Serum Klotho levels are nonlinearly and positively correlated with the prevalence of diabetes, independent of other confounding factors, including age, sex, race, education, BMI, waist, smoking status, alcohol intake, physical activity, CVD, hypertension, dyslipidemia, TG, TC, LDL-C, HDL-C, and eGFR. The gene discussed is KL; the disease is diabetes mellitus.