Clinical Relevance of Serum Klotho Concentration and Sagittal Abdominal Diameter

Klotho is an anti-aging gene. Studies have revealed its association with insulin resistance. Visceral fat is related to insulin resistance, and the sagittal abdominal diameter (SAD) can serve as a biomarker for visceral fat (VF). This study investigated the association between SAD and serum Klotho concentration (SKC). We enrolled 2301 participants from the 2011−2012 National Health and Nutrition Examination Survey (NHANES) dataset, and 49.2% of the enrolled individuals were male. Qualified participants were separated into four quartiles according to the SAD value. SKC values were obtained by ELISA. Demographic characteristics, body mass index (BMI), systolic blood pressure, and biochemistry parameters with significance were analyzed using multivariate linear regression models. The mean age of the study participants was 57.22 ± 10.53 years. The fully adjusted regression model showed a negative association between SAD and SKC (p < 0.05), with a β-coefficient of −12.02. We also analyzed subgroups of participants according to age and BMI. Participants with an age ≥65 and <65 years old were each negatively associated with SKC, and this association was significant for participants with a BMI ≥ 30 kg/m2 (p = 0.001, β-coefficient: −18.83). We also found a concentration-dependent relationship between SAD and SKC. In conclusion, VF and SKC are associated, and SAD can serve as a surrogate of VF and an indicator of SKC.