Is Physical Activity, Obesity, and Ethnicity Associated With the Tethering and Migration of Pro-inflammatory Monocytes?
Condition: Physical Activity; Central Obesity; Inflammation
MeSH terms: Obesity; Obesity, Abdominal; Inflammation
Study type: Observational

Summary: 
      Being south Asian or centrally obese may be associated with an increased risk of
      inflammation. The investigators are seeking to investigate whether this is the case by
      recruiting white European and south Asian men who are lean or have central obesity. Further,
      the investigators wish to investigate whether physical activity influences the associations.
    

Detailed description: 
      Central obesity is associated with an increased risk of cardiovascular disease. Further,
      south Asians have been shown to be at an increased risk of cardiovascular disease compared to
      white Europeans.

      Cardiovascular disease is underpinned by inflammation. Evidence suggests that people with
      obesity have a more pro-inflammatory and pro-migratory monocyte profile compared with
      individuals who are lean. The excessive monocyte migration contributes to metabolic
      dysfunction over time, increasing the risk of chronic disease. However, there is no evidence
      in south Asians.

      One modifiable risk factor which may be able to influence this is physical inactivity, with
      higher levels of physical activity being associated with reduced inflammation. However,
      although south Asians are more at risk of cardiovascular disease than white Europeans,
      evidence suggests south Asians are also less physically active than white Europeans.

      The investigators are looking to recruit south Asian and white European men who are lean or
      have central obesity to investigate 1) is there an association between ethnicity and the
      tethering and migration of pro-inflammatory monocytes? 2) is there an association between
      central obesity and the tethering and migration of pro-inflammatory monocytes, and is there
      an interaction with ethnicity? 3) do higher levels of physical activity influence the
      tethering and migration of pro-inflammatory monocytes, and is this influenced by ethnicity or
      central obesity?

      To investigate this, the investigators are looking to recruit south Asian and white European
      men who are either centrally obese or lean. The investigators require 1 blood sample and the
      participants to wear an activity monitor for 7 days.

      Peripheral blood mononuclear cells (PBMCs) will be isolated from the whole blood sample.
      Then, the investigators will quantify the migratory capacity of PBMCs to a fixed chemokine
      gradient over time. Further, the investigators will phenotype the monocytes to indicate the
      characteristics of the monocytes that migrate towards the chemokine mix.

      The activity monitor will quantify habitual physical activity, which will be used in the
      statistical analyses to investigate whether physical activity may influence the response.

      It is important to investigate as it will further scientific knowledge on the underpinnings
      of chronic disease and enable a better understanding on the role of physical activity to
      potentially reduce the risk.
    

Intervention name(s): Habitual physical activity assessment
Intervention type(s): Behavioral
Intervention description(s): 7 days habitual physical activity via accelerometry (ActiGraph GT3x). Specifically steps per day, light physical activity (minutes per day), and moderate to vigorous physical activity (minutes per day).
Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        All participants will be recruited from the local community using advertisements published
        online and across local facilities and shops.
      
Biospecimen description: 
      Plasma samples will be stored for the measurement of metabolic markers (triacylglycerol,
      glucose, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein
      cholesterol, non-esterified free fatty acids, c-reactive protein, interleukin-6.
    
Keywords: Physical activity; Central obesity; Ethnicity; Inflammation