<p>Salivary Amylase Gene Copy Number Is Associated with the Obesity and Inflammatory Markers in Children</p>

Abstract

Background: We have recently shown that the copy number of salivary amylase (AMY1) gene was significantly decreased, and the obesity-related salivary biomarkers resistin, MCP-1, TNF-α, IL-6, and CRP were significantly increased in overweight/obese children compared to normal weight. This study aimed to evaluate the association of AMY1 copy number variant (CNV) with obesity and inflammatory markers. Seventy-six participants aged between 6 and 10 years have participated, and the saliva samples were collected along with the anthropometric measurements. Methods: AMY1 copy number was analyzed by 3D digital PCR, and obesity-related biomarkers were performed with a Bioplex multiplex analyzer. Results: The mean AMY1 copy number was higher in normal weight (7.90 ± 0.38) compared to the overweight/obese group (6.20 ± 0.29). The association of AMY1 CNV with obesity and inflammatory markers showed significant negative correlation [CRP, β = −0.238 (p < 0.05); resistin, β = −0.25 (p < 0.05); MCP-1, β = −0.304 (p < 0.01)] except for complement factor D, TNF α and IL-6. The anti-inflammatory cytokine, IL-10 reported a positive correlation with AMY1 copy number with a β = 0.268 (p < 0.05). The multivariable model adjusted with age and gender depicted a similar correlation with obesity markers. Conclusion: Our results report that AMY1 CNV is associated with obesity and inflammatory biomarkers in children's saliva sample.

High plasma salivary α-amylase, but not high AMY1 copy number, associated with low obesity rate in Qatari adults: cross-sectional study

“…The distribution of AMY1 gene CN in our study sample (2–20 copies) is comparable to what was reported previously across modern human populations 38 . The median of AMY1 gene CN was 7, which is like the one reported recently 15 , 17 . However, other studies previously reported a median of 4 7 , 14 , 27 .…”

“…Several studies have investigated the relationship between AMY1 gene CN and predisposition to metabolic disorders, including obesity, T2D and insulin resistance, in both children and adults. However, contradicting results were reported 7,[12][13][14][15]18,19,[21][22][23][24][25][32][33][34] .The reported discrepancies remain unexplained, and possible reasons include the different techniques used to estimate the AMY1 gene CN 35 as well as the different ethnicities 21,36 www.nature.com/scientificreports/ and age 37 of the populations studied. The distribution of AMY1 gene CN in our study sample (2-20 copies) is comparable to what was reported previously across modern human populations 38 .…”

“…body mass index (BMI) and waist circumference 7,[12][13][14][15][16][17][18][19][20][21] . However, other studies reported no association [22][23][24] or a positive association between AMY1 gene CN and BMI 25 .…”

Influence of AMY1A copy number variations on obesity and other cardiometabolic risk factors: A review of the evidence

“…Another study in 40 normal‐weight children and 36 children with overweight or obesity from Alabama, USA, 25 found negative associations between AMY1A copy numbers estimated by ddPCR and BMI, WC, and WHR. Participants with overweight and obesity had mean of 6.6 AMY1A copy numbers compared with a higher mean of 7.9 copies in normal‐weight participants ( p < 0.01) 25 . Similarly, in a cohort of 127 healthy elementary school children (age 6–10 years) in Alabama, 26 AMY1A copy numbers were estimated by ddPCR, and weight and BMI z ‐scores were assessed, with results showing that normal‐weight participants had higher AMY1A copy numbers (mean = 7.84) compared with participants with obesity (mean = 5.89) 26 .…”

“…A further nine cohort studies 22‐30 have assessed associations between AMY1A copy number variations and different measures of obesity: five in children and four in adults. In one study of 597 Mexican children 29 utilizing ddPCR to estimate AMY1A copy numbers, higher AMY1A copy numbers were associated with significantly lower odds of obesity (odds ratio = 0.84 per copy) 29 .…”