PRE-DONATION OBESITY AND POST-DONATION HYPERTENSION IN LIVING KIDNEY DONORS

Abstract

Objective: The association of obesity status during the pre-kidney donation period with the risk of developing post-donation hypertension (HTN) is unclear. We aim to evaluate the effect of pre-donation obesity status on the rate of post-donation systolic and diastolic hypertension (SHTN and DHTN). Design and method: A retrospective cohort study using the SRTR database included living kidney donors (LKD) undergoing donation between March 2008 and July 2020. Risks for developing SHTN and DHTN defined as SBP and DBP >/ = 130 and >/ = 80 mmHg, respectively among 3 groups categorized by pre-donation obesity status (normal weight, overweight, and obesity) was examined by multiple Cox regression analysis. Results: Of 174,359 LKD, mean±SD age was 41±12 years and 60% were female. Pre-donation normal weight, overweight, and obesity account for 36%, 41, and 23%, respectively with median (IQR) BMI of 22.81 (21.30, 23.96), 27.35 (26.16, 28.57), and 32.19 (30.96, 33.98). SBP and DBP at 6 months, 1 year, and 2 years post-donation were 120.06/74.51, 120.08/74.63, 120.35/75.07 mmHg, respectively (PSBP and PDBP <0.001) (Figure 1). After adjusting for demographics, pre-donation SBP and DBP, pre- and post-operative creatinine, post-donation urine protein, and the interaction term between the pre-donation BMI and gender, overweight and obese groups had a significantly greater risk for developing SHTN compared to normal weight group (HRoverweight 1.32, 95%CI 1.23, 1.41; HRobese 1.70, 95%CI 1.57, 1.84; Figure 2) only in those with normotensive during pre-donation. The pattern of the association was the same for DHTN (HRoverweight 1.28, 95%CI 1.21, 1.35; HRobese 1.52, 95%CI 1.43, 1.62; Figure 3). Stratifying patients into those with and without pre-donation hypertension, gender was an effect modifier with a higher risk for developing STHN and DHTN observed in obese female patients with pre-donation normotension (Pinteraction for SHTN 0.002 and DHTN 0.019). Conclusions: Pre-donation overweight and obesity increase the risk of developing post-donation SHTN and DHTN. Obese female donors are at greater risk than obese male donors among those with pre-donation normotension.