IL-6 was 31% higher (95% CI, -2, 65) in the supplement group compared with the non-supplemented groups after 12 and 18 months. These between-group differences did not persist after adjusting for changes in fat mass. In the PRT group, mid-tibia muscle cross-sectional area increased less in men with higher pre-training inflammation compared with those men with lower inflammation (net difference ~2.5%, p < 0.05). In conclusion, serum IL-6 concentration decreased following PRT, whereas it increased after supplementation with fortified milk concomitant with changes in fat mass. Furthermore, low-grade inflammation at baseline restricted muscle hypertrophy following PRT.
authors: The University of Queensland, School of Human Movement Studies, Brisbane, Australia.
authors: Jonathan M
authors: JM
authors: Peake
authors: Sonja
authors: S
authors: Kukuljan
authors: Caryl A
authors: CA
authors: Nowson
authors: Kerrie
authors: K
authors: Sanders
authors: Robin M
authors: RM
authors: Daly
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D002136:Calcium, Dietary / Q000008:administration & dosage; D002762:Cholecalciferol / Q000008:administration & dosage; D019587:Dietary Supplements; D015444:Exercise / Q000502:physiology*; D005527:Food, Fortified; D006801:Humans; D007249:Inflammation / Q000097:blood; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D008892:Milk; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology; D055070:Resistance Training; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*
chemical_list: D015415:Biomarkers; D002136:Calcium, Dietary; C508600:IL6 protein, human; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002762:Cholecalciferol