The Association Between Serum α 1‐Acid Glycoprotein and Obesity and Abdominal Obesity in Women: A Cross‐Sectional Study Based on NHANES Data From 2015 to 2018

Background Obesity and abdominal obesity are major public health issues closely related to metabolic diseases. Serum α 1‐acid glycoprotein (SSAGP), an acute‐phase reactant influenced by inflammation and metabolic status, has an unclear relationship with obesity and abdominal obesity. This study investigates this association in women. Methods Using cross‐sectional data from NHANES (2015–2018), 2219 adult women were divided into three groups based on SSAGP levels (low, medium, and high). Multiple regression analyses assessed the relationship between SSAGP and BMI, waist circumference, obesity (BMI ≥ 30 kg/m 2 ), and abdominal obesity (waist circumference ≥ 90 cm). Threshold and interaction analyses were also conducted. Results As SSAGP levels increased, BMI, waist circumference, fasting blood glucose, insulin, and hs‐CRP levels rose significantly ( p < 0.001), while HDL levels decreased ( p < 0.001). SSAGP was positively correlated with BMI, waist circumference, obesity, and abdominal obesity ( p < 0.0001). After adjusting for confounders, a one‐unit increase in SSAGP was associated with a 4.42 increase in BMI (95% CI: 3.08, 5.76), a 12.18 cm increase in waist circumference (95% CI: 9.22, 15.14), a 3.63‐fold increase in obesity risk (95% CI: 1.96, 6.72), and a 10.75‐fold increase in abdominal obesity risk (95% CI: 4.85, 23.85). Threshold effect analysis showed an inflection point ( K = 1.2), with SSAGP having a stronger promoting effect below this point and an inhibitory effect above it ( p < 0.001). Educational level significantly influenced the SSAGP‐obesity relationship ( p = 0.0096). Conclusion SSAGP levels are significantly associated with obesity and abdominal obesity in women, with educational level playing a modulatory role. SSAGP may serve as a potential biomarker for obesity risk. Future studies should explore the causal relationships and underlying mechanisms.