To Örebro University

CONTEXT: Chronic inflammation increases diabetes risk and may be exacerbated by excess adipose tissue. Whether cardiovascular fitness can offset chronic inflammation associated with excess adipose tissue in older adults is unclear.

OBJECTIVE: The study aimed to examine the influence of cardiorespiratory fitness on links between adiposity and pro- and anti-inflammatory biomarkers related to metabolic risk in physically active older women.

DESIGN, SETTING AND PARTICIPANTS: Cross-sectional study comprising older community-dwelling women (n = 109; age, 65-70 yr).

MAIN OUTCOME: Cardiorespiratory fitness was assessed using a standardized submaximal test and participants were categorized into high and low adiposity-related metabolic risk (body mass index, waist-to-hip ratio (WHR) and total fat mass). The inflammatory biomarkers C-reactive protein (CRP), interleukin-6 (IL-6), IL-10, IL-18, adiponectin, monocyte chemoattractant protein-1 (MCP-1), and macrophage inflammatory protein (MIP-1α) were analyzed.

RESULTS: Regardless of adiposity measure, women in the metabolic high-risk group had significantly (P<0.05) elevated CRP and lower adiponectin levels. Levels of IL-6 and MIP1-α were significantly elevated in the high-risk group defined by WHR and total fat mass. IL-18 level was significantly elevated in the high-risk group based on WHR only. Importantly, a high cardiorespiratory fitness level did not attenuate the detrimental links between adiposity measures and inflammation.

CONCLUSIONS: Altogether, cardiorespiratory fitness does not offset the detrimental links between adiposity and several inflammatory biomarkers related to metabolic risk in physically active older women. Reducing abdominal adipose tissue in older adults should be emphasized in efforts aiming to attenuate age-related systemic inflammation and metabolic risk regardless of cardiorespiratory fitness.

PURPOSE: To examine the influence of reallocating time spent at different objectively measured physical activity (PA) behaviours on markers of systemic inflammation in older women with different levels of metabolic risk.

METHODS: Accelerometer-based monitoring of PA was conducted in a population of community-dwelling older women (n = 111; age = 65-70 yr) for determination of daily sedentary time, time in light (LPA) and moderate-to-vigorous physical activity (MVPA). Blood samples were collected for the assessment of the systemic inflammatory markers CRP, fibrinogen and adiponectin. Metabolic risk was assessed by standardized procedures based on definitions for the metabolic syndrome. Data were analysed by linear regression models based on isotemporal substitution analysis.

RESULTS: Reallocating 30 minutes of sedentary time with either time in LPA (β = -0.47; p<0.05) or MVPA (β = -0.42; p<0.05) was related to reduced fibrinogen level, whereas no corresponding effect was evident when shifting time in LPA with time in MVPA, while holding sedentary time constant. In contrast, reallocating a 30-minute time period in sedentary (β = -0.70; p<0.01) or LPA (β = -0.71; p<0.01) with MVPA was associated with a significant reduction in CRP level, while no impact on CRP was observed when a time period of sedentary behavior was replaced with LPA. Importantly, all significant influences on fibrinogen and CRP by displacement of different PA behaviours remained after adjustment for metabolic risk status among participants. No significant associations with adiponectin were observed.

CONCLUSION: Altogether, this work supports the existence of different intensity thresholds mediating beneficial effects of PA on important clinical markers of systemic inflammation in older women across different stages of disease prevention.

The study aimed to examine sex-specific associations between objectively measured sedentary patterns and pro- and anti-inflammatory biomarkers in older adults when considering the moderating impact of physical activity (PA). Accelerometer-based monitoring of sedentary patterns and PA was conducted in a population of older men (n = 83; age: 67.4 ± 1.5; height: 178.7 ± 6.6 cm; weight: 80.9 ± 10.6 kg) and women (n = 146; age: 67.4 ± 1.6; height: 164.2 ± 6.1 cm; weight: 64.6 ± 10.1 kg) aged 65-70. Blood samples were collected for the assessment of the inflammatory biomarkers C-reactive protein (CRP), fibrinogen, interleukin-6 (IL-6), IL-10, IL-18, and monocyte chemoattractant protein-1 (MCP-1). Data were analyzed using multiple linear regression models. Total and bouts of ≥10 min of sedentary time were inversely associated with the anti-inflammatory marker IL-10 in older men (accumulated sedentary time: β = -0.116; bouts: β = -0.099; all p < 0.05). Associations were independent of moderate-to-vigorous physical activity (MVPA) and total PA volume. In women, total and bouts of ≥10 min of sedentary time were detrimentally associated with the pro-inflammatory marker fibrinogen (accumulated sedentary time: β = -0.130; bouts: β = -0.085; all p < 0.05). Associations remained between accumulated sedentary time and fibrinogen when adjusting for MVPA and total PA volume. This study highlights sex-specific routes by which sedentary patterns impact on pro- and anti-inflammatory biomarkers in older adults. The findings support efforts to promote accumulation of time spent in PA at the expense of time in sedentary pursuits on low-grade inflammation in older men and women. 

Systemic inflammation is believed to contribute to declining muscle health during aging. The present study aims to examine associations between indicators of muscle health and pro- and anti-inflammatory biomarkers in older men and women, while also considering the impacts of physical activity and protein intake. An assessment of skeletal muscle index (SMI) by bioelectrical impedance analysis, handgrip strength, and 5-sit-to-stand time, using standardized procedures, was conducted in a population of older men (n = 90) and women (n = 148) aged 65-70 years. The inflammatory biomarkers C-reactive protein (CRP), fibrinogen, interleukin (IL)-6, IL-10, IL-18, tumor necrosis factor (TNF)-α, monocyte chemoattractant protein-1, and macrophage inflammatory protein-1α were assessed in blood samples. Data were analyzed and stratified according to biological sex using multiple linear regression models. In older women, SMI was inversely associated with the pro-inflammatory markers CRP (β = -0.372; p < 0.05), fibrinogen (β = -0.376; p < 0.05), and IL-6 (β = -0.369; p < 0.05). Importantly, these associations were independent of abdominal adiposity (waist circumference), protein intake, physical activity level, as well as any adherence to muscle strengthening guidelines (≥2 sessions/week). In contrast, no corresponding associations were observed in men. In conclusion, our findings indicate the detrimental influence of a pro-inflammatory environment on muscle health regardless of important lifestyle-related factors in older women. However, the lack of such associations in older men highlights the importance of considering biological sex when examining the complex interaction between the systemic inflammatory environment and muscle health.