Effect of Different Doses of Aerobic Exercise Training on Total Bilirubin Levels

Department of Preventive Medicine, Pennington Biomedical Research Center, Baton Rouge, LA, USA.
Medicine and science in sports and exercise (Impact Factor: 3.98). 09/2011; 44(4):569-74. DOI: 10.1249/MSS.0b013e3182357dd4
Source: PubMed


Low serum bilirubin levels have been associated with increased risk for cardiovascular disease, and recent data suggest that lower body fat and reductions in weight are associated with higher bilirubin levels. However, it is unknown if exercise training can increase bilirubin levels and whether a higher dose of exercise will further increase bilirubin levels compared with a lower dose.
The primary aim of our current report was to examine whether exercise dose affects bilirubin levels in obese postmenopausal women from the Dose-Response to Exercise in Women trial. In addition, we evaluated whether changes in fitness, insulin sensitivity, and waist circumference associated with exercise training were associated with change in bilirubin levels.
Participants (n = 419) were randomized to the control group or to 4, 8, and 12 kcal·kg⁻¹·wk⁻¹ (KKW) of exercise training at an intensity of 50% of aerobic capacity. Total bilirubin levels were evaluated at baseline and at follow-up.
Exercise training significantly increased serum bilirubin levels only in the 12-KKW group (0.044 mg·dL⁻¹, P = 0.026) compared with the control group (0.004 mg·dL⁻¹). Subgroup analyses showed that there was a significant increase in bilirubin levels in participants in the 12-KKW group (0.076 mg·dL⁻¹) who were classified as insulin resistant (homeostatic model assessment for insulin resistance score > 2.6) compared with insulin-resistant control participants (0.018 mg·dL⁻¹, P = 0.028).
Our findings suggest that high doses of exercise training are necessary to significantly increase bilirubin levels in previously sedentary postmenopausal women and especially those with impaired glucose metabolism.

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    • "Increased heel-strike, weight bearing physical activity may facilitate increased hemooxygnase-1 activity (HO-1) [24], which is the enzyme responsible for the conversion of biliverin to bilirubin. In addition to increases in HO-1 activity, other potential mechanisms include weight-bearing physical activity-induced hemolysis (due to increased heel strike) [13,24]. Speculatively, cycling training may not be sufficient enough to increase the activity of the HO-1 system or induce hemolysis. "
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    ABSTRACT: Total serum bilirubin has been identified as a novel biomarker for metabolic disease, with higher levels providing protection against metabolic disease. Only 3 studies, to date, have examined the association between physical activity and total serum bilirubin, with these studies reporting mixed findings. On potential reason for the mixed findings may be the exclusive use of self-report physical activity methodology. The purpose of this study was to examine the association between accelerometer-assessed physical activity and total serum bilirubin among a national sample of U.S. insulin sensitive and insulin resistant adults. Data from the 2003-2006 National Health and Nutrition Examination Survey were used. Physical activity was objectively-measured using an accelerometer over a 7 day period. Bilirubin levels were assessed from a blood sample. Data was analyzed in 2013. After adjusting for age, gender, race-ethnicity, BMI, comorbid illness, cotinine, and poverty level, moderate-to-vigorous physical activity (MVPA) was associated with bilirubin for insulin resistant individuals (beta = 0.08; p = 0.04), but not insulin sensitive individuals (beta = 0.02; p = 0.38). MVPA is associated with total serum bilirubin levels among U.S. adults with insulin resistance. Future experimental and prospective studies are needed, with further attention focused on the mechanisms that may help to explain the association between physical activity and bilirubin.
    Journal of Diabetes and Metabolic Disorders 04/2014; 13(1):47. DOI:10.1186/2251-6581-13-47
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    ABSTRACT: A study by Chan et al in this issue of Diabetologia (DOI: 10.1007/s00125-012-2818-4 ) reports that low plasma bilirubin levels are associated with an increased risk of amputation in patients with type 2 diabetes mellitus participating in the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study. These findings raise the interesting and clinically relevant hypothesis that bilirubin protects against risk of amputation in patients with type 2 diabetes. This commentary considers some of the limitations associated with research aiming to define any link between circulating bilirubin levels and vascular disease. Numerous confounding factors (several of which may be present in patients with type 2 diabetes) may explain why the literature regarding this potentially protective role of bilirubin remains controversial.
    Diabetologia 01/2013; 56(4). DOI:10.1007/s00125-013-2840-1 · 6.67 Impact Factor
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    ABSTRACT: Objective: Low levels of bilirubin have recently been associated with obesity, diabetes mellitus, and metabolic syndrome. Here, we hypothesized that serum bilirubin levels might be already altered in overweight asymptomatic middle-aged individuals before full development of the metabolic syndrome. Methods: Healthy nonsmoking adults aged 25-49 (64 women and 32 men) participated in this cross-sectional study. All participants who reported stable weight within the last three months underwent standard anthropomorphological measurements of body composition, blood pressure measurements, aerobic and anaerobic capabilities assessment, dietary intake evaluation, and fasting serological measurements of total and direct bilirubin, glucose, insulin, triglycerides, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and C-reactive protein. Participants were divided into normal-weight and overweight groups. Linear correlation and multiple regression analyses were used to examine the association of serum bilirubin levels with all metabolic syndrome risk factor changes. Results: Serum bilirubin levels were lower in overweight healthy individuals of both sexes, and were negatively associated with abdominal obesity, insulin resistance, fasting glucose, fasting insulin, fasting triglycerides, total cholesterol, low-density lipoprotein cholesterol, and C-reactive protein levels but positively associated with aerobic body capabilities. Conclusion: Our findings suggest that serum bilirubin levels have the potential to be employed as an early biomarker for indicating asymptomatic individuals at increased risk of developing metabolic syndrome.
    Metabolism: clinical and experimental 02/2013; 62(7). DOI:10.1016/j.metabol.2013.01.011 · 3.89 Impact Factor
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