Loss of Anthropometry-Lipids Relationship in Obese Adults: A Cross-Sectional Study in Southern China

BACKGROUND: Emerging data suggest that the interpretation of the association between obesity and lipids appears to be oversimplified. This study aimed to quantify the complex relationships between anthropometric indices and lipid profile. METHODS: This is a cross-sectional study including 9620 participants in Southern China. Anthropometric indices included the indices of general obesity (ie, body mass index (BMI)) and central obesity (ie, waist circumference (WC) and waist-to-hip ratio (WHR)). Lipids included low-density lipoprotein cholesterol (LDLc) and atherogenic lipids (ie, high-density lipoprotein cholesterol (HDLc), triglycerides (TG) and TG/HDLc ratio). LOESS regression and general linear model were the main statistical methods. RESULTS: Almost all associations between anthropometric indices and lipids were lost in obese adults. The loss of association occurred quicker with LDLc than that with atherogenic lipids; the break point for the association loss was at BMI of 24 kg/m(2) with LDLc (Slope (Below break-point) = 1.81, P<0.001; Slope (Above break-point) = 0.29, P=0.121), while at 28 kg/m(2) with HDLC (Slope (Below break-point) = −1.41, P<0.001; Slope (Above break-point) = 0.07, P=0.666) or TG (Slope (Below break-point) = 4.96, P<0.001; Slope (Above break-point) = 2.93, P=0.01), and at 30 kg/m(2) with TG/HDLc ratio (Slope (Below break-point) = 0.15, P<0.001; Slope (Above break-point)= 0.01, P=0.936), respectively. Similar relationships were found for WC and WHR. Besides, the presence of other metabolic disorders contributed to the loss of anthropometry-lipids relationships, for example, the BMI-LDLc association attenuated to null in both obese adults and non-obese population but with more than one other metabolic disorders. CONCLUSION: The relationships were lost between anthropometric indices and lipids in obese adults with different break points across different lipids, which appeared to be dependent on metabolic status.