Association between weight change and serum anti-aging protein α-Klotho: a cross-sectional study in middle-aged and older adults.

The relationship of weight change has extended to accelerated ageing, yet little is known about the association between weight change and anti-aging protein α-Klotho. This study included 10,972 subjects from the National Health and Nutrition Examination Survey 2007-2016. Participants were measured body weight and height at baseline and recalled weight at young adulthood and middle adulthood. α-Klotho concentrations were quantified. Generalized linear regression models were used to assess the association between weight change and α-Klotho. Across adulthood, maximal overweight, non-obese to obese, and stable obesity were consistently associated with lower serum Klotho levels. Compared with participants who remained at normal weight, from middle to late adulthood, participants experiencing maximal overweight, moving from the non-obese to obese, and maintaining obesity had 27.97 (95% CI: - 46.57 to - 9.36), 39.16 (95% CI: - 61.15 to - 17.18), and 34.55 (95% CI: - 55.73 to - 13.37) pg/ml lower α-Klotho, respectively; similarly, from young to late adulthood, those had 29.21 (95% CI: - 47.00 to - 11.42) , 34.14 (95% CI: - 52.88 to - 15.40), and 36.61 (95% CI: - 65.01 to - 8.21) lower, respectively. Interestingly, from middle to late adulthood, the absolute weight change values of 590 participants who changed from obese to non-obese were negatively associated with serum α-Klotho. Each 1 kg of weight loss during the process of changing from obese to non-obese brought about a relative increase in α-Klotho levels of 3.03 pg/ml. The findings suggest the potential role of weight management across adulthood for aging.