Box-and-whisker plots illustrating klothoconcentrations based on sex, age, UPC, and blood pressure. The boxes representthe 25th and 75th percentiles, and the central lines in the boxes represent themedian values. The whiskers represent the range of concentrations. Dotsrepresent outliers. Serum klotho and sex (a),age (c), UPC (e), and blood pressure (g).Urinary klotho-to-creatinine ratio (UrKl/Cr) and sex (b), age (d), UPC (f), and blood pressure (h).