Genomic ancestry and education level independently influence abdominal fat distributions in a Brazilian admixed population

Abstract

We aimed to identify the independent associations of genomic ancestry and education level with abdominal fat distributions in the 1982 Pelotas birth cohort study, Brazil. In 2,890 participants (1,409 men and 1,481 women), genomic ancestry was assessed using genotype data on 370,539 genome-wide variants to quantify ancestral proportions in each individual. Years of completed education was used to indicate socio-economic position. Visceral fat depth and subcutaneous abdominal fat thickness were measured by ultrasound at age 29–31y; these measures were adjusted for BMI to indicate abdominal fat distributions. Linear regression models were performed, separately by sex. Admixture was observed between European (median proportion 85.3), African (6.6), and Native American (6.3) ancestries, with a strong inverse correlation between the African and European ancestry scores (ρ = -0.93; p<0.001). Independent of education level, African ancestry was inversely associated with both visceral and subcutaneous abdominal fat distributions in men (both P = 0.001), and inversely associated with subcutaneous abdominal fat distribution in women (p = 0.009). Independent of genomic ancestry, higher education level was associated with lower visceral fat, but higher subcutaneous fat, in both men and women (all p<0.001). Our findings, from an admixed population, indicate that both genomic ancestry and education level were independently associated with abdominal fat distribution in adults. African ancestry appeared to lower abdominal fat distributions, particularly in men.

The Demographic Specific Abdominal Fat Composition and Distribution Trends in US Adults from 2011 to 2018

“…It is also worth noting that there was a VAT% trend disparity by racial/ethnic groups and VAT% was constantly higher in Hispanic in comparison to other racial/ethnic groups at all time points. However, no trend disparities were observed in other demographic groups even though VAT% was higher in respondents with lower education in comparison to their counterparts at all data points which is consistent with existing literature [19].…”

“…Previous research indicated that visceral adipose tissue varied by age, sex, race/ethnicity, income [16][17][18][19][20]. Specifically, men have higher VAA than women [16], Black men have less visceral fat than their White counterpart [16][17][18], and both education income levels are inversely related to visceral fat depots [19,20].…”

“…Previous research indicated that visceral adipose tissue varied by age, sex, race/ethnicity, income [16][17][18][19][20]. Specifically, men have higher VAA than women [16], Black men have less visceral fat than their White counterpart [16][17][18], and both education income levels are inversely related to visceral fat depots [19,20]. Moreover, a recent cardiometabolic health trend study revealed that US adults' cardiometabolic health has been worsening from 1999 to 2018 and there are cardiometabolic health disparities by sex, age, race/ethnicity, education and family income [21].…”

“…Moreover, a recent cardiometabolic health trend study revealed that US adults' cardiometabolic health has been worsening from 1999 to 2018 and there are cardiometabolic health disparities by sex, age, race/ethnicity, education and family income [21]. Given the visceral adipose tissue variation by demographics [16][17][18][19][20] and its related cardiometabolic health trend [3,4,[8][9][10][11][12][13], it is important to understand abdominal adiposity trends by demographics. Available studies on abdominal adiposity trends using anthropometric index-waist circumference-revealed that there were race/ethnic disparities [22,23].…”

Visceral and subcutaneous abdominal adiposity and pulmonary function in 30-year-old adults: a cross-sectional analysis nested in a birth cohort

“…SAT was defined as the distance on the sagittal plane between posterior line of dermis to the outer bowel wall and VAT as the distance from the peritoneum boundary to the lumbar spine (in millimeters) [ 14 , 15 ] Two different static images were obtained at the end of a quiet expiration by applying minimal pressure, ensuring no displacement of the abdominal cavity. As previously described [ 16 ] three trained technicians performed the ultrasound scans using a standardized protocol, and all measurements were performed immediately after obtaining each image (Figure 1 ). Quality control procedures were conducted during the data collection.…”