The Link between Obesity and Inflammatory Markers in the Development of Type 2 Diabetes in Men of Black African and White European Ethnicity

Abstract

In this study, we aimed to assess ethnic differences in visceral (VAT), deep subcutaneous (dSAT), and superficial subcutaneous (sSAT) adipose tissue and their relationships with inflammatory markers between white European (WE) and black West African (BWA) men with normal glucose tolerance (NGT) and type 2 diabetes (T2D). Forty-two WE (23 NGT/19 T2D) and 43 BWA (23 NGT/20 T2D) men underwent assessment of plasma inflammatory markers using immunoassays alongside Dixon magnetic resonance imaging to quantify L4-5 VAT, dSAT and sSAT. Despite no ethnic differences in sSAT and dSAT, BWA men exhibited lower VAT (p = 0.002) and dSAT:sSAT (p = 0.047) than WE men. Adiponectin was inversely associated with sSAT in WE (p = 0.041) but positively associated in BWA (p = 0.031) men with T2D. Interleukin-6 (IL-6) was associated with VAT in WE but not in BWA men with NGT (WE: p = 0.009, BWA: p = 0.137) and T2D (WE: p = 0.070, BWA: p = 0.175). IL-6 was associated with dSAT in only WE men with NGT (WE: p = 0.030, BWA: p = 0.833). The only significant ethnicity interaction present was for the relationship between adiponectin and sSAT (Pinteraction = 0.003). The favourable adipose tissue distribution and the weaker relationships between adiposity and inflammation in BWA men suggest that adipose tissue inflammation may play a lesser role in T2D in BWA than WE men.

Associations between DNA methylation and BMI vary by metabolic health status: a potential link to disparate cardiovascular outcomes

“…As the CpG sites identified in this study were adjusted for cell composition which uses surrogate measures from six cell types [ 34 ], we may be identifying unique immune cell subsets associated with these disease exposures not captured by this method which may drive differences in outcomes. Additionally, several studies have also observed a unique relationship between inflammatory markers and adiposity in individuals of African descent, where these markers do not appear to be as sensitive to adiposity compared to individuals of European descent [ 35 , 36 ]. This may explain the significant differences observed when we exclude the ARIC AA cohort in sensitivity analyses.…”

“…When we adjusted for physical activity, no sites were significantly associated with BMI × MHZ. We included this analysis as several studies have touted that MHO may be the product of increased fitness in this population [ 36 , 37 ]. This may be due to true confounding by physical activity.…”

Effect of Weight Loss by Low-Calorie Diet on Cardiovascular Health in Type 2 Diabetes: An Interventional Cohort Study

“…Although small compared to most cardiovascular risk studies, the large effect size permits highly significant results. Secondly, only people of white European ethnicity were studied, reflecting the population of the North East of England, and specific studies are required to examine the biomarker relationships in other ethnicities [ 44 ]. Thirdly, our follow up period was short, and the study did not include a non-diabetic control group for comparison with the normal range in blood parameters and CVD risks.…”

Exploring the determinants of ethnic differences in insulin clearance between men of Black African and White European ethnicity

“…IL, interleukin; VAT, visceral adipose tissue; VEGF, vascular endothelial growth factor; TNF-α, tumour necrosis factor alpha; IFN-ɣ, interferon gamma. Data from subjects included in this study have been previously published in [22][23][24]. A two-way betweengroup ANOVA was used to analyse the dependent variables of ethnicity and glucose tolerance on the outcome measures takes account of first-pass hepatic insulin extraction, which is not captured by the MCRI.…”

“…The SouL-DeEP study was an observational cross-sectional study aimed at exploring ethnic differences in a range of mechanisms underlying the development of T2D between men of WE and BA ethnicity with NGT and early T2D. The study was designed to enable the exploration of a wide range of hypotheses, several of which have been published [22][23][24]. Data collection took place between April 2013 and April 2019.…”